798
FXUS61 KPHI 120530
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
130 AM EDT Sun May 12 2024

.SYNOPSIS...
Weak high pressure over the region will move offshore this
evening. Low pressure centered over Lake Huron early this
afternoon will move eastward through this evening into Sunday.
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 TODAY/...
As of 1:15am...A decaying squall line is now moving onshore the
Eastern Shore of MD and across the Delmarva region. Some
intermittent flashes of lightning have occurred over the past
15 minutes, so still think there may be a few rumbles of
thunder across the Delmarva region over the next hour or two.
However, the line is weakening and winds associated with the
line are 30 mph or less. Further north across E PA, some light
rain and misty conditions are found and will continue to
overspread the remainder of the area through the early morning.
This is all due to a low approaching from the west, while being
accompanied by a cold front. However, the overall strength of
the system will be weakening as it nears. Rainfall up to a
quarter of an inch is expected. Lows will be in the mid to upper
40s.

H5 trough with associated vorticity advection will be moving
over the region on Sunday. With additional lift provided by weak
warm air advection, Sunday looks to be a rather wet and cool
day. Maximum temperatures are expected in the upper 50s to lower
60s. Have added drizzle and mist/patchy fog to the forecast for
late tonight and Sunday given persistent southeasterly upslope
flow, cloud cover and moisture.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
Sunday night will feature improving conditions and the surface
low continues to move away and the upper trough passes through.
It`s possible that skies may become partly cloudy late giving
aurora viewing possibilities. One possibility will bring patchy
fog to the area if conditions become clear overnight.

Monday/Monday night... High pressure arrives during the day and
a partly sunny day is expected. Temperatures will be close to
normal for early May with highs in the low/mid 70s and lows (For
Tue morning) in the low/mid 50s. Clouds will increase over the
area Monday night.

Tuesday... Another slow moving low pressure approaches the
region. Increasing clouds thru the morning with rains arriving
during the day. Most models seem to agree with the overall
scenario and we`ll continue with chance pops for the morning
then mostly likely pops for the afternoon. It`s possible that
the furthest east areas may escape rains until late afternoon.
Temperatures will remain seasonable with mostly low 70s for
highs and 50s for lows.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Rather unsettled much of the long term as low pressure slowly
deepens while moving up the Ohio Valley and then ambling across
the Middle Atlantic region. Likely/categorical pops beginning
Tue night and continuing Wednesday before scaling back Wed
night. After a period of lesser pops Thu into Friday morning,
more showers/rains overspread the region for next weekend. We`ll
have chance pops for Fri night and into Sat for now. There
enough differences between the operational models to have less
confidence with regards to next weekends fcst attm.

Normal high temperatures for our region this time of year are
in the low/mid 70s with upper 60s for the southern Poconos.
We`ll arrive close to these values much of the week with
readings perhaps a degree or two below normal Wed and above
normal for Thu/Fri. Lows will be in the 50s most days.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Today...VFR expected through about 08-09Z before CIGs are
expected to drop to around 1500-2500 feet as rain showers move
into the region. CIGs may temporarily lower to IFR at KRDG/KABE
early Sunday morning. Visibilities should generally remain in
the 4-6 SM range at all terminals. Periods of drizzle and mist
may be possible this afternoon. SE winds around 5-10 kt.
Moderate confidence overall.

Tonight...Any lingering sub-VFR CIGs early, should give way to
clearing skies as skies scatter out by 00Z-03Z. Some increase in
low-level clouds will be possible into early Monday especially
near KRDG/KABE. E-SE winds around 5 kt or less. Moderate
confidence.

Outlook...

Monday through Tuesday...No significant weather expected.

Tuesday Night through Wednesday night...Sub-VFR conditions
expected with occasional showers.

Thursday... VFR probable.

&&

.MARINE...
Winds and seas will remain below SCA criteria through Sunday.
Southeast winds around 10-15 kt. Seas 3-4ft.

Outlook...

Sunday night through Monday...No marine headlines expected.
Fair.

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

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Advisories were issued for tonight`s high tide
for coastal zones from Ocean County on south and for communities
along the Delaware Bay. Minor tidal flooding is expected with
some inundation of roadways possible. Elsewhere, spotty minor
flooding is expected within the tidal Delaware River, tidal
Raritan Bay, and along the NJ coast north of Ocean County.

Spotty minor flooding is also expected with tomorrow morning`s
high tide within the Chesapeake Bay. Some of the guidance
suggests an advisory may be needed, but have elected to hold off
for now. Stay tuned to the forecast for any further updates.

No further tidal flooding issues are expected beyond
tonight/tomorrow morning`s high tide.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory until 5 AM EDT early this morning for
     NJZ016.
     Coastal Flood Advisory until 4 AM EDT early this morning for
     NJZ020>027.
DE...Coastal Flood Advisory until 5 AM EDT early this morning for
     DEZ001.
     Coastal Flood Advisory until 4 AM EDT early this morning for
     DEZ002>004.
MD...None.
MARINE...None.

&&

$$

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