799 
FXUS61 KBOX 121917
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
317 PM EDT Sat Apr 12 2025

.SYNOPSIS...
Low pressure south of New England will slowly shift to Gulf of 
Maine Sunday and will bring occasional drizzle and a renewed 
area of rain to coastal locations tonight into Sunday. The storm
pulls away Sunday night. Much milder Monday and Tuesday with 
highs into the 60s. Dry weather should prevail Monday, but a 
disturbance will bring scattered showers to the region Monday 
night and perhaps into Tuesday, but a washout is not expected. 
Dry, but blustery and cooler weather returns Wednesday into 
Thursday. Temperatures then rebound Friday into Saturday with 
perhaps a few showers sometime Friday night and/or Saturday with
the next disturbance.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Key Messages: 

* Patchy drizzle tonight along with redeveloping rain along the 
  coast. Little if any temperature change from overnight.

Closed upper low emerges off the mid Atlc coast and sets up south of 
New Eng with slow moving surface low lifting NE to east of New Eng 
late tonight. Deep moisture plume will back into eastern New Eng 
tonight with low level isentropic lift resulting in an area of rain 
redeveloping across Cape/Islands tonight and backing into eastern MA 
overnight. Abundant low level moisture persists tonight and expect 
patchy drizzle or light rain at times across the rest of SNE. Temps 
will be near freezing in the higher elevations so can't rule out 
patchy freezing drizzle as moisture is limited in snow growth 
region. Little temp change tonight with lows in the 30s and gusty NE-
N winds will continue along the coast. 

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Key Messages: 

* Periods of rain in eastern MA. Improving conditions in western New 
  Eng with perhaps some breaks of sun in the afternoon. Cool and 

* Clearing Sunday night

Sunday...

Slow moving coastal low moves to the Gulf of Maine. Deep moisture 
wrapping around closed mid level low to the NE will result in 
continued periods of rain for eastern New Eng. Some uncertainty with 
westward extent of rainfall which may briefly get into RI and 
central MA in the morning but confidence is low. May see some 
improvement in the afternoon but overall a cool and raw day in 
eastern New Eng with highs in the mid 40s and gusty N winds making 
it feel cooler. Further W toward the CT valley, much lower 
probability of rain and it should be a mostly dry day. In fact, 
enough mid level drying during the afternoon should allow for some 
breaks of sun developing and highs into the lower 50s. 

Sunday night...

Vertically stacked low will gradually lose its grip on SNE as it 
pulls away with mid level ridging developing overnight and surface 
ridging building in from the west. This will lead to clearing skies 
and gradually diminishing wind. Lows will settle into the 30s. 

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Key Messages:

* Much milder Mon & Tue with highs well into the 60s
* Scattered showers Mon night perhaps into Tue...but not a washout
* Dry, blustery & chillier Wed with highs upper 40s to lower 50s
* Dry & still breezy Thu with highs in the 50s
* Temps moderate Fri and Sat with a few showers Fri night and/or Sat

Details...

Monday and Tuesday...

Mid level ridging ahead of the next trough working into the Great 
Lakes will result in much milder temps Mon into Tue. High temps 
should reach well into the 60s both days with a low risk a few spots 
reach 70 on Tue. Dry weather should prevail during the day Mon...but 
a mid level shortwave will bring a round of scattered showers to the 
region Mon night. A few more showers are possible sometime Tue with 
the actual cold front...but much of the day may end up dry.

Wednesday and Thursday...

Blustery and much chillier air works into the region by Wed behind a 
fairly strong cold front. While it will be dry, high temps will be 
held in the upper 40s to the lower 50s with gusty west winds. Lows 
Wed night may be down near freezing or a few degrees below in some 
of the typically prone outlying locations. And it still will be dry 
and a bit breezy Thu with seasonable highs in the 50s. 

Friday and Saturday...

The upper trough shifts east of the region with rising height fields 
by the end of the week. Highs will probably back into the 60s Fri 
and Sat. The next shortwave approaching may bring a few more showers 
to the region sometime Fri night and/or Sat.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

18z TAF Update:

Through tonight: Moderate confidence.

Widespread IFR-LIFR conditions eastern half New Eng in 
occasional drizzle and fog with steadier rain redeveloping 
across Cape/Islands and SE MA tonight. MVFR-IFR CT valley. 
NE wind gusts 20-30 kt slowly diminishing later tonight but 
remaining gusty along the immediate coast.

Sunday: Moderate confidence. 

MVFR-IFR with areas of rain eastern MA in the morning, with
slow improving conditions in the afternoon, possibly to VFR in 
the CT valley. Western extent of rainfall remains uncertain. N 
wind 10-20 kt with gusts to 25 kt along the immediate coast, 
slowly diminishing in the afternoon. 

Sunday night: Moderate confidence.

VFR with clearing skies from W to E overnight. Lingering MVFR in
the evening Cape/Islands. 

KBOS TAF...Moderate confidence. Mainly IFR into Sunday morning 
although some periods of MVFR possible.

KBDL TAF...Moderate confidence.

Outlook /Monday through Thursday/...

Monday: VFR. 

Monday Night: Mainly VFR, with local IFR possible. Chance SHRA.

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

Wednesday: Mainly VFR, with local MVFR possible. Windy with
local gusts up to 30 kt. 

Wednesday Night through Thursday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Sunday night: High confidence.

Small craft advisories for all waters into Sunday. NE winds 
backing to N with 25-30 kt gusts tonight slowly diminishing Sun
afternoon and dropping below 20 kt Sun night. Rough seas 6-9 ft
over outer waters will slowly subside Sun afternoon through Sun
night. 

Outlook /Monday through Thursday/...

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

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

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. Slight chance of rain
showers. 

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Local rough seas. Slight chance of rain
showers. 

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. 

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

Thursday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 PM EDT Sunday for ANZ230-233>237.
     Small Craft Advisory until 2 AM EDT Monday for ANZ231-251.
     Small Craft Advisory until 8 PM EDT Sunday for ANZ232.
     Small Craft Advisory until 8 AM EDT Monday for ANZ250-254-255.
     Small Craft Advisory until 10 PM EDT Sunday for ANZ256.

&&

$$

SYNOPSIS...KJC/Frank
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...Frank
AVIATION...KJC/Frank
MARINE...KJC/Frank