Upper Darby, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

689
FXUS61 KPHI 190020
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
820 PM EDT Thu Jun 18 2026

.WHAT HAS CHANGED...
Coastal Flood Advisory and HIGH rip current risk were allowed
to expire as the threats for each decrease.

The aviation section updated for the 00z TAFs.

&&

.KEY MESSAGES...
1. Diminishing winds tonight, and some showers late tonight and
Friday morning for parts of the region.

2. Threat for widespread minor tidal flooding is diminishing.

3. A system moves through sometime Monday into Monday Night,
likely bringing unsettled weather to the area.

&&

.DISCUSSION...
KEY MESSAGE 1...Diminishing winds tonight, and some showers late
tonight and Friday morning for parts of the region.

The strong winds will continue to diminish tonight as the core
of the low to mid level jets continue to shift to our east and
northeast. A ripple of energy sliding by Delmarva late tonight
and Friday morning should bring some showers, and perhaps a
rumble of thunder, mainly to areas of Delmarva and southern New
Jersey.


KEY MESSAGE 2...Threat for widespread minor tidal flooding is
diminishing.

High tide has past and water levels have decreased. Therefore,
the previous Coastal Flood Advisory was allowed to expire. Spotty
minor tidal flooding may recur with tonight`s high tide within
the backbays of Atlantic coastal Delaware and New Jersey. With
offshore winds though, no additional rounds of widespread minor
tidal flooding are expected.

Beyond tonight, astronomical tides should be low enough to
prevent any additional flooding impacts. We`ll also have a
modest offshore wind through at least Saturday, which will help
drain the bays most substantially.


KEY MESSAGE 3...A system moves through sometime Monday into
Monday Night, likely bringing widespread rainfall to the area.

Medium range guidance continues to hint at a stretch of unsettled
weather to start next week. The main question will be the track of
the low pressure as it moves through the region, which will have
notable consequence in specific impacts. The main takeaway though is
that Monday is currently looking unsettled, with some thunderstorms
likely mixed in as the area of low pressure moves through, mainly in
the afternoon. Consensus guidance already shows PWAT values (1.75-
2.00") near the climatological maxima, setting up the risk for heavy
rainfall. Still a lot of uncertainty remains, but the overarching
synoptic setup will be favorable for an impactful system.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...VFR, with increasing clouds. West-southwest winds
15-20 knots with gusts to 25-30 knots will gradually diminish
to 10 knots or less and become west-northwest. Moderate confidence.

Friday...VFR ceilings for a time. Some showers at KMIV and KACY in
the morning, and a PROB30 was included for now. West to west-northwest
winds 5-10 knots increasing to 10-15 knots with some gusts 20-25 knots.
The strongest winds should be in the afternoon. Low confidence with
morning shower coverage.

Outlook...

Friday Night...VFR. No significant weather.

Saturday...VFR. West/northwest wind gusts around 20 to 25 knots.

Saturday Night through Sunday...VFR. No significant weather.

Monday...Sub-VFR conditions with showers and possibly some
thunderstorms.

Tuesday...Mainly VFR conditions.

&&

.MARINE...
A Small Craft Advisory remains in effect until midnight tonight.
Winds remain out of the southwest with gusts up to 30 knots
through early this evening with seas of 4 to 6 feet.

Winds and seas quickly diminish tonight with sub-SCA conditions
expected by late tonight.

On Friday, winds out of the west in the morning turn more out of the
southwest in the afternoon at around 10 kt. Seas are forecast at 3-4
feet.

Outlook...

Friday night through Sunday...Winds and seas continue to diminish.
No marine hazards anticipated.

Monday...Advisory conditions likely developing, with gusts over 25
kts and seas over 5 feet.

Tuesday...Sub-SCA conditions.

Rip Currents...

For Friday, west-southwesterly winds generally 5-15 mph. There
will be a south-southeasterly swell of 3 to 5 feet at around 7
seconds. Breaking wave heights of 1 to 3 feet are anticipated.
Have opted for a MODERATE risk for the Jersey Shore and a LOW
risk for Delaware beaches for the development of dangerous rip
currents, where flow is more offshore. Did consider downgrading
the Jersey Shore given tranquil conditions, but will have to see
how quickly windy and rough conditions in the surf zone taper
off.

For Saturday, westerly winds remain around 10-15 mph. However,
the onshore swells begin to weaken, decreasing to around 2 to 4
at around a 7 second period. Breaking waves in the surf zone
should be around 2 feet or less as a result. Therefore, a LOW
risk for the development of dangerous rip currents is forecast
for all beaches on Saturday.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ430-431-
     450>455.

&&

$$

DISCUSSION...AKL/Gorse/Guzzo/Hoeflich/MJL/Staarmann
AVIATION...Gorse/Guzzo/MJL
MARINE...AKL/Guzzo/MJL