textproduct: Boston / Norton

WHAT HAS CHANGED

Updated Aviation section, otherwise no significant changes.

KEY MESSAGES

- Scattered showers tonight, the dry and seasonable this weekend.

- Summer-like warmth much of next week. Monday will be the our transition day to milder weather, with highs well into the 60s to the lower 70s. Then potentially 80+ Tue through Fri. However, the arrival and departure of the warmth is uncertain, especially in eastern MA with a backdoor cold front lurking nearby. Other than a few brief showers possible at times...dry weather dominates.

DISCUSSION

KEY MESSAGE 1...Scattered showers tonight, the dry and seasonable this weekend.

Northern stream shortwave crosses northern New Eng tonight with the attendant cold front moving through SNE after midnight. A narrow band of PWATs briefly spike to around 1" ahead of the front. Modest forcing for ascent combined with this increase in moisture will lead to a few showers developing and moving across the region. However, given the column doesn't fully saturate areal coverage will be limited and not all locations will see measurable rainfall.

The front moves off the coast late tonight followed by rapid drying Sat as PWATs crash. Expect full sunshine and seasonable temps with highs upper 50s to lower 60s, but it will be blustery in the cold advection pattern with NW gusts to 25-30 mph at times. High pres builds over New Eng Sat night so it will be a cold night with light winds and clear skies resulting in lows in the 30s, except upper 20s in the normally colder locations. Another dry day Sun as the high slowly moves offshore. Sunshine will give way to increasing mid-high clouds in the afternoon in the developing warm advection pattern, but any showers ahead of the warm front will should hold off until Sun night. Near seasonable temps Sun with highs mid-upper 50s.

KEY MESSAGE 2...Summer-like warmth much of next week. Monday will be the transition day to milder weather, with highs well into the 60s to the lower 70s. Then potentially 80+ Tue through Fri. However, the arrival and departure of the warmth is uncertain, especially in eastern MA with a backdoor cold front lurking nearby. Other than a few brief showers possible at times...dry weather dominates.

Main story next week is the subtropical ridge building up the east coast, advecting an impressive warm sector airmass into SNE with summer-like warmth, potential with highs 80+ multiple days next week. The caveat, is that there is a large spread among the model guidance, including AI models on the arrival and departure of the warm weather. Ensembles, including AI guidance offer probs of 80+ temps Tue through Fri, with eastern MA lowest given potential of a backdoor front. Given the uncertainty and time range we followed the national blend of models (NBM) for highs next week. The warming airmass with dew pts eventually climbing into the 60s in the warm sector, there will be a low risk of convectively driven isolated showers from time to time, as short wave energy traverse north of the region. However, most days will feature dry weather.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

Forecaster Confidence Levels...

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

00z TAF update: High confidence.

Bank of low clouds with IFR ceilings and visibilities near South Coast should expand into parts of eastern CT, RI, and southeast MA tonight. Not confident it will get as far north as PVD-PYM though. Otherwise, mostly VFR with a few showers moving across the region. SW wind 10-15 kt with a few higher gusts. Areas of LLWS associated with a modest low level jet due to 020 winds 230/40-50kt.

VFR Saturday and Saturday night. NW gusts to 25 kt diminishing and becoming light Sat night.

KBOS Terminal... High confidence in TAF.

KBDL Terminal... High confidence in TAF.

Outlook /Sunday through Wednesday/...

Sunday: VFR.

Sunday Night: VFR. Breezy. Chance SHRA.

Monday: VFR. Windy with local gusts up to 30 kt. Slight chance SHRA.

Monday Night: Mainly VFR, with local MVFR possible. Breezy. Slight chance SHRA.

Tuesday: VFR.

Tuesday Night: VFR. Chance SHRA.

Wednesday: VFR. Breezy. Slight chance SHRA.

MARINE

Forecaster Confidence Levels...

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

Tonight through Saturday night...High confidence.

SW wind gusts to 20-25 kt through tonight. Wind shift to NW late tonight and early Sat with gusts to 25 kt, especially over nearshore waters. Winds diminish Sat night as high pres builds over the waters. Marginal SCA seas over outer waters.

Outlook /Sunday through Wednesday/...

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

Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of seas approaching 5 ft. Chance of rain showers.

Monday: Strong winds with gusts up to 30 kt. Areas of rough seas. Slight chance of rain showers.

Monday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Slight chance of rain showers.

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

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

CLIMATE

Since we are potentially looking at our first 80-degree temperatures of the season early next week, here are some stats regarding average, earliest, and latest 80-degree temperatures.

Note that Hartford (Bradley) already hit 80 degrees this year back on March 31.

Boston: Average May 4, Earliest March 21, 1921, Latest June 16, 1924

Providence: Average May 4, Earliest March 20, 1945, Latest June 18, 1924

Hartford: Average April 28, Earliest March 9, 2016, Latest June 15, 1924

Worcester: Average May 4, Earliest March 15, 1990, Latest June 10, 1997

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 2 AM EDT Saturday for ANZ231>235- 251. Small Craft Advisory until 2 AM EDT Sunday for ANZ250-254. Small Craft Advisory until 8 PM EDT Saturday for ANZ255-256.