Thursday, February 26, 2015

Weekend should be cold with only a little snow for Star Valley

The weekend weather video for western Wyoming focuses on generally cold but little in the way of significant snow.



Weekly Weather Video 

Tuesday, February 24, 2015

Spring 2015 Snowmelt Flood Potential-issued February 24th

Wyoming Spring 2015 Snowmelt Flood Potential---issued February 24th

Quick Synopsis:

Mountain snowpack and associated snow water equivalents (SWEs) across northern Wyoming were generally above average by late February; while SWEs across southern Wyoming basins were generally below average.  SWEs at the peak snowmelt runoff elevations (8,000’ – 9.500’) were thehighest across the Powder, Bighorn, and Upper Green Basins at 115 to 135percent of median.  The Little Snake and Sweetwater Drainages had SWEs at70 to 75 percent of median at the peak snowmelt runoff elevations.


This outlook is based on various diverse hydrological factors such as snow water equivalents (SWEs) in the mountain snowpack, basin morphology (i.e. how basins respond to snowmelt runoff),  antecedent soil moisture, amount of bark beetle kill, low elevation snow depths, and likely temperature and precipitation trends during late spring/early summer.


HIGHLIGHTS:

Low to Moderate potential for flooding associated with snowmelt is expected across headwater streams along the western Big Horn Mountains. Streams with the highest potential for snowmelt flooding include Medicine Lodge Creek, Ten Sleep Creek (Ten Sleep), and portions of the Nowood River…

…All other of headwater basins across Wyoming can expect a generallyLow potential for flooding due to springtime snowmelt...

The next graphical outlook will be issued around the 25th of March. 

*****************************************************************************************
Other hydrological information for Wyoming can be found at the NOAA hydrology website:
http://www.crh.noaa.gov/riw/?n=cms_hydro

Monthly Wyoming Hydrologic Summary and Graphics:
(updated monthly around the 15th of every month)

Wyoming Drought Information Page:
(updated at least once a month)


Wyoming Graphical Water Supply Outlook:
(updated by the 15th of every month—January-June)

Wyoming Average Precipitation by Basin:
 (updated monthly)

Wyoming Spring Snowmelt Runoff Flood Potential Graphic:
(updated around the 25th of the month---January-May)
Current and Forecast Wyoming Streamflows and/or River Stages:


*******************************************************************************
The current Wyoming Spring 2015 Snowmelt Runoff Flood Potential Outlook graphic:



Sunday, February 22, 2015

Snowfall Totals Feb 20-21 2015

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
907 PM MST SAT FEB 21 2015

...SNOWFALL TOTALS FOR FRIDAY AND SATURDAY...

A WINTER STORM BROUGHT SIGNIFICANT SNOWFALL TO PORTIONS OF WESTERN
AND CENTRAL WYOMING. BELOW ARE PRELIMINARY SNOWFALL TOTALS THROUGH
THE DAY SATURDAY. ADDITIONAL DATA WILL BE ADDED SUNDAY MORNING...
WITH A FINAL TOTAL SUNDAY AFTERNOON.

NOTE...SNOTELS (SNOW TELEMETRY) ARE REMOTE SENSING SITES IN HIGH
MOUNTAIN WATERSHEDS.  SNOWFALL DATA FROM SNOTELS IS ESTIMATED BASED
ON SNOW WATER EQUIVALENT.


LOCATION                             SNOWFALL
LINCOLN COUNTY...
 COMMISSARY RIDGE...                  3 INCHES.
 WILLOW CREEK SNOTEL...               3 INCHES.
 COTTONWOOD CREEK SNOTEL...           3 INCHES.
 2 SE THAYNE...                     2.5 INCHES.
 KELLEY RANGER STATION SNOTEL...      2 INCHES.
 3 SE BEDFORD...                      2 INCHES.
 SALT RIVER SUMMIT SNOTEL...          2 INCHES.
 BLIND BULL SUMMIT...                 2 INCHES.
 SPRING CREEK DIVIDE SNOTEL...        2 INCHES.
 STAR VALLEY RANCH...                 2 INCHES.
 FAIRVIEW...                        1.8 INCHES.
 AFTON...                             1 INCH.
 BOX Y RANCH...                       1 INCH.
 5 SSE SMOOT...                       1 INCH.
 BLIND BULL SUMMIT SNOTEL...          1 INCH.
 FOSSIL BUTTE...                      1 INCH.
 HAMS FORK SNOTEL...                  1 INCH.
 INDIAN CREEK SNOTEL...               1 INCH.
 LA BARGE...                        0.5 INCHES.

BIG HORN COUNTY... SHELL CREEK SNOTEL... 5 INCHES. BONE SPRINGS DIVIDE SNOTEL... 4 INCHES. BALD MOUNTAIN SNOTEL... 3 INCHES. GREYBULL... 0.6 INCHES. BASIN... 0.5 INCHES. FREMONT COUNTY... 4 WSW LANDER... 14 INCHES. 6 SW LANDER... 12 INCHES. 9.5 SW LANDER... 10 INCHES. 9 SSE LANDER... 10 INCHES. DEER PARK SNOTEL... 7 INCHES. LANDER AIRPORT... 6.3 INCHES. LANDER... 4 TO 6 INCHES. HUDSON... 5 INCHES. ST. LAWRENCE ALT SNOTEL... 5 INCHES. TOWNSEND CREEK SNOTEL... 5 INCHES. BROOKS LAKE... 4 INCHES. RIVERTON... 3.1 INCHES. BURROUGHS CREEK SNOTEL... 3 INCHES. 5 N RIVERTON... 3 INCHES. RIVERTON AIRPORT... 2.4 INCHES. ATLANTIC CITY... 2.1 INCHES. HOBBS PARK SNOTEL... 2 INCHES. SOUTH PASS SNOTEL... 2 INCHES. CROWHEART... 2 INCHES. LITTLE WARM SNOTEL... 2 INCHES. 14 NW RIVERTON... 2 INCHES. 10 NNE RIVERTON... 1.6 INCHES. BURRIS... 1 INCH. COLD SPRINGS SNOTEL... 1 INCH. BOYSEN DAM... 1 INCH. HOT SPRINGS COUNTY... THERMOPOLIS... 2 TO 3 INCHES. OWL CREEK SNOTEL... 1 INCH. 9 NE THERMOPOLIS... 0.4 INCHES. JOHNSON COUNTY... CLOUD PEAK RESERVOIR SNOTEL... 8 INCHES. LITTLE GOOSE SNOTEL... 5 INCHES. BEAR TRAP MEADOW SNOTEL... 5 INCHES. SOLDIER PARK SNOTEL... 5 INCHES. HANSEN SAWMILL SNOTEL... 4 INCHES. BUFFALO... 3.1 INCHES. 12 SSE BUFFALO... 2 INCHES. NATRONA COUNTY... GRAVE SPRING SNOTEL... 6 INCHES. RENO HILL SNOTEL... 5 INCHES. CASPER MOUNTAIN SNOTEL... 5 INCHES. CASPER... 3 TO 4 INCHES. MIDWEST... 3 INCHES. CASPER MOUNTAIN... 3 INCHES. 10 WSW CASPER... 2.5 INCHES. PARADISE VALLEY... 1.6 INCHES. 11 ESE CASPER... 1.3 INCHES. PARK COUNTY... 3 NE SUNSHINE... 3.2 INCHES. WOLVERINE SNOTEL... 3 INCHES. BLACKWATER SNOTEL... 3 INCHES. 26 SW CODY... 3 INCHES. MEETEETSE... 3 INCHES. TIMBER CREEK SNOTEL... 3 INCHES. 5 ESE CODY... 2.2 INCHES. 3 W WAPITI... 2 INCHES. KIRWIN SNOTEL... 2 INCHES. 2 WSW CODY... 2 INCHES. EVENING STAR SNOTEL... 2 INCHES. 4 ENE POWELL... 1 INCH. PAHASKA... 1 INCH. 3 NE CLARK... 0.8 INCHES. 4 SE CODY... 0.7 INCHES. SUBLETTE COUNTY... BIG PINEY... 3.5 INCHES. GUNSITE PASS SNOTEL... 3 INCHES. TRIPLE PEAK SNOTEL... 3 INCHES. KENDALL RANGER STATION SNOTEL... 3 INCHES. POCKET CREEK SNOTEL... 3 INCHES. NEW FORK LAKE SNOTEL... 2 INCHES. BIG SANDY OPENING SNOTEL... 2 INCHES. 1 SW PINEDALE... 2 INCHES. ELKHART PARK G.S. SNOTEL... 2 INCHES. SNIDER BASIN... 1 INCH. LARSEN CREEK SNOTEL... 1 INCH. LOOMIS PARK SNOTEL... 1 INCH. EAST RIM DIVIDE SNOTEL... 1 INCH. BONDURANT... 0.3 INCHES. SWEETWATER COUNTY... ROCK SPRINGS... 1 INCH. TETON COUNTY... TOGWOTEE PASS SNOTEL... 7 INCHES. GRAND TARGHEE SNOTEL... 6 INCHES. JACKSON HOLE - RAYMER... 5 INCHES. JACKSON HOLE - RENDEZVOUS BOWL... 4 INCHES. JACKSON HOLE - MID MOUNTAIN... 4 INCHES. PHILLIPS BENCH SNOTEL... 4 INCHES. 3 SSW WILSON... 3 INCHES. GRAND TARGHEE - CHIEF JOSEPH... 3 INCHES. GRASSY LAKE SNOTEL... 3 INCHES. TOGWOTEE MOUNTAIN LODGE... 3 INCHES. BASE CAMP SNOTEL... 2 INCHES. 4 SW JACKSON... 2 INCHES. JACKSON HOLE - BASE... 2 INCHES. 1 ENE TETON VILLAGE... 1.5 INCHES. MOOSE... 1 INCH. SNOW KING... 1 INCH. SNAKE RIVER STN SNOTEL... 1 INCH. JACKSON... 1 INCH. DARWIN RANCH... 0.6 INCHES. WASHAKIE COUNTY... MIDDLE POWDER SNOTEL... 12 INCHES. 7 E TEN SLEEP... 11.5 INCHES. POWDER RIVER PASS SNOTEL... 7 INCHES. 16 SSE TEN SLEEP... 4.8 INCHES. WINCHESTER... 2 INCHES. 27 S TEN SLEEP... 1.8 INCHES. 4 N TEN SLEEP... 1.7 INCHES. 8 SW WORLAND... 0.5 INCHES. YELLOWSTONE NATIONAL PARK... TWO OCEAN PLATEAU SNOTEL... 4 INCHES. PARKER PEAK SNOTEL... 2 INCHES. SYLVAN LAKE SNOTEL... 2 INCHES. YELLOWSTONE EAST ENTRANCE... 1.5 INCHES. SNAKE RIVER RANGER STATION... 1.5 INCHES. LAMAR RANGER STATION... 1 INCH. LEWIS LAKE DIVIDE SNOTEL... 1 INCH. TOWER FALLS RANGER STATION... 0.5 INCHES.

Friday, February 20, 2015

Snow Returns this Weekend

SYNOPSIS: After a couple of mild days, a series of Canadian Cold Fronts will push southward across the state beginning Friday morning. Snow, possibly mixed with rain at times, will then push southward during the day Friday. Widespread snow will be found across the state by late Friday afternoon or early Friday evening. Another cold front will then bring the next round of snow, beginning Saturday morning. Snow could then continue through the day Saturday, and linger through Saturday night. Snow will then generally diminish from north to south Sunday morning, however, could linger across far southern Wyoming during the daytime hours. Very cold air is then expected behind these fronts, with high temperatures struggling to get into the mid to upper teens on Sunday for areas east of the divide. No matter your plans for the weekend, make sure to check for the latest forecasts and hazards for this winter storm. Many of the latest forecast details can be found below.     
IMPACTS: For anyone traveling this weekend, expect snow and wind to create slick roads and difficult driving conditions at times. Those with outdoor interests should also be prepared for drastically changing weather conditions along with moderate to heavy snow, especially across the Wind River, Absaroka, and Bighorn Mountains.
SNOW ACCUMULATIONS: Daytime accumulations on Friday will generally remain light across the lower elevations east of the divide. The mountains of central and northern Wyoming could see moderate to heavy snow at times on Friday and thorugh the weekend. The second front that pushes through Saturday will then bring widespread measurable snow to most areas. Overall new snow accumulations by Sunday morning of 1 to 2 feet across the central and northern mountains will be possible, with 2-6 inches across the lower elevations east of the divide, and 1-5 inches across the lower elevations west of the divide. Areas near Lander could also see locally higher amounts of 5-10 inches by Sunday morning.     

Advisories and Snow Amounts
Click to enlargeClick to enlarge
   
Click Image To Enlarge

Current Advisories 
Bighorn Mountains, Absaroka Mountains, and eastern Wind River Mountains Winter Storm Warning valid through 5 AM Sunday morning (Absaroka Mountains expires at 5 PM Saturday evening).
Lander Foothills Winter Storm Watch from 5 AM Saturday morning through 5 AM Sunday morning.
Yellowstone National Park, Cody Foothills, Owl Creek and Bridger Mountains, and southwest Bighorn Basin Winter Weather Advisory from 5 PM Friday evening through 5 PM Saturday evening (Yellowstone National Park expires 5 AM Saturday morning).
Click or scroll down to "Forecast" to find the latest Watches, Warnings, and Advisories.
Click Image To Enlarge
Friday Through Sunday Evening Snow Forecast 
Storm Totals For Selected Areas
Riverton Area: 3-5"
Lander Area: 5-10"
Casper Area: 2-5"
Rock Springs and Green River Basin: 2-5"
Cody Area: 2-6"
Thermopolis: 1-4"
Buffalo: 2-5"
Jackson: 1-3"
Wind River, Absaroka, & Bighorn Mountains: 1-2 Feet
Western Mountains: 5 to 12"
Click or scroll down to "Forecast" to find the latest snow accumulation maps.

  



Storm Timing 
Click to enlargeClick to enlarge
Click Loop To Enlarge
Model Depiction of Temperature (background image) & Wind (arrows, the longer the tail of the arrow, the stronger the wind) at the 10kft level and Precipitation (spotty image).
The loop advances in 6 hour time steps, beginning at 5 am Friday and ending on Monday at 5am. The time stamp in the bottom right hand corner shows the valid time in "Z Time"  (where 00Z = 5pm and 12Z = 5am MST)
Click Image To Enlarge
Cold air to return Sunday: This image shows the forecasted High Temperatures for Sunday. Notice how highs will struggle to get out of the teens.

Click or scroll down to "Forecast" to find the latest high and low temperature maps.


Travel is expected to be adversely impacted with Interstate delays or closures expected, several passes and side roads could also see extended times of difficult travel and/or closures as well. If you plan to travel this weekend, especially Friday night and Saturday, then we recommend checking the conditions along your route and staying on top of road closures here. If you are on Twitter, follow the hashtag: #WyoRoad for the latest weather affecting roads and road conditions in and around Wyoming. 

  

Traveling This Weekend? 
Click to enlarge

Wednesday, February 18, 2015

Northwest States Ski Season much worse than Western Wyoming



While Star Valley and Western Wyoming have experienced little snow in the month of February, higher elevation snowpack remains near or just slightly below normal.  Such is not the case in much of the western states.  While precipitation in the Pacific Northwest has been generous, the abnormally mild winter has resulted in poor snow accumulations .  Jim Steenburgh has blogged about the disastrous  ski season thus far.  








A Northwest Ski Disaster

Even if the pattern shifts and starts producing heavy snowfall, the winter of 2014-2015 will probably go down as one of the worst if not the worst snow years in Pacific Northwest history.

The ski season has been an unmitigated disaster.  Snoqualmie Pass is home to four ski areas, all with base elevations near 3,000 feet.  Here's what it looked like at the Summit Central ski area this morning.
Source: http://www.summit-at-snoqualmie.com/
How bad is this year?  Data collected by the Washington Department of Transportation shows that Snoqualmie Pass averaged 400" of snow the past five winters.  The average accumulation by February 10th was 205".  This year they've had 79" and obviously a lot of that snow has melted.

If you have a season's pass for the Snoqualmie Pass ski areas, Crystal Mountain will let you ride for free, but if you go there, here's what you'll find.
http://crystalmountainresort.com/
Yup, no snow at the base.  What's open?  The upper mountain Green Valley Express chair, with access provided by the Mt. Rainier Gondola.  The upper mountain doesn't look half bad, but the photo above looks more like late May than mid February.

Paradise Ranger Station on Mt. Rainier is one of the snowiest places in the world, but not this year.  SNOTEL data from Paradise shows that they've had plenty of precipitation (compare black and grey lines) and are actually a bit above average since the start of the water year on October 1st.  However, much of that precipitation has fallen in the form of rain and the amount of water retained in the snowpack is well below average (compare blue and red lines).
Source: NRCS
There is actually a remarkably long record of snowfall kept by the National Park Service at Paradise Ranger Station.  The record low snowfall is 313" in 1939–40.

Thursday, February 12, 2015

Colder Weather on the Way

The weekly weather video issued by Riverton Forecast Office highlights the change to colder by the first of the week.



Weekly Weather Video

Wednesday, February 11, 2015

Water Supply Outlook as of February 9 2015

Wyoming Water Supply Outlook---issued February 9th

…Wyoming January precipitation was nearly 70 percent of average...
...Current water year precipitation is averaging near 95 percent of normal across Wyoming…
…Mountain snowpack across Wyoming is 90 to 95 percent of average... 
Below normal snowmelt streamflow volumes are expected across major basins in Wyoming...
…Wyoming carryover reservoir storages are 115 to 125 percent of average for February…

....Synopsis...

January precipitation totals across Wyoming were nearly 70 percent of average. Precipitation numbers varied between 119 percent of normal over the Big Horn River Basin to near 32 percent of normal over the Little Snake Drainage (South Central Wyoming).  Current water year (October 2014 - January 2015) precipitation across Wyoming is nearly 95 percent of average.
Mountain snowpack across Wyoming was 90 to 95 percent of normal by early February.  Snowpack "water" numbers and/or SWEs were the highest across basins in northern Wyoming---varying between 105 to 125 percent of median.  SWEs across basins in southern Wyoming varied between 75 to 100 percent of median.
Below normal (85 to 95 percent) snowmelt streamflow volumes are expected across almost all major basins across Wyoming.  Slightly above average streamflow volumes are expected across the Yellowstone/Clarks Fork as well as portions of the Powder River Drainage.  Several southern drainages—including the Sweetwater, the Little Snake,  the North Platte, the Laramie, and the Bear---are forecasted to have below normal streamflow volumes during the upcoming snowmelt season.
Carryover reservoirs storages across Wyoming are above average (greater than 115 percent) for February. 
The latest Wyoming water supply outlook graphic:


Thursday, February 5, 2015

Wednesday, February 4, 2015

Final Snow Report Feb 2-4 2015


Snowfall Reports
CountyStation NameSnowfall
Big Horn26 E Lovell3.5
Big HornBone Springs Divide Snotel3
Big HornShell Creek Snotel3
Big HornBald Mountain Snotel2
Big HornShell1.5
Big Horn2 SSW Lovell1.5
Big HornBasin1
Big HornLovell1
Fremont10 W Dubois9.5
FremontBrooks Lake9
FremontLittle Warm Snotel7
FremontCastle Creek Snotel6
FremontCold Springs Snotel6
FremontBurroughs Creek Snotel5
FremontDeer Park Snotel5
FremontDubois5
FremontHudson4.5
FremontRiverton4-4.2
FremontAtlantic City4
FremontSouth Pass Snotel4
FremontLander Airport3.4
FremontLander2-3.3
Fremont6 SW Lander3.1
FremontHobbs Park Snotel3
FremontRiverton Airport3
FremontBurris3
Fremont7 WNW Lander2.3
Fremont7 ESE Kinnear2
FremontTownsend Creek Snotel2
FremontSt. Lawrence Alt Snotel2
Fremont10 NW Riverton2
Fremont9 S Lander2
Fremont9 SSE Lander1.5
Fremont6 SE Lander1.5
Fremont15 W Jeffrey City1
FremontBoysen Dam1
Hot SpringsThermopolis3.2
Hot SpringsOwl Creek Snotel3
Hot Springs9 NE Thermopolis2.6
Hot SpringsKirby2.5
JohnsonBear Trap Meadow Snotel5
JohnsonHansen Sawmill Snotel4
Johnson1 NW Buffalo4
JohnsonLittle Goose Snotel3
JohnsonSoldier Park Snotel2
JohnsonKaycee2
JohnsonCloud Peak Reservoir Snotel2
Johnson17 E Kaycee1.8
JohnsonBuffalo1.2
LincolnWillow Creek Snotel16
LincolnSpring Creek Divide Snotel14
LincolnCottonwood Creek Snotel13
LincolnBlind Bull Summit12
LincolnIndian Creek Snotel11
LincolnBlind Bull Summit Snotel10
LincolnSalt River Summit Snotel8
LincolnCommissary Ridge8
LincolnHams Fork Snotel7
LincolnKelley Ranger Station Snotel7
LincolnBox Y Ranch2
Lincoln2 SE Thayne0.7
LincolnAfton0.5
NatronaReno Hill Snotel6
NatronaGrave Spring Snotel6
NatronaPowder River5
NatronaCasper4
Natrona5 SSW Casper3.5
NatronaMidwest3-3.5
Natrona10 WSW Casper3
NatronaCasper Airport2.9
NatronaCasper Mountain Snotel1
ParkBlackwater Snotel6
Park3 NE Sunshine5.1
ParkTimber Creek Snotel5
ParkMeeteetse4-4.5
Park8 WSW Meeteetse4
ParkKirwin Snotel4
ParkWolverine Snotel3
ParkEvening Star Snotel3
Park26 SW Cody2.5
ParkMarquette Snotel2
ParkPahaska2
Park3 W Wapiti1.6
Park2 WSW Cody1.5
Park1 W Cody1.5
Park5 ESE Cody1.5
ParkCody1.3
Park3 NE Clark0.5
SubletteTriple Peak Snotel17
SubletteGunsite Pass Snotel10
SubletteLoomis Park Snotel10
SubletteSnider Basin Snotel9
SubletteBig Sandy Opening Snotel8
SublettePocket Creek Snotel8
SubletteKendall Ranger Station Snotel7
SubletteLarsen Creek Snotel7
Sublette15 WNW Daniel7
SubletteNew Fork Lake Snotel6
SubletteDaniel6
SubletteElkhart Park G.S. Snotel6
SubletteDaniel Fish Hatchery5.2
SubletteEast Rim Divide Snotel5
Sublette14 NW Pinedale4
Sublette1 N Pinedale3.5
SublettePinedale3.2
SubletteBoulder Rearing Station1
SubletteBig Piney1
TetonPhillips Bench Snotel20
TetonGrand Targhee Snotel18
TetonTogwotee Pass Snotel14
TetonJackson Hole - Mid Mountain13
TetonJackson Hole - Rendezvous Bowl13
TetonJackson Hole - Raymer13
TetonGros Ventre Summit Snotel11
TetonGranite Creek Snotel11
TetonGrassy Lake Snotel10
TetonBase Camp Snotel9
TetonGrand Targhee - Chief Joseph9
TetonTogwotee Mountain Lodge8
TetonSnake River Stn Snotel5
TetonJackson Hole - Base4
Teton1 ENE Teton Village3.5
TetonMoose3
Teton12 NE Jackson2.5
TetonSnow King2
Teton12 NE Jackson2
TetonJackson1
WashakiePowder River Pass Snotel6
Washakie16 SSE Ten Sleep3.5
WashakieMiddle Powder Snotel3
WashakieTen Sleep2.3
Washakie5 NNW Ten Sleep1.1
Washakie8 SW Worland1
YellowstoneTwo Ocean Plateau Snotel8
YellowstoneLewis Lake Divide Snotel6
YellowstoneParker Peak Snotel4
YellowstoneEast Entrance Ranger Station3.5
YellowstoneSylvan Road Snotel3
YellowstoneCanyon Snotel3
YellowstoneSylvan Lake Snotel2
YellowstoneOld Faithful Ranger Station1.5
YellowstoneThumb Divide Snotel1
YellowstoneTower Falls Ranger Station1
YellowstoneLamar Ranger Station0.5