12:52AM
DAYS 1-5 (SEPTEMBER 30-OCTOBER 4)…
A lot to cover because in comparison to recent weather, it’s an action-packed 5 days ahead. Now a word of caution: Don’t misread what I say here. My approach is always to take a step back and see what I am most certain of, explain it as best I can, and separate that from what I’m not sure of and lay out the scenarios or tell you what I think is most likely to happen regarding that. I’m also not going to hide from the fact that this week’s pattern is far different than what I was calling for during last week for this week. But that’s weather. A couple missed details and your entire medium range forecast is finished. But this is why we update this blog every day. Things change sometimes, and this time they did. So enough primer. Let’s get to the actual paint job then see what may need another coat or 2 later. A cold front will settle southeastward across southern New England during today, creating its own lift as it pushes a warm and muggy air mass out of the region. This lift will be enhanced today by a low pressure area moving up from the Mid Atlantic into southern New England just ahead of the front, and finally linking up with it before exiting. This low will send some downpours through the region during the morning and midday with a few additional downpours possibly trailing behind the departing low later. I think this moves quickly enough that the most common rain amounts will be in the 1 to 2 inch range. Spotty higher amounts are possible, especially northwest of Boston during the morning and possibly over far southeastern MA later in the day as the front finally makes it to that area. And then comes a bit of a break as the front sits offshore and high pressure builds across southeastern Canada. This high will be rather large and sprawling, not close enough to push it’s clear, dry air in, but enough to create a moderate to strong north to northeast air flow across all of New England Thursday and Friday. The impact from this will be large waves and rough surf along the coast, especially north-facing and east-facing shores, where coastal flooding is possible during high tide times. Additionally, it appears that the front that comes through today and sits offshore through Thursday may bend back westward across the region during Friday, sending more rain into the region from east to west. It may move far enough westward to leave us in a lull for much of Saturday. All the while the high will continue to be stretched out to the north of the region and he wind will turn more easterly on Saturday. Now, while all of this is going on, we’ll be keeping an eye on Joaquin, a tropical storm as of this writing but forecast to become a category 1 to 2 hurricane as it mills around east of the Bahamas through Thursday. It’s what happens with it after that which is the big question. The scenarios are wide-ranging, but I can see the most likely one at this time being one in which the storm is drawn northward starting on Friday and continuing through early Sunday before it takes a turn to the northwest and possibly makes a landfall later Sunday somewhere in the Middle Atlantic. It is important to note and remember that this is just one scenario, the one I feel is most likely, but far from a certainty. A set-up like this would send an area of significant rain northward into southern New England later Sunday. Though we would not see the strongest winds from the actual storm in this scenario, with high pressure still holding on to the north, there would be some significant wind between it and the storm system. So now to simplify all this into a detailed forecast…
TODAY: Cloudy. Numerous to widespread showers in the morning becoming numerous to scattered during the afternoon. Some heavy rain. Chance of thunder with some of the downpours. Humid. Temperatures steady in the 60s may fall into the 50s west and north of Boston by late. Wind S to SW 10-20 MPH shifting to N from west to east across the region.
TONIGHT: Cloudy. A few showers. Areas of fog. Lows 50-55. Wind N 10-20 MPH with higher gusts.
THURSDAY: Cloudy. Patchy drizzle. Areas of fog. Highs 55-60. Wind N 15-25 MPH with higher gusts.
FRIDAY: Overcast. Periods of rain. Temperatures in the 50s. Gusty NE wind.
SATURDAY: Mainly cloudy. Slight risk of showers and patchy drizzle. Temperatures rise into the 60s. Gusty E wind.
SUNDAY: Cloudy. Rain arrives south to north, may become heavy late. Temperatures in the 60s. Windy.
DAYS 6-10 (OCTOBER 5-9)…
Based on current thinking, the remains of Joaquin in the form of broad low pressure would track northeastward from the northern Mid Atlantic through New England with additional showers and wind Monday October 5, diminishing as the low exits Tuesday October 6, followed by dry and breezy weather October 7-8 with a warm up by October 9.
DAYS 11-15 (OCTOBER 10-14)…
Showers possible early in the period followed by a return to dry weather. Temperatures near to above normal.