035
FXUS61 KPHI 110201
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1001 PM EDT Thu Apr 10 2025

.SYNOPSIS...
A low pressure system will track toward the Mid-Atlantic region
tonight. This system will move into the forecast area on Friday and
then linger through Saturday. This will result in below normal
temperatures as well as some wet weather. The system will move east
over the Atlantic on Sunday. This will allow high pressure to move
into the region. The high should remain in place through most of
Monday providing us with moderating temperatures. A cold front will
move through the region later on Tuesday. The will result in below
normal temperatures on Wednesday. The region could see a slight
warmup on Thursday.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of late this evening, an initial surface low pressure center
continues to weaken over western Pennsylvania while in the
upper levels a trough deepens over the eastern U.S.
Observations continue to indicate light precipitation reaching
the ground, now scattered across much of the region. The more
concentrated showers remain just to the west of the region
though they have become a bit more diminished as they have
progressed eastward. However, heading into the overnight, more
widespread rain/showers are expected to form as forcing
strengthens with the upper trough deepening and more moisture
moving in. At the surface, low pressure will start to reorganize
farther south near North Carolina but there will still be a
trough extending north from this associated with the decaying
northern low. PoPs increase to around 60-80% across the area
after midnight, though precipitation will remain on the lighter
side. With the loss of daytime heating, temperature profiles in
the Poconos support some wet snow falling overnight, with
accumulations up to an inch possible. Rainfall amounts will
range from a tenth to a quarter of an inch overnight. Lows fall
into the upper 30s/low to mid 40s with temperatures near/below
freezing within the Pocono Plateau.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Coastal low pressure will affect the region through the short term,
though maximum impact looks likely to occur through Friday night.
System develops over the Carolinas on Friday, with rain slowly but
surely heading northeastward toward us. During the day, the rain
looks likely to remain fairly light and more intermittent,
especially the farther north and east one gets. With the clouds,
occasional rain and easterly winds, temps will struggle to rise. In
fact the majority of the area will see highs only in the 40s with
highs in the low 50s confined mainly to parts of far southern NJ and
Delmarva. So all in all, a cool, raw day. By late day we will have
northeast winds gusting up to 30 mph along the coast and up to 25
mph inland.

Most guidance focuses the bulk of the rain and strongest winds over
the region Friday night as the low pressure system heads northeast
off the Virginia/Carolina coast. Rain may be heavy at times, and
there might be enough elevated instability for a thunderstorm across
southern parts of the forecast area. Winds will be gusty from the
northeast, with gusts reaching 25 to 35 mph. Overnight lows will
range from the low to mid 40s north to the low to mid 30s north,
especially over the higher elevations. For this reason, a mix
with or change back to wet snow is likely over the Pocono
Plateau with the potential for another inch or so in places.
Otherwise, rain amounts falling during the evening and overnight
period should amount to a half inch to inch over the 12 hour
period so not enough to cause any widespread flooding issues but
there will be rises on rivers and streams and there could be
some urban and poor drainage type flooding.

The low starts heading farther off the coast during the day Saturday
and Saturday night, but the upper trough nearby and continuing
northeasterly flow likely keeps a few showers around at least on
Saturday, probably abating Saturday night. Saturday will also remain
breezy and chilly under mostly cloudy skies. Expect storm total
rainfall for the period running from tonight through Saturday night
generally 1 to 1.5 inches with locally higher amounts of 1.75 to
2.00 inches possible. Again, the heaviest will fall late Friday
through Friday night but rises on rivers will continue into the
weekend.

By Sunday, the system should finally pull far enough away to the
north and east to bring mainly dry conditions with even some partial
sunshine possible by afternoon...especially over eastern PA.
Temperatures will also rebound with highs getting back up into the
middle to upper 50s for most.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The weekend low pressure system will continue to slide east Sunday
night. A weak mid-level ridge will take its place. Overnight lows
will be in the mid 30s to lower 40s.

Monday may be the nicest day of the long term with high pressure in
place and westerly downsloping winds. Highs will be in the 60s for
most of us, possibly touching 70 across the Delmarva.

A series of cold fronts will cross the region Tuesday into
Wednesday. At the moment, we have the first front moving through
Tuesday morning and the second one sometime during the day on
Wednesday. It doesn`t appear there will be a significant change in
airmass behind the first cold front, so high temperatures on Tuesday
will still be in the 60s for most of us. We`ll hold the far
northwest zones in the 50s. I have chance PoPs painted in the grids.

Cooler air will push into the region behind the second cold front on
Wednesday. Highs will get knocked down into the 50s for most, with
some 40s in the Poconos. For Wednesday night, we may have
frost/freeze concerns with lows possibly dipping into the 30s. And
by this point, the majority of the forecast area, sans LV/Poconos/NW
NJ, will be frost/freeze active. No precipitation is expected on
Wednesday.

Thursday looks to be precipitation free as well with moderating
temperatures (but only slightly) spurred on by some mid-level zonal
flow.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Tonight...MVFR ceilings will develop at KRDG and KABE by around 03Z.
The I-95 terminals will follow between 03Z-07Z. KMIV and KACY may
hold on to VFR ceilings for a bit longer, but still MVFR by around
06Z. Ceilings should lower to IFR between 08Z-10Z for all terminals.
Rain showers move in, though any vsby restrictions should be fairly
minimal through most of the night. Southeast wind around 10 kt
shifting to east-northeast overnight. High confidence in the overall
pattern, moderate confidence in timing.

Friday...IFR ceilings will likely be in place areawide to start the
day, and should remain through 00Z. Widespread rainfall will also
cause vsby restrictions at times (2-3 SM in the heaviest rain),
though vsby restrictions will likely be isolated and fairly brief
compared to the prolonged and widespread ceilings of less than 1
kft. East-northeast wind around 10 kt. A few gusts around 15-20 kts
can`t be ruled out in the afternoon and evening. Moderate
confidence.

Outlook...

Friday Night...IFR through most of the night in low clouds and
rain.

Saturday...IFR/MVFR in rain and low clouds to start the day.
Some improvement is possible late.

Saturday Night...sub-VFR at times as some rain showers and low
clouds linger.

Sunday through Tuesday...Mainly VFR. A few passing showers and
increased cloud cover possible Monday night into Tuesday.

&&

.MARINE...
Winds and seas will start to ramp up through tonight with seas
around 4 feet by morning and east winds 15 to 20 knots gusting up to
25 knots by morning. A Small Craft Advisory goes into effect at 6 AM
Friday for our ocean zones and 9 AM Friday for the Delaware Bay.
These conditions continue through the day Friday.

Outlook...

The strongest winds associated with a coastal low look to be Friday
night into Saturday with Gale conditions possible over our ocean
zones where a Gale Watch is now in effect 6 PM Friday to 6 PM
Saturday. Small Craft Advisory conditions persist on the Delaware
Bay. Seas building upwards of 6 to 9 feet.

Winds abate Saturday night but seas could stay at or above Small
Craft Advisory levels through at least a portion of Sunday.

Sunday night...Seas will continue to diminish Sunday night. There
still could be some residual SCA conditions in play during the
evening hours. Sub-SCA conditions are expected overnight.

Monday and Monday night...Sub-SCA conditions are expected Monday and
most of Monday night. We could see seas tick up a notch to 5 feet
toward dawn on Tuesday.

Tuesday...Like late Monday night, SCA conditions are possible.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 9 AM Friday to 6 PM EDT Saturday for
     ANZ430-431.
     Small Craft Advisory from 6 AM to 6 PM EDT Friday for
     ANZ450>455.
     Gale Watch from Friday evening through Saturday afternoon for
     ANZ450>455.

&&

$$

SYNOPSIS...Kruzdlo
NEAR TERM...AKL/Fitzsimmons/Hoeflich
SHORT TERM...Fitzsimmons/RCM
LONG TERM...Kruzdlo
AVIATION...Cooper/Guzzo
MARINE...Fitzsimmons/Kruzdlo