Good Morning Everybody,
Sunday's De-brief - Yesterday the jet streak caused lots of radar echoes over western and central Colorado. In our area, we did receive echoes but we still had to deal with evaporation. The best precip occurred up higher, rain/snow/graupel happened at Snowmass/Highlands/Ajax. In the valleys, some rain reached the ground here and there down valley but totals were quite light. In Aspen proper and at the airport, mainly sprinkles fell.
Moral of the story, even with upper air support we are not there yet because ambient water is too low. Dewpoint values yesterday in the valleys were in the mid to upper 20s, we need mid 30s this time of the year for rain to reach the ground everywhere.
Quick Forecast for Today (Monday):
Aspen: Decent AM, mixed clouds and some intervals of sun this afternoon. Risk of an afternoon shower in a couple spots. High 71 Aspen, 75 Basalt. Wind SW 10 to 20mph. Low tonight 40 to 45.
On-Mtn: Decent AM, mixed clouds and some intervals of sun this afternoon. Risk of an afternoon shower. High 57 at mid-slope, 52 near 11K. Wind SW 11 to 22.
Today (Monday)...Updated 545am - A new closed low will develop near the southern Nevada/California border today. Looking at forecast soundings, our wind profile will be downslope SW, we all know this is not a great wind for us. In terms of ambient water, values are not very high and our surface dewpoints will be in the 20s this afternoon. Instability is OK but overall nothing to brag about. I do see a touch of mid and high level energy this afternoon which is something.
Summation, there is a lack of upper air support this morning so I will call it a decent AM. This afternoon cumulus clouds will be around along with some high clouds (Cirrus). In terms of precip, since ambient water is not very high and we have a downslope SW wind, I think we will be vulnerable to evaporation. I will allow for a PM shower but only in a couple spots. High temps hit the low 70s in Aspen. Indices for Today....UV Outlook a 5 or 6, Outdoor Index a 6 or 7, Thunderstorm chance 15%.
Tuesday (Updated 545am) - The closed low will end up along the Nevada/Utah border. It appears some jet energy will rotate around the eastern side of the closed low and make it into our area especially in the PM. Our wind profile will remain downslope with SSW trajectories. The models have our PM dewpoints in Aspen near 32, based on the last few days that's probably overdone.
Summation, I'll call it a decent morning then becoming variably cloudy in the PM. I will allow for an afternoon/evening shower or storm in a few spots. I won't go crazy with precip because I think the models are overdone with moisture. If it were to end up higher we might have a shot, I'll keep an eye on it. Indices for Tuesday...UV Outlook a 5, Outdoor Index a 6, Thunderstorm chance 25 to 30%
Wednesday (Updated 545am) - The closed low lifts northward and weakens. The models have differences in the weather under this scenario. The European model allows for a PM shower roaming around, the GFS model is dry. At this point I'll keep things the same and say a decent AM followed by a shower in a few spots during the PM.
Extended Forecast (Thur-Sat 5/24-5/26) - The global models are in decent agreement concerning the extended pattern. Upper air ridging takes hold from Thursday to Saturday. I think each day will have good deal of sun in the morning, during the afternoon scattered cumulus clouds will develop. I will keep the period dry and a warming trend will commence. Look for mid 70s in Aspen on Thursday, upper 70s Friday, low 80s on Saturday. Outdoor Indices Thursday through Saturday likely end up an 8. The entire Memorial Day weekend probably ends up dry and pretty decent, there will be more breezes by Sunday.