Wet Period Ahead for Wyoming

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

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

By Jim S

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.

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

By Jim S

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 opensnow.com, 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.

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 *****

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

Click on map to enlarge

  

Precipitation Totals from Monday, September 14th through 7 AM Friday, September 18th County Station Name Rainfall Big Horn Mill Creek 0.57 Big Horn Shell 0.25 Big Horn 9 NNW Shell 0.15 Big Horn Lovell 0.12 Big Horn 2 SSW Lovell 0.12 Big Horn Deaver 0.10 Big Horn Hyatt High 0.08 Big Horn Greybull 0.03 Big Horn Greybull ASOS 0.01 Fremont Raspberry 1.23 Fremont 10 WNW Dubois 0.52 Fremont Elkhorn 0.27 Fremont Dubois 0.24 Fremont Anderson Ridge 0.14 Fremont Wind River 0.11 Fremont Camp Creek 0.09 Fremont Atlantic City 0.08 Fremont Riverton 0.5 NW 0.03 Fremont 9 SSE Lander 0.03 Fremont 6 SW Lander 0.03 Fremont Burris 0.03 Fremont Jeffrey City 0.02 Fremont Riverton 0.01 Fremont Riverton ASOS 0.01 Hot Springs 9 NE Thermopolis 0.06 Johnson School House 0.10 Johnson Buffalo ASOS 0.10 Johnson 12 SSE Buffalo 0.06 Johnson 17 NNW Kaycee 0.01 Lincoln 5 NNE Thayne 3.07 Lincoln 3 NW Etna 2.92 Lincoln Star Valley Ranch 2.81 Lincoln 2 SE Thayne 2.75 Lincoln 1 S Bedford 2.28 Lincoln 5 SSE Smoot 1.98 Lincoln Afton 1.92 Lincoln 1 SW Afton 1.86 Lincoln Kelly 1.67 Lincoln Etna 1.42 Lincoln Fossil Butte 1.10 Lincoln 3 WNW Kemmerer 0.95 Lincoln 3 SE Bedford 0.94 Lincoln 5 SSE La Barge 0.39 MONTANA Soda Butte 1.12 Natrona 11 ESE Casper 0.05 Natrona 5 SSW Casper 0.03 Natrona 7 SSW Casper 0.02 Natrona 12 NE Lysite 0.02 Natrona Casper Mountain 0.01 Natrona 10 WSW Casper 0.01 Park Quadrant 2.92 Park Pahaska 1.12 Park Cabin Creek 0.90 Park Eagle 0.57 Park Crandall 0.30 Park 26 SW Cody 0.27 Park 2 WSW Cody 0.12 Park Rattlesnake Mountain 0.12 Park Cody 0.09 Park 3 NE Sunshine 0.07 Park 4 SE Cody 0.05 Park 5 ESE Cody 0.03 Park 3 NE Clark 0.03 Park Meeteetse 0.02 Park Cody 0.01 Park 2 SW Powell 0.01 Park 4 SW Powell 0.01 Park 7 SW Cody 0.01 Sublette Hoback 1.45 Sublette 15 WNW Daniel 1.35 Sublette 14 NW Pinedale 1.08 Sublette Bondurant 1.03 Sublette Daniel Fish Hatchery 1.03 Sublette Half Moon 0.95 Sublette Snider Basin 0.94 Sublette Pinedale 0.91 Sublette Pinedale 1NE 0.57 Sublette 13 SE Pinedale 0.30 Sublette Big Piney ASOS 0.24 Sublette Boulder Rearing Station 0.10 Sweetwater Rock Springs ASOS 0.33 Sweetwater 4 NNW Rock Springs 0.28 Sweetwater Green River 0.23 Sweetwater Rock Springs 0.22 Sweetwater 5 N Farson 0.19 Sweetwater Wamsutter 0.19 Sweetwater Snow Springs Creek 0.17 Sweetwater 8 NNW Rock Springs 0.15 Sweetwater 1 SE Green River 0.11 Sweetwater McKinnon 0.11 Sweetwater Buckboard Marina 0.06 Teton Bechler 2.50 Teton Jackson 2.32 Teton 12 NE Jackson 2.29 Teton 2 NE Teton Village 2.17 Teton Moose 2.17 Teton Burro Hill 2.06 Teton Coyote Meadows 2.04 Teton 5 NW Jackson 2.03 Teton 4 SW Jackson 1.96 Teton Grand Teton 1.88 Teton Jackson Dam 1.80 Teton South Park 1.69 Teton Hoback Junction 1.28 Teton 1 NNW Alta 1.24 Washakie Leigh Creek 0.25 Washakie Worland 0.24 Washakie Winchester 0.22 Washakie 27 S Ten Sleep 0.20 Washakie Worland ASOS 0.10 Washakie Ten Sleep 0.10 Washakie 2 NE Worland 0.10 Washakie 8 SW Worland 0.08 Washakie 5 NNW Ten Sleep 0.07 Washakie 16 SSE Ten Sleep 0.04 Washakie Split Rock Creek 0.03 Yellowstone Old Faithful Ranger Station 2.33 Yellowstone Snake River Ranger Station 1.82 Yellowstone Bechler River Ranger Station 1.76 Yellowstone Grebe 1.54 Yellowstone Lake Yellowstone ASOS 1.28 Yellowstone Yellowstone East Entrance 1.20 Yellowstone Tower Falls Ranger Station 0.97 Yellowstone Yellowstone Mammoth 0.67

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

County	Location	Wind Gust (mph)
Fremont	Red Canyon	73
Fremont	9 SW Lander (Sinks Canyon)	64
Fremont	3 NNW Hudson	54
Fremont	10 W Fort Washakie	51
Fremont	2 W South Pass City	50
Fremont	7 SW Muddy Gap	48
Fremont	Jeffrey City	48
Fremont	Riverton Airport	48
Hot Springs	Boysen Peak	51
Hot Springs	10 S Meeteetse	47
Johnson	25 ESE Buffalo	53
Johnson	12 N Kaycee	50
Lincoln	Mt. Coffin	62
Lincoln	Kemmerer Airport	54
Lincoln	13 W Kemmerer	48
Lincoln	Deadman Mountain	45
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