021
FXUS61 KPHI 122249
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
549 PM EST Sun Jan 12 2025

.SYNOPSIS...
High pressure builds in from the west this afternoon and remains in
place through Monday. An arctic front passes through the region
Monday night and ushers in a cold Canadian high pressure system that
dominates through midweek. The next chance of widespread
precipitation is towards the end of the week into next weekend.

&&

.NEAR TERM /THROUGH MONDAY/...
High pressure across the area brought mostly sunny skies and a
rather mild day across the region. High temps topped out a
couple degrees on the plus side of normal for many spots. This
is the first time this has happened (at PHL) since Jan 2. The
fair weather will continue tonight with just some high clouds at
times. Low temperatures should bottom out in the 20s for most
areas with low 20s across NW areas and Delmarva while mid 20s
will be found for the urban spots.

There will be more clouds around Monday. The high pressure will
retreat while a sharp cold front approaches from the Great Lakes.
The front will cross the area from west to east during the
afternoon. Temperatures will rise early to levels similar to today
with upper 30s/low 40s most spots. Once the front crosses, winds
will increase and temps will drop. We`ll continue with a dry fcst
with models not showing any showers developing in our region.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A low pressure system will track through southern Ontario/Quebec on
Monday night as a cold front approaches the area. This front will
cross through our region late Monday night, but with little
moisture supply, the front is forecast to pass through dry. So
other than some passing clouds, the weather will remain
tranquil. Lows in the teens and 20s expected.

Following the frontal passage, cold Canadian high pressure will
build in over the High Plains on Tuesday as the cold front moves
offshore. This will usher in a reinforcing cold airmass through mid-
week. A modest pressure gradient will also develop over the region
on Tuesday, so Tuesday looks to be quite breezy with more clouds
than sun. Have continued to blend in higher wind guidance due to the
cold air advection push behind the front. So continue to think that
we`ll see wind gusts upwards of 30-40 mph during the afternoon. High
temps will also be noticeably cooler compared to Monday; mainly in
the 20s, so many places will struggle to reach the freezing mark for
Tuesday afternoon. Combined with the gusty conditions, wind chill
values will be in the teens during the afternoon.

The cold air advection push continues for Tuesday night, with lows
falling into the teens for the majority of the area. On top of that,
winds will remain quite gusty upwards of 30-35 mph despite the loss
of diurnal mixing. As a result, wind chills will be in the single
digits to near 0 degrees for most and as cold as -5 degrees in the
Poconos. Will continue to monitor wind chills over the next few
forecast cycles to see if a Cold Weather Advisory is warranted.
Also, cannot rule out a rogue snow shower across the Pocono Plateau.

Wednesday will virtually be a rinse and repeat of Tuesday as high
pressure moves into the Midwest. Temperatures will be a few degrees
warmer though, topping out in the upper 20s to low 30s with a little
more sun than clouds. Gusty winds up to 35-40 mph will continue
however, as the pressure gradient remains overhead.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
High pressure will gradually shift from the Midwest to Southeast US
through the end of the work week, keeping the forecast dry through
Friday. Other than a slight chance of snow showers north and west on
Thursday with a shortwave aloft passing by, no precipitation is
expected. Below normal temperatures will continue through Thursday
with temperatures returning close to normal on Friday.

For Saturday and Sunday, there continues to be signals from both
global deterministic and ensemble guidance for some unsettled
weather to return to the area. Low pressure looks to pass to our
north, allowing above normal temperatures to return for Saturday.
Eventually a cold front does look to cross through the area on
Sunday, as temperatures return closer to normal. In terms of
precipitation type, any precipitation will most likely be in the
form of rain with frozen precipitation generally limited to the
Pocono region.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Tonight...VFR. Winds light and variable (5 kt or less) though
favoring a southwesterly direction. High confidence.

Monday... VFR expected. SCT/BKN stratocumulus deck expected
basically from the I-95 corridor on west with mostly clear skies
over the South Jersey terminals. Winds pick up out of the
southwest around 5-10 kt. High confidence.

Monday Night...VFR. Westerly winds 5-10 kt. High confidence.

Outlook...

Tuesday through Wednesday night...VFR. Gusty winds up to 30-35
kt possible on Tuesday and Wednesday. Otherwise, no significant
weather expected.Thursday through Friday...VFR. A slight chance
of a snow at KRDG/KABE on Thursday, otherwise no significant
weather expected.

&&

.MARINE...
Winds and seas will remain below SCA conditions tonight and Monday
as high pressure ridges up into the area tonight and then moves away
Monday. Fair weather is expected. Later Monday, winds will increase
from the Southwest with some gusts close to 20 kts by sunset. The
better chance for these gusts will be across the northern NJ ocean
waters.

Outlook...

Monday night through Wednesday...SCA conditions likely with gale
force conditions possible. A Small Craft Advisory has been issued
for all ocean waters including the Delaware Bay for Monday night and
Tuesday. A Gale Watch has also been issued for the ocean waters
south of Little Egg Inlet including the Delaware Bay for Tuesday
night.

Wednesday night through Friday...Lingering SCA conditions possible
on Wednesday night, otherwise no marine headlines are expected.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 4 AM to 6 PM EST Tuesday for ANZ430-
     431.
     Gale Watch from Tuesday evening through late Tuesday night for
     ANZ430-431-452>455.
     Small Craft Advisory from 7 PM Monday to 6 PM EST Tuesday for
     ANZ450-451.
     Small Craft Advisory from 10 PM Monday to 6 PM EST Tuesday for
     ANZ452-453.
     Small Craft Advisory from 1 AM to 6 PM EST Tuesday for ANZ454-
     455.

&&

$$

SYNOPSIS...DeSilva/MJL
NEAR TERM...Hoeflich/OHara
SHORT TERM...DeSilva/MJL
LONG TERM...DeSilva/MJL
AVIATION...DeSilva/Hoeflich/OHara
MARINE...DeSilva/OHara