Sunday, January 27, 2019

Wintry week with both snow and cold and a milder early February outlook

The upcoming week will be about as wintry as it gets for the state. The talk of snow in the last update will now get amplified; and as advertised, bitterly cold temperatures and even colder wind chills will follow in the wake of that snow late in the week.

It certainly helps to get an over-performance on snowfall from what was a rather pathetic looking weather system on Sunday. The high country has thus regained its powdery prominence and can look forward to the arrival of an even bigger storm late on Tuesday.  In the meantime, northerly winds will usher in some dry air on Monday and although temperatures will be chilly, it will pale in comparison to conditions we will experience late in the week. Some sunshine and good visibility can't hurt either.

Tuesday's temperatures will moderate, reaching the 20's during the afternoon as clouds thicken. Snow should develop during the late afternoon or early evening. The southern stream is going to feed this storm a little juice but if there is a theme for the week, it is that everything will happen very fast. Snow will arrive, accumulate 6-12 inches during the overnight and will taper to flurries Wednesday morning. There will be a brief opportunity for some additional snow showers before the thrust of the shallow and bitterly cold arctic air pushes into the region by later in the day Wednesday. Temperatures will fall into the single digits by the evening and wind chills will be well below zero but the ski day itself will prove to be pretty darn good. Thursday on the other hand will be windy and bitterly cold in spite of some sunshine with temperatures struggling to make it above zero on the mountain. Interestingly, this polar vortex will make waves in the upper midwest for bringing temperatures of close to 20-below to Chicago. The windy city hasn't seen such readings in a while. After that however, the PV will rotate northeastward and rapidly retreat deep into Quebec. Though the region will be in close proximity to the PV on Thursday, we will not get the direct assault. It's analogous in some ways to a landfalling hurricane where Vermont is sitting 500 miles inland while states like Illinois, Wisconsin, Iowa and Minnesota are right along the coast. Temperatures will certainly be very cold Thursday but may even fall short of being the coldest of the season with MLK day beating it out. Furthermore, temperatures will moderate very quickly, reaching 10 Friday with somewhat calmer winds and well into the 20's on Saturday.

The first full weekend of February could see some snow induced by warm advection. The push of milder air however is of growing concern because it appears, as of now, capable of bringing temperatures  back above the freezing mark sometime between the 4th and 6th of the month.  This is not, by any means, etched in stone and there are hints that lingering arctic air in Canada could fight for a piece of the proverbial pie. Forecasts of the PNA index however strongly suggests that arctic air will shift its focus westward in early February and will leave the door open for a milder intrusion. What happens thereafter appears conflicting as of now. Enough blocking is indicated to persist at high latitudes to keep some arctic cold in Canada, but at the same time, the jet stream in the Pacific is indicated to intensify. Though the longer range outlook continues to look milder, there are still no glaring indications that another February will succumb to El Torchy. For now its just the one potential mild scourge on February 4th-6th.


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