textproduct: Boston / Norton

SYNOPSIS

High pressure builds overhead for Wednesday and Thursday, bringing relatively light winds and continued seasonable temperatures. A cold front will bring a period of unsettled weather Friday, which may linger into Saturday, then high pressure returns next Sunday.

NEAR TERM /THROUGH WEDNESDAY/

Key Messages:

* Dry with below normal temperatures and increasing clouds towards the south coast

The wind finally dies off after sunset this evening as high pressure builds overhead. A low pressure passes by to our south late tonight but we shouldn't see much more than increased cloud cover, with rain staying well to the south with too much dry air over southern New England. Good radiational cooling conditions until the clouds arrive, so there should at least be a few hours to permit temperatures to reach below normal levels.

SHORT TERM /WEDNESDAY NIGHT/

Key Messages:

* Mainly dry with below normal temperatures.

Clearing skies as a passing low pressure moves offshore during the morning hours. More clouds expected to return later Wednesday night as another low pressure takes a similar track. Dry weather expected to prevail with a weak high pressure and abundant dry air in place. Not as windy Wednesday into Wednesday night.

LONG TERM /THURSDAY THROUGH TUESDAY/

Key Messages:

* No impactful weather expected.

Dry conditions and light winds continue Thursday with surface high pressure remaining positioned across the region. Temperatures will remain seasonably cool with highs in the mid to upper 40s.

Ensemble guidance continues to agree on a northern stream shortwave trough tracking to the north of the region Fri-Sat. Weak warm advection and SW flow ahead of the trough will bring in warmer temperatures with highs in the upper 40s for the higher terrain and low-mid 50s elsewhere. A plume of slightly above normal moisture pushes across the region for during the day. This will be sufficient enough to support some scattered showers Fri/Fri Night. Exact timing is still uncertain, but model guidance is in good agreement with this being a low QPF event. Recent runs have trended downward in amounts. Overall, looking like a range from a trace to 0.25". Can't rule out light snow showers/flakes mixing in for the higher elevations of northern MA if any showers develop early Fri or later Fri night/early Sat AM.

A cold front will accompany the trough passage Saturday night, bringing in cooler temperatures aloft. Fairly zonal flow aloft Saturday with high pressure building in. This will bring dry and cooler weather for Saturday with highs in the low to upper 40s. Similar conditions prevail Sunday with the same pattern overhead.

Early next week, ensemble guidance agrees with generally zonal aloft aloft over the region with a few weak waves embedded in the flow. Timing and moisture availability vary across solutions with some showing potential for light precipitation. Temperatures will likely lean close to normal in the mid/upper 40s to near 50 degrees.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Forecaster Confidence Levels...

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

Rest of Tonight... High Confidence.

VFR. Light westerly winds under 10 knots

Wednesday and Wednesday night...High Confidence.

VFR. West winds turning NW less than 10 knots. Showers possible at ACK Wed morning, otherwise dry for the rest of the region.

KBOS Terminal...High confidence in TAF.

VFR. W winds turning NW around 10 knots.

KBDL Terminal...High confidence in TAF.

VFR. Light NW winds around 5 knots.

Outlook /Thursday through Sunday/...

Thursday: VFR.

Thursday Night: Mainly VFR, with local MVFR possible.

Friday: Mainly VFR, with local IFR possible. Breezy. Slight chance RA.

Friday Night: Mainly VFR, with local MVFR possible. Slight chance RA.

Saturday: VFR. Slight chance RA.

Saturday Night through Sunday: VFR.

MARINE

Forecaster Confidence Levels...

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

Through Wednesday Night...High Confidence.

A weak low pressure passes south of the waters late tonight into Wednesday morning. A few early morning showers are possible for the waters south of the islands, but expecting most of the waters to remain dry with good visibility. Weak high pressure over the waters leads to rather light winds and seas Wednesday through Wednesday night.

Outlook /Thursday through Sunday/...

Thursday through Thursday Night: Winds less than 25 kt.

Friday: Winds less than 25 kt. Slight chance of rain.

Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain.

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

Sunday: Winds less than 25 kt.

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...None.