Observation: Moab

Observation Date
2/20/2019
Observer Name
T. Matthews J. Mundell
Region
Moab
Location Name or Route
Laurel Highway
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
Southwest
Wind Speed
Light
Weather Comments
Sky was OVC with the sun visible every now and then, but then it would disappear again. There was about a half inch or less of new at the trailhead when we set out for the day. Snow continued very lightly throughout the day and picked up slightly as we were making our way out and back to the trailhead. We departed at about 15:00 and at this time there was a new inch or less. Winds remained calm to light throughout the day. It wasn't until we popped out above the treeline did we encounter anything that resembled wind. The SW facing aspects of trees near and at treeline had a very light coating of rime on them confirming the winds were coming out of the SW. For the short time we spent above treeline today I did not observe any snow being transported. Although, I was able to see that yesterdays skin tracks above treeline were slightly filled in by the wind. With the temps being as cold as they were it was nice to not be hammered by the winds.
Snow Characteristics
New Snow Depth
1"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments
About 1 inch of new low density snow had fallen by our departure time. This was on top of the 8 inches of low density snow that had fallen on Monday night. Anything on the north half of the compass was nice and fluffy powder. The sunny period in between Sunday nights storm and Monday nights storm was enough to create a melt freeze crust on the westerly aspects I looked at today. This crust was buried by Monday nights snow and was easily breakable. I'd assume the same for southerly aspects, but I did not observe them.
Red Flags
Red Flags
Recent Avalanches
Poor Snowpack Structure
Red Flags Comments
There was a report of a remotely triggered avalanche from a group of snowmobilers from yesterday. With todays low visibility I was not able to see any activity in the big alpine terrain. No cracking or collapsing was experienced today. As mentioned above I did not see any wind transported snow happening today, but I also, spent only about ten minutes above treeline.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments
Although, I didn't spent any real time today in the high alpine terrain I bet on the right slope you could certainly find a wind slab avalanche. I did notice a few older rounded pillows of snow in safe locations that I took the time to pounce on with no cracking results. If tonights storm is well behaved without any real wind transport (unlikely). I'd say that the wind drifted snow problem with ease off, but there is tons of low density snow available for transport and we will be adding a bunch of new snow to that in the near future, so It will likely become more of a problem.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #2 Comments
I received word that yesterdays remotely triggered avalanche failed on PWL's near the ground on old October snow. It's no secret that we have a poor snowpack structure with multiple PWL's throughout the pack. It's tricky out there right now. Some areas in the pack are gaining strength and other areas are still capable of producing full depth remotely triggered avalanches. As uncertainty in the snowpack increases, our terrain choices must reflect these uncertainties, and become more simple. With the current storm delivering in upwards of 2 to 3 feet of new snow by Friday. I'd think that the PWL's laying dormant in the pack will become cranky and reactive again until they have the time to adjust to the weight of the new load. With high precip rates and possibly new snow avalanches happening during the storm it's also, possible that these new snow, or wind drifted snow avalanches could step down into these deeper PWL's and create much larger avalanches.
Comments
Quick pic looking east towards Mt. Mellenthin to illustrate todays lower visabilities. I didn't dig a hole in the snow today to nerd out on layering. I only had a few hours today and wanted to ski some pow. My terrain choices were inline with the forecasted avalanche dangers.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
High
Coordinates