233
FXUS61 KPHI 131349
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
949 AM EDT Sat Jul 13 2024

.SYNOPSIS...
Several weak waves of low pressure will ride along a stationary
front draped over our region today. High pressure returns late
tonight and persists through Tuesday night. A cold front
approaches from the northwest on Wednesday before crossing our
area during Wednesday night. High pressure then builds back in
from the west to end the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
The threat for heavy rain is waning along and east of the front.
still may see a few more showers to the east of the front
through early afternoon, but not expecting a widespread issue,
so have cancelled the flood watch.

Later this afternoon, another round of showers and
thunderstorms are possible into this evening. Severe threat
will be minimal, and expect limited coverage.

Tonight, high pressure builds in from the west. Abundant low
level moisture will remain in place, so patchy fog is likely to
develop. Fog may become locally dense, especially along the
coasts and in areas where we have had heavy rain over the past
two hours.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Going forward, high pressure will then hold influence over the
region through the remainder of the short term period. Upper
heights begin to increase and surface flow becomes southerly.
This will usher in the return of the heat and humidity on
Sunday. Basis the latest available guidance, high temps will be
in the low to mid 90s (80s down the shore and in Poconos). Dew
points will also range from the upper 60s and low 70s. This
equates to heat indicies around 100 degrees across much of the
coastal plain into the Lehigh Valley. As a result, have opted to
issue a Heat Advisory for Sunday where conditions warrant.
Also, cannot rule out an isolated shower or thunderstorm across
eastern PA or the Delmarva which lies in proximity of the
dissipating front.

Rather benign conditions continue into Sunday night under mostly
clear skies. Lows may be a degree or two warmer compared to
Saturday night as southerly flow is a bit stronger than the
night before.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
High heat and humidity will continue to impact the area through
Tuesday, possibly lingering into Wednesday before a cold front
crosses through the area on Wednesday night.

Afternoon highs are forecast to be in the mid to upper 90s on Monday
and Tuesday, when the highest temperatures are likely to occur. Dew
points are also expected to further increase into the low to mid 70s
which will result in heat indicies upwards of 105-110 degrees across
most interior locations. Due to this potential, have opted to issue
an Excessive Heat Watch for Monday and Tuesday with this update
for the same areas where Heat Advisories are in effect for
Sunday. A chance of diurnally driven thunderstorms are possible
each afternoon as well.

On Wednesday, the heat and humidity will continue but is expected to
be a touch lower compared to the days prior as a cold front
approaches. This should result in a more widespread chance for
showers and storms late in afternoon into the evening hours.
Depending on the progression of the front, shower activity may
linger into Thursday as well. However, with the front working
its way through the region, temperatures by late week are
expected to be a few degrees below normal.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today.... Conditions should continue to improve to VFR across
the region. Some sites are already VFR, but expect everywhere to
return to VFR by 18Z. There is a chance for some afternoon
SHRA/TSRA, but that threat/coverage is minimal and confidence
is too low to warrant mentioning in the TAF. Light S winds,
becoming 5 to 10 kt this afternoon. Moderate confidence overall.

Tonight...VFR initially. Sub-VFR VSBYs in fog is likely.
LGT/VRB winds. Moderate confidence.

Outlook...

Sunday through Tuesday night...VFR. Otherwise, a slight chance
of a shower or thunderstorm each afternoon.

Wednesday...Primarily VFR but sub-VFR conditions possible. A chance
for showers and thunderstorms in the afternoon.

&&

.MARINE...
Sub-Small Craft Advisory conditions for today and tonight for S
winds 10 to 15 kt with occasional gusts up to 20 kt.

VSBY restrictions in showers and fog, and rain may be heavy at
times today. Scattered thunderstorms possible as well. VSBY
restrictions in fog likely tonight, and VSBYs may be reduced to
under 1 NM late tonight as well.

Outlook...

Saturday night through Tuesday night...No marine headlines expected.
Wind gusts generally between 10-20 kt and seas around 2-4 feet.

Wednesday...SCA conditions possible due to winds around 20 kt and
seas build to around 4-5 feet.

Rip Currents...

For Saturday, southerly winds around 10-20 MPH with an onshore
component in Cape May, Atlantic, and Ocean County will result in
a MODERATE risk for rip currents. This is aided by breaking
waves of 2 to 4 feet. Flow will be more shore parallel in
Monmouth County and the Delaware Beaches with a LOW risk for rip
currents.

For Sunday, weak flow out of the south remains, though with
decreasing wave heights and a 5 to 7 second period, a LOW risk
for rip currents is in place at all coastal locales.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory from 10 AM Sunday to 6 AM EDT Monday for
     PAZ060>062-070-071-101>106.
     Excessive Heat Watch from Monday morning through Tuesday
     evening for PAZ060>062-070-071-101>106.
NJ...Heat Advisory from 10 AM Sunday to 6 AM EDT Monday for NJZ009-
     010-012-013-015>022-027.
     Excessive Heat Watch from Monday morning through Tuesday
     evening for NJZ009-010-012-013-015>022-027.
DE...Heat Advisory from 10 AM Sunday to 6 AM EDT Monday for DEZ001.
     Excessive Heat Watch from Monday morning through Tuesday
     evening for DEZ001.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...DeSilva/Wunderlin
NEAR TERM...Johnson
SHORT TERM...DeSilva
LONG TERM...DeSilva/Wunderlin
AVIATION...DeSilva/Gorse/Johnson/MPS/Staarmann
MARINE...DeSilva/Gorse/Hoeflich/MPS/Staarmann