New England Weather This Week: Summer-Like Start, Fall-Like End

This week will start off where the weekend left off. A cold front mid-week will bring a nice slug of rain before cooling things back off to our October reality. There will be a potential coastal storm to watch for the upcoming weekend as well.

MONDAY & TUESDAY

All of New England, right to the coast, will see peak warmth Monday and Tuesday. As the high pressure begins to shift to the east, the pressure gradient will increase, allowing a stronger southwesterly flow. This flow will prevent sea breezes from developing and 80+° temperatures will likely push to the coast. Each day will be similar to each other with highs likely only a degree or two different. Clouds will likely begin to increase slightly from the full sunshine expected over the weekend.

Daily record highs will be possible across the region during this stretch. Daily records are highly variable across the region during this stretch, ranging from the upper 70s to low 90s depending on the location in New England. October 7th (Tuesday), for example, has a record high of 91° in Hartford and 90° in Boston and Manchester. Caribou and Houlton, Maine's daily record on that same day is just 76°. On Monday, Caribou and Houlton's records in the low 70s are expected to be topped by several degrees.

Below: AIFS showing potential high temperatures this afternoon:

A strong cold front will begin to approach New England later Tuesday into Tuesday night. Showers ahead of the actual front will likely break out in westernmost New England by Tuesday afternoon, keeping temperatures a notch cooler. For everyone else, it will be another very warm and dry day. Most of the region will see frontal showers Tuesday night into Wednesday morning.

Below: HRRR showing potential weather Tuesday afternoon:

WEDNESDAY

That strong cold front will cross most of New England overnight Tuesday into Wednesday morning. By the morning, the front will likely be draped near the New England coastline. A ribbon of enhanced moisture will flow into New England ahead of the front. Cold air advection will begin to occur rather quickly after this frontal passage, so Wednesday will be a much cooler day.

Areas that see this ribbon line up with the cold front will see the most amount of rainfall. Exactly where this occurs across New England remains a bit of a point of contention. No matter what, a widespread quarter to half inch of rain is likely region-wide. The moisture ribbon may produce two areas of enhanced rainfall over New England: one over northwestern areas as the front will be strongest and one over southeastern New England as the merger with the moisture-plume will be complete.

This continues to be a much-needed rainfall. Some rumbles of thunder will be possible, but with the frontal passage occurring overnight and into the morning, it will limit convection activity. This may also preclude widespread torrential downpours from developing, which is what's holding the rainfall back on the map below.

Most of New England will be done with the rainfall by Wednesday afternoon. Rain will hold on the longest across southern New England and the northern New England coastal plain, where showers may linger right up to midday. It will be turning much cooler behind the front with highs in the 50s in western and northernmost New England. Highs in the 60s are likely for areas farther east and south.

Below: Euro showing potential temperatures Wednesday afternoon:

THURSDAY & FRIDAY

Cool, Canadian high pressure will build into New England behind the cold front, helping to lock in the cooler air through the rest of the work week. It may initially be breezy on Thursday as the pressure gradient between the center of the high pressure to our northwest and the departing trough to our east will be rather tight. The high pressure will sink southeastward through this time, gradually reducing winds as the center of the high moves directly over New England Thursday night into Friday.

Below: Current weather map for this Friday (October 10):

Temperatures during this time will be much more October-like. Widespread highs in the 50s to low 60s are likely. High pressure in place will lead to mostly to fully sunny days. Low temperatures Thursday night will likely bottom out with ideal radiational cooling conditions likely. Lows on Friday morning will likely be in the 20s north to 30s south.

WEEKEND

High pressure looks to remain in control initially, with a mainly dry and potentially warmer Saturday on tap. A developing coastal storm will be taking shape off the southeast coast. This system will work up the east coast, likely arriving in the Mid-Atlantic by Sunday morning. The high pressure over New England will likely be forced north as the system works up the coast.

This may set up a Rex block situation (when high pressure sits directly north of low pressure). The question will be how far north the system can push given the high pressure (will New England be on the dry and warm side of the block or the cooler and unsettled side?). As of now, showers may push into southern New England Sunday and early next week. How far north it gets will be the main thing to watch throughout this week.

Below: Current weather map for Sunday morning (October 12):