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000
FXUS61 KPHI 131924
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
324 PM EDT Sat Apr 13 2024

.SYNOPSIS...
High pressure will briefly be in control through Sunday morning
before an area of low pressure passes to the north of the region and
drags a cold front and a line a storms across the Mid-Atlantic
region Sunday night. High pressure builds back in Monday into
Tuesday, before a series of frontal boundaries and low pressure
systems affect the east coast Wednesday through Friday.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
Clouds are starting to lift out this afternoon with skies clearing,
mainly from Philadelphia on south. Skies will continue to clear from
south to north as the afternoon and evening go on. Wind gusts have
come down slightly, and the Wind Advisory has been cancelled as a
result. Gusts will remain between 25-35 kt through the rest of the
day, gradually diminishing into the evening. Any lingering light
showers in northern New Jersey and the Poconos will also lift out
within the next hour or two.

For tonight, expect mostly clear skies and quiet weather.
Temperatures will get down into the low to mid 40s, with higher
elevations getting down into the upper 30s. A light westerly breeze
will continue through the night, around 5 to 10 MPH. It will be just
warm enough and breezy enough to prevent any frost from forming.

Tomorrow looks a bit more interesting, especially in the afternoon
and evening. The entire area will get into the warm sector, with
temperatures getting into the upper 60s and low to mid 70s. A cold
front will approach from the northwest, with showers and
thunderstorms developing out ahead of it, taking on a linear mode.
The highest instability will be to our west, though with good
forcing and relatively high shear, especially in the low-levels,
some organized convection will likely make it into our area. The
limiting factor is the instability over our region, roughly 300-500
J/KG of MUCAPE. The steepest lapse rates will also be well ahead of
the better dynamics. Most of the CAM guidance also has the line of
storms coming in right around sunset or even later.

Overall, everything really isn`t lining up perfectly for a
widespread severe event, and the thinking is that it will be more
localized to northern New Jersey, the southern Poconos, and the
northern Lehigh Valley. The Storm Prediction Center has an ENHANCED
risk for Carbon/Monroe County and a SLIGHT risk for northern
New Jersey and parts of the Lehigh Valley. The threat diminishes
significantly the further south you go as guidance has the line
fizzling rather quickly once the sun goes down. Delmarva and
far southern New Jersey actually will likely stay dry. The main
threat is damaging wind gusts as a 50-60 kt low level jet will
be overhead around the time the line of storms make it to our
area which could mix down with any stronger storms. Cannot rule
out a tornado as well with good low-level shear and SRH in the
0-1 km layer.

The cold front passes overnight and any showers should dissipate by
midnight or so. Temperatures will drop into the 50s overnight with
upper 40s in the Poconos/northern New Jersey.


&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
High pressure will largely be in control Monday and Tuesday with
afternoon highs in the low to mid 70s with nighttime lows in the
upper 40s to low 50s.

We will see dry weather through Tuesday night before rain chances
return during the late overnight hours Tuesday as our next system
approaches from the west.


&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Heading into Wednesday and continuing through the end of the work
week, the forecast becomes decidedly wetter. A pair of expansive
upper-level lows will be slowly transiting across the north central
United States and eastern Canada. This action will bring several mid-
level waves to the Eastern Seaboard and provide ample opportunities
for showers or a few thunderstorms to develop and move through the
area. As of now, the most organized of these waves looks to move
through the region Wednesday-Wednesday night and the highest PoPs of
the long term period (55-65%) are in this period to reflect that.
Overall though, it is still a bit premature at this time to say any
particular day through the back half of the week will be a complete
washout. High temperatures through the end of the work week remain
near to above normal in the mid 60s-mid 70s.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Rest of Today...VFR. Westerly winds of 20-25 kt with gusts up
to 35-40 kt possible through the early evening. Highest gusts at
KRDG. Moderate confidence.

Tonight...VFR with mostly clear skies. Westerly winds of 10-20
kt early diminishing to 5-10 kt by 06Z, gradually backing and
becoming southwesterly. High confidence.

Sunday...VFR through the early afternoon. Winds increase by late
morning, out of the southwest, around 10-15 kt, gusting 20-25
kt. Some showers and scattered thunderstorms move in during the
late afternoon/early evening, mainly west of the I-95 corridor.
Sub-VFR conditions possible around that time (around 30-40%),
especially at KRDG/KABE, with prevailing VFR otherwise. Moderate
confidence overall.

Outlook...

Sunday Night...Any sub-VFR conditions will lift to VFR once the
cold front comes through.

Monday and Tuesday...VFR conditions expected with fair weather.

Wednesday and Wednesday night...Sub-VFR conditions possible (30-40%)
with showers. SSE winds around 10 kts to start, gradually increasing
to 15 kts by late afternoon with gusts up to 20 kts at night.
&&

.MARINE...
Gale Warning was downgraded to a Small Craft Advisory for coastal
waters south of Great Egg Inlet and for the Delaware Bay as winds
have fallen below 34 kt. 25-30 kt gusts are expected for the rest of
the afternoon and early evening, with 4 to 6 foot seas on the ocean.
The SCA goes until 10 PM this evening. A brief period of sub-SCA
conditions are expected, though winds will ramp up tomorrow
afternoon as a cold front pushes through.

For coastal waters north of Great Egg Inlet, the Gale Warning
remains until 6 PM as gusts are still around 35-40 kt. That should
be good to expire at 6 PM this evening, though SCA conditions will
continue into part of the night. Similar to the rest of the waters,
there will be a brief lull in winds, though gusts will ramp back up
tomorrow with the incoming cold front.

Outlook...

Monday and Tuesday...Small craft conditions gradually wind down
Monday morning. Otherwise, sub-SCA conditions expected through
Tuesday night

Wednesday and Wednesday night...Winds and seas gradually build as
the next storm system approaches. SCA conditions possible by
Wednesday night.


&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ430-
     431-453>455.
     Gale Warning until 6 PM EDT this evening for ANZ450>452.

&&

$$

SYNOPSIS...AKL/MJL
NEAR TERM...Hoeflich
SHORT TERM...AKL/MJL
LONG TERM...AKL/MJL
AVIATION...Hoeflich/MJL
MARINE...Hoeflich/MJL