Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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738
FXUS61 KPHI 021747
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
147 PM EDT Thu May 2 2024

.SYNOPSIS...
A cold front moves through tonight, with high pressure building in
for the end of the week. A weakening cold front approaches on
Saturday, stalling out on Sunday. The front lingers through early
part of next week, before lifting north as a warm front by the
middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
145 PM...As of early this afternoon, low pressure was moving
into western New England with a trailing cold front extending
west from this feature back into upstate NY and northern PA.
Meanwhile a surface trough extended to the south and west right
across the mid Atlantic I-95 corridor. As this trough continues
to move through, winds will shift from southwest to more
westerly across the area this afternoon with a drop in dew
points. However actual air temperatures will remain quite warm
with highs still expected to top out in the mid to upper 80s
across much of the region. The exceptions will be over the
Poconos and right along the coast where it will be cooler.
However winds becoming mainly offshore will keep any sea breezes
from really getting inland so while right at the shore
temperatures will be in the upper 60s to low/mid 70s, just a
couple miles inland it will be in the 80s. Otherwise, it will be
a mainly sunny and precipitation free afternoon across the
area.

As we head into this evening, the cold front moves southward
through the region as low pressure moves southeastward off the
coast of New England and high pressure builds into eastern
Canada. This setup will cause the winds to shift to an
east/northeast direction over the mid Atlantic and it`s likely
this will eventually bring in some marine stratus along the
coast by Friday morning. Expect overnight lows mainly in the
50s...ranging from low 50s over the southern Poconos, NW NJ, and
and the NJ coast to mid/upper 50s near the urban corridor of SE
PA extending south into interior portions of Delmarva.

For Friday, ridging aloft will keep the area dry for at least
one more day as it helps to keep the approaching system from
the west at bay. Meanwhile the front will be stalled to our
south but then arcing back to the north and west into PA just
west of our region. The upshot of this is it will be a much
cooler day with continuing easterly winds and variable cloud
cover. Through the morning, marine stratus near the coast will
try to push inland for a time and could get to near the I-95
corridor before starting to retreat. Meanwhile by afternoon
there will be some clouds moving in from the west. So not a
completely sunny day but much of the region should see at least
a little sun at some point except perhaps right along the coast.
Speaking of which, expect highs near the coast will only get
into the upper 50s to low 60s with warmer temperatures the
farther west you go. Eastern PA should see highs mainly in the
upper 60s to low 70s except some mid 70s over portions of Berks
County.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
Dry conditions will persist for Friday as an upper level ridge
slides overhead. A little bit of a tricky high temperature forecast
for Friday though as high pressure over New England will result
in an onshore flow and a backdoor cold front setting up near
the I-95 corridor. Still some uncertainty where exactly this
boundary sets up, but temperatures west of the front (primarily
the Lehigh Valley) will get into the 70s, with upper 50s/60s
near and east of the backdoor front. Temperatures on Friday
Night will fall into the upper 40s/low 50s.

For Saturday, upper level ridging and high pressure begin to move
offshore. A cold front will slowly move across Pennsylvania with
some showers moving in ahead of it. The bulk of the rain will come
for the back half of the weekend, but a small chance (15-25%) of
showers are expected west of the I-95 corridor for Saturday.
Otherwise, it will be mostly cloudy and cool with temperatures in
the low to mid 60s.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Weakening cold front approaches on Saturday night with numerous
shortwaves moving over the region through Sunday. A solid push of
moisture works in from the southwest as well and PWATs climb into
the 1.3-1.5 in. range which is around the 90th percentile for early
May. Periods of rain are expected for Sunday, some of which could be
heavy at times. Not overly concerned at the moment with flooding
given dry antecedent conditions however. Instability is lacking
overall as well, so the threat for thunderstorms is rather low.
Temperatures will hover in the 60s, with lower 70s in lower
Delmarva.

The early and middle portions of next week look rather unsettled,
though not expecting any significant impacts at this time. A stalled
boundary looks to set up over the southern portion of the region
with several waves of low pressure riding along the stationary
front. High pressure nudging in from the northwest could limit
shower activity, depending on how much influence it has over the
region. Temperatures Monday/Tuesday will hover near/slightly
above seasonal levels for early May, with mid to upper 70s
expected. That boundary looks to eventually lift north as a warm
front by midweek and we should return to the 80s by Wednesday.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

This afternoon...VFR with west to WNW winds around 10 to 15
gusting upwards of 20 to 25 knots. High confidence.

Tonight...Mainly VFR except some MVFR cigs possible towards 12z
at ACY. Winds diminishing early this evening to 5-10 knots and
becoming northwesterly before veering to northeasterly by the
late evening through the overnight. Moderate confidence.

Friday...Mainly VFR except a period of MVFR cigs possible in the
morning at ACY (60 percent chance) and MIV (40 percent chance)
due to marine stratus. Winds generally easterly around 10 knots.
Moderate confidence.


Outlook...

Friday through Friday Night...Primarily VFR, though sub-VFR
conditions possible (30-50%) later in the day at KMIV/KACY with
marine stratus working in.

Saturday through Saturday Night...sub-VFR conditions possible (30-
50%) with CIG restrictions. Slight chance (15-25%) of showers for
the I-95 and Lehigh Valley terminals.

Sunday through Monday...sub-VFR conditions likely (60-80%) with
periods of rain.

&&

.MARINE...
Sub-Small Craft Advisory conditions today and tonight. SW winds
will increase to 10 to 15 kt with gusts up to 20 kt this
afternoon, then winds veer to northeast around 10 kt tonight.
Seas will average 2 to 3 ft through tonight and then 3 to 4 ft
by later Friday.

Outlook...

Friday night through Saturday Night...No marine headlines
anticipated.

Sunday...SCA conditions possible (20-30%) as seas near 5 feet on the
ocean.

Sunday through Monday...No marine headlines anticipated.

&&

.FIRE WEATHER...
Warm, dry, and breezy conditions on tap through today under
sunny skies. Minimum RH values will drop to 25 to 35 percent
across the region this afternoon due to the combination of highs
in the mid to upper 80s and surface dew points dropping into
the 40s over much of eastern PA into northern NJ with 50s south
of here. Southwest winds shifting to northwest will increase to
10 to 15 mph with 20 mph gusts this afternoon. While a wetting
rainfall occurred on Tuesday across the Lehigh Valley, southern
Poconos, and northern New Jersey, remaining areas of
southeastern Pennsylvania, New Jersey, and Delmarva have not
experienced a wetting rainfall in well over a week now. This
will result in some concerns for wildfire spread today.
Coordination will be needed with our fire weather partners to
determine if any products will be needed to highlight this
potential threat.

&&

.CLIMATE...
Near record breaking high temperatures are expected today. Records
for our climate sites are listed below:

Record High Temperatures
                            May 2
Site                  Record/Year
Allentown (ABE)           90/2001
AC Airport (ACY)          91/2018
AC Marina (55N)           85/1913
Georgetown (GED)          90/2018
Mount Pocono (MPO)        83/1913
Philadelphia (PHL)        89/2010
Reading (RDG)             89/1899
Trenton (TTN)             88/2010 & 2018
Wilmington (ILG)          90/1894

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...Hoeflich
NEAR TERM...Fitzsimmons
SHORT TERM...Hoeflich
LONG TERM...Hoeflich
AVIATION...Fitzsimmons/Hoeflich/MPS
MARINE...Fitzsimmons/Hoeflich/MPS
FIRE WEATHER...
CLIMATE...