Thursday, January 2, 2014

New England winter weather at its finest

Winter is raging early this 2014. Sub-zero temperatures cover most of interior New England Friday morning and even Logan airport, on the water reported heavy snow for a few hours with a temperatures within a few degrees of 5. That is winter ! Mad River Glen enthusiasts have not been on the receiving end of all the goodness. We underperformed on 12/29, missing the heavy snow by 20 or so miles, did do particularly well on Champlain/terrain induced snow in spite of cold weather this past week, and the windblown snow Thursday and Thursday, although much needed, fell short of what we had hoped for a few days ago.

This has been a classic New England winter so far and will live up to that billing Saturday and Sunday. On Saturday morning, temperatures will be close to -20 F and by Sunday night we could be seeing plain rain and temperatures surging to 40. This type of weather is absolutely excruciating if your a Vermont powder hound, but I guarantee this is not the first time many of you have seen this happen and it won't be the last either. The Euro was on to this problem very early and some of the other models have finally caught up. The Jet Stream will send a polar vortex southward into the Great Lakes carving out the "bowling ball" configuration by the end of this weekend. This allows a widespread outbreak of very intense cold weather to move into the middle part of the U.S. but at the same time, warm air will surge north ahead of a storm poised to track north through the eastern Great Lakes. The very "unforgiving" shape of the jet stream will prevent this storm from making any sort of real contact with the Atlantic Ocean. This means that the storm will fail to make the all-important jump to the coast which thwarts many of the would-be warm surges. This warm push will be a brief one, but it will make it to Vermont and allow for a period rain Sunday night and Monday morning following some freezing rain Sunday afternoon. I would allow for the chance that a greater percentage of Sunday night's precipitation is freezing rain but none of this is particularly good news. Saturday will be on the dry side with good visibility. Temperatures after that cold start should rebound to near 20 with tolerable winds compared to that of Friday.

The cold air that follows the storm Sunday night is incredibly intense but since it took the scenic route south of the Great Lakes, the air mass will have modified a touch. Temperatures will nonetheless be in the single numbers for high temperatures Tuesday and Wednesday and below zero during the morning. We should see a period of snow on the back end of the storm Monday (1/6) and a shallow layer of instability through much of Tuesday should keep snow showers and even a few squalls in the area. This should freshen up the mountain somewhat by the middle of the week in spite of the very cold weather. The intensity of the cold should relax along with the snow shower activity by later Wednesday into Thursday. We could see some snows Friday into the weekend thanks to some warm advection.

I have hinted at a more ominous looking long range but didn't update this a few days ago. The "evil empire" is showing its face, especially in the European Ensemble package by around the 10th of the month. The "evil empire" has been prevalent each of the last two years and it basically consists of a large ridge in the jet stream across the eastern Pacific coupled with trough that covers the Bering Sea and Alaska. The two features act to tighten the jet stream in the Pacific thus scouring out the Arctic air in the U.S. and displacing it with mild Pacific air. It's important to note that the different ensemble packages are showing varying degrees of this. The American and Canadian ensembles both showed an east coast warm-up, peaking out around January 13th before giving way to colder weather by the 15th or so. The way this winter has behaved, I think this is totally reasonable. There is no reason to expect a prolonged shift to warmer weather but I would expect a significant 1-2 day push of warm temperatures before it ends.

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