US Forest Service Manti-La Sal National Forest

 Introduction:  Good morning, this is Max Forgensi with the USFS Manti-La Sal Avalanche Center with your avalanche and mountain weather advisory.  Today is Monday, February 19th, at 7:45 AM. This advisory will expire in 24 hours. 

 

To see past advisories check out the ARCHIVE.  To see current conditions go to our WEATHER PAGE.  To see photos go to the AVIPHOTOS page.

Please give us your observations from the field HERE.  The more observations we get, the better this forecast can be. 

 

We’ve re-scheduled our Level I American Institute for Avalanche Research and Education Course for March 2-4 here in Moab. Cost will be 130$. SMOKIN’ deal. Give us a call at 435-636-3363 to sign up or get more info.

 

  

General Conditions:

There is a change in the weather pattern!  The hose (jet stream) is dialing in the La Sal’s today and tonight and we could receive 4”-7” out of this storm.  This storm is a fast mover…the winds have been steady out of the South through Southwest for the past 30 hours up high.  Wind speed averages have been between 15-30 mph…enough to read on to the avalanche conditions.  Powder conditions will reign today and tomorrow…expect warm temperatures and clear skies by mid-week to settle things out for a bit before another storm affects the area by Friday. 

L.U.N.A. was up on Friday and groomed into Gold Basin…they will be up today to groom the whole track. I don’t know how long it is going to last with the snow coming down though!   And mark your calendars for the Lasaloppet on March 24th! er

The road to the Geyser Pass Trailhead is not plowed today (it’s a holiday) 4wd is recommended.  Expect our hero’s, the Grand County Road Department to be up bright and early on Tuesday though!    

  

Mountain Weather: (At 10,500’)

Presidents' Day: Periods of snow. High near 31. Breezy, with a southwest wind around 20 mph, with gusts as high as 35 mph. Chance of precipitation is 80%. Total daytime snow accumulation of 2 to 4 inches possible.
Tonight: Snow likely, mainly before 11pm. Mostly cloudy, with a low around 19. Breezy, with a west southwest wind 15 to 20 mph becoming west 5 to 10 mph. Winds could gust as high as 35 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 2 inches possible.
Tuesday: A 20 percent chance of snow before 11am. Partly cloudy, with a high near 32. Calm wind becoming south southwest between 10 and 15 mph.
Tuesday Night: Mostly clear, with a low around 23. Southwest wind around 15 mph.

                                                                                                                                                                                                                                           

Weather Station/ Location

Snow Depth (HS):  in./cm

New Snow (HN) in./cm

6:00 a.m. Temp (F)

Current Observations:  Wind, 48 hour snow

Geyser Pass Trailhead (9,600’): (snotel link)

20.1”

2”

28

Its still snowing

Geyser Pass

43”

2”

N/a 

~

Gold Basin and South Mountain

43”

2”

n/a

65% of normal

Pre-Laurel Peak Station (11,705’)

N/a 

N/a 

17.4

Winds out of the SW at 22 gusts to 52

 

Avalanche Conditions: (Link to the International Avalanche Danger Scale here) –

There is a big difference between yesterday and today’s conditions.  Although the winds started to pick up yesterday morning for six hours and continued throughout the day and into last night, the difference is in the Relative Humidity.  When there is a dry atmosphere and winds, snow transported by these dry winds are sublimated into the atmosphere and active wind loading is decreased.  When the relative humidity gets into the upper 90%, there isn’t as much room in the moist atmosphere for the snow to be sublimated from a solid snow grain into a gas.  For the past six hours, Relative Humidity values of 97%, new snow and transport winds are actively loading North through NE through East aspects.  Starting zones are being loaded, small cornices are beginning to develop…ALL OVER THE WEAKEST SNOW IN THE LA SAL MOUNTAINS.    There are weak layers in the bottom of our snow pack and in the mid-layers (buried near-surface-facets) that have been waiting for a new load to be applied to react and avalanche.  Therefore, the BOTTOM LINE for today will be an AVALANCE DANGER of CONSIDERABLE on North through East aspects at and above tree-line.  The rest of the areas will be MODERATE.  You can expect a decent avalanche cycle out of this storm…the fragile balance between strength and stress will be tested today.