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000 
FXUS61 KBOX 220209
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1009 PM EDT Sat Apr 21 2018

.SYNOPSIS...
High pressure remains in control through Tuesday bringing dry
weather with moderating temperatures. Wet weather returns
Wednesday into Thursday as low pressure moves through our 
region. Mainly dry weather follows on Friday before becoming 
dreary again next weekend.

&&

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

High pressure is still centered over the Great Lakes. But the
pressure gradient over New England has greatly relaxed, with
surface winds 10 knots or less. Satellite images show clear
skies over our area, with an area of cirrus covering PA and the
New York City area but moving southeast and so not a threat to
our skies.

Clear skies, light winds, and dry air overnight will allow good
radiational cooling.

Dew points this evening were several degrees lower than
forecast, so we brought those grids back in line. With this
extra space for temperatures to fall, we nudged min temps down
1-2F, with a general range in the upper 20s and 30s. Coldest
spots will be the usual radiators, except the Vineyard where dew
points are around 33F. 

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
High pres in control will result in clear skies and light winds
which will allow seabreezes to develop in the afternoon. Highs
will range from the upper 50s to lower 60s away from the
immediate coast. Another chilly night Sunday night with good
radiational cooling. Subfreezing temps likely in some of the
colder locations.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
*/ Highlights...

 - Warm up early next week, except where seabreezes develop
   Monday
 - Wet and breezy midweek
 - Perhaps a reprieve Friday
 - More showers possible Saturday

21/12Z guidance remained in rather good agreement with the 
overall synoptic pattern through Wednesday. Then typical timing 
and amplitude differences creep into the solutions. Prefer a 
consensus blend to smooth over the less predictable features for
this time range.

Expecting well defined mid level northern and southern stream
features to phase over the central Appalachians about mid week.
Guidance remained consistent with that idea from previous runs.
It's how the pattern evolves after this phasing where some
questions remain, particularly with timing. In most cases,
looking like a period of wet weather sometime Wednesday, and
perhaps lingering into Thursday. Depending on timing, another
front may pass through our region sometime Friday into Saturday. 

Temperature-wise, looking much closer to normal early next week.
Seabreezes likely on Monday, so cooler towards the coasts. Below
normal temperatures should return mid week, then remain near to
below normal into next weekend.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

Short Term /through Sunday Night/...High confidence.

VFR through the period with light wind. Coastal seabreezes will
develop Sunday midday/afternoon. 

KBOS Terminal...High confidence in TAF. Moderate probability of
a sea breeze Sunday midday/afternoon.

KBDL Terminal...High confidence in TAF.

Outlook /Monday through Thursday/...High confidence.

Monday through Tuesday: VFR. 

Tuesday Night: Mainly VFR, with local MVFR possible. Breezy.
Chance RA.

Wednesday: Mainly MVFR, with areas IFR possible. Breezy. RA
likely.

Wednesday Night: Mainly VFR, with areas IFR possible. Breezy.
Chance RA.

Thursday: Mainly VFR, with local MVFR possible. Chance RA,
slight chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Short Term /through Sunday Night/...High confidence. 

Light winds and seas. Winds turning onshore near the coast 
Sunday midday/afternoon as sea breezes develop. 

Outlook /Monday through Thursday/...High confidence.

Monday through Tuesday: Winds less than 25 kt. 

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

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

Wednesday Night: Winds less than 25 kt. Areas of rough seas.
Chance of rain. 

Thursday: Winds less than 25 kt. Areas of rough seas. Chance of
rain, slight chance of rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$
SYNOPSIS...Belk/KJC
NEAR TERM...WTB

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