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202
FXUS61 KPHI 111043
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
643 AM EDT Sat May 11 2024

.SYNOPSIS...
Weak high pressure arrives today before another low moves
through this evening into tomorrow. High pressure builds south
of the Mid- Atlantic region Sunday night into Monday. Another
area of low pressure brings more unsettled weather by the
middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 6:40am...Little changes were made to the forecast this
morning. Mainly updated sky and temperature grids over the next
couple of hours as skies are mostly clear to start Saturday
morning. Also, patchy dense fog is being observed in the sheltered
valleys of northern New Jersey and northeast Pennsylvania.
However, with the sun now rising, any fog should quickly burn
off within the next hour or two.

This will give way to an overall pleasant day across the area
as a brief surface high slides across the Mid-Atlantic. Skies
should be mostly sunny for the first half of the day, before an
increase in clouds this afternoon is expected as the next
disturbance approaches the area tonight. High temps should
recover nicely into the low to mid 60s this afternoon for most,
with temps only reaching into the mid to upper 50s across the
Poconos and along the coast as onshore flow develops late in the
afternoon.

For tonight, some shower activity will begin to work its way into
the area after sunset from west to east as surface low exits the
Great Lakes region. The low will be accompanied by a cold front,
however the overall strength of the system will be weakening as it
nears. Widespread rain showers are anticipated with higher PoPs over
western areas where better forcing will be present. Have kept the
slight chance of thunder mentioned in the forecast tonight as a
narrow axis of MUCAPE (~500 J/kg) is present in forecast soundings
across SE PA and into the Delmarva. Overall, no severe weather is
expected as instability will be elevated in nature. Rainfall amounts
up to a quarter of an inch is expected. Lows will be in the mid to
upper 40s.
-- End Changed Discussion --

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
Strong PVA will be moving over the region as a mid level trough digs
in through the Great Lakes on Sunday. With weak warm air advection
and sufficient lift provided by PVA expect a wet Sunday. Modest
amounts of instability will be possible but the strong shear is
displaced to the south with 40+ kts of 0-6km shear forecast over
southern VA with just 20-30kts over the forecast area.  Lapse rates
are decently strong (>7 over the northern portions of the forecast
area) so if a storm does develop it will likely take on pulse
characteristics with little moment.  With temps still below normal
and the warm air advection fairly weak it will be another dreary day
across the region with periods of rain and temperatures in the upper
50s/low 60s for Mother`s Day.

By Sunday evening, the trough starts to clear and the area should
begin to dry out as ridging builds in from the west. Expecting a
spread of 40s for overnight lows to close out the weekend.

A nice start to the week is expected with a broad area of high
pressure working in. Temperatures moderate back to near-normal
levels for mid-May, with low to mid 70s expected for most. The
exception being the southern Poconos and along the coast, where
highs will stay in the 60s. Skies will be mostly sunny with some
passing clouds at times

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The work week looks to continue to be somewhat active with a
couple of systems moving through during the week. Temperatures
are forecast to be close to normal for early to mid May.
Ensemble guidance points to rainfall but continues to suggest
that forcing is not currently lining up to lead to much in the
way of any severe weather for the week ahead.

The first system to bring showers and thunderstorms should move
through on Tuesday but again the best shear and instability
don`t overlap so while there is a medium to high chance
(60-70%) of showers and embedded thunderstorms, we are not
anticipating any severe weather. The wet weather is expected to
linger through the day on Wednesday before a ridge builds in for
Thursday bringing dry sensible weather. Towards the end of the
week or perhaps the weekend, the next system starts moving
towards the region and will have the potential to bring another
round of showers with embedded thunderstorms.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Today...VFR expected today. BKN-OVC CIGs early this morning are
forecast to scatter out by 12Z, except at KRDG/KABE where skies may
remain BKN. Patchy fog is also possible at KRDG/KABE this morning,
but confidence in occurrence is low. Otherwise, light northerly
winds this morning will veer and become E-SE this afternoon around 7-
12 kt. Moderate confidence overall.

Tonight...VFR early, likely becoming sub-VFR as rain showers move
into the area. CIGs are expected to fall to MVFR at KRDG/KABE by 03Z
and the remainder of the terminals after 06Z. Localized visibility
restrictions may become possible. Southeast winds around 5-10 kt.
Moderate confidence.

Outlook...

Sunday and Sunday Night...MVFR/IFR conditions expected with low
ceilings and reduced visibility with periods of rain moving
through with a 10% chance of embedded thunderstorms.

Monday through Monday Night..VFR. No significant weather.

Tuesday...VFR to start but sub-VFR conditions likely (60-70%)
later in the day as showers move in.

Tuesday Night through Wednesday...Sub-VFR conditions expected
with showers. Chance of thunderstorms (15-25%) Tuesday night
into Wednesday.

&&

.MARINE...
A SCA remains in effect for the ocean waters from Manasquan Inlet to
Fenwick Island until 6 PM today due to seas remaining above 5 feet.
Elsewhere, seas will remain below SCA criteria. Northeast winds
around 15-20 kt this morning will diminish and become east-southeast
winds around 10-15 kt this afternoon. Southeast winds then continue
into tonight around 10-15 kt. Fair weather expected through this
afternoon before rain showers approach this evening.

Outlook...

Saturday Night through Monday...No marine headlines expected.

Monday Night through Wednesday...SCA conditions possible
(30-40%) as wind gusts get near 25 kt. Seas will get near 5 feet
on Wednesday.

&&

.TIDES/COASTAL FLOODING...
High tide for the Atlantic coastal waters has passed and thus
the additional threat for flooding has ended for move of the
Atlantic waters and Delaware Bay. The exception is across Ocean
county NJ and Susses county DE where water remains trapped in
the Back Bays. Additional flooding is expected in these back
bay areas until the flow turns offshore. Water levels on the
Delaware River are starting to push up towards Burlington and
Philadelphia as of 4am and flood waters are expected to continue
rising over the next two hours before starting to recede.

Additional minor coastal flooding is forecast with the
evening/overnight high tide Saturday night into early Sunday.

Flooding is not expected at this time for our Maryland zones
along the Chesapeake through Saturday.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 7 AM EDT this morning for PAZ070-
     071-106.
NJ...Coastal Flood Advisory until 10 AM EDT this morning for NJZ020-
     026.
     Coastal Flood Advisory until 7 AM EDT this morning for
     NJZ017>019.
DE...Coastal Flood Advisory until 10 AM EDT this morning for DEZ003-
     004.
MD...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
     ANZ451>455.

&&

$$

SYNOPSIS...Deal
NEAR TERM...Desilva
SHORT TERM...Deal
LONG TERM...Deal/Hoeflich
AVIATION...Deal/Desilva
MARINE...Deal/Desilva
TIDES/COASTAL FLOODING...WFO PHI