wxgeek's weather-Cold and snow to return-Update 1/29

Update Wed Jan 29

Very interesting and dynamic weather picture across CO the next 48 hours. Winter Storm Warning across most of western CO from the Front Range mountains west from this evening through Friday morning, Winter Storm Watch now extends to the foothills and Urban Corridor from Thursday evening through Friday morning, and High Wind Warning in effect for the foothills through 5 am Thursday.

Snow will move into western CO this afternoon and become heavy overnight and continue through the day on Thursday accompanied by westerly winds of 25-50 mph causing white out conditions. Some of this snow will spill over into the western foothills tonight and Thursday, but accumulations in the foothills not expected to be over an inch through Thursday afternoon. Strong westerly winds of 25-50 mph with gusts to 80 mph possible in the foothills from this afternoon into early Thursday morning, so power outages a distinct possibility. Snow will move east into the foothills and Urban Corridior and plains north of the Palmer Divide by late Thursday afternoon and evening with snow level 5000-6000 ft. Snow will become moderate to heavy at times Thursday night into Friday morning with snow level lowering to plains level by Friday morning, with a slight break possible Friday morning, then a second surge of snow is expected Friday afternoon into Friday night. Snow will continue the entire time in the mountains. Snow will lessen by Saturday morning with just some flurries expected in the mountains and foothills through Saturday evening, then general clearing by Sunday morning. Impressive snow totals expected in the mountains, and a decent snow event expected in the foothills and plains, snow totals look like this from this afternoon through Saturday morning:

Mountains: 20-36 inches
Foothills and Palmer Divide: 5-12 inches
Urban Corridor: 3-8 inches
Plains: 2-6 inches

Driving in the mountains will be difficult at best and likely impossible at times tonight into Saturday morning, with avalanch danger rising with the large amount of moisture laiden snow. For the foothills, looks like snow should hold off in earnest until about 6-9 pm Thursday, so early evening commute should be ok, but deteriorating later. Friday commute will have snow and ice packed roads. With moisture coming in off the Pacific, temps will be warmer and this snow will have higher water content, and in my experience this makes for slicker roads than the cold and dry stuff.

By Sunday weather looks clear and cool. For next week, snow chances return to CO on Monday into Tuesday, but amounts look fairly light, maybe a few inches possible. More light snow chances for eastern CO Wednesday and Thursday with cool temps, then the possibility for a more significant system Thursday night into Saturday morning, with fair weather returning next Sunday, and more snow chances return the following week. Hope we make the best out of this change in the pattern with the storm door wide open into mid February.

Super Bowl weather continues to look good. Chance for some rain or snow Saturday night into Sunday morning, but skies should be mostly clear by game time with temps in the mid to low 30's during the game, and northwest winds of 10-15 mph.

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Update Tue Jan 28

For the last system, 4-8 inches fell north of I-70 in Larimer and Boulder counties, while in general 2-6 inches south of I-70. Sunny day today across the state with temps remaining below seasonal norms east of the Divide. Major shift in upper level pattern will be felt in CO starting Wednesday. Mild and breezy day for most of CO with snow beginning to move into western CO late in the day. As flow aloft becomes westerly and increases, expect gusty Chinook winds to develop in the foothills with wind speeds of 20-40 mph and gusts to 60 mph possible by late afternoon and will persist overnight into Thursday morning. Snow will become heavy Wednesday night west of the Divide and spill east to the Front Range Crest by Thursday. Snow will persist in the mountains all day Thursday with some snow moving east into the foothills and Urban Corridor by late Thursday afternoon into Thursday night. Next upstream system will rapidly move into Co on Friday, so renewed snow in the mountains with better chances for snow in the foothills and plains during the day on Friday with snow persisting into Friday night. Winter Storm Watch issued for all CO mountain areas for late Wednesday into Thursday evening. This will likely become a Winter Storm Warning and extend into Saturday. Amounts in the mountains will be impressive, expecting 2-3 feet by Thursday evening, and another 1-2 feet Friday into Saturday. Travel in the mountains from Wednesday afternoon through Saturday will be difficult to impossible, with winds of 30-60 mph to accompany snow. For the foothills, looks like 1-3 inches possible Thursday afternoon into Friday morning, then another 2-6 inches possible Friday morning into Saturday morning, slightly lower amounts for the Urban Corridor. Snow level will be 6000-7000 ft Wednesday, lowering to 5500-6500 ft Thursday, then remaining 5500-6500 ft Friday and lowering to plains level by Friday night. Only expecting mountains flurries this weekend, with cool and pt cloudy conditions east of the Divide.

Models indicating snow chances nearly every day next week, with the potential for more significant systems Mon/Tue and then again late next week into next weekend.

Super Bowl weather looks dry with temps in the low to mid 30's, and northwest winds 10-15 mph, so decent football weather.

_________________
"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 Mon Jan 27

Well, the cold arrived as expected. The snow has been a different story. Dusting came in just behind arctic front, but banded snowfall remained north of I-70 overnight with 2-6 inches of snow reported along and west of I-25. Not much snow overnight south of I-70, but models continue to suggest that the banded snow associated with dynamics aloft will sag south this afternoon into tonight, and radar confirms that this is indeed underway. So, expect light to moderate snow to move south into the Metro area, eastern plains, foothills and Palmer Divide this afternoon into tonight. Looks like an additional 1-4 inches of snow will be possible through Tuesday morning. System is complex in that arctic air only extends up to about 7500-8000 ft with upslope flow, while above that northwesterly winds prevail. This would normally shut off precip for the foothills, but dynamics aloft associated with jet stream are providing lift for snowfall. Northern and central mountains should also receive additional snowfall through Tuesday morning. Most snow expected to diminish after midnight tonight with some light snow persisting until sunrise. Thus, the evening commute today will be slick and slow for most areas with cold temps keeping snow on roads, and roads could still be snow and ice packed for the Tuesday morning commute. Roads should be fine by Tuesday afternoon and evening with temps gradually warming Tuesday but remaining well below seasonal norms.

A complete change of our weather pattern is expected later this week. As upper ridge retreats into Alaska, westerly flow from the Pacific will move into the western U.S. This will bring snow to the mountains of CO west of the Divide by Wednesday afternoon, with dry and breezy conditions along the foothills and plains. A series of systems will move from west to east during the latter half of the week, so snow will be nearly constant from Wednesday afternoon into Saturday afternoon west of the Divide. As the air is from the Pacific, it will be warmer and snow levels will begin around 7000-8000 ft Wednesday into Thursday, lowering to near 6000 ft Friday and down to 4000 ft Saturday. Between Wednesday and Saturday, some mountain areas could receive 2-3 feet of snow. For areas east of the Divide, currently looks like there will be chances for snow Thursday afternoon into Friday morning, then again Friday afternoon into Saturday evening. Amounts will generally be light, but foothill areas could see a few inches during each period. Sunday looks mostly dry, maybe a few mountain flurries before a potentially more significant system impacts the state on Monday into Tuesday. In general, the pattern will allow snow chances for most of next week into next weekend and beyond. Finally appears we may see abundant snowfall into at least the middle of February.

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

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

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After a beautiful weekend with temps well above seasonal norms, winter will return early this week. Another large and cold arctic blast will plunge south from Canada into the central and eastern U.S. with CO being on the western edge. Arctic front will push into CO Sunday evening and upslope flow and snow will develop behind front. Snow will begin between 6 pm and 9 pm north of I-70, and between 9 pm and midnight over the Metro area and foothills south to the Palmer Divide. Snow will push south and persist overnight and continue most of the day on Monday into Monday night. Snow will generally be light, but as jetstream aloft will be overhead, this will aid in creating areas of heavier banded snow in northwest flow aloft. The upslope easerly flow will exist up to about 8000-9000 ft and extend up to the Front Range Crest. This system will have snow west to the Divide into the northern and central mountains associated with jetstream aloft. Snow looks to diminish after 9pm to midnight Monday night. For totals, in general 1-3 inches looks good for most areas of the plains, Urban Corridor, foothills and Palmer Divide. With the banding, there could be heavier areas in the northern mountains, foothills and Palmer Divide where some areas could see 3-6 inches, but I believe these will be isolated areas, so most areas can expect 1-3 inches. Thus, the morning and evening commute on Monday is expected to be slick anbd slow. Warm recent temps will lead to melting of initial snow, and with very cold temps and additional snow, ice underneath will be likely. Hopefully CDOT will be as attentive as last system and keep roads in good shape. Also, very cold temps expected with this arctic blast, with highs only in the single digits to teens on Monday with onbly slightly warmer temps Tuesday.

For the remainder of the week, warmer temps and mostly dry east of the Divide with snow possible along and west of the Divide from Wednesday into the weekend. Some snow is possible into the foothills Wednesday night and again Friday into the weekend, but only light amounts expected east of the Divide. heavier snow expected west of the Divide. The long expected upper pattern change is still expected to take place this week, with upper ridge moving northwest into northern Alaska, which allows a more zonal flow across the U.S. by late this week. Storms will be allowed to progress from the Pacific easterward into the west coast and into CO by the coming weekend and next week. Hence, beter snow chances for all of CO from late this week into next week. For the eastern U.S. very cold early this week then temps will begin to moderate by late this week and into the weekend. For the Super Bowl, still appears snow will be in the area Saturday, and may last into early Sunday, but looks like most precip will be gone by game time. Cold temps, but not arctic cold, will be in place, so expected game temps in upper 20's, with westerly winds of 10-20 mph. Not great weather, but not horrible either. Models have been all over the place, have begun to be more consistent, but forecast could still change.

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

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

Bump for 1/27 update

Bump for 1/28 Update

Bump for 1/29 Update