wxgeek's weather-Thanksgiving Forecast-Update 11/23

Update Wed Nov 23

A beautiful day across CO today, as well as much of the middle portion of the country. A powerful cold front is existing the east coast today, and a persistent stationary front is bringing copious amounts of rain (2-5 inches past 24 hours) and wind to the Pacific Northwest. Some minor airport delays in Philadelphia and the New York Metro area today, as well as in San Francisco, otherwise a decent air travel day.

For CO, dry and mild weather will continue through Thanksgiving Day with temps well above seasonal norms with breezy winds at times.

Upper level trough currently along the west coast will split, with southern portion bringing rain to CA tonight and Thursday, and then will move across southern AZ and NM on Friday. This system will bring precip to AZ and NM, but no precip is expected north into CO. The northern branch of the upper trough will move into CO on Friday, but nearly all precip will remain north of CO, only some light snow will fall in the northern mountains on Friday. Associated cold front with the northern branch will move through the foothills Friday afternoon and continue east. The big impact from this ssytem will be much cooler temps Friday night into Saturday, and strong northwest winds will develop behind the cold front on Friday night into Saturday morning. Wind speeds at higher elevations (above 8000 ft) look to be in the 30-50 mph range Friday night. Strong winds will move east onto the eastern Plains by Saturday afternoon, so just breezy in the foothills by Saturday afternoon.

Upper ridge begins to build back in Sunday which will warm temps and keep CO dry for a while. Long range models keep CO dry through all of next week, with the next chance for any precip being next weekend. It appears we will end November with 35 inches of snow on Conifer Mountain, which is right at normal snowfall. Of course, we have not had any significant snowfall since very early November, so quite dry since then.

For travelers beyond CO, the system that moves through CO on Friday will become a significant storm when it moves east into the central US on Saturday. A good snowstorm will develop across MN, western WI and IA on Saturday, so some travel delays in Minneapolis possible. A strong cold front will bring the chance for heavy rain and thunderstotrms through the Ohio Valley into the lower Mississippi Valley on Saturday as well, so some travel delays possible in ORD, MEM amd MSY. This system will slowly move east on Sunday affecting the eastern Great Lakes, Northeast, mid Atlantic states into the Southeast, so some travel delays possible at BUF, PIT, IAD/DCA, and ATL on Sunday. A new Pacific storm will also move onshore in the Pacific Northwest bringing a new round of rain and wind to SEA and PDX.

---

A weak upper trough is moving across CO today, and will bring some light snow to the southwest and central mountains. A few light flurries are possible along the southern foothills this afternoon, but no accumulation is expected as the majority of energy with this trough will remain to our south.

Upper ridge then builds back over CO through Turkey Day, which will keep CO dry and raise temps well above seasonal averages, to near record levels Wednsday and Thursday. In the foothills, we will see breezy conditions during the overnight hours from tonight into Thursday, with westerly winds of 15-35 mph at times.

The next system to affect CO will split it's energy. The southern branch will remain far enough south that all precip should remain south of the CO/NM border on Thursday and leave CO with a very nice Thanksgiving Day across the state. The northern branch of energy will move into western CO on Friday and bring snow to the northern and central mountains during the day on Friday. Associated cold front will move across the foothills Friday afternoon and bring a chance for some isolated flurries, but I doubt we will see any accumulayions beyond a dusting. After the frontal passage, temps will drop dramatically, and it appears a Bora wind event will set up for Friday night into Saturday morning. Strong northwest flow aloft combined with a strong surface pressure gradient will cause northwest surface winds of 30-60 mph Friday night into saturday morning with stronger gusts possible.

Upper ridge then builds back over CO this weekend bringing temps back to or above seasonal norms and keeping the state dry. Long range models keep CO dry next week as well. Next chance for any precip appears to be the following weekend (Dec 3/4).

For Holiday travelers, looks like a tranquil weather pattern across most of the US this week. Some rain along the east coast on Wednesday, and some rain moving onto the west coast on Thursday with snow in the Cascades and Sierras. For the weekend, an upper low will cut off over the midwest, bringing snow to the western Great Lakes, WI and western IL, and rain to the eastern Great Lakes, Ohio Valley into the South. Travel cities with possible flight delays over the weekend could be Chicago, St. Louis, Detroit and Cleveland.
_________________
"Climatology is what you expect, Weather is what you get".

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

Update 11/23