textproduct: Boston / Norton

WHAT HAS CHANGED

No significant changes to the forecast.

KEY MESSAGES

- Scattered early morning showers quickly give way to plenty of sunshine, breezy and unseasonable warm high temps well into the 80s today.

- Plenty of sunshine with comfortable humidity Fri-Sat. Highs mainly in the 70s. Lows Fri night in the 40s-lower 50s.

- Period of showers likely sometime late Sat night into Sun with perhaps some downpours. Dry & seasonable weather follows Mon.

- Unseasonable warmth may return for a day or two by the middle of next week ahead of our next cold front.

DISCUSSION

KEY MESSAGE 1...Scattered early morning showers quickly give way to plenty of sunshine, breezy and unseasonable warm high temps well into the 80s today.

Scattered showers early this morning will quickly exit the coastal plain by early-mid morning. Otherwise...westerly flow aloft and at the surface will allow skies to become mostly sunny by late morning- early afternoon. Post frontal airmass still quite warm with 925T on the order of +22C to +24C. This coupled with lots of sunshine and westerly flow should allow highs to reach the middle 80s in many locations with even a few upper 80s possible. Bufkit soundings also indicate good mixing...so expect westerly wind gusts on the order of 20 to 30 mph with a few gusts near 35 mph across parts MA especially the higher terrain.

KEY MESSAGE 2...Plenty of sunshine with comfortable humidity Fri- Sat. Highs mainly in the 70s. Lows Fri night in the 40s-lower 50s.

Large high pressure builds in from the west Fri into Sat. This will result in absolutely beautiful September weather. Plenty of sunshine with highs mainly in the middle to upper 70s both days with very comfortable humidity. Mainly clear skies, light winds, and a dry airmass in place will allow for a good night of radiational cooling Friday night. Lows Fri night should mainly be in the 40s to the lower 50s and 55-60 in the Urban Heat Island of Boston.

KEY MESSAGE 3...Period of showers likely sometime late Sat night into Sun with perhaps some downpours. Dry & seasonable weather follows Mon.

High pressure moves off the coast for the second half of the weekend allowing a shortwave and associated mid-level warm front to approach. This will likely bring a period of showers sometime late Sat night and/or Sun. Pwats reach around 2 inches so some downpours are possible too...especially if there is a low level boundary in place. Some of the guidance indicates this potential near and south of the MA Turnpike...so something to watch over the next few days.

A ridge of high pressure should return by Monday...bringing mainly dry and seasonable weather for the start of the next work week.

KEY MESSAGE 4...Unseasonable warmth may return for a day or two by the middle of next week ahead of our next cold front.

An anomalous upper level ridge of high ridge will build across the southeast states during the first half of next week. This will result in west to southwest flow aloft and above normal height fields across southern New England. We will have to see how much southwest flow/mixing we can generate at the surface ahead of the next cold front. But given the setup...there is the potential for highs to reach back into the 80s for a day or two by the middle of next week ahead of the next cold front.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

12z TAF Update...

Today...High confidence.

Mainly VFR, brief MVFR conditions are possible through early to midmorning associated with brief scattered showers. Otherwise, SW gusts of 20 to 30 knots early this morning will shift to more of a W direction later this morning and afternoon. Brief gusts up to 35 knots this morning towards the south coast and Cape Cod.

Tonight...High confidence.

VFR. Diminishing NW winds which should decouple in the normal low- lying locations overnight.

Friday...High confidence.

VFR. NW winds 6-12 knots.

KBOS Terminal...High confidence in TAF.

Wind shift from the SW to W occurs by 14/15z. Gusts diminish after 01z.

KBDL Terminal...High confidence in TAF.

Outlook /Friday Night through Monday/...

Friday Night through Saturday: VFR.

Saturday Night: Mainly VFR, with local MVFR possible. Scattered SHRA.

Sunday: Mainly VFR, with local IFR possible. Scattered SHRA.

Sunday Night through Monday: VFR.

MARINE

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

Today through Thursday...High confidence.

Southwest winds were gusting to between 25 and 35 knots early this morning. The strongest of those wind gusts were the typically prone areas of near Buzzards/Cape Cod Bay as well and Nantucket sound. Buoys indicating SW winds gusting to around 35 knots in those spots...so Gale Warnings continue there this morning. Otherwise...WSW wind gusts of 20-30 knots expected later this morning and afternoon across all waters. Strongest of those will be nearshore...but small craft headlines will remain in effect for the rest of our waters through the afternoon.

Winds diminish below small craft advisory thresholds by early-mid evening...But will keep SCA headlines for our southern outer-waters into the overnight hours for lingering 5 foot swell. Otherwise...winds/seas should drop below small craft advisory thresholds for all waters shortly after midnight and persist into Friday. This a result of high pressure building in from the west.

Outlook /Friday Night through Monday/...

Friday Night through Saturday: Winds less than 25 kt.

Saturday Night: Winds less than 25 kt. Isolated rain showers.

Sunday: Winds less than 25 kt. Scattered rain showers.

Sunday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers.

Monday: Winds less than 25 kt.

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ230- 235>237-250-251. Gale Warning until noon EDT today for ANZ231>234. Small Craft Advisory until 2 AM EDT Friday for ANZ254>256.