Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 172302
AFDBOX

Area Forecast Discussion
National Weather Service Taunton MA
702 PM EDT Tue Oct 17 2017

.SYNOPSIS...
High pressure will maintain dry weather and warmer than normal
temperatures through the weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

700 PM Update...

Temperatures are beginning to drop across the region early this
evening as radiational cooling begins. Light WAA aloft will
help lead to light southerly flow tonight. While winds will be
light, temps aloft will warm overnight which could limit the
frost potential. Aside from a few minor adjustments, the
overall trend in the forecast remains on track.

Previous Discussion...

High pres south of New Eng tonight with light SW flow
developing. Still decent radiational cooling with clear skies
and dry airmass will allow temps to drop to mid 30s in the
coldest spots with patchy frost. No frost headlines as growing
season has ended in those areas with the best chance of frost.
Some patchy frost possible outside of this area but likely not
widespread enough for headlines. Patchy late night valley fog
possible.

&&

.SHORT TERM /WEDNESDAY NIGHT/...
Wednesday...
With high pres to the south, W/SW flow will bring milder
airmass into SNE. Airmass remains very dry through column so
plenty of sunshine will push afternoon high temps into the
upper 60s to lower 70s.

Wednesday night...
Another clear night with light winds, but airmass is moderating
so not as cool with low temps mostly in the 40s.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Highlights...

* Above average temps and dry conditions lasting into the weekend
* Next shot for precip appears to be around Tuesday

Pattern Overview/Confidence...

12z guidance is in good agreement for the long term. Upper level
shortwave will move through the flow on Thursday. Behind this wave,
anomalous ridging will develop across the East Coast. Heights and
temperatures will rise to 2-3 STD above normal. This strong ridge
will last into early next week before a pattern change appears to
take hold of the area. This switch will be associated with the
digging trough across the eastern half of the CONUS by the Tuesday
timeframe.

Details...

Temperature Forecast...

Overall trend in the forecast is for above average temperatures
through the period. Thursday`s breezy southwest flow combined with
850 mb temps near 10-12C will result in highs in the low to mid 70s.
Cool front will sweep through the region Thursday night leading to a
cooler day on Friday. Anomalous ridge will begin to build for the
weekend into Monday resulting in high temps into the mid 70s.
Tuesday`s temperature forecast is a bit trickier as it is dependent
on the timing of the front. Thus will trend towards a model
consensus until guidance gets a better handling on the FROPA.

Precipitation Forecast...

Frontal system on Thursday will pass through, but lack of moisture
with the front will lead a dry passage. High pressure will take over
the area on Friday through Monday leading to dry weather. Next
chance or precipitation will be around the Tuesday timeframe when a
potent trough will dig into the Ohio Valley and towards the East
Coast. Several waves of low pressure will ride along this through
resulting in a more unsettled weather pattern Tuesday and beyond.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

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

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

VFR through Wed night. Localized late night river valley fog
possible. SW winds may gust to 20 kt over the outer Cape
tonight.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Thursday through Sunday/...

High Confidence. VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

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

Shortwave passing well to the north will bring a period of
increasing W/SW winds tonight as high pres settles to the south.
A few gusts to 25 kt possible across mainly eastern MA waters
with building seas so will issue SCA for these waters. Gusts to
20 kt elsewhere. Winds diminish Wed through Wed night.

Outlook /Thursday through Sunday/...High confidence.

High pressure prevails through the upcoming weekend with sub SCA
conditions. The only exception is that SCA conditions may be
approached Thursday night ahead of a passing front as SW winds could
gust up to 25 kts.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 10 PM this evening to 11 AM EDT
     Wednesday for ANZ250-254.
     Small Craft Advisory from 10 PM this evening to 7 AM EDT
     Wednesday for ANZ231-251.

&&

$$
SYNOPSIS...KJC/Dunten
NEAR TERM...KJC/Dunten
SHORT TERM...KJC
LONG TERM...Dunten
AVIATION...KJC/Dunten
MARINE...KJC/Dunten


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