Sunday, December 17, 2023

Better outlook remains as we head closer to 2024, but so does the windswept heavy rain at all elevatios for Monday

Though the holiday season is certainly in full swing, the sea of green on the NWS BTV forecast map is not bringing out my festive spirit. Those "greens" indicate that a flood watch has been issued for most of the state with heavy rain expected for much of Monday. We won't pull any magic tricks with this storm with El Nino bringing us its very worst personality traits. Encouraging signs are still on the horizon as we approach the start of 2024, but the shorter range outlook is not looking especially wintry. 

Here are the gory details regarding the rain. It arrives Sunday evening as a light rain along with calmer winds. By Monday morning, the heavier rain and stronger winds will have arrived and when combined with the mild, near 50 degree temperatures and high dewpoints, the snow will melt very quickly. The high resolution model data is converging on the 2-plus inch of rain scenario; which, when combined with the snow melt will produce the flooding potential that the National Weather Service is highlighting. Rain will end abruptly Monday evening and colder temperatures will arrive by Tuesday morning though with substantially less snow on the ground. Elevation won't save us from this rain, even at the top of Mt Washington.

The rest of the upcoming week will manage to feature mostly sub-freezing temperatures across the northern Vermont high country though valley locations will continue to climb above freezing on the afternoons of Wednesday, Thursday and Friday. I can't promise much snow, but there is a strong jet impulse associated with the arrival of Tuesday's cold. Had this feature arrived a little sooner it might have inspired a snowy finish to the Monday storm, but it still appears capable of bringing snow showers and snow squalls to the MRV during the day on Tuesday. I get the sense that someone in Vermont will get lucky with this snow and see 6 inches but most areas will see 3 or less with a dry outlook Wednesday to Friday. 

With growing confidence, the dry weather forecast mentioned above can be extended into the Christmas holiday weekend, a period that looks very tranquil with above normal temperatures, but no torching. Across North America, the days leading up to Christmas will feature a massive jet stream ridge over the central part of the continent, a classic feature of El Nino that will will cause record breaking temperatures across the upper Midwest and central Canadian provinces. Northern New England will escape the record temperatures and also be on the receiving end of some much needed sunshine during the darkest period of the year. By Christmas Day, our next storm will be organizing and gathering strength and certainly could spread clouds back into the region though precipitation might be able to hold off until Monday night or Tuesday, though there remains some uncertainty as to the timing. 

The potential storm on the 26th certainly looks colder than December 18tth, but the glaring lack of arctic cold remains. The pattern will gradually be undergoing a more favorable transformation with the large North American jet stream ridge retrograding toward the western part of the continent. At the same time, Pacific storminess is showing the potential to undercut this ridge producing the split flow setup that I just love. That said, we still need just a little arctic cold and it's going to take a little time to build up a decent pool of said cold to our north. This makes a potential storm on the 26th appear marginal in terms of rain or snow, but the odds appear better with a possible next storm around the New Years holiday weekend time frame. Close your eyes and take a deep breath and have faith that we will get through this.


 

1 comment:

Dan Feller said...

Thanks so much. We’re using your forecasts around Mt Washington too with great success. Boot top powder on gulf of slides ski trail last weekend