wxgeek's weather-Cold and some snow this week-Update 11/12

Update Wed Nov 12

Cold and snowy day for eastern CO. Arctic air mass still up to about 10,000 ft with coldest air near the top. Snow amounts were higher than expected in some areas, such as northern foothills where up to 14 inches fell overnight, due to CSI banding associated with jetstream aloft and snow to water ratios of 20:1 or higher. Snow will persist through this evening and into tonight until about midnight for most areas and in the foothills, then some clearing after midnight. This will cause temps to drop even lower than last night, so lows in the -5 to -15F range in the foothills. Thursday will see gradual clearing and some warming of temps after a cold start for eastern CO, while clouds and precip will move into western CO from the Divide west. Snow level will be in the 6000-7000 ft range west of the Divide as snow increases Thursday afternoon into Thursday night with 4-9 inches of snow possible. Snow may make it east to the Front Range crest, so western foothill areas could see some blow off snow, but only light amounts expected.

By Friday, arctic air scours out and temps will rise above freezing most areas of eastern CO. Snow showers will persist west of the Divide most of the day with light additional accumulations.

Next system is looking stronger on recent model runs. System will move down from the northwest and bring snow to most of CO by late Saturday morning and persist into Saturday night, diminishing after midnight. Foothills could see 3-7 inches of snow from this system, while mountains could see an additional 4-10 inches, and Urban Corridor and plains maybe 2-5 inches. So more tough travel statewide on Saturday.

Sunday into most of next week is looking mostly dry with temps near seasonal norms now. Some snow possible west of the Divide Wednesday and Thursday but dry east. Next precip chances for eastern CO will be next weekend as a more zonal flow aloft prevails, so systems from the Pacific will move into the West Coast and move east across CO, thus warmer systems next week with higher snow levels.

_________________
"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 Tue Nov 11

My gratitude to all the veterans out there, thank you for your service to our country.

Arctic air firmly in place across eastern CO today, as well as much of the central part of the U.S. Light snow to fall much of the day along the Urban corridor and plains with fog into the foothills. New surge of even colder air will move south into eastern CO this evening through Wednesday. Snow will become heavier and expand coverage from late this afternoon through tonight and persist all day Wednesday. Temps will lower, so temps below zero tonight in the foothills with high temps Wednesday struggling to get above single digits east of the Divide. Snow amounts to remain light due to cold air mass, so another dusting to 2 inches for most areas from this afternoon into Thursday morning. Commute could be slow again Wednesday as roads may have snow, although much less melting so not as much ice.

By Thursday, snow ends, and temps moderate some, so slightly warmer. West of the Divide, precip increases as system from the northwest moves down, so mountains could see 1-4 inches of snow above 6000-7000 ft. By Friday, eastern Co will see the sun and temps above freezing finally, with a few showers lingering west of the Divide.

Next system moves into Co Saturday morning, with another shot or arctic air and more snow. Temps will not be as cold, but snow amounts may be a it higher, with 1-3 inches possible in the foothills. Snow looks to persist into Saturday night, then diminish after midnight.

Sunday looks to be mostly sunny with temps near seasonal norms.

Models suggest Pacific air will break through next week from Tuesday through next weekend, so warmer systems with precip possible each day. Majority will be west of the Divide with snow levels in the 7000-8000 ft range.

_________________
"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 Nov 10

Arctic cold front is ahead of schedule, as is often the case. Cold front currently passing Denver heading towards the Palmer Divide. Behind front, temp has dropped 20 deg F in one hour near Ft. Collins and Greeley. Also, northeast winds in the 30-50 mph range occur just behind front, so expect some very gusty winds in the few hours after frontal passage. Next, snow is not too far behind. Precip currently along the CO/WY border and will slip south during the day. Currently looks like timing will put heaviest snow along the Urban Corridor just in time for the afternoon/evening commute, so expect a slower ride home today. Snow amounts still expected to be in the dusting to 2 inch range for most Front Range and foothill areas through Tuesday morning, so roads could be slick for the drive home today, as initial precip may melt due to warm pavement, then quickly freeze. Once temps go below freezing this afternoon, we may not see temps above freezing for a while, probably Friday or this weekend. Expect a long period of very cold temps, fog, clouds and occasional snow over eastern CO. Models bring second surge of snow into eastern CO Tuesday afternoon through Thursday morning, so another dusting to 2 inches for most areas. This is a week that some pets normally left outdoors may need some warmer shelter. Temps expected to be in the 0 deg F to 20 deg F much of this week.

Models suggest Friday we see mostly dry weather and temps back above freezing, before another surge of cold air from the northwest moves into CO on Saturday, with more snow into Sunday morning. Models then dry things out and warm temps back to near seasonal norms for early next week before more precip is possible late next week. Models still uncertain whether cold air will prevail or a wetter and warmer westerly flow will prevail late next week.

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

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

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One last nice day across CO before winter arrives for real. Near record temps across the state today along with some gusty westerly winds in the mountains and foothills. Winds will remain gusty overnight in the foothills with speeds of 15-35 mph, and some gusts to 50 mph possible.

Big change still on tap for Monday. Upper level low and associated arctic front will plunge south during the day. Cold front will be near the CO/WY border by sunrise, near the I-70 corridor by Noon, and down to near Pueblo by evening. Temps will drop by 20-30 degrees withing a few hours after frontal passage, and northeast upslope flow will develop east of the Divide. Light snow will develop behind front and persist into Monday night, but amounts expected to be light, generally from a dusting to an inch or two with heaviest amounts north of I-70 and in the northern mountains where 2-4 inches possible. Arctic air will be in place from Monday afternoon through Thursday night as deep upper level low settles over the Northern Plains, so expect very cold temps and low clouds and fog to persist for most of the coming week. A second surge of cold air will increase snow chances Tuesday night into Wednesday evening, again another dusting to an inch or two expected. With clouds into foothills most of the week, expect reduced visibility and also the chance for ice fog much of the week. Cloud deck is expected to persist up to about 10,000 to 12,000 ft most of the week. Temps are expected to range from around 5 deg F to 25 deg F the entire week, with coldest temps in the foothills.

Arctic air mass finally expected to scour out and move east by Friday. However, upper level high builds over the Yukon by late this week, which will keep cold Canadian air driving south into CO. Snow chances are back Friday across western CO as a new upper trough moves across CO from the northwest. Snow will be possible statewide on Saturday, although amounts expected to be light.

Models now bring mostly dry weather to Co next Sunday, then bring snow chances back as a new upper trough moves down from the northwest next Monday and Tuesday. Then mostly dry with seasonal temps next Wednesday into the 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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