textproduct: Boston / Norton

WHAT HAS CHANGED

No significant changes to the forecast.

KEY MESSAGES

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

- Chances for showers return late Saturday night into Sunday. Dry and seasonable weather returns Monday.

- A quick bought of summer like heat is possible towards the middle of next weak ahead of a cold front.

DISCUSSION

KEY MESSAGE 1...Plenty of sunshine with comfortable humidity Fri-Sat. Highs mainly in the 70s. Lows Fri night in the 40s and 50s.

Large high pressure arrives from the west Friday, then moves overhead for Saturday. This will mean mainly dry weather with relatively light winds. Expecting rather good radiational cooling conditions Friday night. Some of the colder locations could fall into the mid 40s, while the more urban centers should be 55-60.

KEY MESSAGE 2...Chances for showers return late Saturday night into Sunday. Dry and seasonable weather returns Monday.

As the high pressure system moves offshore Saturday, a shortwave pushes through southern New England likely bringing a wave of showers with it Saturday night into Sunday. Dewpoints surging to near 70 degrees and PWATs climbing to near 2" by Sunday morning indicate the possibility that some showers could have some heavier banding set up, especially south of the Mass Pike. Initial model guidance is hinting at rainfall totals upwards of 0.75", but we're not quite within range of the CAMs yet. Certainly something to keep an eye on.

Another ridge of high pressure should begin to move in sometime later Sunday evening or Monday bringing mainly dry and seasonable weather for the start of the next work week.

KEY MESSAGE 3...A quick bought of summer like heat is possible towards the middle of next weak ahead of a cold front.

Global guidance is suggesting an anomalously strong upper level ridge builds by the middle of next week over the southeastern states and Appalachian region. This would indicate southern New England returns to predominantly west-southwest flow, pushing warmer air from the south into New England. Depending on how much mixing we can generate at the surface ahead of the next cold front, there is potential for high temperatures to reach back into the 80s for a day or two by the middle of next week.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Forecaster Confidence Levels...

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

Through 00Z...High confidence.

VFR, although brief low-end VFR possible in some diurnal stratocumulus, especially across the Worcester Hills and the east slopes of the Berkshires. Gusty SW to W winds will diminish after sunset.

Tonight...High confidence.

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

Friday and Friday Night...High confidence.

VFR. NW winds 6-12 knots, becoming light NW to N Friday night.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Saturday through Tuesday/...

Saturday: VFR.

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

Sunday: Mainly VFR, with local IFR possible. Breezy. Chance SHRA, slight chance TSRA.

Sunday Night through Tuesday: VFR.

MARINE

Forecaster Confidence Levels...

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

Through Friday Night...High confidence.

Winds and seas are expected to gradually subside this evening, with rough seas lingering longer across the southern coastal and outer waters. Anticipating that Small Craft Advisories will be able to be dropped in stages this evening and overnight. High pressure moving over the waters should result in relatively light winds and seas Friday through Friday Night.

Outlook /Saturday through Tuesday/...

Saturday through Saturday Night: Winds less than 25 kt.

Sunday through Sunday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers, slight chance of thunderstorms.

Monday through Tuesday: 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. Small Craft Advisory until 4 PM EDT this afternoon for ANZ232>234. Small Craft Advisory until 1 AM EDT Friday for ANZ254. Small Craft Advisory until 4 AM EDT Friday for ANZ255-256.