BOX issues Area Forecast Discussion (AFD) at Nov 9, 3:18 AM EST628
FXUS61 KBOX 090818
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
318 AM EST Sat Nov 9 2024
.SYNOPSIS...
Seasonably cool Saturday with dewpoints dropping into the 10s.
A bit warmer Sunday ahead of a cold frontal passage Sunday night
into Monday that brings a wetting rain to southern New England.
Dry conditions return late Monday through Wednesday before
another low- pressure system could bring rain again on Thursday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A seasonably cool Saturday is in store for southern New England
behind a cold front that swept across the region Friday evening. We
remain on the western edge of a trough dipping into the western
Atlantic, such that 925mb temps between minus 2 and minus 4C linger
over the region for the better part of the day. Moderately strong
925mb jet that brought wind gusts as high as 40mph to the region
overnight will slowly shift to the east through the day, which allow
winds to ease gradually into this afternoon; from ~35mph to less
than 10-15mph by sunset. This same jet, however, will lead to
efficient mixing on northwest flow, as high as ~875mb mid day,
resulting in high temps in the mid 40s across the high terrain to
low 50s across the coastal plain. While these temperatures are to be
expected this time of year, they will come as a shock to many after
our recent prolonged warm stretch. Aside from the noticeable wind
and near average temperatures, abundant sunshine is expected.
Dewpoints will be at their lowest of the season so far, dropping
into the 10s across the interior this afternoon. Did think the NBM
was a bit too high so utilized a strong blend of the CONSAlL
dewpoints to derive today's values. Nonetheless, with dews in the
10s and temps in the 40s/50s, RH values will drop below 30% in most
locales. This dryness, combined with windy conditions, has led to
the continuation of a Red Flag Warning through 6pm tonight.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Tonight...
Surface high pressure nudges over New England tonight as mid level
ridging replaces Saturday's trough. With near calm winds, low
dewpoints, and very little cloud cover, tonight appears to be an
optimal radiational cooling night. Given this, took the opportunity
to further cut low temps tonight, with widespread 20s expected.
Parts of interior NW MA and our typical "radiators" may even drop
into the high 10s by sunrise.
Sunday...
Temps are expected to tack around 5 degrees onto Saturday highs
tomorrow as SE surface flow develops as high pressure sags southeast
of the region. Low pressure system lifts north across Michigan and
Ontario during the daylight hours, with resultant cold front
approaching our region. Through sunset, expect little impact other
than increasing cloud cover, but rain shower chances will begin to
increase closer to 00Z with hi-res guidance showing shower activity
beginning to creep into western New England between 22-00Z. At
first, showers will be up against steep dewpoint depressions, as
high as 10-15F, which will prohibit most radar returns from reaching
the surface until greater moisture can advect into SNE overnight
Sunday. For this reason, delayed PoPs a few hours compared to
previous forecasts and opted to keep the 6 hour QPF at zero prior to
00Z.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Sunday night and Monday:
Upper-level shortwave swings through the Great Lakes into northern
New England Sunday night into Monday. With several rounds of weak
shortwave energy ahead of the main shortwave, periods of light
showers are likely Sunday night into Monday. Unfortunately, a
widespread soaking rain continues to look less likely as guidance
has been trending back rain totals. The GFS now shows less than a
tenth of an inch across the region, while the EURO maintains around
a quarter inch. Ensembles show a similar spread, with the 25th
percentile around 0.10 inches and the 75th percentile around 0.30
inches.
Rain moves offshore quickly Monday morning with clearing skies
behind. Winds remain blustery from the SSW, gusting 20-30mph. Temps
warm well above normal for mid-November into the mid to upper 60s.
Tuesday and Wednesday:
A cold front drops south Tuesday, moderating high temps back down
into the upper 50s on Tuesday, then low 50s on Wednesday. Winds
remain elevated from the north, gusting 15-25mph. High pressure
moves overhead Wednesday, allowing the pressure gradient to relax
and winds to diminish.
Thursday:
Another Shortwave moves through Thursday, but uncertainty in timing,
QPF, and Ptype are highly uncertain at this time. Winds turn
onshore and become blustery again at 10-20mph. High temps become
more seasonable in the upper 40s to low 50s with mostly cloudy skies.
Friday and Beyond:
Forecast confidence decreases significantly beyond Thursday as the
ensemble 500mb height pattern becomes spread out. Breaking down the
cluster analysis from the GEFS, ENS, and GEPS, roughly 60% of the
ensemble members keep the Eastern U.S. in a troughing pattern, while
the other 40% return the region to a ridging pattern.&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
09Z Update...
Through Saturday Night...High Confidence.
VFR. Gusty W to NW winds through Saturday morning at 20-30
knots. Gusty NW winds diminish some Saturday afternoon to 15-25
knots then Saturday night. Scattered cloud bases down to
040-060 with the passage of a cold front late this afternoon and
evening.
KBOS TAF...High Confidence in TAF.
VFR with gusty W to NW winds at 25-30 knots through saturday
morning, dropping to 20-25 knots in the afternoon.
KBDL TAF...High confidence in TAF.
VFR with gusty W to NW winds at 20-25 knots.
Outlook /Sunday through Wednesday/
Sunday Night: Mainly MVFR, with local IFR possible. Breezy.
SHRA likely.
Veterans Day: Mainly VFR, with local MVFR possible. Breezy.
Chance SHRA.
Monday Night through Wednesday: VFR. Breezy.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Gale Warnings and Small Craft Advisories continue into this
morning. Winds and waves will gradually diminish Saturday
afternoon with Gale Warnings transitioning to Small Craft
Advisories at that time.
Outlook /Sunday Night through Wednesday/...
Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Local rough seas. Rain showers likely.
Veterans Day: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Chance of rain showers.
Monday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.
Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft.
Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Areas of rough seas.
Wednesday: Winds less than 25 kt. Local rough seas.
&&
.FIRE WEATHER...
The prolonged period of dry weather coupled with a very dry
ground will continue to result in elevated fire weather concerns
through today. Plenty of sunshine is expected. Afternoon high
temperatures Saturday in the 40s to lower 50s. Northwest wind
gusts up to 35 mph are expected. Minimum afternoon relative
humidity values Saturday are expected to range between 25 and 40
percent.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Red Flag Warning until 6 PM EST this evening for CTZ002>004.
MA...Red Flag Warning until 6 PM EST this evening for MAZ002>024-
026.
RI...Red Flag Warning until 6 PM EST this evening for RIZ001>008.
MARINE...Small Craft Advisory until 10 AM EST this morning for ANZ230-
233>237.
Gale Warning until 1 PM EST this afternoon for ANZ231-232-250-
251-254.
Gale Warning until 10 AM EST this morning for ANZ255-256.
&&
$$
SYNOPSIS...KP/KS
NEAR TERM...KS
SHORT TERM...KS
LONG TERM...KP
AVIATION...KP/KS
MARINE...KP/KS
FIRE WEATHER...KP/KS
Source:
BOX issues Area Forecast Discussion (AFD) at Nov 9, 3:18 AM EST----------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
