Record cold temperatures this morning quickly rebounded into the upper 20s to mid 30s in SNE. Tonight, lows will stop around the upper teens and low 20s under increasing clouds. Showers will move into the region tomorrow ahead of a storm system from the midwest. Much warmer air will flow in from the southwest. Highs will hit the low 40s. Saturday Night, despite a continuous southerly flow, temperatures at the surface will still drop into the upper 20s to low 30s, so precipitation will change to snow for a few hours. All precipitation will wrap up before dawn Sunday, and skies will quickly clear. High pressure will move in from the west bringing sunny skies but keeping temperatures to the low 40s. By Monday, high pressure will move offshore, allowing a southerly flow to develop again, and pushing temperatures to around 50 in Keene. Highs across SNE will range between 45 and 60. A shot at the 60s will come by Wednesday for parts of SNE. Temperatures will reach the mid to upper 50s in Keene. A storm system will move out of the northern Plains on Wednesday and begin spreading precipitation into the region by Wednesday Night. There will be some instability in place, so we need to monitor this storm for the possibility of our first thunderstorms of the season. South and west of the region, there will exist a severe weather threat in the Ohio Valley and into PA and western NY state. Whatever the case may be, the models are indicating storm QPFs above .5" so we cannot rule out brief downpour potential. The associated cold front will cross the region Thursday morning. Cold air at the surface will move in quickly, possibly changing precipitation to a wintry mix before ending. We will be allowed 12 hours to dry out before another low moves northward from southern Plains to our west and brings another chance of rain starting up Thursday Night. There is some indication of secondary development off the coast, and a rapidly deepening low moving east of the region on Friday. The NWS talked briefly about this potential in this mornings AFD. Coastal development could mean a flash freeze event for New England on Friday and a 12 hour period of wind driven snows before the low moves east Saturday morning. This potential does not have much confidence from me. The NWS is going with highs in the upper 30's (still pretty chilly). If we do get a coastal low to form, then the high would likely be recorded in the morning (around 30 degrees) before a drop into the 20s occurs in the afternoon.
Forecast verification:
My forecast for the 1-7 period has been pretty good except for the fact that I underestimated the arctic outbreak in the Northeast.
Through March 25th:
Whatever happens with the late week storm, a brief return to winter will occur next weekend between the 16th and the 19th. Highs during this period will range in the 30s (5 to 10 degrees below normal). A strengthening positive AO will allow a warm up to our west and eventually reaching the east coast. This will be an especially warm period through the 28th. One thing I want to talk about is the abundance of cold air at the surface up in Canada. This is one thing I overlooked when I forecasted a prolonged warm spell in March for the region a couple weeks ago. The pattern will be set up for ridging in the east, however periodic northern stream storms could pull surface cold down into the region for a few days before a resurgence in the ridging. So even our week of warmth towards the end of the month could be interupted by a few arctic intrusions.
March 28th through April 15th:
A pattern change will happen around the start of April that will allow all the cold bottled up in Canada to spill down into the region. It will all start with what looks to be a good storm potential for the last 3 days of March. Right now, it looks like the storm will ride the southern stream up into the Great Lakes region. Secondary development will be possible and a strong cold front will swing through the region behind the storm. The associated low pressure system will situate itself east of Newfoundland and encourage strong ridging to build over Greenland, forming a solid block, and -NAO. I feel confident in a two week period of temperatures around 5 to 8 degrees below normal during the beginning of April. I also feel somewhat confident in one more 6+" storm between the 1st and 5th of April. After the 15th, strong ridging out west will shift eastward as the -NAO block decays rapidly. Surface cold will be absent from the picture and I think that we will end April on a warm note.
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