wxgeek's weather-Weather-remainder of 2013-Update 12/30

Update Mon Dec 30

Mild and breezy day for most of CO today with temps above seasonal norms for most foothill and Urban Corridor areas. CO remains under northwest flow aloft, and we will see small impulses next few days embedded in the flow aloft. First impulse will increase snow from late this afternoon into Tuesday morning over the central and northern mountains, with generally 1-2 inches possible. Foothills will remain dry and breezy through Tuesday, with Chinook winds picking up again Monday night into Tuesday morning with speeds of 15-35 mph, gusts to 50 mph possible. Second impulse will bring additional snow to the central and northern mountains Tuesday night into Wednesday. This impulse will be stronger, so perhaps 4-8 inches of snow for the High Country, and a slight chance for snow to creep east to the foothills and plains Tuesday night into Wednesday morning. Best chances for eastern CO appear to be on the northeast plains, but any amounts likely to be less than 1 inch. Some flurries possible during the day on Wednesday with temps on the cool side of seasonal norms.

Dry and mild conditions expected Thursday and Friday statewide, with gusty Chinook winds likely Thursday night into Friday along the foothills. Next disturbance expected to move into CO from the northwest Friday night into Saturday. Snow likely for the mountains with 2-5 inches possible, while some light snow looks possible for eastern CO as well, but amounts expected to be from a trace to 2 inches from the foothills east. Some flurries possible during the day on Saturday with temps again below seasonal norms. Conditions look dry and mild for Sunday into early next week as upper level pattern remains locked. Models do not indicate a change until the following week at this time.

For travelers, winter storm will take shape Thursday over the Ohio Valley with rain across the Southeast, and will spread east to the Mid Atlantic region and Northeast on Friday, so some travel issues possible during this period, especially mid Atlantic and Northeast locations. The weekend currently looks pretty calm nation wide outside of some snow across the Great Lakes and northern Rockies.

_________________
"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 Sun Dec 29

Nice layer of fresh snow yesterday, generally 1-4 inches reported from the mountains to the plains, 3 inches at my loctaion on Conifer Mountain. Mostly sunny today with temps on the cool side of seasonal norms. We remain under brisk northwest flow aloft with upper ridge along the west coast and upper trough along the east coast. This will keep temps on the mild side through next weekend, with gusty westerly winds at times, and some light snow for the mountains. Specifically, gusty westerly winds likely tonight into Monday morning, then again Monday night through Wednesday morning. Some mountain snow possible Monday through Wednesday, but amounts expected to remain light, maybe 1-2 inches each day along west facing slopes across the northern and central mountains. Not much snow likely east of the Front Range crest, so mostly dry this week for the foothills and plains. Next system with snow chances will be Friday night into Saturday. Snow moves into western CO Friday night, then spreads east during the day on Saturday. Latest models have slightly higher amounts with this system, so mountains could see several inches, and maybe 1-3 inches for the foothills and adjacent plains. As this system moves east, could become a significant winter system for the central and eastern U.S. Sunday into Monday, so could cause travel issues next weekend.

Models have been suggesting the potential for the west coast upper ridge to retrograde west next week, which would allow cold systems to move into the western U.S. and bring cold temps and snow to CO. However, latest GFS and ECMWF runs keep upper ridge along the west coast a bit longer into at least the end of next week. Will have to wait and see how things evolve. Basically there are 3 ways this persistent pattern could go. It could simply remain in place for most of the winter, upper ridge could retrograde west and allow cold systems into the western U.S. for a while, or upper ridge could move slightly east over the Rockies. Only the second scenario would allow for decent snow for eastern CO. First scenario would allow some snow over western CO, while last scenario would keep the entire state dry. January tends to be a dry month climatologically for CO, as Conifer Mountain averages 13.7 inches in Jan, so it appears with current global pattern CO will remain relatively dry through Jan. We will once again have to hope for a snowy Spring.

_________________
"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 Sat Dec 28

Cold front currently in northern WY will push rapidly south today into northern CO this afternoon. Upslope flow and snow will devlop behind cold front by late this afternoon and evening and persist overnight across most of the state. Snow amounts expected to be light, maybe 1-3 inches in the mountains, a trace to 2 inches in the foothills, and a trace to an inch Urban Corridor and plains. Much of the initial snow likely to melt due to warm temps this week, especially below 8000 ft. This may cause some ice and snow packed roads tonight into Sunday morning at higher elevations. Lower elevation roads may only see wet to slushy conditions. Snow should be done by Sunday morning, except it may persist south of US 50 into mid morning Sunday. Sunday expected to be mostly sunny with cool temps. Some gusty westerly winds may develop Sunday night into Monday morning causing some blowing and drifting of recent snow.

For next week, upper ridge builds back in Monday, so mild temps and dry conditions expected. Some snow may develop west of the Divide on Tuesday under northwest flow aloft mostly north of I-70. By Tuesday night (New Years Eve), weak system skirts to our north and may cause some light snow along the mountains, foothills and Urban Corridor, but amounts would be very light if any snow at all for foothills and Urban Corridor. Mountains may see an inch or two.

Wednesday through Friday next week looks dry and mild statewide. Next system would move down from the northwest and bring a chnace for snow Friday night into Saturday, mostly north of I-70, and amounts would again to very light.

Long range models have hinted at a pattern shift the following week, where our dominant upper ridge along the west coast retrogrades west into the Pacific, and allows a cold system to move down the west coast and into the Inter-Mountain west. If models have this correct, it would allow for a more significant snow event in CO, but too early to put much stock in this yet.

For any remaining Holiday travelers, fairly significant storm will develop over the Southeast today and move up the East Coast on Sunday. This will primarily be a heavy rain event, but some snow and freezing rain will be possible along the northern edges of the system affecting portions of the Appalachians, eastern Great Lakes and New England on Sunday. This will impact areas still suffering from previous ice storm where some areas still without power, so this system could delay bringing power back to some areas, and cause new power outages. Some airport delays likely and cancellations possible across the Northeast.

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

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

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Warm and breezy day expected across the state today. Upper ridge will dominate weather across the western U.S. next few days, which translates to mostly sunny and mild days through Saturday for CO. Gusty Chinook winds expected today, and again Friday night into Saturday which will keep temps very mild in the foothills. Next change in the weather will occur Saturday afternoon as an upper trough will clip CO to the north, and drag a cold front across the state. Front looks to move through late Saturday afternoon or evening. Cooler temps and some upslope flow expected behind the front which will lead to a chance for snow Saturday night into Sunday morning. Mountains may see 1-3 inches, while the foothills and Urban Corridor may see a dusting to an inch or so. Flurries may linger in the mountains through Sunday evening. Monday expected to be mostly dry with temps near seasonal norms.

For later next week, brisk northwest flow aloft expected to remain over CO, which will bring breezy conditions to the foothills Tuesday with mild temps, while some snow will be possible west of the Divide. New Years eve a weak disturbance will increase snow chances for the mountains as well as the foothills and Urban Corridor Tuesday night into Wednesday morning. Again, a few inches possible in the mountains and a dusting to an inch or two possible east of the Divide. New Years Day through next Friday look dry and mild, then more snow chances for next weekend statewide.

Pattern in general remains locked, with upper ridge along the West Coast and upper trough along the Eastern U.S. CO remains under northwest flow aloft with disturbances moving down from the northwest affecting CO every 2-3 days. Under this regime, mountains receive the majority of moisture with the foothills and Urban Corridor getting brief amounts. Foothills also tend to be breezy at times as disturbances approach CO. Long range models give no indication this pattern will change anytime soon, so looks like this pattern will be with us at least into mid January. This pattern also keeps the Central and Eastern U.S cold with more snow than average, especially the Great Lakes and Northeast, and creates the potential for significant winter storms impacting the eastern U.S. Related, CA remains very dry, as San Francisco will post their driest year on record (since 1846) with just over 5 inches of precipitation for the calendar year, smashing the previous record of just over 9 inches.

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

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

Bump for 12/29 Update

Bump for 12/30 update