730
FXUS61 KPHI 240541
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
141 AM EDT Mon Jun 24 2024

.SYNOPSIS...
A cold front will move across the east coast tonight, then
offshore and out to sea on Monday. High pressure will build to
the south the region through Tuesday. Another cold front is
expected to move across the east coast Wednesday night and
offshore by Thursday morning. High pressure builds across the
Mid Atlantic and northeastern states Friday, then offshore
Friday night. Another cold front is expected later Saturday into
Sunday.

&&

.NEAR TERM /THROUGH TODAY/...
As of 130 AM...Latest radar shows much fewer storms across the
region than earlier in the night. Expecting this lull to
continue for a few hours before a possible uptick in some
showers and storms come daybreak. The main cold front is still
pushing east from central PA this morning and some of the latest
guidance has it moving through right around sunrise this
morning. As a result, while showers and thunderstorms are
expected to dissipate after the front pushes through, we could
see one more round of showers and storms, mainly across the
Delmarva and extreme southern NJ early this morning before the
drier air filters in later in the day.

Lows will remain very warm with upper 60s N/W and low/mid 70s
S/E. The cooler/drier air will arrive well behind the front.
Winds turn from Southwest to West overnight.

For Monday, the front will be east of the area Monday morning.
Drier and cooler air arrives behind it. Any early morning
showers across ern Delaware or extreme SE NJ around dawn will
end by mid-morning. Clouds will decrease from NW to SE across
the area. Daytime temperatures will be quite a bit cooler for
most areas with mid/upper 70s for the Southern Poconos and
Lehigh Valley areas and low/mid 80s for metro Philadelphia and
much of NJ. A few upper 80s for Delmarva are possible. The dew
points will be much lower with a more comfortable feel to the
air. Winds will be West to Northwest and increase to 10 to 15
mph with gusts to 25 mph at times.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
The short term forecast begins with dry weather expected for
Monday night through Tuesday night. High pressure will build out
of the Ohio River Valley Monday night, across Virginia and
North Carolina during the day Tuesday, then offshore Tuesday
night. Our area will be on the northern fringe of the high, and
even though there area a couple of short wave/vorticity impulses
expected in the northwest to west flow aloft Monday night and
Tuesday, low PW values will not be conducive to precipitation.
By Tuesday night, moisture will be increasing across the area,
but there is not expected to be any forcing mechanism to help
create showers.

As we move into Wednesday and Wednesday night, a cold front
will approach the area from the west late in the day, then move
across the Mid Atlantic region Wednesday night. Wednesday will
likely be another hot and humid day ahead of the approaching
front, similar to this past week and weekend. But thankfully it
looks like the heat should not last long. There will be
instability across the area with CAPE values 500-1000 J/kg,
along with some enhanced shear with values reaching 30-40 knots.
So there will be the potential for some stronger storms to
develop. The cold front will move through overnight, so there
may be a greater chance of showers and thunderstorms overnight,
although the storms may not be as strong during the overnight
hours.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The aforementioned cold front will move offshore by Thursday
morning and out to sea during the day. There could be some
lingering showers near the coast as the front departs the area,
but most areas will be dry. High pressure will then build across
the Mid Atlantic and northeastern states Friday, then offshore
Friday night. This will bring another period of dry weather to
the area.

Yet another cold front is expected to move across the area next
weekend, although there are some timing differences with the
models. While the GFS and Canadian have the front moving through
as early as Saturday night, the ECMWF has the front moving
through during the day Sunday. So we will keep the higher chance
of precipitation for the Saturday night through Sunday night
period, although it will not likely rain the whole time.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Rest of tonight (through 12Z)...A few isolated to scattered
showers will linger around through the rest of the overnight
hours. One final round of showers and storms are possible
towards daybreak, mainly for MIV/ACY. Sub VFR conditions will
be possible with any shower or thunderstorm. Outside of any
shower or thunderstorm, however, conditions will remain VFR.
Winds will be southwest 5-10 knots with gusts 15-20 knots,
higher in and near thunderstorms. Winds become west the
northwest overnight 5-10 knots. Lower confidence in
showers/thunderstorms, higher confidence otherwise.

.Monday...VFR conditions are expected. Winds will increase out
of the northwest to 15-20 knots, with gusts 25-30 knots. High
confidence.

Outlook...

Monday night...VFR conditions expected. Gusty northwest winds
20-25 knots early in the evening, then northwest 5-10 knots.

Tuesday...VFR conditions expected. Gusty northwest winds around 15
knots during the day.

Tuesday night...VFR conditions expected.

Wednesday...Mostly VFR conditions expected. Chance of showers and
thunderstorms in the afternoon which may lead to lower conditions.
Gusty southwest winds 15-20 knots.

Wednesday night...Periods of sub-VFR conditions possible with
showers and thunderstorms likely.

Thursday...VFR conditions expected. Gusty northwest winds 15-20
knots.

Thursday night...VFR conditions expected

Friday...VFR conditions expected.

&&

.MARINE...
The SCA flag will continue tonight and into Monday for the ocean
waters. We added the upper Delaware Bay as winds have been
gusting 25+ knots for a few hours and will likely continue into
the night. Stronger gusts and choppy seas expected to develop
this evening associated with showers/tstms. Once the front
passes overnight, surface winds will switch around to W/NW and
continue to be gusty into Monday. Fair weather for Monday.

Outlook...

Monday night-Tuesday night...Conditions expected to remain below
advisory levels.

Wednesday-Wednesday night...Conditions may reach Small Craft
Advisory levels.

Thursday-Friday...Conditions expected to remain below advisory
levels.

Rip Currents...

Monday...West-northwest winds around 10-15 mph with gusts up to
20 mph and breaking waves around 2 to 3 feet. Although wind
direction will be directed offshore, wave periods are expected
to increase to around 7 to 8 seconds. For this reason, have
maintained a MODERATE Risk for the development of dangerous rip
currents for both NJ/DE beaches.

Tuesday...Northwest winds will back to southerly as the day
goes on around 10 mph. Breaking waves around 1 to 2 feet. With
winds mainly directed offshore or parallel to the coast and
much lower wave heights, have opted to go with a LOW Risk of rip
currents for all beaches.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.CLIMATE...
Record high temperatures for today.

Location          Record High (6/23)

Philadelphia, PA      97/1888
Allentown, PA         95/1965
Reading, PA           96/1908
Mount Pocono, PA      90/1908
Trenton, NJ           97/1894
AC Airport, NJ        98/1988
AC Marina, NJ         91/1909
Wilmington, DE        100/1894
Georgetown, DE        100/1988

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ430-
     431-450>455.

&&

$$

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