textproduct: Boston / Norton

SYNOPSIS

The windy conditions this afternoon dissipate some tonight and Tuesday, but it still will be blustery and chilly. 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 /UNTIL 6 AM TUESDAY MORNING/

Key Messages...

* Dry but blustery & chilly tonight * Low temps tonight in the middle 20s to the lower 30s

Details...

Closed upper level low will continue to lift further north across the Canadian Maritimes. This coupled with the loss of daytime heating will result in wind gusts diminishing some this evening. However...it will remain blustery overnight with NW wind gusts of 15 to 25 mph at times. While winds will not decouple...still expect a chilly night with low temps bottoming out in the middle 20s to the lower 30s across the region.

SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/

Key Messages...

* Sunny, breezy & seasonable Tue but with less wind/tad milder than today...Highs near 40 high terrain with middle-upper 40s elsewhere

* Chilly Tue night...lows in the 20s to near 30 for most with any precipitation from a fast moving system staying to our south Details...

Tuesday...

Closed low continues to lift further northwest well into northern Quebec on Tue. As this happens upper level trough will start to lift north and away from the region as well. This should result in sunny skies Tue with little if any diurnal CU unlike today. Still some westerly wind gusts of 20-25 mph with a few gusts near 30 mph...but not nearly as windy as the past two days. High temps will also be a tad higher than today. Highs should top out near 40 in the highest terrain...to mainly the middle to upper 40s elsewhere.

Tuesday night...

Shortwave across the southern Great Lakes will move east towards the mid-Atlantic coast. Upper level confluent flow should keep this system to our south with just a period of some clouds overnight mainly across CT/RI/SE MA. The 12z HRRR is an outlier which brings some very light precipitation in our far southern areas late Tue night. Given the other guidance is south and the atmosphere is quite dry will not include any precipitation in the forecast at this time. Low temperatures should drop into the 20s to near 30 across the region.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Key Messages:

* Dry with less wind Wednesday and Thursday. Cooler than normal.

* Scattered showers Friday into early Saturday. Cooler for weekend.

Details...

By Wednesday the upper level pattern transitions to more quasi-zonal flow. A southerly wave will exit offshore early in the morning, more likely staying well enough south to keep it dry. There is good agreement across model guidance for a surface high to slide across the region Wednesday which will owe to dry conditions and lighter winds on Wednesday. It will still lean on the cooler side with highs a little below normal in the low to mid 40s with a some upper 40s possible in CT Valley and south coast. Similar conditions are expected on Thursday. A weak shortwave trough moves through the zonal flow; however, both deterministic and ensemble guidance shows this wave to be fairly moisture-starved. This will likely keep things dry, but perhaps bring some additional cloud cover for the day.

Ensemble guidance continues to agree on a northern stream shortwave trough tracking to the north of the region Fri-Sat. Although the stronger synoptic forcing is further north, there is a consensus that there will be broad weak ascent for SNE. Coupled with a plume of above normal moisture, this will support showers across the region mainly Fri into early Sat. Global models and ensemble solutions begin to diverge when it comes to the details, particularly with respect to the evolution of a secondary low and track. This may bring more widespread rainfall if the low tracks closeby. Can't rule out some flakes mixing in briefly for the high terrain very early Sat AM. Otherwise, this is appearing to likely be a low QPF rain. Weak WAA ahead of the wave will bring temperatures to around normal on Friday in the low 50s. A cold front should move across Saturday, but speed is less certain and may depend on how the southerly wave tracks. Overall this should trend highs cooler Saturday with conditions clearing into the afternoon. Cool and dry conditions for Sunday.

Looking even further ahead into the following (holiday) week, pattern looks overall benign with no strong signal for an impactful system to impact southern New England. It's still plenty far away, so continue to monitor the forecast for updates.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

Forecaster Confidence Levels...

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

06Z TAF Update...

Today through Wednesday...High confidence.

VFR through Wednesday. Winds remain NW and diminish slightly overnight, with gusts likely continuing near the waters and near higher terrain. Lower spots like the CT river valley may see lighter winds overnight. NW gusts kick back in this morning, although only around 20 knots inland, 25 knots near the waters. Winds finally become light to calm Tuesday night and Wednesday

KBOS Terminal...High confidence in TAF.

VFR. Gusty NW winds continue through Tuesday afternoon up to 25 knots.

KBDL Terminal...High confidence in TAF.

VFR. Gusty NW winds continue through Tuesday afternoon up to 20 knots.

Outlook /Wednesday through Saturday/...

Tuesday Night: VFR. Breezy.

Wednesday through Thursday: VFR.

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

Friday: MVFR/IFR conditions possible. Breezy. Chance RA.

MARINE

Forecaster Confidence Levels...

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

This afternoon through Tuesday night...

Strong pressure gradient with good mixing over the waters were yield W wind gusts of 30 to 40 knots this afternoon. As upper level low continues to lift northward across the the Maritimes wind gusts will diminish some tonight. We should be able to gradually transition Gales to small craft headlines this evening into the overnight hours.

Still enough of a gradient to result in W wind gusts of 20 to 30 knots on Tuesday and will need small craft advisories for all waters. A weak ridge of high pressure builds in for Tuesday night allowing winds/seas to finally diminish below small craft advisory thresholds.

Outlook /Wednesday through Saturday/...

Tuesday Night: Winds less than 25 kt. Seas locally approaching 5 ft.

Wednesday through Thursday: Winds less than 25 kt.

Thursday Night: Winds less than 25 kt. Slight chance of rain.

Friday: Winds less than 25 kt. Chance of rain.

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 1 AM EST Tuesday for ANZ230-236. Small Craft Advisory until 7 AM EST Tuesday for ANZ231-233-234- 251. Small Craft Advisory until 1 PM EST Tuesday for ANZ232-235-237. Gale Warning until 1 AM EST Tuesday for ANZ250-254>256.