We had our prolonged period of sunny dry weather, and now as if someone hit a switch, sunny weather is hard to come by. Meanwhile, we are steadily making up for the rainfall deficit. The storm yesterday brought a period of moderate to heavy rainfall (.32" in an hour and .74" total in Jaffrey) with some thunder and lightning along for the ride. Today, cyclonic flow and residual moisture will allow for scattered showers through the day. Currently on radar, most of the shower activity is across upstate NY into VT and W MA. Clouds will keep temperatures on the cooler side today along with brisk westerly winds.
Tonight, scattered showers will continue to rotate through central and northern New England. Thermal profile tonight also supports snow, so some flakes are not out of the question mainly after 9pm. Surface temperatures will fall to the upper 20's to around 30. Strong winds, sustained between 10mph and 15mph, gusting to 30mph to 35mph are likely to continue through tonight.
Low pressure will be pulling away Sunday morning with high pressure building in. Residual low level moisture will still keep some pesky clouds in the region, limiting full solar heating, nevertheless, temperatures will reach the low 50's - notably warmer than today.
Again, a short lived respite from rain. Clouds will advance Sunday night ahead of the next storm system currently over the central Plains. Low pressure will move into Ohio by Sunday evening and strengthen steadily as it becomes vertically stacked Monday morning in western PA. Triple point low develops near the Delmarva peninsula and moves north. Aided by a strong 140+kt upper level jet over the southeast, the secondary low will strengthen rapidly to between 985 and 988mb by Monday evening off the New Jersey coast. A strong low level jet of 50kt to 60kt at 925mb will nose into southeastern New England Monday evening, transporting moisture northward while at the same time being the focus for gale force winds at the surface.
Showers will overspread the region from west to east between 2pm and 5pm. PWATs will increase to around 1.0" in Keene to 1.5" across eastern New England. Total totals into the low 50's will support convection and thunderstorms over eastern New England, however for Keene, TTs in the mid 40's won't be sufficient. Nevertheless, a large expanding rainshield with moderate to embedded heavy rates will overspread all of New England Monday evening, with the heaviest rain occuring between 6pm and 10pm in Keene. Precipitation will become more showery again after midnight Tuesday, but will continue through the day. Model guidance is a little spread on total rainfall specifically across SNE. This is because it depends significantly on how fast the secondary low strengthens. The GFS which bombs the low to 977mb over upstate NY by Tuesday morning also has a swath of 1.5" to 2" across SNE and CNE. In contrast, the NAM which develops the secondary a little later, doesn't pull the LLJ as far west and consequently leaves a dry slot up the Connecticut River valley. HPC takes a compromise with widespread 1.25" to 1.5".
Tuesday Night, cyclonic flow and moisture remains locked in, and scattered rain / snow showers will be likely. Strong westerly winds will usher in temperatures around 5 to 10 degrees below normal, with 850mb temps down to around -5C. Cloudiness continues on Wednesday, with scattered rain showers and again possibly some flakes.
The huge upper level low finally moves out on Thursday, allowing for at least a break from precipitation. Still looks like a moist column though, with continued cloudiness.
A deep trough currently in the Gulf of Alaska will rotate into the western states by the middle of next week. There is some uncertaintly with regards to the evolution of this next system, but it looks like at least some of the energy will eject eastward toward the region on Friday. The question is the magnitude of the storm that affects us.
All in all, a stormy pattern looks to continue through next weekend, with a persistent GOA trough ejecting rounds of energy into the SW states and then eastward across the nation.
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