490
FXUS61 KPHI 060535
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
135 AM EDT Thu Jun 6 2024

.SYNOPSIS...
A warm front is moving northward across the region early this
morning. A cold front crosses the region later this afternoon
into tonight. Heading into the weekend unsettled weather looks
to persist into early next week as several shortwaves pivot
around the upper low over southern Canada.

&&

.NEAR TERM /THROUGH TODAY/...
As of 1:30AM...The thunderstorms earlier this evening have now
waned as they have now moved into a more stable environment.
Main concern looks to be the remaining hydro threat as we do
have several flash flood warnings up at the current time. The
warm front has now lifted north of Philadelphia, where the
heaviest showers and embedded thunderstorms remain. This should
continue to lift north over the next 2-3 hours. Elsewhere, just
some left over spotty showers are occuring to the south of
Philadelphia.

Previous discussion...Showers end from south to north by
Thursday morning as the front lifts through the region. Quite
warm and humid on Thursday with highs in the low to mid 80s and
dew points in the low 70s, which should yield a max heat index
near 90.

Cold front then approaches from the west Thursday afternoon and
works its way east into Thursday evening. Another round of
showers and thunderstorms will affect the area starting around
midday. SB CAPE values will once again be up around 1500 to 200
J/kg, but again, there will not be much lift, and shear values
will be minimal as well. Some thunderstorms may be severe with
damaging winds and large hail. SPC has the area in a Marginal
Risk, which is a 1 out of 5.

PWATs will be up around 2 inches, so locally heavy rain is
possible once again.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
Showers/thunderstorms move offshore on Thursday Night as the
cold front pushes through. The front will dry things out and
dewpoints are expected to fall a good 10 to 15 degrees once it
passes. Skies will clear out as the night goes and temperatures
will drop into the low to mid 60s with 50s in the higher
elevations.

Things have trended drier for the end of the week and first
half of the weekend. The upper level low will slowly move
eastward through the northern Great Lakes and Ontario. A series
of shortwaves will rotate around the base of the low both Friday
and Saturday. This will result in some scattered showers and
isolated thunderstorms developing in the afternoon/evening of
both days, mainly from the I-78 corridor on north. South of
that area, it should stay dry with mostly sunny to partly cloudy
skies. Temperatures both days will be in the upper 70s/low 80s.
Not expecting any severe weather however.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The long term period is forecast to be generally unsettled
through at least the weekend. The aforementioned upper trough
and low will meander across southern Canada and the northern
Great Lakes through early next week. As it does so, multiple
shortwaves will round through the upper trough resulting in
several rounds of showers and occasional thunderstorms through
the weekend into next week. While no singular day appears to be
a washout, there will be quite a bit of showers around, more
likely north and west of Philadelphia with drier conditions
south and east. The highest probability of precipitation will be
during the afternoon hours as diurnal heating allows
instability to be maximized.

More uncertainty comes for the start of next week as guidance
diverges after Sunday. Though there is a decent chance it
remains unsettled, but similar to the weekend, severe weather
impacts do not appear on the table.

Temperatures during this period will remain quite seasonable
for early June with a mix of 70s/80s during the day and 50s/60s
at night.

&&

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

Through 12Z...Periods of MVFR/IFR are expected through the
remainder of the overnight period. Most of the thunderstorm
threat has now ended so generally expect just some showers
around through 08-09Z. S winds around 5-10 kt. Moderate
confidence.

Today...MVFR/IFR CIGs are likely to continue through the morning
hours before lifting to VFR in the afternoon. A cold front will
approach from the west, bringing the return of some
thunderstorms during the afternoon. CIGs/VSBYs restrictions are
possible in any thunderstorm. SW winds around 10 kt with gusts
up to 20 kt. Moderate confidence.

Tonight...Showers and thunderstorms should wane after 01-02Z.
Skies should begin to clear through the overnight hours. All
terminals should be VFR tonight. W-NW winds around 5-8 kt.
Moderate confidence.

Outlook...

Friday...Primarily VFR though some showers/thunderstorms
(20-30%) possible at KRDG/KABE. Wind gusts out of the west in
the upper teens/low 20s anticipated.

Friday Night...VFR. No significant weather.

Saturday through Wednesday...Conditions will mainly be VFR but
each day features shower chances and the possibility of
restrictions, mainly in the afternoon/early evening. Best chance
each day to see showers and restrictions will be at the Lehigh
Valley terminals.

&&

.MARINE...
Sub-Small Craft Advisory conditions tonight with S winds 15 to
20 kt and seas around 4 feet. Showers and thunderstorms will
result in reduced VSBYs. VSBY restriction in fog will also
occur. On Thursday, SW winds increase to 15 to 20 kt with gusts
up to 25 kt on the ocean and seas build to 5 feet. A SCA has
been issued for most of the day.

Patchy fog will continue into midday Thursday. Another round of
showers and thunderstorms will develop by Thursday afternoon.

Outlook...

Thursday Night...A Small Craft Advisory is in place for the
first half of the night for the New Jersey coastal waters as
seas will be near 5 feet with gusts in the 20-25 kt range. No
marine headlines are in place for Thursday Night for the
Delaware coastal waters or Delaware Bay. Some thunderstorms
possible on the waters.

Friday through Tuesday...No marine headlines expected. Fair
weather outside of some showers on Sunday Night.

Rip Currents...

For Thursday, SSW winds around 10-15 mph will parallel the
shoreline for NJ and offshore for DE beaches. With breaking
waves of 2-3 feet, a medium period swell, and a new moon, the
risk for rip current development is MODERATE for the more
southeasterly facing beaches in New Jersey beaches and LOW for
the more easterly facing beaches in New Jersey and Delaware.

For Friday, winds become a bit more westerly but still have a
southwesterly overall direction, and though slightly lighter,
should still be parallel enough to the southeasterly facing
beaches in New Jersey for a MODERATE risk, with LOW elsewhere.

Rip currents occur often in the vicinities of jetties and
piers. Utilize any guarded beaches if venturing out into the
water. For specific beach forecasts, visit weather.gov/beach/phi

&&

.TIDES/COASTAL FLOODING...
A Coastal Flood Advisory remains in effect for southern NJ,
southern DE, as well as the Delaware Bay counties and Delaware
River counties for the high tide cycle tonight. The threat for
widespread minor flooding increases as winds strengthen then
turn and become shore parallel on Thursday, potentially trapping
water along the coast. In addition, tide cycles will be
elevated due to the New Moon on Thursday. Will continue to
monitor upcoming high tides and make adjustments to the forecast
accordingly. Additional Coastal Flood Advisories may be needed
for the Thursday night high tide cycles.

Overall, the threat for tidal flooding appears to be lower
along the Chesapeake Bay than elsewhere in the region but by the
early morning high tide Thursday, water levels may also
approach spotty minor.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Coastal Flood Advisory until 5 AM EDT early this morning for
     PAZ070-071-106.
NJ...Coastal Flood Advisory until 5 AM EDT early this morning for
     NJZ015-017>019.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 11 AM this morning to 2 AM EDT
     Friday for ANZ450>453.
     Small Craft Advisory from 11 AM this morning to 6 PM EDT this
     evening for ANZ454-455.

&&

$$

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