567
FXUS61 KPHI 251906
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
306 PM EDT Tue Jun 25 2024

.SYNOPSIS...
A weak ridge of high pressure across the region will move east
overnight. Low pressure and its associated front will move
towards eastern Pennsylvania later Wednesday and then move
offshore by Thursday morning. More high pressure moves in for
the last past of the week. Another disturbance will be across
the area for the upcoming weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
Dry weather will continue for the remainder of this afternoon with
only some high level clouds blowing off the convective complex moving
across the Ohio River Valley. As the short wave/vorticity impulse
associated with this convective complex moves across our area later
this evening and overnight, there could be some showers move across
portions of northeast Pennsylvania and northern New Jersey. However,
most areas are expected to remain dry as this activity will mostly
dissipate before reaching our area.

Wednesday is expected to be another hot and humid day across much of
the area as southwest/return flow will lead to increasing temperatures
and dewpoints across the area. We have kept the Heat Advisory in
place where it was before as temperatures north and west of the advisory
may stay suppressed enough with increasing clouds, and they may stay
on the western side of a pre-frontal trough that develops and moves
across the area. Heat Index values across the advisory area are expected
to reach the 100-105 degree range. Areas south of the advisory are
expected to remain below the 105 heat index criteria; although it
will be quite hot and humid there.

In addition to the heat and humidity, there remains the potential
for a round of showers and thunderstorms during the afternoon hours.
There will be plenty of instability across the area with CAPE values
potentially reaching 1000-2000 J/kg, shear values increase to 25-35
knots, and there will be a short wave/vorticity impulse moving across
the area during the afternoon that could help enhance the lift along
with the pre- frontal trough. We remain in a slight risk for severe
weather from the SPC, with damaging winds being the main threat due
to DCAPE values in the 1000-12000 J/kg range although there will
be a chance for hail, and an isolated tornado cannot be ruled out.
Heavy rainfall will also be possible with any thunderstorms as
PW values approach 2 inches, but they should be progressive
enough to preclude a flash flood threat.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Showers and thunderstorms will be across the area Wednesday
night as the low and front pass through. The activity will end
from west to east during the overnight hours with some showers
possible along the shore areas around sunrise. Clouds will remain
most of the night most areas. Lows will drop into the low 60s
across the far NW areas where cold air advection will begin before
Thu. morning. Other areas will remain mild/humid with lows mostly
mid/upper 60s. Winds will turn W/NW overnight and remain around
10 mph with some gusts 20-25 mph early.

For Thursday and Friday, fair weather is expected as high pressure
arrives from the Midwest Thu and crests over the area Fri. Dry weather
with seasonable temperatures are expected. Highs will favor the mid/upper
80s for both days. Humidity levels will be comfortable by in large
with dew points in the 60s Thu and 50s for Fri.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The closing days of June, this weekend, will feature summerlike
conditions more typical of July with `low-end` hot temperatures and
ample humidity. While the heat builds there will also be
opportunities for showers and a few tstms too as shortwave energy
and a few surface front move towards the area from the Great Lakes
area. The activity will be scattered however and while it may affect
both days, the overall amount of time with rains will not be that
great. A higher chance for rains is expected Sunday, mostly in the
morning and early afternoon, so likely pops are in the grids while
other areas have chance pops. High temperatures will be above normal
with upper 80s/low 90s across most spots. Cooler highs will be found
at the shore and southern Poconos. The overnight lows will be mild
and humid.

As July arrives, cooler and drier air drops down from the N/W areas
and brings more temperate conditions. Highs Mon/Tue will be in the
low/mid 80s most areas with comfortable humidity levels too. Not
much in the way of disturbances for the new week, so pops will be
low and skies should be mostly sunny both Mon/Tue.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Rest of today-Tonight...VFR conditions expected. South-southwest
winds 5-10 knots with gusts 15-20 knots this afternoon.

Wednesday...Mostly VFR conditions expected. Chance of showers and
thunderstorms in the afternoon which may lead to lower conditions.
Southwest to west winds 5-10 knots, occasional gusts 15-20 knot sin
the afternoon. Stronger winds in thunderstorms.

Outlook...

Wed night... Showers and tstms with lower CIGS/VSBYS will be moving
through this period. MVFR or possible IFR conditions with the
rains. Conditions improve late from West to East.

Thu thru Friday... Mostly VFR expected.

Sat/Sunday... VFR most of the time, but scattered showers/tstms
with lower conditions at times. Most likely Sat evening thru
Sunday morning.

&&

.MARINE...
Tonight-Wednesday...Small Craft Advisory remains in effect for the
Atlantic Ocean waters tonight through Wednesday due to increasing
winds and waves. Tstms expected Wed afternoon/evening.

Outlook...

Wed night... SCA conditions early with showers/tstms over the
waters. Conditions improve late with winds and seas diminishing.

Thu thru Fri night... sub-SCA expected. Fair weather.

Sat/Sat night/Sunday... Scattered showers tstms Sat becoming
more numerous Sunday. Low-end SCA winds and seas developing Sat
afternoon and lasting into the overnight.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory from 9 AM to 9 PM EDT Wednesday for PAZ070-071-
     102-104-106.
NJ...Heat Advisory from 9 AM to 9 PM EDT Wednesday for NJZ010-012-
     013-015-017>020-027.
DE...Heat Advisory from 9 AM to 9 PM EDT Wednesday for DEZ001.
MD...None.
MARINE...Small Craft Advisory from 8 PM this evening to 6 AM EDT
     Thursday for ANZ450>453.
     Small Craft Advisory from 11 PM this evening to 11 PM EDT
     Wednesday for ANZ454-455.

&&

$$

SYNOPSIS...OHara
NEAR TERM...Robertson
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...OHara/Robertson
MARINE...OHara/Robertson