BOX issues Area Forecast Discussion (AFD) at Oct 12, 12:55 PM EDT483
FXUS61 KBOX 121655
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
1255 PM EDT Sat Oct 12 2024
.SYNOPSIS...
Seasonably mild but blustery today as a cold front crosses the
region. Much cooler Sunday as a warm front stalls to the south with
periods of rain developing, especially across northern MA. The rain
expands to all of southern New England Sunday night into Monday as
low pressure tracks across the region. Dry weather follows for the
rest of the week. Blustery conditions with colder than normal
temperatures Tuesday and Wednesday give way to a warming trend by
Thursday and Friday.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM Update:
Latest WPC surface analysis shows the cold front already
arriving into northern MA. Expect winds to increase quickly
through mid morning. Upstream observations have been recording
gusts 25-35 mph with the passage of the front with some 40+ mph
gusts sprinkled in there. Mount Washington gusted to 112 mph
with the front, but luckily gusts will stay in the 25-40 mph
range here!
Previous Discussion:
A dry cold front pushes south across the region this morning. The
front will be followed by rather gusty NW winds. While the low level
jet will be departing, a deepening and well mixed boundary layer
will tap into the stronger winds aloft and support a brief period of
25-35 mph gusts this morning, and perhaps up to 35-45 mph over
interior high terrain. Gustiness will gradually diminish through the
afternoon as gradient relaxes. Very dry airmass moves in behind the
front with PWATs falling to around 0.25". Other than a few mid-high
clouds with the front this morning, full sunshine is expected with
mild temps. Highs will top out around 70 across CT, RI and SE MA and
mid-upper 60s elsewhere.
&&
.SHORT TERM /SUNDAY/...
Tonight...
High pres builds across the region tonight. Clear skies and light to
calm winds will set the stage for excellent radiational cooling
conditions. Clouds will increase, especially in the west late
tonight but won't have a significant impact on temps. Expect lows to
settle into the 30s for most locations, and possibly close to 30 in
the colder locations in the Pioneer valley of western MA. It will be
milder in Boston and the outer Cape and Nantucket with lows in the
low-mid 40s. A warm front will set up to the SW late tonight with
increasing moisture approaching from the west. However, dry low
levels will keep it dry through the night with just a low risk for
some light rain moving into NW MA toward daybreak.
Sunday...
Amplifying upper level trough amplifies across the Gt Lakes as low
pres moves east from the Ohio valley. A warm front south and west of
New Eng will slowly lift northward and overrunning north of this
boundary will bring periods of rain to portions of SNE. The deep
moisture axis and best forcing along the low level front will likely
set up close to northern MA where best chance of widespread rainfall
on Sunday, mainly north of the MA Pike. Further to the south across
CT, RI and SE MA, there is less moisture and guidance is suggesting
some mid level drying moving up from the south so only spotty light
rain is possible here while it may remain dry along the immediate
south coast and Cape/Islands. There is still some uncertainty where
the moisture axis sets up so PoPs may need further adjustments.
Forecast rainfall Sunday 0.10 to 0.50" north of the MA Pike,
highest amounts NW MA with amounts decreasing to less than 0.10"
to the south.
The location of the warm front will determine temps for Sunday. It
is lifting north but much of the guidance only has it possibly
getting to the immediate south coast late in the day. The GFS is
furthest north but it appears too far north given westerly flow
aloft and high pres to the NE. North of the front, especially where
it's raining in northern MA it will be rather chilly with highs only
in the 40s. Otherwise, expecting highs ranging through the 50s
across CT, RI and eastern MA, with best chance of 60+ and warm fropa
late in the day over Cape Cod and especially the Islands. Forecast
confidence in temps is below normal.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Key Points:
* A low pressure system brings periods of rainfall Sunday into
Monday followed by mainly dry conditions through remainder of week.
* Below normal temperatures Tuesday and Wednesday coupled with
chillier nights. Warming trend starting Thursday.
Details:
Sunday Night - Monday:
The bulk of the rainfall will likely occur Sunday night into Monday
as the low pressure system tracks across the region. This will bring
steady rainfall overnight with the last batch of rain pushing across
in the morning-early afternoon period Monday. Drier works in
gradually drying conditions out into the early evening. Most models
keep the stronger frontogenetical forcing to the north which will
more likely contain the higher rainfall amounts. Totals will most
likely range 0.10-0.40" along the South Coast with higher amounts
favored further north due to the track of the system (0.50-1.0").
The ECMWF and GFS still differ in track leading to differences in
QPF. A more north track (GFS) would result in less QPF overall for
southern New England. Cold air advects in from the west later in the
afternoon into the evening hours.
A closed upper low remains in place across the northeast early next
week, slowly pushing out by Thursday. Below normal 850mb
temperatures accompany this pattern resulting in a fairly cool
couple of days. Highs Tuesday and Wednesday remain in the 50s, with
upper 40s in spots. Cool nights can be expected as well with lows
dipping into the 30s for the interior, with even some upper 30s
possible along the coastal areas. Conditions trend mainly dry during
this period, but a few spotty showers can't be ruled out. With the
cooler airmass exited Thursday, temperatures trend warmer
Thursday/Friday.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Rest of today and tonight...High confidence.
VFR. Gusty NW winds to 25-35 kt will gradually diminish this
afternoon and evening, eventually becoming calm tonight.
Sunday...Moderate confidence.
Guidance has trended VFR and drier for much of Sunday. Highest
chance for MVFR will be across northern MA in the middle to late
afternoon. Light rain showers are possible in the late
afternoon mainly north of the MA Pike.
Sunday Night...Moderate confidence
MVFR/IFR with scattered light rain showers continuing.
KBOS TAF...High confidence in TAF.
VFR. Gusty NW winds begin to subside later this afternoon into
the evening. Winds turn to the ESE tomorrow morning. MVFR with
light rain showers possible in the afternoon
KBDL TAF...High confidence in TAF.
VFR. Gusty NW winds begin to subside later this afternoon,
becoming light and variable overnight. Winds turn ESE tomorrow
afternoon with light rain showers possible.
Outlook /Sunday Night through Wednesday/...
Sunday: Mainly VFR, with local MVFR possible. Chance RA.
Sunday Night: Mainly MVFR, with areas IFR possible. Breezy.
SHRA.
Columbus Day: MVFR/IFR conditions possible. Breezy. SHRA
likely.
Monday Night: VFR. Breezy. Slight chance FZRA.
Tuesday through Wednesday: VFR. Breezy.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
High confidence through Sunday.
We upgraded to a Gale Warning for eastern MA waters this morning for
a period of 35 kt gusts behind the cold front. SCA continues for
rest of the waters. Winds gradually diminish through the afternoon
and evening, becoming light overnight. Easterly flow developing on
Sunday, becoming south late in the day over southern most waters.
Rain developing over eastern MA waters Sunday, mainly north of
Provincetown.
Outlook /Sunday Night through Wednesday/...
Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain.
Sunday Night: Winds less than 25 kt. Local rough seas. Chance
of rain showers.
Columbus Day: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. Rain showers.
Monday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas.
Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain
showers.
Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Seas up to 5 ft. Chance of rain
showers.
Wednesday: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for
ANZ230>237-251.
Small Craft Advisory until 5 AM EDT Sunday for ANZ250-254.
Small Craft Advisory until 11 PM EDT this evening for ANZ255-
256.
&&
$$
SYNOPSIS...KJC/Mensch
NEAR TERM...KJC/KP
SHORT TERM...KJC
LONG TERM...Mensch
AVIATION...KP
MARINE...KJC/Mensch
Source:
BOX issues Area Forecast Discussion (AFD) at Oct 12, 12:55 PM EDT----------------
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!
