Big warm spike expected Friday followed by at least another week of more winter-like temperatures

Upwards of 9 inches of new snow has brought the powdery goodness back to Mad River Glen and certainly replenished an already well-conditioned backcountry. If you like powder, get out and enjoy because we've entered into a traditional March-mode, consisting of changeable weather conditions and more frequent above-freezing temperature spikes. Late his week, we have an especially strong temperature spike which will precedes the advance of an especially powerful midwest storm system. A full dose of March sunshine will help boost Wednesday temperatures from a low of near 10-degrees to a high of near 40. Given the expected low dewpoints, snow conditions aren't likely to get too corned-up except in particularly sun-drenched areas such as the base or south facing terrain. That will change on Thursday with the help of 10 additional degrees on the thermometer and a gradually strengthening south wind.

The aforementioned wind is my big concern for late this week. I have no issues with temperature spikes in March given that they are rather commonplace, but the southerly winds ahead of that strong northeastward pushing storm system will persist from Thursday night through much of Friday. As was the case in early February, the wind has the effect of melting snow at a much faster rate than it would in calm conditions. Clouds and a few short periods of rain are also likely but rainfall amounts don't appear to be especially high, likely around or less than a quarter of an inch. The combination of wind and extended period where temperatures are above 45 from late Thursday through all of Friday will melt off a  healthy percentage of the existing snowpack. Temperatures on Friday could briefly approach 60 degrees before gradually falling back toward the freezing mark Friday night into early Saturday. There is the possibility of some new snow later Saturday across the high country thanks to the combined effect of general instability and the passage of a weak weather disturbance.

A surging PNA index will bring some welcomed warm weather to areas like Montana which have been in the deep freeze for over a month and a period of colder weather to eastern North America, Vermont included. The strength of this cold beginning this Saturday, measured by the expected amplification of the jet stream does not appear as strong the past two days and models have backed off on the possibility of any big storm for the time being. I would not entirely despair over this yet however since March is notoriously volatile and stormy and the middle of next week (around the equinox) is a period where something substantial could yet occur so its worth watching.

The PNA is expected to peak next week and subside somewhat around the time frame of March 25th though not vanish entirely. This makes the outlook for the last week of March appear mostly seasonable in the aggregate but likely very changeable from one day to the next. For those hoping for an extended period of spring-like warmth and soon, I am not expecting it, at least this month. More likely is a few sporadic days of nice weather mixed with a few more winter-like days.