564
FXUS61 KPHI 060541
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
141 AM EDT Mon May 6 2024

.SYNOPSIS...
An east to southeasterly flow off the Atlantic ocean will
result in cloudy weather through Monday morning with areas of
light rain and drizzle. A cold front will work its way through
the region late Monday and Monday night. This boundary will
become stationary over the area through the mid- week period. A
series of disturbances will track along this boundary through
the middle of the week. A stronger area of low pressure moves
through the region on Thursday, followed by a cold front on
Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of early this morning, fog and low cloud cover remains
entrenched within the region. With a good amount of locations
recording 1/2 to 1/4 mile visibility, have elected to issue a
Dense Fog Advisory for all of our PA counties with the exception
of Philadelphia. The Dense Fog Advisory goes until 10 AM this
morning. Previous discussion follows...

This is all part of a weak warm advection pattern overruning a
very moist and cool marine layer will keep low clouds and light
rain or drizzle for most locations through Monday morning.

Winds become southerly Monday morning ahead of a cold front that
will usher an increasingly humid airmass into the region with
surface dewpoints rising into the 60s. Any fog in the morning will
lift and dissipate by midday. The cold front passes through the
region Monday afternoon and Monday evening. Some shortwave
energy passing through the region will help kick off widely
scattered afternoon showers and thunderstorms, mainly across
the southern portions of the forecast area.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Periods of unsettled weather are expected early in the week as
a cold front will move to the south of the area on Monday night,
then stall to our south into Tuesday, then begin lifting back
north Tuesday night. Showers will be possible on Monday night
near the front as it sags southward, but Tuesday may end up
being dry for many areas since we will be north of the front.
There will still be a chance of showers and isolated
thunderstorms for the southern third to half of the area later
in the day as they will be closer to the front. On Tuesday
night, the area with the greatest chance for showers and
isolated thunderstorms shifts northward as the front lifts back
to the north and short wave/vorticity impulse moves across the
northern areas.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Unsettled weather continues for the second half of the week. On
Wednesday, an area of low pressure will move our of the Great
Lakes and into the northeastern states, eventually bringing a
cold front to the area. After a round of showers and isolated
thunderstorms early in the day Wednesday across the northern
areas, much of the day into the evening hours could be mostly
dry for many areas as the front stalls near the area. However,
this dry weather will not last as showers and isolated
thunderstorms are expected to increase later Wednesday night
into Thursday and continue through Friday as multiple waves of
low pressure move along the stalled boundary across the Mid-
Atlantic region, before the final low and cold front move
offshore of the Mid Atlantic coast Friday into Friday night.
Although the forecast has a chance of showers for next weekend,
drier weather may return as high pressure could begin to affect
the area.

&&

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

Rest of Tonight...IFR/LIFR CIGs expected with IFR/MVFR
visibility. Dense fog possible, mainly within the Lehigh Valley
and southern Poconos. Winds favoring an east/southeast direction
around 5 kt or less, but varying or even calm winds are to be
expected at times. Moderate confidence.

Monday...Low ceilings and patchy fog should lift by 15z-16z or
so. Some sites could lift all the way to VFR. Thinking the
highest chance for that will be within the Lehigh Valley at
KRDG/KABE. Otherwise, MVFR CIGs for most of the day once the
fog/low stratus lifts with VFR VSBYs for the afternoon and early
evening. Winds gradually veering, favoring a south/southwest
direction around 5 kt or less. Moderate confidence in timing
and extent of restrictions.


Monday Night...MVFR/VFR conditions likely drop to IFR around
midnight or so. Some patchy fog possible. Winds light and
variable. Low confidence in timing/extent of restrictions.

Outlook...

Tuesday...Areas of VFR to MVFR conditions with a chance of showers
and thunderstorms.

Tuesday night...Areas of IFR developing with showers likely with a
chance of thunderstorms.

Wednesday-Wednesday night...Conditions may improve to VFR with a
chance of showers and thunderstorms.

Thursday-Friday...Sub-VFR conditions likely with showers and
possible thunderstorms.

&&

.MARINE...
No marine headlines expected through Monday as seas will be 2
to 4 feet with winds from the east to southeast at 10 to 20 kt.
Periods of showers expected with a slight chance of
thunderstorms early Monday morning.

Outlook...

Monday night-Friday...Conditions likely to remain below Small
Craft Advisory levels for much of the period. Winds may gust
around 20 knots at times, and seas may approach 5 feet Thursday
night.

&&

.TIDES/COASTAL FLOODING...
Approaching new moon middle of this week promises to bring very
high astronomical tides. It will thus be very difficult to avoid
at least some advisory level coastal flooding in some locations,
and a few spots might hit moderate even with weakening onshore
flow. Will continue to monitor, but coastal flood advisories
look likely by late Tuesday.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Dense Fog Advisory until 10 AM EDT this morning for PAZ054-055-
     060>062-070-101>106.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...Franklin/MPS
NEAR TERM...DeSilva/Franklin/Hoeflich
SHORT TERM...Robertson
LONG TERM...Robertson
AVIATION...DeSilva/Franklin/Hoeflich/Robertson
MARINE...DeSilva/Franklin/Hoeflich/Robertson
TIDES/COASTAL FLOODING...