textproduct: Boston / Norton

WHAT HAS CHANGED

Wind headlines have expired. River Flood Warnings for Sudbury River at Saxonville and Wood River at Hope Valley have been cancelled. River Flood Warnings for Pawtuxet River at Cranston and Taunton River at Bridgewater remain in effect.

KEY MESSAGES

- Gusty post-frontal westerly winds gradually diminish overnight. This will be followed by a period of abnormally cold and dry weather.

- Temperatures gradually moderate Thursday with near-normal temperatures continuing through the weekend. Trending unsettled late week through early next week.

DISCUSSION

KEY MESSAGE 1...- Gusty post-frontal westerly winds gradually diminish overnight. This will be followed by a period of abnormally cold and dry weather.

Winds continue to gust between 20-30 knots this afternoon before gradually diminishing overnight. Post-frontal environment and moderate pressure gradient will continue to support gusty winds overnight, but we should see gusts drop below 20 mph around or shortly after midnight. Low-level temperatures continue to fall in response to cold air advection with 925 hPa temps dropping to near - 10C. This will result in widespread low temperatures in the upper teens/low 20s tomorrow morning.

Winds become more calm Wednesday afternoon as high pressure builds over southern New England. However, temperatures will remain much cooler than normal withs highs peaking in the low to mid 30s. The column will be very dry, so expect plenty of sunshine. Cold/dry conditions carry through the end of the week.

KEY MESSAGE 2...Temperatures gradually moderate Thursday with near- normal temperatures continuing through the weekend. Trending unsettled late week through early next week.

High pressure remains in control through the end of the week with winds becoming southerly and beginning to advect warmer air into the region. 850 mb temps increase from -12C on Wednesday to -1C on Friday. Still have a cold pool aloft which will keep diurnal clouds around on Thursday mixing with the sun, and more moisture moves in in the low/mid levels on Friday bringing partly cloudy skies. Even so, highs should reach the mid 40s on Thursday and the upper 40s/low 50s on Friday into the weekend.

Precipitation-wise nothing high impact like we saw the next 24 hours is expected. That being said, the pattern does become more unsettled over the weekend. After a weak passing wave moves overhead Thursday night bringing a slight chance for some low elevation rain/high elevation snow showers a series of stronger waves crosses the region first around Saturday then again late Sunday into Monday. Moisture is better with the second round (PWATs near 1") but jet dynamics are less certain owing to significant differences amongst the global guidance. Regardless, flooding rains are not expected at this time.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Forecaster Confidence Levels...

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

Through 00Z...High Confidence

VFR. Gusty westerly winds between 20 and 30 knots.

Tonight...High Confidence

VFR. Gusty westerly winds gradually diminish with sub-20 knot gusts by 06Z almost everywhere. Winds become light (5-10 knots) out of the northwest by 12Z.

Tomorrow...High Confidence

VFR. Stead 5-10 knot northwest winds early become more light/variable as the day progresses.

Tomorrow Night...High Confidence.

VFR. Light winds becoming south/southeast by Thursday morning.

KBOS Terminal...High confidence.

KBDL Terminal...High confidence.

MVFR gradually improves to VFR this morning with SW gusts around 25-30 kt thru this afternoon. Occasional flurries possible today.

Outlook /Thursday through Sunday/...

Thursday: VFR.

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

Friday through Friday Night: VFR. Slight chance RA.

Saturday through Sunday: VFR. Breezy. Chance RA.

MARINE

Forecaster Confidence Levels...

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

Rest of Today through Tomorrow Night

Gusty westerly winds offshore gradually diminish overnight. Gale Warning remains in effect for the coastal waters with 34+ knot wind gusts possible for a few more hours. Should see gale force winds come down after sunset. High seas, especially over the south coastal waters gradually subside overnight in respond to weakening winds, but remain elevated with 8-12 foot seas this evening becoming 4-5 feet by early tomorrow afternoon. Should see sub-SCY criteria conditions across the coastal zones tomorrow afternoon and tomorrow night, with the exception of some of the outer south coastal zones where 5 foot seas may persist for an extended period of time.

Outlook /Thursday through Sunday/...

Thursday: Winds less than 25 kt. Areas of seas approaching 5 ft.

Thursday Night through Friday: Winds less than 25 kt. Seas locally approaching 5 ft.

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

Saturday: Winds less than 25 kt. Seas up to 5 ft. Chance of rain.

Saturday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Chance of rain.

Sunday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain.

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ230- 236. Gale Warning until 8 PM EDT this evening for ANZ231>235-237- 250-251-254>256.