wxgeek's weather-Snow forecast this weekend-Update 3/23

Update Sat Mar 23

A wonderful snowy Saturday, of course unless you have to make your way out and about today. Nearly all roads across eastern CO are closed at this time, including I-70, US 24 and US 36. I suspect they will remain closed until Sunday morning, so lots of stranded travelers across our state today. Snow reports showing 6-12 inches for the foothills so far, with 3-7 across the Urban Corridor and 5-12 across the eastern plains. Models did not have a very good handle on this system. There is currently an upper level circulation over west central CO, and this feature will move east across south central CO today. This will keep upslope flow and snow going north of the Plamer Divide through this evening, with an additional 3-8 inches of snow for most areas. Snow begins to diminish from west to east this evening. Most current snow warnings and advisories set to expire at 6 pm this evening. Northerly winds will increase later this morning into this afternoon which will cause blowing and drifting of snow, especially across the plains and reduce visbility. If you don't have to travel, good day to stay put.

Skies will clear tonight and temps will be very cold for this time of year, with many areas below zero, and very cold wind chills. Still expecting a secondary impulse Saturday afternoon into Monday morning, so snow showers likely Sunday afternoon into Monday morning, with another 1-4 inches of snow possible, mainly over the mountains and foothills, but also Urban areas west of I-25. Gradual warming trend begins on Tuesday with dry conditions through Friday and temps back to near seasonal norms. Next system still on track for next weekend. More typical spring type storm, so wet and heavy snow for next weekend versus the winter fluff we are seeing this weekend.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Friday Mar 22

Upper level trough from western Canada will move into the northern and central Rockies today through Monday. Cold front currently moving south through WY and is expected to move into northern CO this afternoon, and south to the Palmer Divide by midnight tonight. Snow will begin in the mountains this afternoon, and spread south to I-70 later this afternoon into this evening. I am not all that impressed with snow amounts for this system, except on the far northeast plains, but I am impressed with the cold air mass for late March. This will feel much more like a dead of winter system than a spring system. I spoke with a colleague this morning in Seattle who reported snow overnight in the Seattle area, which is pretty rare for late March. NWS has issued a Winter Storm Warning for portions of the mountains for 8-16 inches of snow, and also for the eastern plains from I-70 north for 8-16 inches of snow and blowing snow from 9 pm tonight to 6 pm Saturday. Winter Weather Advisory has been issued for other mountains areas, and a Winter Storm Watch has been issued for the Palmer Divide area. No advisories at this time for the Urban Corridor or the foothills. Forecast is expected to progress like this:

Snow will move into northern Co this afternoon, spreading south through this evening and tonight. Heavy snow is possible tonight over the mountains and portions of the northeast plains as northeast upslope flow develops. Snow will continue through the day on Saturday, heavy at times over the northeast plains. Snow will be accompanied by northerly winds of 20-40 mph across the plains creating near blizzard and whiteout conditions. Expect road delays and closures across northeast CO, such as I-70 and I-76 and US 36. For the foothills, snow is possible this afternoon, becoming likely this evening and tonight, and will persist into Saturday afternoon or evening. Heaviest snow for the foothills looks to be during the day on Saturday, so expect ice and snow packed roadways if you venture out tonight and Saturday. Northerly winds will create blowing and drifting snow at times, with reduced visibility, so tough traveling most areas of CO tonight through Saturday. Models keep vast majority of the precip along and north of the Palmer Divide, so areas farther south only expected to receive light amounts. Latest snow amounts for this afternoon through Saturday night look like this:

Mountains: 5-16 inches (highest amounts over northern mountains)
Foothills and Palmer Divide: 4-9 inches, with up to 12 inches in favored areas
Urban Corridor and Banana Belt: 3-7 inches
Plains north of I-70: 8-16 inches (highest amounts near the CO/NE border)
Plains south of I-70: 2-6 inches

Snow from this system should dissipate Saturday evening, with some clearing Saturday night into Sunday morning. there is a second impulse that will rotate south from the parent upper level low over MT late Sunday into Monday. Models keep most precip from this impulse over the mountains and foothills, although some snow showers possible along the Urban Corridor. Looks like mountains and foothills could get an additional 2-5 inches of snow from this impulse. There could be some convective snow showers embedded, so could see some heavy brief showers Sunday afternoon and evening. This activity could persist into late Monday morning, so roads could be slick for the Monday morning commute. Temps will remain very cold through Monday. High temps not expected to make it above freezing this weekend for nearly all of CO, with low temps near or below zero in the mountains and foothills and single digits on the plains. Temps will begin to rise back to near seasonal norms by Tuesday with dry conditions expected across the state Tuesday through next Friday. Models continue to suggest another system will bring more precip to CO next weekend, with the potential for a good spring system, meaning abundant heavy and wet snow is possible.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Thu Mar 21

System currently moving across CO. First wave of moisture moved across this morning, and second more significant band will move through this afternoon and evening. Mountains getting a fair amount of snow currently, with some convective (lightning) elements embedded. As this band moves east onto the plains expect some stronger thunderstorms to develop this evening. Snow level currently 8000-9000 ft but will lower to 7000-8000 ft by this evening. Don't expect much accumulation in the foothills beyond a dusting to an inch or so.

Models a little more robust with our weekend storm today, but still keep the system moving trhough as an open trough, which means a shorter duration of snow and less upslope flow. Forecast starts Friday off as mostly sunny, but clouds increase from north to south during the day. Snow moves into northern CO Friday afternoon, and pushes south of I-70 by Friday evening. Snow may be heavy at times Friday night into Saturday morning, although models currently output highest precip totals over far northeast CO. This system will be colder and bring all snow to all areas of CO. Snow looks to persist into Saturday afternoon/evening, then begin to clear. Limited upslope flow with this system, so snow amounts will be lower than past few storms. Snow totals currently look like this from Friday into Saturday night:

Mountains west of Divide: 5-10 inches
Foothills and Palmer Divide: 4-8 inches
Urban Corridor and Banana Belt: 2-6 inches
Plains north of I-70: 5-12 inches
Plains south of I-70: 2-6 inches

Sunday should start out mostly sunny, but clouds increase leading to a chance of snow showers in the afternoon and evening hours, best chances along the foothills and mountains along and east of the Divide. Amounts of 1-2 inches possible. Monday looks very similar to Sunday with 1-2 inches of snow possible during the afternoon and evening hours. Temps will remain well below seasonal norms Friday through Monday. Tuesday through Friday next week look mild and dry with temps back near seasonal norms. Then just in time for next weekend, more precip is forecast Friday through Sunday. Snow level looks to be 7000-8000 ft with this next system, which has the potential for a fair amount of precip.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

I heard 6-10 in town, but the local boys like to pump up the snow totals.

Bump for Friday, 3/22 update

Bump for Saturday 3/23 Update