wxgeek's weather-Weather Outlook December 1-15-Update 12/8

Update Sun Dec 7

Beautiful day across the state. This dry and mild pattern will persist through Friday. Mostly sunny skies expected with temps from 10-25 degrees above seasonal norms by mid to late in the week. Fire danger will continue to rise. Some gusty westerly winds will be possible in the foothills late in the week.

Next system to possibly impact CO will be this coming weekend. Potent Pacific system will bring very heavy rain to CA Thursday and Friday, then spread moisture into western CO by late Friday. The big question with this coming system will be the track of the upper level trough. Recent GFS runs have dropped the upper trough down into southern NM by next Sunday morning, which would mean only limited snowfall for eastern CO. The ECMWF has a better track with the upper trough near the 4 Corners region by Sunday morning, which would bring moderate to heavy snow to all of CO. So as usual, we will have to wait and see how models evolve this scenario during the week. I suspect we will have a better handle on the situation by Wednesday or Thursday. Since the European model is usually more accurate, I am hoping this will be the case with this system, as we definitely need some snowfall. The European solution would bring significant snow to all of CO, especially the foothills and adjacent plains from Saturday afternoon through Monday morning, while the GFS solution would bring only light snow to the foothills on Sunday. Beyond that, models suggest more dry weather the following week with the next chance for precip the following weekend. Overall, still looking like a very dry December with well below average snowfall unless a big system is lurking late in the month.

Looking at past records, there have been some previous dry Decembers. Notable is December of 2002 when only 3 inches fell on Conifer Mountain, and the first snow of the month did not fall until Dec 18.

In the Philippines, Typhoon Gupit has weakened to a category 1 storm, but is bringing very heavy rain to portions of the central Philippines, including the capitol of Manilla. Heavy rain will persist through Tuesday morning local time as Gupit moves into the South China Sea.

_________________
"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 6

Mostly cloudy across CO today as weak upper level trough passes. Some light precip will be possible this afternoon into tonight, mostly along and west of the Divide with snow level around 8000 ft. Foothills could see a few flakes, but not much more. Flow aloft southwesterly today and will shift to northwesterly Sunday, so expect more sunshine and warmer temps Sunday, with some gusty westerly winds in the High Country and foothills.

For next week, models persist a dry and warm pattern statewide. No precip is expected Monday through Friday with possible record warm temps mid to late week. Also some gusty westerly winds late next week, so along with warm temps fire danger will be elevated.

Models are beginning to come into better agreement on next weekend. Strong Pacific system will bring very heavy rain to CA Thursday and Friday, and then move into CO Saturday and Sunday. If the current forecast is accurate, it could be a decent system for most of CO, including the foothills and plains. However, there is the chance this system will cut off over AZ and leave CO high and dry, so will keep my hopes up that it continues as models currently advertise. Beyond that, the following week looks mostly dry with temps near seaosnal norms, then longer range models suggest a pattern change, which would bring snow and colder temps to CO the following weekend, but will have to wait and see if that actually develops.

Elsewhere, Typhoon Gupit is a category 3 Typhoon off the central coast of the Philippines, and is forecast to move slowly to the west northwest across the Philippines over the next 72 hours. This storm could cause widespread damage mostly due to very heavy rain, with up to 10-20 inches of rain possible over the next 72 hours.

_________________
"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 Dec 2

Mostly sunny, breezy and warm day across CO. Temps are some 10-20 degrees above seasonal norms in many locations today, especially east of the Divide where downsloping westerly winds aiding in warmup. Potent system bringing 1-5 inches of rain to areas of CA today will bring an increase of clouds and some precip to western CO on Wednesday. Temps expected to be closer to seasonal norms with less wind and more clouds across eastern CO. Best chances for precip will be along and west of the Divide from late tonight into Wednesday night. Snow level expected to be in the 8000-9000 ft range as moisture is from the Pacific, with 1-3 inches of snow possible at higher elevations, and mostly west facing slopes.

On Thursday, system along the West Coast weakens and slowly moves east, thus more precip chances for western CO with snow level again 8000-9000 ft and only light accumulations expected. Areas east of the Divide will remain dry and mild with temps rising back above seasonal norms.

Friday looks dry and mild statewide. Another weak system from the Pacific will move across CO this weekend, but models currently suggest only light precip expected west of the Divide Saturday afternoon with snow level around 8000 ft. Sunday looks dry and mild statewide.

For next week, models persist the dry and mild pattern for CO, with near record temps possible by mid to late next week. The persistent dry pattern this Fall has caused an increase in fire danger with little snow left in the foothills, and lots of dry grass and low humidity. Platte Canyon Fire announced today a ban on all open burning until conditions improve, which does not appear to be anytime soon. Next chance for precip looks to be next weekend, but those chances are iffy at best as models have recently suggested system would cut off over AZ versus moving through CO. Still too early to tell which way things will go.

Seasonal snowfall well is below average, with just 11.5 inches so far this season on Conifer Mountain, while average is around 28 inches at this time of year. December averages around 22 inches, but the first half of December is looking quite dry, so we will need to see a significant pattern change in mid to late December to get significant snowfall.

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Cold front has moved through eastern CO today, but cold air is quite shallow, only up to about 7000-7500 ft, so higher foothills are clear and mild, while areas east are cloudy and cold. Some light snow may be possible across the northern mountains and northeast plains through tonight, but only very light if any accumulation expected. Cold air mass will remain in place east of the foothills through Monday morning, so low clouds and fog will persist tonight across the plains into the lower foothills. By Monday afternoon, conditions will clear over eastern CO and temps will remain below seasonal norms.

By Tuesday, upper ridge builds over CO and will keep conditions dry with mild temps above seasonal norms. On Wednesday, remnants of an upper trough that will bring heavy rain to CA on Tuesday and Wednesday will weaken as it moves across CO. Some light snow will be possible along and west of the Divide on Wednesday with snow level 7000-8000 ft, but only light accumulations expected, maybe 1-2 inches. No precip expected for the foothills.

Thursday through Saturday look dry and mild statewide with temps above seasonal norms. By Sunday, models still trying to resolve a pattern that looks to bring a weak upper trough to the Southwest, then slowly move east through Monday. Depending on the exact track and intensity of the upper trough, CO could receive some light precip with the southern and central mountains being favored at this time. Snow level looks to be in the 6000-7000 ft range. At this time, little if any precip expected for the foothills and Urban Corridor but that could change if the track and intensity of the upper trough change. Longer range models then continue the dry and mild pattern the week after.

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

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

Bump for 12/2 update

Update Thu8 Dec 4

Cloudy day across CO as a system of sub-tropical origin passes to our south. Precip appears to be limited to areas mostly south of US 50, but some showers will be possible north to I-70 through tonight. Any accumulations are expected to be light with snow level around 9000 ft. Clouds and precip will clear out by morning leaving a mostly sunny and mild day in store for Friday, with mostly light winds.

For the weekend, a weak system from the west will move across CO Saturday. Precip looks to be limited to areas along and west of the Divide with snow level 7000-8000 ft. Mountain areas could receive 1-3 inches of snow Saturday afternoon and evening. East of the Divide, partly cloudy with mild temps and some gusty westerly winds in the foothills. Sunday looks dry statewide, temps above seasonal norms and gusty westerly winds in the foothills.

For next week, dry Monday through Friday statewide with temps well above seasonal norms, perhaps some record temps possible. Also some gusty westerly winds at times in the foothills. Fire danger will continue to rise through next week on the plains and in the foothills.

For next weekend, models are struggling with a consistent solution. Models have moved a potent west coast system across CO next weekend which would bring precip to at least western CO and possibly all of CO, while other model runs have cut the systemn off over AZ or Baja leaving CO dry next weekend. Will have to wait and see how things evolve next week. Either way, CA has more rain in it's future which is good news for a parched state. Beyond next week, will have to wait and see how models evolve, as too early to tell whether the long wave upper trough will move far enough east to allow systems into CO or if they will die before getting to the Rockies. The overall good news is that the pattern across the Pacific is looking much more El Nino like, which hopefully will translate into more snow for CO later in December and beyond. So far, December has been very dry statewide and looks to remain that way at least through mid December. If this pattern were to persist, could be one the warmest and driest Decembers for CO on record. Hopefully this changes in late December. I really do not like discussing fire danger in December.
_________________
"Climatology is what you expect, Weather is what you get".

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

Bump for 12/7 update

Bump for 12/8 update