279
FXUS61 KPHI 060752
AFDPHI

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

.SYNOPSIS...
A warm front will lift north of the area this morning. A cold
front will cross the region later this afternoon into tonight. A
series of shortwaves will pivot through the region this weekend
with some unsettled weather at times. High pressure will return
early next week and persist into the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
The warm front continues to make progress north this morning
currently extending on a line from Mount Pocono to Belmar area. To
the north of the front, periods of rain continue with some rumbles
of thunder. To the south of the front, just some residual showers
continue. The front should lift clear of the area over the next 2-3
hours. There should still be a lull in the action this morning as we
may see at least a few breaks in the clouds by late morning into the
early afternoon. This will allow temps to rise into the upper 70s to
mid 80s across much of the area. It will feel awfully humid outside
thanks to the high dew points, with heat indicies in the mid 80s to
near 90 in some spots during the afternoon.

The main concern as we head into the afternoon today will be another
round of showers and thunderstorms as the cold front approaches from
the northwest. Taking a look at the environment from available
forecast soundings, much of the area will settle within a corridor
of SBCAPE near 1500-2000 J/kg and effective bulk shear values near
20-25 kt. This suggests that there should be at least some organized
updrafts despite weak lapse rates and rather unidirectional shear.
As a result, the Storm Prediction Center has maintained a Marginal
Risk (Level 1/5) for the region today with the primary threat being
damaging wind gusts as DCAPE values will be around 1000 J/kg. PWATs
will again be around 2 inches, so locally heavy rain is possible.

Hi-res guidance depict that storms will fire as early as mid-day
north and west, before tracking east-southeast through the afternoon
for the northern half of the area. For the southern half of the
area, the CAMs and other hi-res guidance continue to hint on a
potential linear line of storms across southern NJ and into the
Delmarva later in the afternoon. Will have to continue to monitor
this potential as we progress through the day.

By the early evening, showers and thunderstorms will come to an end
as the front moves offshore. In wake of the front, dew points will
fall back into the 50s to around 60 degrees and skies will clear
into early Friday morning. Low temps will be in the upper 50s to mid
60s, but it will feel much more comfortable thanks to the lower dew
points!

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
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 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 /08Z 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-SCA conditions are expected through much of this morning with
south-southwest winds around 15-20 kt, locally higher gusts, and
seas around 3-4 feet.

As we move towards mid-day, winds are forecast to gust around 25 kt
or so with seas nearing 5 feet through much of this afternoon. As a
result, a Small Craft Advisory is in effect beginning at 11 AM this
morning through tonight. No headlines are in effect for the Delaware
Bay today.

Fair weather is expected this morning, before another round of
showers and thunderstorms are expected this afternoon with an
approaching cold front. Fair weather should return in wake of the
front with sub-SCA conditions late.

Outlook...

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...
The threat for widespread minor flooding increases as winds
strengthen then turn and become shore parallel today,
potentially trapping water along the coast. In addition, tide
cycles will be elevated due to the New Moon today. Will
continue to monitor upcoming high tides and make adjustments to
the forecast accordingly. Additional Coastal Flood Advisories
may be needed for tonight`s high tide cycle.

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