Old Res Weather

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 041927
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
327 PM EDT Tue Oct 4 2022

.SYNOPSIS...
Persistent low pressure south of New England will generate 
gusty northeast winds and periods of rain tonight into 
Wednesday. 2 to 3 inches of rain can be expected across RI and 
southeast MA, with localized higher amounts may result in
localized urban and poor drainage flooding. Less rainfall is 
expected across CT into western-central MA. Dry and much warmer 
weather arrives Thursday and lingers into Friday. Then a cold 
front crosses the region Friday night, ushering in dry, but 
blustery and cool weather for the weekend. Dry weather is likely
into Columbus Day, along with moderating temperatures and less 
wind.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

* Steadier rain overspreads the region tonight, with localized 3
  to 4 inches totals possible through tomorrow morning for
  portions of SE MA. 

Surface low pressure associated with a vertically stacked upper
level low is centered over southern NJ. That upper low will
slowly track towards the 70W/40N benchmark, bringing a period of
steadier rain to much of our area. There will be a rather sharp
gradient between areas with generally 0.25 to 0.5 inches of rain
and areas that receive 1 to 3 inches of rain. The latter areas
appear to be mainly across eastern MA, and especially southeast
MA including Plymouth county and the Cape Cod Canal. This is
where the nose of the mid-level dry slot and low-level jet is,
and local research has shown that rainfall amounts tend to
overperform due to the jet dynamics. In addition, the Trough of
Warm Air Aloft (TROWAL) will help to further boost rainfall
rates and even lead to elevated convection or a few rumbles of
thunder overnight. Upon coordination with WPC, have used the
HREF Probability Matched Mean (PMM) product to boost rainfall
towards the 90th percentile of guidance for overnight tonight
into Wednesday morning. 

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...

Expect plenty of clouds with steadier rain becoming more showery
as the day goes on. Winds remain gusty but should become less
blustery by the afternoon as pressure gradient relaxes. Another
unseasonably cool day with highs mainly in the 50s and perhaps 
a few low 60s readings. Going into Wednesday night, skies should
start clearing across the northwest zones, so NW MA should dip
into the mid 40s but SE MA stay in the 50s under plentiful cloud
cover. 

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...

Highlights...
  
* Dry Thu and Fri, along with a big warmup

* Blustery and cool Fri night, Sat & Sun, then moderating with less 
  wind Columbus Day

Details...

Persistent low pressure south of New England should finally move 
farther out to sea Thursday. A weak high pressure should then be in 
place along the spine of the Appalachians. As this high pressure 
moves east, looking like a warmer pattern with southerly winds 
developing into Friday. As is typical for Autumn, this will not last 
long, with another cold front expected sometime late Friday into 
Friday night. Overall, there looks to be enough moisture for clouds 
at times, but not quite enough to result in much precipitation. Kept 
the forecast largely dry for this portion of the forecast. 

Temperature-wise, more of a rollercoaster. We should start out with 
near to above normal temperatures Thursday into Friday, before 
falling below normal this weekend into early next week. The weak 
flow Thursday and Friday will likely mean local seabreezes along the 
immediate coast both days, leading to cooler conditions there. 
Thinking there will be modest improvement in temperatures from this 
weekend into early next week.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels:

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

1920z update...

Rest of today...Moderate confidence. Ceilings range from IFR to
VFR across southern New England with even LIFR conditions 
across far southeastern MA and the Islands this afternoon. VFR 
continues to prevail across far northwest areas that remain 
dry. Northeast winds continue to gust between 20 and 30 kt 
during the day today. Isolated gusts to 35 kt possible across 
the Cape and Islands. 

Tonight...Moderate confidence

Steadier precipitation expected tonight as IFR conditions 
prevail across much of the region. VFR ceilings will deteriorate
to MVFR across the far northwest interior as precipitation 
continues to pivot northward. Gusty northeast winds continue 
overnight, again between 20 and 30kt; highest across coastal RI 
and the Islands. 

Wednesday... Moderate confidence

Persistent precipitation will extend into Wednesday, especially
across eastern MA and RI; the heaviest precipitation of the
period may be observed Wednesday morning. IFR conditions persist
across eastern MA and RI much of the day. Ceilings across the
interior will improve from MVFR to VFR as the day wears on.
Gusty NE winds will finally begin to subside late Wednesday as 
winds fall back to between 10 and 20 kt. 

Wednesday night....Moderate confidence

Skies clear from NW to SE with winds becoming lighter at 5 to 10
kt except for 15-20 kt gusts for the Cape terminals. Improving
to VFR across interior terminals with MVFR to localized IFR
persisting across Cape terminals. 

KBOS Terminal...Moderate Confidence in TAF. 

KBDL Terminal...High Confidence in TAF. 

Outlook /Thursday through Sunday/...

Thursday through Friday: VFR. 

Friday Night through Sunday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels:

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

320 PM update...

Low pressure centered to our southwest continues to generate gusty, 
gale force conditions across the southern waters as winds gust over 
35 kt. Elsewhere, NE winds continue to gust between 25 and 30 kt. 
Persistent NE flow allows waves to grow to between 7-10 ft outside 
bays and harbors. Conditions will be hazardous to pleasure 
craft through at least Wednesday evening. Seas gradually fall
below 5 ft overnight Wednesday. Gale Warnings continue across 
the southern waters with SCAs elsewhere. 

Outlook /Thursday through Sunday/...

Thursday: Winds less than 25 kt. Seas up to 5 ft. 

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

Friday: Winds less than 25 kt. 

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

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

Sunday: Winds less than 25 kt. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 2 PM EDT Wednesday for ANZ231-251.
     Small Craft Advisory until 8 PM EDT Wednesday for ANZ232>235-
     237.
     Small Craft Advisory until 8 AM EDT Wednesday for ANZ236.
     Small Craft Advisory until 2 AM EDT Thursday for ANZ250-254.
     Gale Warning until 8 PM EDT this evening for ANZ255.
     Gale Warning until 2 AM EDT Wednesday for ANZ256.

&&

$$
SYNOPSIS...Belk/Chai
NEAR TERM...Chai
SHORT TERM...Chai
LONG TERM...Belk
AVIATION...Belk/Chai
MARINE...Belk/Chai