textproduct: Boston / Norton

WHAT HAS CHANGED

No major changes to the forecast. The coastal storm threat Sunday night into Monday continues to diminish with the track likely too far south of southern New England.

KEY MESSAGES

- Tranquil/seasonable high temps Fri/Sat with dry weather outside a few brief spot flurries/snow showers possible late Fri night/Sat am.

* The coastal storm threat Sunday night into Monday continues to diminish with the track likely too far south of southern New England.

* Above normal temperatures for the first half next week.

DISCUSSION

KEY MESSAGE 1...Tranquil/seasonable high temps Fri/Sat with dry weather outside a few brief spot flurries/snow showers possible late Fri night/Sat am.

A ridge of high pressure to our west coupled with the mid-level trough axis to our east will result in mainly dry/tranquil weather through Sat. A moisture starved shortwave may bring a few brief spot flurries/snow showers to the region late Fri night-Sat morning...but nothing more than that expected. Otherwise...seasonable highs mainly in the 30s Fri and probably upper 30s/near 40 by Sat. Good radiational cooling coupled with a deep snowpack will allow for lows tonight in the single digits and lower teens in many locations to the upper teens to around 20 in the urban heat islands of Boston and Providence. Low temps Fri night will be milder with more clouds mainly in the teens to between 20 and 25 in the urban centers of Boston and Providence.

Key Message 2...The coastal storm threat Sunday night into Monday continues to diminish with the track likely too far south of southern New England.

Guidance is still indicating a strong mid-level shortwave crossing the Texas panhandle this weekend and continuing to track east. The northern stream shortwave with decent mid-level troughing moving across the Great Lakes and into the northeast may be what helps keep this potential storm away from southern New England. Most ensemble members across the guidance suites have continued to trend this system to the south of southern New England, passing Sunday night into Monday. However, a few members within all the ensembles do still have this system taking a closer track, exiting offshore of Virginia moreso than the Carolinas and south. Deterministic guidance does also have this system remaining well to our south and offshore, and with a weaker temperature gradient, precipitation may not expand very far north from the center of the low. With a few ensemble members in each of the suites still indicating a slightly more north track that would end up impacting the region, confidence is still somewhat low regarding this system's track. Though with the overall continuation of the more southern track, we trended PoPs down once more for Sunday night into Monday.

Key Message 3...Above normal temps for the first half of next week.

Temperatures continue to improve next week, becoming above normal. Temperatures aloft start to approach 0C and exceed 0C early in the week into Wednesday and more W to SW flow kicks in over the region within that timeframe. Ensembles, namely the GEFS and GEPS, were even getting probs of 50F highs up to 20 percent for SE MA Tuesday and Wednesday. If we get good SW flow, then we could see this actualized. Generally, though, highs in the 40s can be expected for next week. Tuesday night and Wednesday night could even see some spots remain above freezing.

Ensembles are signaling the chance for another system approaching southern New England sometime in the latter half of the week, which will be something to monitor in upcoming forecasts. As this event is roughly a week out, details are uncertain at this time.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Forecaster Confidence Levels...

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

00z TAF Update...

Through Saturday...High confidence.

VFR conditions persist right through Sat afternoon except perhaps brief marginal MVFR conditions late Fri night/Sat am in a few spot flurries/snow showers. Winds generally from the WNW at sustained speeds of less than 15 knots that will decouple in some of the typical locations during the overnight/early morning hours.

KBOS Terminal...High Confidence in TAF.

KBDL Terminal...High Confidence in TAF.

Outlook /Saturday Night through Tuesday/...

Saturday: VFR. Breezy. Chance SHSN.

Saturday Night through Sunday: VFR.

Sunday Night: VFR. Slight chance SN.

Washingtons Birthday: Mainly VFR, with local MVFR possible. Slight chance RA, slight chance SN.

Monday Night through Tuesday: VFR.

MARINE

Forecaster Confidence Levels...

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

Tonight through Saturday...High confidence.

Lingering swell across the outer-waters and NW wind gusts up to 25 knots continue to diminish through tonight. Otherwise...high pressure just to our west will keep winds/seas below small craft advisory thresholds Fri and Sat.

Outlook /Saturday Night through Tuesday/...

Saturday: Winds less than 25 kt. Chance of snow showers.

Saturday Night through Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.

Sunday Night: Winds less than 25 kt. Slight chance of snow.

Washingtons Birthday: Winds less than 25 kt. Slight chance of rain, slight chance of snow.

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

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

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until midnight EST tonight for ANZ231-251- 256. Small Craft Advisory until 7 AM EST Friday for ANZ250-254-255.