wxgeek's weather-Thanksgiving week forecast- Update 11/28

Update Thu Nov 28

A very Happy Thanksgiving and Hanukkah to all. I certainly have much to be thankful for in my life, but mostly it is my wonderful wife that loves me for who I am, and hopefully that feeling is returned to her. I am also thankful for two happy and employed adult children, and my parents in their 80's who continue to enjoy life.

Another beautiful weather day on tap across the state. A weak cold front slipped into eastern CO overnight, so temps will be cooler east of the Divide today, closer to seasonal norms under mostly sunny skies. No travel concerns across the state today. Conditions will remain mostly sunny and temps will warm slightly Friday through Sunday. Only a slight chance for some flurries across the northern and central mountains mostly north of I-70 on Sunday. These should not cause any travel issues for those returning on Sunday.

For next week, models continue to suggest a major shift in the weather pattern across the western U.S. Upper level trough/low will move south into the northern Great Basin early next week and persist over the western U.S. through most of next week. Some differneces in timing and intensity between the GFS and ECMWF model, bit overall pattern is agreed upon. Currently looks like arctic air will move south into CO sometime late Tuesday into Tuesday night. Snow will develop behind the arctic front over CO, and we will experience periods of snow statewide from Tuesday night into next weekend. Models still attempting to refine when a more significant snow may occur, but currently looks like chances for heavier snow would be Wednesday into Thursday, and then possibly Friday into Saturday. Timing and amounts still likely to change with future model runs. Things should be better resolved by late this weekend and early next week, but people should be prepared for much colder temps and winter driving conditions for a good portion of next week.

Beyond next week, models keep the upper ridge in the eastern Pacific, which will allow cooler temps and systems from the northwest to affect CO every few days.

Major system that hit the East Coast has moved north and east, so now just cool westerly winds of 15-25 mph affecting much of the Northeast and some lake effect snow over the Great Lakes. Return travel weather looks pretty good across most of the nation this weekend, except for some rain and snow moving into the Pacific Northwest on Sunday.

_________________
"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 26

Beautiful day across CO. A few mid and high clouds drifting by, otherwise lots of sun with temps near seasonal norms. This weather is expected to last through at least Friday statewide thanks to an upper level ridge that will keep temps near to slightly above seasonal norms. An upper trough will develop off the Southern CA coast late this week, and will combine with a weak upper trough from the Pacific Northwest this weekend to bring a chance for snow showers to the northern and central mountains, mostly along and west of the Divide with snow level 5000-6000 ft. Only a few inches at most expected. Dry conditions expected to prevail this weekend for the foothills and plains with temps near seasonal norms.

Extended range models continue to bring a big change to our weather pattern next week due to a big change in the upper level pattern. Upper ridge over the western U.S. this week is forecast to retrograde westward into the Pacific and extend northward into Alaska. This will make room for a large and deep upper level trough/low to move from western Canada south into the western U.S. for most of next week. This will bring cold arctic air south over much of the western U.S. and create periods of snow across the region. Still too far out to pin down timing of events and snowfall amounts, but suffice to say if models have a handle on this pattern, expect very cold temps and periods of snow across all of CO from next Tuesday into next weekend. This looks to be in phase with a MJO (Madden-Julian Oscillation) moving east across the Pacific during this time.

For the storm affecting the eastern U.S., heavy rain with isolated tornadoes affecting the lower Mississippi Valley and the Southeast U.S., with snow, freezing rain and sleet affecting the Ohio Valley, mid Atlantic States and eastern Great Lakes. Surprisingly, no significant air travel delays affecting major airports at this time. Airlines have already begun cancelling flights to major Northeast hubs on Wednesday, so it appears Wednesday will be the bad air travel day. Heavy rain and strong winds expected to move north into the mid Atlantic region and Northeast U.S. tonight into Wednesday. Snow will retreat west to the Appalachians and westward overnight into Wednesday morning, then move back to near the Atlantic seaboard by late Wednesday. Westerly winds of 20-45 mph expected along much of the east coast as surface low deepens as it moves up the east coast Wednesday. Localized flooding likely along the east coast with 2-5 inches of rain possible, then below freezing temps move in. Bad weather should be into eastern Canada by Thursday with no major travel impacts expected through Sunday, except for rain, and snow to low levels moving into the Pacific Northwest Sunday. Snow level could drop to 500 ft or lower across WA and OR Sunday as the aforementioned upper level trough begins to move south.

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

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

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A few flurries and light snow persisting across the foothills and southern Urban Corridor, dropping a dusting to an inch in some areas. This is caused by the upper low moving into the TX/OK panhandle and a snow band developed on the north side of the low across CO in northeast flow. Snow will move south this afternoon with skies clearing over the foothills and Urban Corridor.

The remainder of this week will be dry with temps near or slightly above seasonal norms across the state as upper level ridge builds over the region. Travel across CO should have no weather related issues. A weak upper level trough will pass over CO this weekend, which will cool temps some and create the chance for snow showers over the northern and central mountains west of the Divide. Foothills and plains look to remain dry this weekend.

For those traveling outside of CO this week, beware. Significant winter storm will develop as our recent upper low merges with a northern upper low over the Eastern U.S. on Tuesday/Wednesday. Rain, freezing rain and snow is currently moving across the lower and mid Mississippi Valley, and will move into the Southeast U.S. on Tuesday, with precip spreading north into the Ohio Valley and mid Atlantic region. By Wednesday, a major storm has taken shape along the entire eastern seaboard with snow over New England and the Appalachians and heavy rain and strong winds across the entire Atlantic coast. If traveling by air, expect significant delays and many cancellations Tuesday through Wednesday. System moves off the coast by Thanksgiving day. As Wednesday is traditionally the busiest air travel day of the year, this will create a lingering mess for many travelers. Models indicating 3-5 inches of rain over a large area from the Southeast to New England, and 1-3 feet of snow in areas farther west, and throw in some sleet and freezing rain in some areas. You get the picture for a travel nightmare over the most populated region of our country. Air travel issues could have a ripple effect as far away as Denver and the West Coast.

Back to CO. Models have now been consistent in suggesting a big change to our weather pattern for next week. By Monday of next week, a large upper level trough is forecast to envelop most of the western U.S. with cold air plunging south from western Canada. This upper trough is expected to remain in this position for most of next week, possibly into next weekend. At the surface, this translates to much colder temps and the potential for periods of snow over all of CO from next Tuesday through next weekend. Hard to determine how much snow at this time, so will wait for model refinement later this week on that, but a heads up that the potential for an extended period of winter conditions exists for CO next week.

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

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

Bump for 11/26 update

Bump for nov 28 update