Friday, August 28, 2015

Radar and Rainfall

Posted on the CoCoRaHS  site was a discussion how radar is used to measure precipitation


Radar and Rainfall


Radar is an acronym meaning Radio Detection and Ranging. During its initial development in WW II, weather was treated as "clutter", a problem that kept radar operators from seeing enemy targets. Shortly after the end of the war, scientists realized the great benefit of using radar to study storms. The radar displayed previously unseen patterns of storm growth and structure. Doppler capabilities allowed for the detection of tornados and downbursts. Radar also showed its utility in estimating precipitation.
The traditional way of turning radar measurements into rainfall data is to relate the power returned from the cloud to the radar (meteorologists refer to this as the "radar reflectivity") to some estimate of rain intensity measured on the ground. Once this so called Z-R relationship is determined, the radar data can be converted directly to rainfall over the entire coverage region of the radar. Usually, the rainfall estimates in the Z-R relationship come from rain gauge networks, like CoCoRaHS.
The great benefit of using radar is that it can estimate rainfall over a huge area, including most places where there are no rain gauges. However, it turns out that using radar to estimate rainfall is much more difficult than one might think for a number of reasons:
  • 1. The radar reflectivity and rainfall relationship is not unique, it changes constantly within a storm, among different types of storms, and from place to place.
  • 2. The radar looks within the cloud while the gauge is at the ground. The difference in height between where the radar is looking and the gauge can be thousands of feet. A lot can happen to those drops as they fall out of the cloud: some might evaporate and others might be blown far downwind from where the radar is looking.
  • 3. The radar beam might be blocked by hills, trees or building and might not be able to see the cloud producing the rain.
  • 4. The radar volume at all ranges is very much larger than the sample volume of a 4" rain gauge on the ground. This large volume may have a variety of reflectors - i.e. snow, hail, raindrops and cloud drops, all of which contribute to the reflectivity but which have very different water contents.
  • More information and links to information on radar and rainfall can be found on the CoCoRaHS web site by clicking here: “Radar” . . . oh, and don't forget to view Pat Kennedy's 2013 WxTalk Webinar on Radar: “WxTalk Radar”.

    Wednesday, August 26, 2015

    Where Has All the Smoke Gone?

    This satellite photo was taken Wednesday afternoon August 26 2015



    Today's Satellite (MODIS) image from https://worldview.earthdata.nasa.gov/ showing wildfires across the northwest U.S. (red areas) and smoke being carried up and over a ridge of high pressure over the Rocky Mountain region, west and north of Wyoming.

    Friday, August 21, 2015

    July 2015 Earth's Warmest Month Going Back to 1880

    Another blog provided by Jim Steenburgh of the U of U.

    Earth's Fever Reaches Record Levels

    No surprises here.  The National Centers for Environmental Information issued their monthly summary for July and the globally averaged temperature was the highest for any month since the start of records in 1880.  Their full report is available here.

    Meteorologists typically present temperature trends in terms of anomalies (i.e., a departure from some long-term average).  For July, the globally averaged temperature anomaly was 0.81ºC (1.46ºF), the highest on record.  In 2nd place is 1998, also a strong El Nino year.

    Source: NCEI
    Since July is also the warmest month of the year globally (this reflects the greater fraction of land in the Northern Hemisphere), this July was also the warmest in the entire 1627 month record going back to 1880.  Yup, Earth has a fever and the only prescription is more cowbell.


    Or, more accurately, the only prescription is less carbon. It is the combination of long-term global warming with the strong El Nino that is leading to these unprecedented numbers.  

    Like politics, all weather is local and the good news for Utah is despite remarkable high globally average temperatures, Mother Nature was good to us and we actually came out below the 20th century average and enjoyed the coolest July since 1997.

    Source: NCEI
    Our good fortune is clearly evident in the analysis below which shows departures from average temperature for the month.  We're in the blue, indicating below average, but red, indicating above average predominates.  Note that these anomalies are with respect to 1981–2010.  Comparison with the 20th century average would produce a plot shifted even more into the red since the 20th century average temperatures are lower than those of the last 30 years.
    Source: NCEI 
    The likelihood that 2015 will be the hottest year on record continues to increase.  

    Tuesday, August 18, 2015

    Western Fire Season Thus Far

    Thanks to Jim Steenburgh of the U of U, his blog provides a summary of the fire season.  We are very fortunate in Western Wyoming to have had a relatively wet summer.  However the smokey skies locally are evidence of the dire conditions to our west.


    Smoky Views and Fire Numbers

    Generally clear skies over the northwest U.S. enabled an excellent perspective on the smoke from the MODIS sensor on NASA's Aqua satellite.  It seems pretty smoky here, but it barely shows up in this image.  Conditions are far worse to our west and northwest.

    Source: NASA
    Some of the fires have devastated communities.  Here are a couple of photos of damage near Lake Chelan, WA from KING TV.  The bottom one is from Lake Chelan State Park.

    Source: KING-TV
    Source: KING-TV
    The National Interagency Fire Center currently rates the national firefighting preparedness level at a V, the highest possible, which indicates that major incidents have the potential to exhaust all agency resources.  Yesterday the center called in 200 active military troops to help with wildfire fighting efforts across the west.  This is the first time they have done so since 2006, although 200 seems like a small number and I wonder if more will be called soon.

    Here are some remarkable numbers for active incident firefighting efforts in the various geographic areas.  Resources are heavily concentrated in the northwest (NWCC) and northern California (ONCC).  
    Source: NIFC
    And some numbers for the year to date on the number of fires and acres burned, which have now eclipsed 40,000 and 7 million acres, respectively.  5 million of these acres are in Alaska.  

    Source: NIFC
    Utah has avoided major problems so far.  Let's hope it stays that way and that things improve elsewhere. 

    Thursday, August 13, 2015

    Potential for Big El Nino this Winter








    Latest forecast suggests 'Godzilla El Niño' may be coming to California
    The strengthening El Niño in the Pacific Ocean has the potential to become one of the most powerful on record, as warming ocean waters surge toward the Americas, setting up a pattern that could bring once-in-a-generation storms this winter to drought-parched California.
    The National Weather Service’s Climate Prediction Center said Thursday that all computer models are predicting a strong El Niño to peak in the late fall or early winter. A host of observations have led scientists to conclude that “collectively, these atmospheric and oceanic features reflect a significant and strengthening El Niño.”
    “This definitely has the potential of being the Godzilla El Niño,” said Bill Patzert, a climatologist with NASA’s Jet Propulsion Laboratory in La Cañada Flintridge.

    El Nino: 1997 vs. 2015


                 
     At the moment, this year’s El Niño is stronger than it was at this time of year in 1997. Areas in red and white represent the highest sea-surface heights above the average, which are a reflection of how warm sea-surface temperatures are above the average. (Source: NASA Jet Propulsion Laboratory climatologist Bill Patzert)
    Patzert said El Niño’s signal in the ocean “right now is stronger than it was in 1997,” the summer in which the most powerful El Niño on record developed.
    “Everything now is going to the right way for El Niño,” Patzert said. “If this lives up to its potential, this thing can bring a lot of floods, mudslides and mayhem.”
    “This could be among the strongest El Niños in the historical record dating back to 1950,” said Mike Halpert, deputy director of the Climate Prediction Center.
    After the summer 1997 El Niño muscled up, the following winter gave Southern California double its annual rainfall and dumped double the snowpack in the Sierra Nevada, an essential source of precipitation for the state’s water supply, Patzert said.
    A strong El Niño can shift a subtropical jet stream that normally pours rain over the jungles of southern Mexico and Central America toward California and the southern United States.
    But so much rain all at once has proved devastating to California in the past. In early 1998, storms brought widespread flooding and mudslides, causing 17 deaths and more than half a billion dollars in damage in California. Downtown L.A. got nearly a year's worth of rain in February 1998.
    During the second largest El Niño on record, in the winter of 1982-83, damage was particularly severe along the coast, especially when powerful storms arrived as high tide surged onto the coast. "Particularly at the end of January 1983, we had some very strong storm wave effects along the coast, and a lot of the vulnerable structures were lost that winter," said Dan Cayan, climate researcher with the Scripps Institution of Oceanography at UC San Diego and the U.S. Geological Survey.
    "Many locations along the California coast recorded their highest sea levels during that winter," he said.
    The effects of this muscular El Niño – nicknamed “Bruce Lee” by one blogger for the National Weather Service – are already being felt worldwide. While a strong El Niño can bring heavy winter rains to California and the southern United States, it can also bring dry weather elsewhere in the world.
    Already, El Niño is being blamed for drought conditions in parts of the Philippines, Indonesia and Australia, as occurred in 1997-98.
    Drought is also persistent in Central America. Water levels are now so low in the waterways that make up the Panama Canal that officials recently announced limits on traffic through the passageway that links the Atlantic and Pacific oceans.
    El Niño also influenced the heavy rainstorms that effectively ended drought conditions in Colorado, Texas and Oklahoma, and has brought floods and mudslides to Chile.
    There are a couple of reasons why scientists say El Niño is gaining strength.
    First, ocean temperatures west of Peru are continuing to climb, reaching their highest level so far this year. The temperatures in a benchmark location in that area of the Pacific Ocean were 3.4 degrees Fahrenheit above the average as of Aug. 5. That’s slightly higher than it was on Aug. 6, 1997, when it was 3.2 degrees Fahrenheit above normal.
    The mass of warm water in the Pacific Ocean is also bigger and deeper than it was at this point in 1997, Patzert said.
    Second, the so-called trade winds that normally keep the ocean waters west of Peru cool -- by pushing warm water farther west toward Indonesia -- are weakening.
    That’s allowing warm water to flow eastward toward the Americas, giving El Niño more strength.
    For this year’s El Niño to truly rival its 1997 counterpart, there still needs to be “a major collapse in trade winds from August to November as we saw in 1997,” Patzert said.
    “We’re waiting for the big trade wind collapse,” Patzert said. “If it does, it could be stronger than 1997.”
    There is a small chance such a collapse may not happen.
    “There’s always a possibility these trade winds could surprise us and come back,” Patzert said.
    Overall, the Climate Prediction Center forecast a greater-than-90% chance that El Niño will continue through this winter in the Northern Hemisphere, and about an 85% chance it will last into the early spring.
    In California, officials have cautioned the public against imagining that El Niño will suddenly end the state’s chronic water challenges.
    In fact, it would take an astonishing 2.5 to three times the average annual precipitation to make up for the rain and snow lost in the central Sierra mountain range over the last four years of drought, said Kevin Werner, the National Oceanic and Atmospheric Administration's expert on climate in the western United States.
    That amount far exceeds what happened in 1983, the wettest year on record for that region, when the area got 1.9 times the average annual precipitation, Werner said.
    "A single El Niño year is very unlikely to erase four years of drought," Werner said.
    "The drought is not ending any time soon," Halpert added.
    California has been dry for much of the last 15 years. Even if California gets a wet winter this year, it could be followed by another severe multiyear drought.
    Another problem is that the Pacific Ocean west of California is substantially warmer than it was in 1997. That could mean that though El Niño-enhanced precipitation fell as snow in early 1998, storms hitting the north could cause warm rain to fall this winter. Such a situation would not be good news “for long-term water storage in the snowpack,” said Daniel Swain, a climate scientist at Stanford University.
    Drought officials prefer snow in the mountains in the winter because it slowly melts during the spring and summer and can trickle at a gentle speed into the state’s largest reservoirs in Northern California. Too much rain all at once in the mountains in the winter can force officials to flush excess water to the ocean to keep dams from overflowing.
    Swain said it’s important to keep in mind that all El Niño events are different, and just because the current El Niño has the potential to be the strongest on record “doesn’t necessarily mean that the effects in California will be the same.”
    “A strong El Niño is very likely at this point, namely because we've essentially reached the threshold already, but a wet winter is never a guarantee in California,” Swain said in an email.
    “I think a good way to think about it is this: There is essentially no other piece of information that is more useful in predicting California winter precipitation several months in advance than the existence of a strong El Niño event,” Swain said. “But it's still just one piece of the puzzle. So while the likelihood of a wet winter is increasing, we still can't rule out other outcomes.”

    Wednesday, August 12, 2015

    Double Punch hits Phoenix Area

    Damaging wind storms hit the Phoenix Metro area on August 11 2015.


    Strong winds and blowing dust affect Phoenix
    Tuesday morning & Tuesday evening

    Updated: 5am Wednesday 12 Aug 2015
    AZ Science CenterAZ Science Center
    Images courtesy Arizona Science Center (10:00am & 10:30pm)
    A fast moving complex of showers and thunderstorms made its way through New Mexico, into Arizona, and through the Phoenix metro area during the morning hours of Tuesday 11 August 2015. Not only were 40-50mph winds common with these storms, but visibilities were reduced dramatically as blowing dust enveloped the metro area. Storms eventually moved into northern Arizona shortly after noon, with quiet weather taking hold during the afternoon/early evening hours.
    A secondary disturbance moved through southeast Arizona several hours later, eventually making its way through the Phoenix metro between 8pm and midnight. For the second time in less than 12 hours, widespread winds (this time in the 50-60mph range) overspread the valley along with near-zero visibility due to blowing dust.
    Additional information will be added to this page in the coming days as more reports become available.

    Round 1 (Tuesday Morning)
    Radar loops: Click each image for a larger view
    Morning radar image
    Morning radar image
    Base reflectivity imagery from KIWA Doppler radar. Brighter colors indicate stronger storms/heavier rainfall. Imagery from approximately 9am - 1050am
    Base velocity imagery from KIWA Doppler radar. Brighter colors indicate stronger winds. Imagery from approximately 9am - 1050am
    Preliminary summary of morning peak winds:
    LOCATION                     SPEED     TIME/DATE       LAT/LON
    
    6 ENE DEER VALLEY            59 MPH    1009 AM 08/11   33.72N/112.02W
    PHOENIX DEER VALLEY AIRPORT  57 MPH    1003 AM 08/11   33.69N/112.08W
    5 NW EAST MESA               57 MPH    0931 AM 08/11   33.47N/111.73W
    1 WSW LUKE AFB               52 MPH    1030 AM 08/11   33.53N/112.38W
    PHOENIX SKY HARBOR INTL ARPT 52 MPH    0958 AM 08/11   33.43N/112.00W
    RDA (PHOENIX) WILLIAMS AIR F 51 MPH    0941 AM 08/11   33.29N/111.67W
    7 SSW CAVE CREEK             49 MPH    1003 AM 08/11   33.72N/111.99W
    CHANDLER MUNICIPAL AIRPORT   46 MPH    0947 AM 08/11   33.27N/111.81W
    SCOTTSDALE MUNICIPAL AIRPORT 46 MPH    0957 AM 08/11   33.62N/111.91W
    3 NE EAST MESA               45 MPH    0931 AM 08/11   33.45N/111.65W
    1 ENE CAREFREE               43 MPH    1024 AM 08/11   33.83N/111.90W
    4 W QUEEN CREEK              42 MPH    0947 AM 08/11   33.23N/111.72W
    2 N GILBERT                  40 MPH    0941 AM 08/11   33.39N/111.79W
    6 W NORTH SCOTTSDALE         40 MPH    1005 AM 08/11   33.65N/112.00W
    5 E DEER VALLEY              40 MPH    1013 AM 08/11   33.66N/112.02W
    3 WSW APACHE JUNCTION        40 MPH    0933 AM 08/11   33.40N/111.60W
    6 ESE DEER VALLEY            39 MPH    1000 AM 08/11   33.65N/112.01W
    1 SSW YOUNGTOWN              39 MPH    1044 AM 08/11   33.57N/112.31W
    6 WNW PARADISE VALLEY        39 MPH    1017 AM 08/11   33.57N/112.05W
    4 SSE NEW RIVER              37 MPH    1017 AM 08/11   33.86N/112.10W
    HIGLEY                       37 MPH    0939 AM 08/11   33.31N/111.72W
    2 ENE TEMPE                  36 MPH    0952 AM 08/11   33.40N/111.88W
    1 W HIGLEY                   35 MPH    0942 AM 08/11   33.31N/111.75W
    FOUNTAIN HILLS               34 MPH    1006 AM 08/11   33.61N/111.73W
    1 NE PEORIA                  34 MPH    1030 AM 08/11   33.59N/112.22W
    3 NNE ODESSA                 33 MPH    1025 AM 08/11   33.57N/112.17W
    AHWATUKEE FOOTHILLS          32 MPH    1004 AM 08/11   33.31N/112.05W
    3 ESE QUEEN CREEK            32 MPH    0915 AM 08/11   33.22N/111.59W
    3 N HIGLEY                   31 MPH    0938 AM 08/11   33.35N/111.71W
    5 E DEER VALLEY              31 MPH    1008 AM 08/11   33.65N/112.03W
    6 NW PARADISE VALLEY         31 MPH    1010 AM 08/11   33.59N/112.03W
    5 SE DEER VALLEY             31 MPH    1004 AM 08/11   33.62N/112.04W
    1 NNE GOODYEAR               30 MPH    1040 AM 08/11   33.46N/112.40W
    1 NW GILBERT                 30 MPH    0948 AM 08/11   33.37N/111.81W
    5 N NORTH SCOTTSDALE         30 MPH    1038 AM 08/11   33.70N/111.88W
    3 SW GUADALUPE               30 MPH    0959 AM 08/11   33.33N/111.99W
    
    Preliminary summary of morning storm reports:
    ..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
    ..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
                ..REMARKS..
    
    0910 AM     DUST STORM       1 NW SAN TAN VALLEY     33.18N 111.58W
    08/11/2015                   PINAL              AZ   TRAINED SPOTTER 
    
                VISIBILITIES DOWN TO 1/4 MILES AND DECREASING IN 
                BLOWING DUST NEAR THE INTERSECTION OF GARY ROAD AND HUNT 
                HWY. 
    
    0917 AM     TSTM WND GST     4 ESE SUPERSTITION SPRI 33.37N 111.62W
    08/11/2015  E45 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
                ESTIMATED 45 MPH WINDS AND CONSIDERABLE DUST ON THE 
                HORIZON FROM APACHE JUNCTION...NEAR SUPERSTITION SPRINGS 
                AND IDAHO. 
    
    0923 AM     DUST STORM       4 ESE SUPERSTITION SPRI 33.37N 111.62W
    08/11/2015                   MARICOPA           AZ   NWS EMPLOYEE    
    
                VISIBILITY 1/4 MILE. WINDS GUSTING TO 45 MPH. 
    
    0930 AM     TSTM WND GST     4 SE TUMBLEWEED PARK    33.24N 111.78W
    08/11/2015  E50 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
    0930 AM     TSTM WND GST     4 ESE CHANDLER          33.27N 111.81W
    08/11/2015  M46 MPH          MARICOPA           AZ   AWOS            
    
                ALONG WITH 2 MILE VISIBILITY IN BLOWING DUST 
    
    0931 AM     TSTM WND GST     3 NNE MESA              33.46N 111.73W
    08/11/2015  M58 MPH          MARICOPA           AZ   AWOS            
    
    0937 AM     DUST STORM       4 SSE TUMBLEWEED PARK   33.22N 111.79W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                LESS THAN 1/8 MILE VIS WITH G40 MPH WINDS. 
    
    0940 AM     TSTM WND GST     GRANITE REEF DAM        33.51N 111.69W
    08/11/2015  M55 MPH          MARICOPA           AZ   MESONET         
    
    0941 AM     DUST STORM       4 E HIGLEY              33.31N 111.66W
    08/11/2015                   MARICOPA           AZ   AWOS            
    
                ONE QUARTER MILE VISIBILITY WITH MEASURED 51 MPH WIND 
                GUST 
    
    0955 AM     DUST STORM       1 S CAMELBACK MOUNTAIN  33.50N 111.96W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                VISIBILITY LESS THAN ONE HALF MILE 
    
    0957 AM     DUST STORM       3 SW DESERT RIDGE MARKE 33.65N 112.01W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                ONE QUARTER MILE VISIBILITY WITH MEASURED 39 MPH WIND 
                GUST 
    
    0958 AM     TSTM WND GST     6 NNW GUADALUPE         33.43N 112.01W
    08/11/2015  M52 MPH          MARICOPA           AZ   ASOS            
    
    1000 AM     TSTM WND GST     4 NNW NORTH MOUNTAIN PA 33.64N 112.10W
    08/11/2015  E55 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
    1000 AM     TSTM WND DMG     2 ENE SKY HARBOR AIRPOR 33.45N 111.99W
    08/11/2015                   MARICOPA           AZ   BROADCAST MEDIA 
    
                PALO VERDE TREE WITH 8-10 INCH DIAMETER TRUNK KNOCKED 
                DOWN ONTO CAR NEAR 44TH ST AND VAN BUREN. 
    
    1003 AM     TSTM WND GST     9 E PEORIA              33.69N 112.08W
    08/11/2015  M58 MPH          MARICOPA           AZ   ASOS            
    
    1005 AM     DUST STORM       9 NNE GLENDALE          33.66N 112.13W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                ONE HALF MILE VISIBILITY NEAR I-17 AND LOOP 101 WITH 40 
                MPH WIND GUSTS 
    
    1015 AM     HEAVY RAIN       2 NNW CHANDLER FASHION  33.32N 111.91W
    08/11/2015  M0.50 INCH       MARICOPA           AZ   TRAINED SPOTTER 
    
                ONE HALF INCH IN 5 MINUTES 
    
    1015 AM     TSTM WND DMG     5 S TEMPE               33.32N 111.93W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                8 INCH DIAMETER TREE LIMB DOWNED 
    
    1015 AM     TSTM WND DMG     2 NE TOLLESON           33.47N 112.24W
    08/11/2015                   MARICOPA           AZ   BROADCAST MEDIA 
    
                AT LEAST TWO PALO VERDE TREES WITH TRUNK DIAMETERS OF 
                SIX TO TWELVE INCHES KNOCKED DOWN OR SEVERELY DAMAGED 
                NEAR 83RD AVE AND MCDOWELL RD. 
    
    1020 AM     TSTM WND GST     SURPRISE                33.65N 112.34W
    08/11/2015  E50 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
                ALONG WITH 4 INCH DIAMETER TREE BRANCHES DOWN 
    
    1030 AM     TSTM WND GST     1 W LUKE AFB            33.53N 112.38W
    08/11/2015  M52 MPH          MARICOPA           AZ   AWOS            
    
    1030 AM     TSTM WND GST     3 SSW BEARDSLEY         33.64N 112.42W
    08/11/2015  E40 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
                ALONG WITH BLOWING DUST 
    
    1055 AM     DUST STORM       5 NNE HASSAYAMPA        33.42N 112.69W
    08/11/2015                   MARICOPA           AZ   AWOS            
    
                ONE QUARTER MILE VISIBILITY WITH WIND GUSTS MEASURED 45 
                MPH 
    

    Round 2 (Tuesday Evening)
    Radar loops: Click each image for a larger view
    Evening radar image
    Evening radar image
    Base reflectivity imagery from KIWA Doppler radar. Brighter colors indicate stronger storms/heavier rainfall. Imagery from approximately 830pm - 1030pm
    Base velocity imagery from KIWA Doppler radar. Brighter colors indicate stronger winds. Imagery from approximately 830pm - 1030pm
    Preliminary summary of evening peak winds:
    LOCATION                     SPEED     TIME/DATE       LAT/LON              
    2 WNW CASA GRANDE            65 MPH    0845 PM 08/11   32.90N/111.79W       
    RDA (PHOENIX) WILLIAMS AIR F 62 MPH    0920 PM 08/11   33.29N/111.67W       
    CASA GRANDE MUNICIPAL AIRPOR 59 MPH    0855 PM 08/11   32.95N/111.77W       
    4 W QUEEN CREEK              56 MPH    0922 PM 08/11   33.23N/111.72W       
    4 SSE COOLIDGE               51 MPH    0835 PM 08/11   32.92N/111.51W       
    2 SSE ROOSEVELT              49 MPH    0846 PM 08/11   33.64N/111.12W       
    QUEEN CREEK                  48 MPH    0905 PM 08/11   33.25N/111.64W       
    3 WSW APACHE JUNCTION        47 MPH    0928 PM 08/11   33.40N/111.60W       
    2 WNW SANTAN                 46 MPH    0929 PM 08/11   33.17N/111.84W       
    5 E SUN LAKES                46 MPH    0915 PM 08/11   33.22N/111.78W       
    1 ESE APACHE JUNCTION        44 MPH    0920 PM 08/11   33.41N/111.53W       
    1 WSW SAGUARO LAKE           44 MPH    0945 PM 08/11   33.56N/111.54W       
    1 NE PUNKIN CENTER           44 MPH    1011 PM 08/11   33.87N/111.31W       
    1 E FOUNTAIN HILLS           43 MPH    0950 PM 08/11   33.60N/111.71W       
    1 ENE CAREFREE               43 MPH    1026 PM 08/11   33.83N/111.90W       
    5 E DEER VALLEY              41 MPH    1000 PM 08/11   33.66N/112.02W       
    1 NNW COOLIDGE               40 MPH    0922 PM 08/11   32.99N/111.53W       
    7 SE AK-CHIN VILLAGE         40 MPH    0916 PM 08/11   32.94N/112.02W       
    3 N HIGLEY                   40 MPH    0928 PM 08/11   33.35N/111.71W       
    FOUNTAIN HILLS               39 MPH    0945 PM 08/11   33.61N/111.73W       
    1 NW SAGUARO LAKE            39 MPH    0959 PM 08/11   33.58N/111.54W       
    6 WNW PARADISE VALLEY        39 MPH    1012 PM 08/11   33.57N/112.05W       
    HIGLEY                       38 MPH    0920 PM 08/11   33.31N/111.72W       
    4 E APACHE JUNCTION          38 MPH    0928 PM 08/11   33.41N/111.47W       
    7 ESE APACHE JUNCTION        38 MPH    0920 PM 08/11   33.35N/111.45W       
    3 E APACHE JUNCTION          34 MPH    0929 PM 08/11   33.42N/111.49W       
    2 SSW SCOTTSDALE             34 MPH    0950 PM 08/11   33.46N/111.94W       
    9 WSW NEW RIVER              33 MPH    1029 PM 08/11   33.85N/112.28W       
    MOUNTAIN SPRINGS GRADE       33 MPH    0850 PM 08/11   32.67N/116.09W       
    5 E DEER VALLEY              33 MPH    1003 PM 08/11   33.65N/112.03W       
    4 W QUEEN CREEK              33 MPH    0918 PM 08/11   33.23N/111.73W       
    3 NNE ODESSA                 33 MPH    1005 PM 08/11   33.57N/112.17W       
    1 NW GILBERT                 33 MPH    0928 PM 08/11   33.37N/111.81W       
    5 NE TORTILLA FLAT           32 MPH    1235 AM 08/12   33.59N/111.34W       
    2 NNE CHANDLER               32 MPH    0930 PM 08/11   33.33N/111.86W       
    PEORIA                       31 MPH    1011 PM 08/11   33.58N/112.23W       
    8 ESE CAREFREE               31 MPH    1000 PM 08/11   33.76N/111.79W       
    15 WNW SUNFLOWER             31 MPH    0959 PM 08/11   33.98N/111.71W       
    3 WSW GLENDALE               31 MPH    1013 PM 08/11   33.51N/112.23W       
    4 W AHWATUKEE FOOTHILLS      31 MPH    1014 PM 08/11   33.31N/112.14W       
    5 NW APACHE JUNCTION         30 MPH    0944 PM 08/11   33.48N/111.61W       
    
    Preliminary summary of evening storm reports:
    ..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
    ..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
                ..REMARKS..
    
    0835 PM     TSTM WND GST     1 NW COOLIDGE AIRPORT   32.94N 111.43W
    08/11/2015  M55 MPH          PINAL              AZ   AWOS            
    
    0835 PM     TSTM WND GST     RANDOLPH                32.92N 111.51W
    08/11/2015  M51 MPH          PINAL              AZ   MESONET         
    
    0845 PM     TSTM WND GST     3 W CASA GRANDE         32.90N 111.79W
    08/11/2015  M65 MPH          PINAL              AZ   MESONET         
    
    0850 PM     TSTM WND DMG     SAN TAN VALLEY          33.17N 111.57W
    08/11/2015                   PINAL              AZ   UTILITY COMPANY 
    
                11400 SRP CUSTOMERS WITHOUT POWER IN PORTIONS OF THE 
                SOUTHEAST VALLEY. WORST AREAS AFFECTED APPEAR TO BE IN 
                THE SAN TAN VALLEY. 
    
    0851 PM     TSTM WND GST     NW CASA GRANDE          32.89N 111.74W
    08/11/2015  E50 MPH          PINAL              AZ   TRAINED SPOTTER 
    
                SPOTTER REPORTED AN ESTIMATED 50 MPH WIND GUSTS AT 
                MCCARTNEY RD AND SIGNAL PEAK. POWER IS OUT. 
    
    0855 PM     TSTM WND GST     5 NNW CASA GRANDE       32.95N 111.77W
    08/11/2015  M59 MPH          PINAL              AZ   AWOS            
    
                0.75 MILE VISIBILITY IN BLOWING DUST 
    
    0855 PM     TSTM WND DMG     2 SSW PHOENIX MESA GATE 33.27N 111.69W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                SEVEN DOWNED TREES IN NEIGHBORHOOD WITH TRUNK DIAMETERS 
                RANGING FROM SIX INCHES TO TWO FEET NEAR POWER ROAD AND 
                GERMANN RD. RAILROAD CROSSING ARM DAMAGED AT POWER AND 
                PECOS. 
    
    0901 PM     TSTM WND GST     2 ESE SAN TAN MOUNTAIN  33.14N 111.62W
    08/11/2015  E50 MPH          PINAL              AZ   TRAINED SPOTTER 
    
                STORM SPOTTER ESTIMATES PEAK WIND GUST AROUND 50 MPH. 
                WINDS OF 38 MPH WERE SUSTAINING FOR 20 MINUTES. THE 
                SPOTTER HAD NO POWER AT HER HOME. 
    
    0901 PM     TSTM WND GST     2 W APACHE JUNCTION     33.40N 111.58W
    08/11/2015  M43 MPH          PINAL              AZ   TRAINED SPOTTER 
    
                SPOTTER MEASURED A PEAK WIND GUST OF 43 MPH AT BROADWAY 
                AND MERRIDIAN 
    
    0904 PM     TSTM WND DMG     1 SE TUMBLEWEED PARK    33.27N 111.82W
    08/11/2015                   MARICOPA           AZ   BROADCAST MEDIA 
    
                AT LEAST TWO SMALL AIRCRAFT OVERTURNED AT CHANDLER 
                MUNICIPAL AIRPORT. AIR STAIRS BLOWN OVER. 
    
    0905 PM     DUST STORM       4 E HIGLEY              33.31N 111.66W
    08/11/2015                   MARICOPA           AZ   AWOS            
    
                0.25 MILE VISIBILITY 
    
    0905 PM     DUST STORM       4 E HIGLEY              33.31N 111.66W
    08/11/2015                   MARICOPA           AZ   AWOS            
    
                AT 0905 PM A VISIBILITY OF ONE EIGTH OF A MILE WAS 
                MEASURED AT MESA-GATEWAY AIRPORT -KIWA 
    
    0906 PM     TSTM WND DMG     2 E QUEEN CREEK         33.23N 111.60W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                PALM TREE UPROOTED NEAR RITTENHOUSE ROAD AND OCOTILLO 
                ROAD. VISIBILITIY DOWN TO ONE QUARTER MILE IN BLOWING 
                DUST. 
    
    0911 PM     TSTM WND GST     5 NW STANFIELD          32.94N 112.02W
    08/11/2015  M40 MPH          PINAL              AZ   MESONET         
    
    0912 PM     TSTM WND GST     SEVILLE                 33.23N 111.72W
    08/11/2015  M56 MPH          MARICOPA           AZ   MESONET         
    
    0914 PM     TSTM WND GST     3 NE BAPCHULE           33.17N 111.84W
    08/11/2015  M46 MPH          PINAL              AZ   MESONET         
    
    0919 PM     TSTM WND GST     2 ENE TUMBLEWEED PARK   33.28N 111.80W
    08/11/2015  E45 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
                SPOTTER REPORTED PEAK WIND GUST OF 45 MPH. 
    
    0919 PM     TSTM WND GST     4 E HIGLEY              33.31N 111.66W
    08/11/2015  M62 MPH          MARICOPA           AZ   AWOS            
    
                AT 0920 PM A PEAK WIND GUST OF 62 MPH WAS MEASURED AT 
                MESA-GATEWAY AIRPORT -KIWA. 
    
    0923 PM     TSTM WND GST     3 N HIGLEY              33.35N 111.71W
    08/11/2015  M40 MPH          MARICOPA           AZ   MESONET         
    
    0923 PM     TSTM WND DMG     FLORENCE JUNCTION       33.26N 111.34W
    08/11/2015                   PINAL              AZ   DEPT OF HIGHWAYS
    
                DOWNED POWER LINES OVER ROAD AT FLORENCE JUNCTION. 
                US-60 CLOSED AT MP 210. 
    
    0924 PM     TSTM WND GST     SEVILLE                 33.23N 111.72W
    08/11/2015  M41 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
                SPOTTER MEASURED 41 MPH WINDS AT CHANDLER HEIGHTS RD 
                AND SE GILBERT 
    
    0929 PM     HEAVY RAIN       SEVILLE                 33.23N 111.72W
    08/11/2015  M0.75 INCH       MARICOPA           AZ   TRAINED SPOTTER 
    
                SPOTTER REPORTED .75 INCHES OF RAINFALL IN LESS THAN 
                HALF AN HOUR. 
    
    0934 PM     DUST STORM       5 WSW FOUNTAIN HILLS    33.59N 111.82W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                SPOTTER ESTIMATED VISIBILITY NEAR HALF A MILE. 
    
    0934 PM     TSTM WND GST     3 E TUMBLEWEED PARK     33.27N 111.78W
    08/11/2015  E40 MPH          MARICOPA           AZ   TRAINED SPOTTER 
    
                SPOTTER ESTIMATED 40 MPH WINDS AT GILBERT AND GERMANN. 
    
    0938 PM     TSTM WND DMG     1 NNW SEVILLE           33.24N 111.72W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                1 FOOT DIAMETER TREE DOWN NEAR CHANDLER HEIGHTS AND 
                HIGLEY 
    
    0944 PM     DUST STORM       2 SSE USERY MOUNTAIN PA 33.44N 111.60W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                QUARTER MILE VISIBILITY 
    
    1007 PM     TSTM WND GST     9 E PEORIA              33.69N 112.08W
    08/11/2015  M52 MPH          MARICOPA           AZ   ASOS            
    
                THUNDERSTORM WIND GUST TO 52 MPH MEASURED AT DEER 
                VALLEY AIRPORT. 
    
    1010 PM     DUST STORM       3 W WADDELL             33.59N 112.41W
    08/11/2015                   MARICOPA           AZ   TRAINED SPOTTER 
    
                VISIBILITY OF ONE HALF TO THREE QUARTERS OF A MILE IN 
                BLOWING DUST NEAR CACTUS ROAD AND SARIVAL AVE. 
    

    Friday, August 7, 2015

    Warmest Summer on Record in the Pacific Northwest

    Pacific Northwest on Track for Warmest Summer on Record

    By: Christopher C. Burt , 3:30 AM GMT on August 01, 2015
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    Pacific Northwest on Track for Warmest Summer on Record

    Another heat wave has engulfed much of the U.S. Pacific Northwest the past few days with Seattle, Washington now having observed twelve 90°+ temperatures so far this summer (as of Aug. 1st), an all-time record (9 such days in 1958 was the previous) and also July has been their warmest month ever observed. For some of the cities in the Northwest this has been the warmest June-July period ever measured and, barring a very cool August, will end up being the warmest climatological summer on record (June-August). Here are some details.

    After enduring its warmest June on record Seattle has now endured its warmest July on record (see tables below for the figures) and thus its warmest single month on record. It also has been exceptionally dry with only .09” precipitation measured in July (normal is .66”) and .23” in June (normal is 1.43”). However, this is still no match for the June-July period of 1922 when only .03” accumulated! The July 2015 average temperature of 71.2° is also the city’s all-time (any month) heat record (previous 71.1° in August 1967). 

    Portland, Oregon is also on track for enduring its warmest summer on record following a record warm June and near-record warm July. In fact, July 30th was one of the hottest days on record for much of Oregon’s Willamette Valley. Corvallis Airport reached 108°, tying the town’s all-time (any month) record last set on August 10, 1981 at Corvallis State University (POR since 1889). Roseburg, further south, also reached 108°, just 1° shy of its all-time (any month) record of 109° set on July 20, 1946. Salem and Eugene both observed daily record highs of 105° (all-time records for both cities are 108° set on August 9, 1981) and Portland reached 103°, short of its record of 107° measured on three previous occasions. In Eugene, seven 100°+ days have so far been recorded this summer (including on Aug. 1st), surpassing the previous record of five such back in 1978. 

    On July 31st The Dalles and Pendleton (in Oregon) hit 109°, the warmest temperatures measured so far during the current heat wave for first order stations. Neither are all-time records (111° on several occasions for The Dalles and 115° for Pendleton). Salem, Oregon has just experienced its warmest month on record (see table below). The coastal sites in northern Oregon and Washington have also been exceptionally mild. Quillayute, Washington was just short of its warmest month on record with a 63.0° average temperature for July (in August 2013 the average was 63.1°). Astoria, Oregon has had its single warmest month since July 1941 with an average of 64.1° (in 1941 the July average was 64.6°).

    In the tables below are sites in the Northwest that observed their all-time warmest June on record, how they fared in July, and what their combined June-July averages have been relative to their warmest climatological (June-August) summers on record. It would appear that Medford, Portland, and Salem in Oregon, as well as Seattle, Yakima, and Spokane in Washington are likely to end up with their warmest summers on record barring a very cool August. One aspect of this is that (should the heat trend continue) Yakima, Washington and Portland, Oregon will see back-to-back record warm summers. They just observed their hottest summer on record LAST summer in 2014!







    New June monthly heat records (average temperature) for selected cities in the Pacific Northwest (top table), average monthly temperatures for July compared to record values for the same cities (middle table), and June-July average temperatures compared to warmest climatological summer (June-August) on record (bottom table).

    Aside from the heat, drought conditions have significantly worsened across the region with 37% of the Pacific Northwest watershed now experiencing extreme drought conditions (a huge weekly jump from just 20% a week earlier).



    Pacific Northwest Watershed drought monitor map for July 28th. Note how rapidly conditions have deteriorated in the past several months. Map from NOAA et al.

    The hot weather and dry conditions have critically impacted the sockeye salmon runs along the Columbia River and its tributaries. Federal and state fishery biologists estimate that up to 80% of the salmon may perish since the fish become stressed at water temperatures above 68° and stop migrating when the water reaches 74° or higher. Many of the Columbian River tributaries are already measuring temperatures above 76°. The Columbian River itself is running at its lowest level for this time of the year in 60 years according to U.S. Fish and Wildlife Service officials.



    The Columbia River is running at its lowest level in almost 60 years for this time of the year, threatening the annual sockeye salmon run. Photo from Freestock. com

    P.S. June of 2015 saw many other all-time monthly records at other sites outside of the Pacific Northwest (PNW figures included in the table as well). See:





    I'll be updating this blog as the new numbers for August and the NOAA/NCDC data for July become available.

    Christopher C. Burt
    Weather Historian

    Wednesday, August 5, 2015

    Severe Thunderstorms Possible Star Valley later Wednesday

    The Storm Prediction Center in Norman OK has forecast the potential for a few severe thunderstorms to move across southeastern Idaho into Western Wyoming, including Star Valley later this afternoon.

    Following are the associated graphics with the forecast.

    Severe Weather Forecast for August 5 2015
    Damaging wind Potential









    Following is the meteorological reasoning for the forecast


       DAY 1 CONVECTIVE OUTLOOK  
       NWS STORM PREDICTION CENTER NORMAN OK
       1129 AM CDT WED AUG 05 2015
    
       VALID 051630Z - 061200Z
    
       ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ID/WY/MT...
    
       ...THERE IS A SLGT RISK OF SVR TSTMS OVER NORTHERN AR...
    
       ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PARTS OF THE NORTHERN
       PLAINS AND NORTHERN ROCKIES...
    
       ...THERE IS A MRGL RISK OF SVR TSTMS FROM OK INTO THE TN VALLEY...
    
       ...THERE IS A MRGL RISK OF SVR TSTMS OVER PARTS OF NEW ENGLAND...
    
       ...SUMMARY...
       A FEW SEVERE STORMS WITH GUSTY WINDS AND HAIL WILL BE POSSIBLE OVER
       PARTS OF ARKANSAS THIS AFTERNOON.  OTHER STRONG TO SEVERE STORMS
       WITH HAIL AND WIND MAY OCCUR OVER PARTS OF THE NORTHERN ROCKIES AND
       INTO THE NORTHERN PLAINS...AND A COUPLE OF STRONGER CELLS POSSIBLY
       CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL MAY AFFECT PARTS OF
       NORTHERN NEW ENGLAND.
    
       ...MID MS VALLEY...
       A REMNANT MCS IS TRACKING SOUTHEASTWARD ACROSS PARTS OF
       AR/OK/MO...AND WILL MOVE ACROSS MUCH OF NORTHERN/CENTRAL AR TODAY. 
       STRONG HEATING IS OCCURRING AHEAD OF THE CONVECTION...WHERE
       DEWPOINTS ARE IN THE MID 70S AND AFTERNOON MLCAPE VALUES OF
       1500-2500 J/KG ARE EXPECTED.  STORMS MAY RE-INTENSIFY ALONG THE
       LEADING EDGE OF THE MCS LATER TODAY...POSING A RISK OF DAMAGING WIND
       GUSTS AND HAIL.  THUNDERSTORMS WILL LIKELY ALSO DEVELOP EASTWARD
       FROM THE MCS ACROSS PARTS OF TN/KY THIS AFTERNOON...BUT WILL BE MORE
       DISORGANIZED AND TRANSIENT.  NEVERTHELESS...THE STRONGEST CELLS WILL
       BE CAPABLE OF DOWNBURST WINDS AND HAIL.
    
       ...NORTHERN ROCKIES INTO ID...
       WATER VAPOR LOOPS SHOW AN IMPRESSIVE SHORTWAVE TROUGH OVER NORTHERN
       NV.  THIS FEATURE WILL TRACK ACROSS ID/UT THIS AFTERNOON...PROVIDING
       LIFT AND FOCUS FOR SCATTERED THUNDERSTORMS.  MODELS ARE IN AGREEMENT
       THAT CONVECTION WILL FORM OVER SOUTH-CENTRAL ID BY MID/LATE
       AFTERNOON AND TRACK NORTHEASTWARD ALONG THE EASTERN SNAKE RIVER
       VALLEY...EVENTUALLY INTO NORTHWEST WY.  SUFFICIENT INSTABILITY AND
       STRONG WINDS ALOFT...COUPLED WITH STEEPENING LOW LEVEL LAPSE RATES
       WILL PROMOTE A RISK OF DAMAGING WINDS WITH THESE STORMS.  GIVEN
       CONSISTENCY IN MODEL SOLUTIONS AND FAVORABLE ORIENTATION OF FORCING
       WITH TERRAIN...HAVE OPTED TO UPGRADE REGION TO SLGT RISK.
    
       ..HART/PICCA.. 08/05/2015

    Sunday, August 2, 2015

    Climate Summaries for Wyoming as of July 31 2015

    Riverton Forecast Office has provided the climate data for much of Western Wyoming covering the period through July 2015.

    Following are some rainfall totals around Star Valley for July 2015.

    Star Valley Ranch            2.62
    Bedford                              2.48
    2 SE Thayne                      2.05
    5  SSE Smoot                     1.86
    Afton                                   1.53










    Climate Summaries

    2014-2015 Water Year Precipitation and Percent of Normal for Selected Stations

    Station Name:
    Airports
    Drought
    Conditions
    Oct
    2014
    Nov
    2014
    Dec
    2014
    Jan
    2015
    Feb
    2015
    Mar
    2015
    Apr
    2015
    May
    2015
    Jun
    2015
    Jul
    2015
    Aug
    2015
    Sep
    2015
    Total for
    Water Year
     click on locationD0D1
     for graphD2D3D4
    Big Piney D00.090.050.120.010.050.060.562.300.231.735.20
    1981-2010 Normals 0.53 0.21 0.30 0.31 0.35 0.44 0.53 0.840.79 0.71 0.69 0.78 5.01
    Percent of Normal  17 24 40 3 141410627429244 104
    BuffaloNone0.210.340.08 0.160.480.080.785.763.230.7711.89
    1981-2010 Normals 0.93 0.54 0.40 0.42 0.35 0.92 1.30 2.53 2.28 1.66 0.81 1.31 11.33
      Percent of Normal  23 63 20 38 13796022814246 105
    Casper  None1.050.811.250.520.790.641.663.891.500.5712.68
    1981-2010 Normals 1.11 0.76 0.49 0.510.57 0.82 1.29 2.02 1.61 1.41 0.85 1.08 10.59
      Percent of Normal  95 107 255 102139781291939340 120
    Snowfall 3.2 10.617.86.4 12.49.34.76.30.00.070.7
    1981-2010 Normals7.4 10.311.09.19.810.911.62.90.10.00.01.873.1
      Percent of Normal  43103 162 70 127854121700 97
    Evanston  D00.110.590.180.640.370.440.574.490.640.888.91
      1981-2010 Normals1.171.040.580.540.610.861.151.771.240.900.961.31 9.86
      Percent of Normal  9 57 31 119 6151502545298 90
    Greybull  None0.010.590.210.220.040.140.111.070.25T2.64
      1981-2010 Normals 0.60 0.30 0.28 0.23 0.18 0.40 0.71 1.65 1.20 0.66 0.42 0.88 6.21
      Percent of Normal 2197 75 962235156521043
    Station Name:
    Airports
    Drought
    Conditions
    Oct
    2014
    Nov
    2014
    Dec
    2014
    Jan
    2015
    Feb
    2015
    Mar
    2015
    Apr
    2015
    May
    2015
    Jun
    2015
    Jul
    2015
    Aug
    2015
    Sep
    2015
    Total for
    Water Year
    Lander None0.500.591.82T1.560.552.316.100.800.5014.73
      1981-2010 Normals 1.29 0.86 0.58 0.41 0.58 1.16 1.87 2.20 1.27 0.780.61 1.0511.00
      Percent of Normal  39 69 209 0 269471242776364 134
    Snowfall T 8.9 21.1 0.3 23.68.910.30.80.00.073.9
    1981-2010 Normals9.8 13.110.17.610.316.116.84.80.10.00.02.7 88.7
      Percent of Normal  0 68209 4 2295561170083
    Riverton None0.160.420.650.031.040.410.824.550.791.10 9.97
      1981-2010 Normals 0.89 0.50 0.32 0.24 0.27 0.55 1.30 1.72 1.28 0.89 0.57 0.90 7.96
      Percent of Normal  18 84 203 13 385756326562124125
    Snowfall 17.5 1.5 6.8 0.4 15.86.73.30.50.0 0.0 38.8
    Rock Springs None0.320.130.110.010.080.220.673.101.112.127.87
     1981-2010 Normals 0.87 0.49 0.50 0.45 0.48 0.68 0.91 1.21 0.79 0.64 0.62 0.92 7.02
      Percent of Normal 37 2722 0.4 173274256141331 112
    Sheridan  None0.161.49 0.740.451.280.401.435.423.050.8415.26
      1981-2010 Normals 1.41 0.71 0.56 0.56 0.54 0.98 1.60 2.352.12 1.18 0.72 1.4312.01
      Percent of Normal  11 210 132 80 237418923114471 127
    WorlandNone0.270.57 0.700.230.54T0.353.061.060.41 7.19
      1981-2010 Normals0.690.350.23 0.230.190.460.861.421.150.710.430.85 6.29
      Percent of Normal  39 163 304 100 2840412159258 114
    Station Name:
    COOPS
    Drought
    Conditions
    Oct
    2014
    Nov
    2014
    Dec
    2014
    Jan
    2015
    Feb
    2015
    Mar
    2015
    Apr
    2015
    May
    2015
    Jun
    2015
    Jul
    2015
    Aug
    2015
    Sep
    2015
    Total for
    Water Year
    Afton D00.651.561.480.580.880.621.474.841.361.5314.97
      1981-2010 Normals1.632.041.251.401.091.401.542.261.971.431.251.4615.45
      Percent of Normal  40105 11841 8144952146910797
    Snowfall 0.2 13.9 24.2 9.6 6.55.96.70.00.00.067.0
    Bitter Creek 4NENone0.170.530.340.090.130.700.343.821.542.5710.21
      1981-2010 Normals0.660.310.510.280.360.300.651.090.700.600.750.73 5.46
      Percent of Normal  26 17167 323623352350220428 187
    Cody None0.421.541.290.100.870.201.665.100.920.5212.62
      1981-2010 Normals0.890.480.330.330.330.561.061.821.681.110.911.06 8.59
      Percent of Normal  47 321 391 30 264361572805547 147
    Snowfall 0.0 19.0 14.0 2.0 7.01.54.00.00.00.047.5
    1981-2010 Normals4.36.38.07.86.76.96.30.80.00.00.00.247.1
      Percent of Normal 0 302 175 26 1042263000 101
    Dubois None0.401.000.690.150.460.350.553.281.311.62 9.81
      1981-2010 Normals0.810.570.280.240.380.401.101.641.281.110.861.24 7.81
      Percent of Normal 49 175 246 63 1218850200102146 126
    Snowfall1.0 13.5 16.5 2.0 10.65.54.5T0.00.053.6
    1981-2010 Normals3.05.85.13.95.76.08.53.90.60.00.02.642.5
      Percent of Normal 33 233 324 51 1869253000126
    Fossil Butte
    National Monument
      D00.520.550.78 0.230.510.680.614.900.810.70 10.29
    1981-2010 Normals1.110.860.740.490.680.820.981.411.030.850.931.10 8.97
      Percent of Normal 47 64 10547 7583623487982 115
    SnowfallT 7.8 10.7 2.2 4.36.05.73.00.00.0 39.7
    Green River None0.360.381.07T0.300.921.524.671.441.10 11.76
      1981-2010 Normals0.810.410.44 0.34 0.430.71 0.851.230.980.55 0.68 0.90 6.75
      Percent of Normal 44 93 2430 70130179380147200 174
    Snowfall0.0 T 9.8T 2.07.06.5T0.00.0 25.3
    1981-2010 Normals0.53.86.54.67.35.03.90.60.00.00.00.032.2
    Percent of Normal0 0 1510 27140167000 79
    Station Name:
    COOPS
    Drought
    Conditions
    Oct
    2014
    Nov
    2014
    Dec
    2014
    Jan
    2015
    Feb
    2015
    Mar
    2015
    Apr
    2015
    May
    2015
    Jun
    2015
    Jul
    2015
    Aug
    2015
    Sep
    2015
    Total for
    Water Year
    Jeffrey City None0.110.211.210.200.400.791.944.700.671.00 11.23
      1981-2010 Normals0.910.590.42 0.31 0.410.86 1.271.851.150.89 0.60 0.80 8.66
      Percent of Normal 12 36 28865 989215325458112 130
    Snowfall0.0 2.1 16.03.0 7.09.020.07.00.00.064.1
    1981-2010 Normals7.36.65.54.66.79.410.24.90.40.00.01.4 55.6
      Percent of Normal 0 3229165 1049619614300 115
    Kaycee None0.510.560.770.320.870.021.166.001.030.74 11.98
      1981-2010 Normals1.040.570.310.300.340.741.462.371.841.420.801.18 10.39
      Percent of Normal 49 98 248 107 2563792535652 115
    SnowfallT 8.5 10.0 3.5 12.0TT3.00.00.037.0
    1981-2010 Normals1.54.26.05.96.38.04.70.60.10.00.00.237.3
      Percent of Normal 0 202 167 59 190005000099
    Moose  D00.54 3.553.262.311.570.670.803.831.032.72 20.28
      1981-2010 Normals1.472.642.672.581.821.621.491.881.611.291.291.44 19.07
      Percent of Normal 37 134 12290 86415420464211106
    SnowfallT 43.3 39.6 26.0 19.111.05.40.00.00.0 144.4
    1981-2010 Normals4.824.144.736.926.615.97.42.20.00.00.00.2 162.6
      Percent of Normal 0 180 89 70 72697300089
    Old Faithful D01.732.492.461.230.750.770.943.751.242.1417.50
      1981-2010 Normals1.662.293.16 2.111.992.212.212.802.471.551.461.46 22.45
      Percent of Normal  104 10978 58 3835431345013878
    Snowfall2.0 20.0 36.3 30.0 6.0 1.03.5T0.00.0 98.8
    1981-2010 Normals7.731.743.837.531.126.819.37.31.20.00.01.4 206.4
      Percent of Normal 26 63 83 80 1941800048
    Powell Field Station  None0.220.430.100.040.030.090.392.130.600.32 4.35
      1981-2010 Normals0.560.180.130.210.130.290.511.401.350.870.52 0.65 5.63
      Percent of Normal 3923977 19 233176152443777
    Snowfall0.0 3.8 1.3 0.3 0.30.1T0.00.00.05.8
    1981-2010 Normals 1.21.31.22.30.52.50.50.50.00.00.00.110.0
      Percent of Normal 0 292 108 13 6040000 58
    Riverton (downtown) None0.180.410.550.041.280.471.104.030.820.819.69
      1981-2010 Normals0.850.410.240.280.330.560.981.451.210.780.500.83 7.09
      Percent of Normal 21 100229 14 3888411227868104 137
    SnowfallT 7.8 7.4 0.7 17.86.61.8T0.00.042.1
    1981-2010 Normals3.74.34.8 4.8 6.0 5.9 6.11.20.00.00.00.336.8
      Percent of Normal 0 181 154 15 29711230000114
    Thermopolis  None0.220.372.040.140.920.061.604.541.500.3811.77
      1981-2010 Normals1.260.800.460.350.450.871.461.861.510.880.581.23 9.90
      Percent of Normal  17 46 443 40 20471102449943 119
    Snowfall0.0 9.0 23.0 3.0 3.51.0T0.00.00.0 39.5
    1981-2010 Normals2.43.74.55.6 4.62.52.80.40.00.00.00.226.5
      Percent of Normal 0243511 54 76400000 149
    Drought Classifications on July 28, 2015     |      XX.X / M - Data partially or completely missing
    Wyoming Climate      |      Click on Image to Enlarge
    Statewide averages and ranks for periods including July 2015 will be available on August 6, 2015* 
    * 2015 Climate Monitoring Release Dates
    Last Month
    Precipitation - Percent of NormalTemperature - Departure from Normal
    Wyoming: Last Month Percent of Normal PrecipitationWyoming: Last Month Departure from Normal Temperature
     Statewide Average (inches) Statewide Average (°F)
     20th Century Average1.84 20th Century Average57.6
     Rank - Driest  to Wettest  (121 Years) Rank - Warmest  to Coldest (121 Years)
     Rank - Wettest to Driest (121 Years) Rank - Coldest to Warmest (121 Years)
     Driest Month on Record: Jun 20120.45  Warmest Month on Record: Jun 198866.4
     Wettest Year on Record: Jun 19674.33  Coldest Month on Record: Jun 195151.5

    Last 3 Months
    Precipitation - Percent of NormalTemperature - Departure from Normal
    Wyoming: Last Three Months Percent of Normal PrecipitationWyoming: Last 3 Months Departure from Normal Temperature
     Statewide Average (inches) Statewide Average (°F)
     20th Century Average5.82 20th Century Average48.3
     Rank - Driest  to Wettest  (121 Years) Rank - Warmest  to Coldest (121 Years)
     Rank - Wettest to Driest (121 Years) Rank - Coldest to Warmest (121 Years)
     Driest Period on Record: Apr - Jun 19192.91 Warmest Period on Record: Apr - Jun 198853.1
     Wettest Period on Record: Apr - Jun 19579.32 Coldest Period on Record: Apr - Jun 191743.7

    2015
    Precipitation - Percent of NormalTemperature - Departure from Normal
    Wyoming: 2015 Percent of Normal PrecipitationWyoming: 2015 Departure from Normal Temperature
     Statewide Average (inches) Statewide Average (°F)
     20th Century Average9.10 20th Century Average35.8
     Rank - Driest  to Wettest  (121 Years) Rank - Warmest  to Coldest (121 Years)
     Rank - Wettest to Driest (121 Years) Rank - Coldest to Warmest (121 Years)
     Driest Period on Record: Jan - Jun 19194.72 Warmest Period on Record: Jan - Jun 193441.5
     Wettest Period on Record: Jan - Jun 1899, 199512.70 Coldest Period on Record: Jan - Jun 191730.3

    2014-2015 Water Year
    Precipitation - Percent of NormalTemperature - Departure from Normal
    Wyoming: 2014-2015 Water Year Percent of Normal PrecipitationWyoming: 2014-2015 Water Year Departure from Normal Temperature
     Statewide Average (inches) Statewide Average (°F)
     20th Century Average12.34 20th Century Average34.1
     Rank - Driest  to Wettest  (120 Years) Rank - Warmest  to Coldest (120 Years)
     Rank - Wettest to Driest (120 Years) Rank - Coldest to Warmest (120 Years)
     Driest Periods on Record: Oct 1918 - Jun 19197.12 Warmest Period on Record: Oct 1933 - Jun 1934 39.7
     Wettest Period on Record: Oct 1994 - Jun 1995 17.66 Coldest Period on Record: Oct 1916 - Jun 191728.6

    Last 12 Months
    Precipitation - Percent of NormalTemperature - Departure from Normal
    Wyoming: Last 12 Months Percent of Normal PrecipitationWyoming: Last 12 Months Departure from Normal Temperature
     Statewide Average (inches) Statewide Average (°F)
     20th Century Average15.94 20th Century Average40.8
     Rank - Driest  to Wettest  (120 Years) Rank - Warmest  to Coldest (120 Years)
     Rank - Wettest to Driest (120 Years) Rank - Coldest to Warmest (120 Years)
     Driest Period on Record: Jun 1933 - May 193411.11 Warmest Period on Record: Jul 1933 - Jun 1934 45.3
     Wettest Period on Record: Jul 1994 - Jun 199520.33 Coldest Period on Record: Jul 1916 - Jun 191736.4

    Last 5 Years (Aug 2010 - Jul 2015)
    Precipitation - Percent of NormalTemperature - Departure from Normal
    Map Not Available For This PeriodMap Not Available For This Period
     Statewide Average (inches) Statewide Average (°F)
     20th Century Average79.51 20th Century Average40.7
     Rank - Driest  to Wettest  (120 Years) Rank - Warmest  to Coldest (120 Years)
     Rank - Wettest to Driest (120 Years) Rank - Coldest to Warmest (120 Years)
     Driest Period on Record: Jul 1999 - Jul 200465.21 Warmest Period on Record: Jul 2002 - Jun 200742.8
     Wettest Period on Record: Jul 1