Wednesday, September 30, 2015

Wet Period Ahead for Wyoming

The Riverton Forecast Office Expects a Wet Period for this weekend in all of Wyoming

Thursday, September 24, 2015

The Globe is Warming

The latest on how the globe continues to warm up courtesy of Jim Steenburgh blog.

2015 Easily on Pace for Warmest on Record

Last week, the August climate numbers were released by the National Centers for Environmental Information (NCEI) and not surprisingly 2015 continues to be a hot one.

For the January–August period, 2015 is well ahead of any previous year on record for global average temperature and a full 0.1ºC ahead of second place 2010.
Source: NCEI
The numbers for August the past two years are really out there.  August 2014 was 0.09ºC warmer than second place August 2009, and then August 2015 doubled down and added another  0.09ºC.

Source: NCEI
These big numbers reflect the long-term global warming combined with the strong El Nino that has developed in recent months.  Similarly, 1998 was a remarkably strong El Nino and it was a real outlier in terms of temperature (see the top bar chart).  Those wishing to argue that global warming "stopped" have frequently used 1998 as the start point of their time series as it results in a relatively flat trend over the last several years.  As we have discussed (see Global Warming Hasn't Stopped), global warming never stopped, even if the short-term trend in global atmospheric temperatures was small, and it was only a matter of time until the shorter-term trend produced by climate variability (such as associated with the development of a strong El Nino) phased with the long-term trend in a way to give us a big warm up.  That time is now.

Monday, September 21, 2015

Potential Weather Related Disasters Utah and Wyoming

Jim Steenburgh's recent blog on not only the most recent deadly flash flooding event in Southern Utah but the potential for other weather related threats is worth sharing.  Both Lightning and Avalanches are phenomena that are a concern that much of Western Wyoming, including Star Valley  need to be aware of.

Two Potential Weather-Related Disasters in Utah

Monday's flash floods contributed to the deaths of 19 individuals, with one still missing.  It's Utah's worst day for weather-related loss of life in history.  Moving forward from here, the good news is that weather forecasts, watches, and warnings have never been better and will continue to improve in the future.  The bad news is that with increasing population, development, tourism, and recreation, Utah's vulnerability to severe weather has never been higher and is only likely to increase in the future.

Here are two potential disasters that have yet to occur, but concern me as a meteorologist.  We probably can't eliminate the potential risks, but there are steps that can be taken to reduce the likelihood or severity of catastrophe.

Avalanches in Little Cottonwood Canyon

As I discuss in chapter 6 of Secrets of the Greatest Snow on Earth, 50 avalanche paths intersect SR-210 and other roads and parking lots in Little Cottonwood Canyon.
Source: Secrets of the Greatest Snow on Earth
This along with heavy traffic, yields the highest avalanche hazard index of any major road in the United States.  On average, the highway is hit by 33 slides per year, most when the road is closed, but not always.

Individuals contributing to the reduction of avalanche threat along the highway, including those at UDOT, Alta Ski Area, and Snowbird, do an exceptional job, but it is impossible to completely eliminate risk along the highway as it exists today.  As noted by retired UDOT Avalanche Program Safety Supervisor Liam Fitzgerald, “Because of the density of traffic, because of the number of avalanche paths that affect the road, and how close the starting zones are to the road, if you open the road to the tune of 5 or 6 thousands vehicles, a small avalanche can come down, block the road, and now you have hundreds of vehicles sitting stationary under these other avalanche paths, and it does turn into a catastrophic situation very quickly.”

As suggested by Liam, perhaps the worst-case scenario is to have traffic snarled in the canyon during a period of rapidly escalating avalanche hazard.  It doesn't take an avalanche for this to happen.  Chances are you've experienced the infamous red-snake, produced by the break lights of a seemingly endless line of cars crawling down the canyon at the end of a big ski day, especially when road conditions are poor.  Such situations, when combined with heavy snowfall and increasing avalanche hazard, could go south quickly if the road is hit by an avalanche, burying cars and sweeping them off the highway.

Catastrophe has been adverted in the past.  In 2006, an avalanche swept an SUV containing nine people off the highway.  Fortunately, all were wearing seat belts and incredibly everyone was shaken up but not seriously harmed.

Improvements in infrastructure, monitoring, and forecasting in recent years have reduced but not eliminated the threat in the canyon (Note: avalanche concerns exist along other Utah highways, but the hazard threat is greatest in Little Cottonwood).  Some additional incremental improvement is likely possible, but reducing this threat significantly likely involves highway realignment, tunneling, and shedding of the highway, or a similar approach for mass transit alternatives (e.g., rail) in the canyon.

Lightning or Severe Weather at an Outdoor Event

Amongst states, Utah ranks in the top 20 for total lightning fatalities and #2 for lightning deaths per million people.  I'm unaware of any lightning catastrophes that have killed more than 2 individuals, but there have been some that have apparently killed hundreds of sheep!

Perhaps the biggest potential for a major catastrophe is at outdoor events such as concerts or football games.  An example of the potential occurred at the NASCAR Sprint Cup Race at Pocono Raceway in 2012 when one fan was killed an nine injured by lightning.

In 2006, Joel Gratz, now CEO of, and Erik Noble, wrote a great article for the Bulletin of the American Meteorological Society evaluating lightning safety at large stadiums in the United States, exposing the need for managers to both anticipate and prepare for lightning threat.

The good news is that some outdoor venues now have developed lightning safety action plans and monitor for lightning during events.  You may recall the lightning delay during the Utah–Michigan game last year.  The bad news is that all of them don't do it, it's difficult to evacuate an outdoor stadium in the event of a rapidly developing storm, and often spectators are reluctant to move to their cars or a safe indoor location.

Encourage your favorite outdoor venue to be doing all they can with regards to lightning safety and promptly move to a safe location in the event of lightning or severe weather.

Saturday, September 19, 2015

Final Update* Storm Summary September 14-18

A series of cold fronts brought widespread precipitation amounts of 1 to 2 inches across the west from Monday through Thursday night.   Portions of the Star Valley and Yellowstone National Park received from 2 to over 3 inches of precipitation; the highest total of 3.07 inches was reported 5 miles north of Thayne in the Star Valley.  A strong cold frontal passage also resulted in some high winds across the area on Wednesday with an automated station 15 miles southeast of Rock Springs reporting a gust to 81 mph Wednesday afternoon. 
***** Final Update *****

Click to enlargeClick to enlarge
 Clouds parting at Jackson Hole Mountain Resort's Cody Bowl (elev. 10,450 ft.) Friday afternoon to reveal a winter wonderland in the last few days of summer.   Click to Enlarge  A 64 mph was recorded in Sinks Canyon on Wednesday morning.   Only 0.01 inches of rainfall fell Thursday afternoon in Sinks Canyon, and then the double rainbow!  Click to Enlarge

Banner image

Click on map to enlarge
Rain Map - Click to enlarge
Precipitation Totals from Monday, September 14th through 7 AM Friday, September 18th
CountyStation NameRainfall
Big HornMill Creek0.57
Big HornShell0.25
Big Horn9 NNW Shell0.15
Big HornLovell0.12
Big Horn2 SSW Lovell0.12
Big HornDeaver0.10
Big HornHyatt High0.08
Big HornGreybull0.03
Big HornGreybull ASOS0.01
Fremont10 WNW Dubois0.52
FremontAnderson Ridge0.14
FremontWind River0.11
FremontCamp Creek0.09
FremontAtlantic City0.08
FremontRiverton 0.5 NW0.03
Fremont9 SSE Lander0.03
Fremont6 SW Lander0.03
FremontJeffrey City0.02
FremontRiverton ASOS0.01
Hot Springs9 NE Thermopolis0.06
JohnsonSchool House0.10
JohnsonBuffalo ASOS0.10
Johnson12 SSE Buffalo0.06
Johnson17 NNW Kaycee0.01
Lincoln5 NNE Thayne3.07
Lincoln3 NW Etna2.92
LincolnStar Valley Ranch2.81
Lincoln2 SE Thayne2.75
Lincoln1 S Bedford2.28
Lincoln5 SSE Smoot1.98
Lincoln1 SW Afton1.86
LincolnFossil Butte1.10
Lincoln3 WNW Kemmerer0.95
Lincoln3 SE Bedford0.94
Lincoln5 SSE La Barge0.39
MONTANASoda Butte1.12
Natrona11 ESE Casper0.05
Natrona5 SSW Casper0.03
Natrona7 SSW Casper0.02
Natrona12 NE Lysite0.02
NatronaCasper Mountain0.01
Natrona10 WSW Casper0.01
ParkCabin Creek0.90
Park26 SW Cody0.27
Park2 WSW Cody0.12
ParkRattlesnake Mountain0.12
Park3 NE Sunshine0.07
Park4 SE Cody0.05
Park5 ESE Cody0.03
Park3 NE Clark0.03
Park2 SW Powell0.01
Park4 SW Powell0.01
Park7 SW Cody0.01
Sublette15 WNW Daniel1.35
Sublette14 NW Pinedale1.08
SubletteDaniel Fish Hatchery1.03
SubletteHalf Moon0.95
SubletteSnider Basin0.94
SublettePinedale 1NE0.57
Sublette13 SE Pinedale0.30
SubletteBig Piney ASOS0.24
SubletteBoulder Rearing Station0.10
SweetwaterRock Springs ASOS0.33
Sweetwater4 NNW Rock Springs0.28
SweetwaterGreen River0.23
SweetwaterRock Springs0.22
Sweetwater5 N Farson0.19
SweetwaterSnow Springs Creek0.17
Sweetwater8 NNW Rock Springs0.15
Sweetwater1 SE Green River0.11
SweetwaterBuckboard Marina0.06
Teton12 NE Jackson2.29
Teton2 NE Teton Village2.17
TetonBurro Hill2.06
TetonCoyote Meadows2.04
Teton5 NW Jackson2.03
Teton4 SW Jackson1.96
TetonGrand Teton1.88
TetonJackson Dam1.80
TetonSouth Park1.69
TetonHoback Junction1.28
Teton1 NNW Alta1.24
WashakieLeigh Creek0.25
Washakie27 S Ten Sleep0.20
WashakieWorland ASOS0.10
WashakieTen Sleep0.10
Washakie2 NE Worland0.10
Washakie8 SW Worland0.08
Washakie5 NNW Ten Sleep0.07
Washakie16 SSE Ten Sleep0.04
WashakieSplit Rock Creek0.03
YellowstoneOld Faithful Ranger Station2.33
YellowstoneSnake River Ranger Station1.82
YellowstoneBechler River Ranger Station1.76
YellowstoneLake Yellowstone ASOS1.28
YellowstoneYellowstone East Entrance1.20
YellowstoneTower Falls Ranger Station0.97
YellowstoneYellowstone Mammoth0.67
Strongest Wind Banner

A cold front brought some strong winds across the area on Wednesday, September 16th.  Locations that recorded wind gusts over 45 mph are included in the following table: 

Wednesday September 16th Notable Wind Gusts
CountyLocationWind Gust (mph)
 Fremont Red Canyon73
 Fremont 9 SW Lander (Sinks Canyon)64
 Fremont 3 NNW Hudson54
 Fremont 10 W Fort Washakie51
 Fremont 2 W South Pass City50
 Fremont 7 SW Muddy Gap48
 Fremont Jeffrey City48
 Fremont Riverton Airport48
 Hot Springs Boysen Peak51
 Hot Springs 10 S Meeteetse47
 Johnson 25 ESE Buffalo53
 Johnson 12 N Kaycee50
 Lincoln Mt. Coffin62
 Lincoln Kemmerer Airport54
 Lincoln 13 W Kemmerer48
 Lincoln Deadman Mountain45
 Natrona 2 SE Hiland 63
 Natrona 16 S Hiland 58
 Natrona 20 N Casper 55
 Natrona 8 S Casper 53
 Natrona Casper Airport 51
 Natrona Casper Outer Drive 51
 Natrona Midwest 49
 Natrona 7 W Alcova 48
 Park Chief Joseph Hwy 49
 Park Hoyt Peak 48
 Park 8 N Meeteetse 46
 Sweetwater 15 SE Rock  Springs 81
 Sweetwater I 80 - Mile Marker 184 50
 Sweetwater I 80 - Mile Marker 157 47
 Sweetwater McKinnon 45
 Sweetwater 5 E Rock Springs 45
 Teton Teton Saddle 70
 Washakie South Bighorn Mountains 48