256
FXUS61 KPHI 200124
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
924 PM EDT Thu Sep 19 2024

.SYNOPSIS...
An area of low pressure will continue to spin off of the east
coast while high pressure remains across eastern Canada, nosing
its way into the region into early next week. A weak disturbance
is expected to move across the area Saturday night and Sunday,
before a stronger weather system possibly impacts the area by
the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
Low pressure will meander well off the New Jersey through the
period. Meanwhile, high pressure will build down from eastern
Canada into the Ohio Valley and Mid-Atlantic. No significant
changes with the late evening update.

Should continue to see dry conditions through at least mid day
Friday. Some guidance is depicting fog overnight, but though
dew point depressions will be low and winds should be relatively
light, high clouds may somewhat limit fog development. Also, it
appears that any saturated layers will be very shallow. For
now, have kept a mention of patchy fog for portions of the
region.

For Friday afternoon, a few different high res models depict
widely scattered showers. Thus, forecast has a slight chance
(20%) of rain primarily along and east of the I-95 corridor.

Lows tonight will be in the mid 50s to mid 60s. Friday`s highs
will be in the low 70s to low 80s, slightly cooler than today.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
An area of low pressure remains offshore of the east coast
Friday night, as high pressure noses its way down the eastern
seaboard from eastern Canada. This high gets squeezed by
Saturday through Sunday as a weak disturbance moves into the
area. This disturbance does not looks to be any frontal passage,
but more of a short wave/vorticity impulse passage. So there
will be a chance of rain Saturday night into Sunday, albeit
20-30 percent at most.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
By Sunday and Monday, the mid-level disturbance moves out of
the area and high pressure noses its way back down into the
region. This will bring dry conditions back to the area.
However, the dry weather may not last long as some much needed
rain may, possibly, move into the area. A messy frontal system
is forecast to move eastward as a an area of low pressure moves
across the Ohio River Vally and into the eastern Great Lakes
Tuesday through Thursday. The front may not actually make it to
the area before a secondary low pressure potentially develops
and impacts the area around Thursday. Cross our fingers this
comes to fruition as conditions have been abnormally dry for the
last month for many areas.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Mainly VFR. Some guidance is depicting BR, primarily
in locations more prone to radiational fog like KMIV, KRDG, and
KABE. However, moisture looks like it will be very shallow, so
if any fog develops, expect localize shallow ground fog.
Consequently, risk is too low at any one site to include in the
TAFs at this time. Winds 5 kt or less. Direction should favor
NE, but there could be a period of variable direction. Moderate
confidence.

Friday...If any fog develops overnight, it may linger for an
hour or two after 12Z, otherwise VFR is expected. NE winds 5 to
10 kts with some gusts up to 15 kts. High confidence.

Outlook...

Friday night-Saturday...VFR conditions expected.

Saturday night...MVFR or IFR conditions possible with a chance
of showers.

Sunday...MVFR or IFR conditions possible early, improving to
VFR.

Sunday night-Monday...VFR conditions expected.

Monday night-Tuesday...MVFR or IFR conditions possible with a
chance of showers.

&&

.MARINE...
SCA conditions, primarily for elevated seas will continue on the
Atlantic coastal waters through this period and into much, if
not all of the weekend. As for winds, N to NE winds will
briefly relax this evening, but pick back up and become 10 to 20
kt with occasional gusts to 25 kt for our ocean waters. Lighter
winds expected across Delaware Bay.

Outlook...

Friday night...Small Craft Advisory in effect due to seas.

Saturday-Tuesday...Small Craft Advisory conditions likely
continue due to seas.

Rip currents...

On Friday, winds become northeast and will increase to 15 to 20
mph with gusts up to 25 mph. Breaking waves will be a bit
higher, generally 4 to 6 ft. As a result, there is a HIGH risk
for the development of dangerous and life threatening rip
currents for the Jersey Shore and for the Delaware Beaches.

The HIGH risk will continue on Saturday, and may continue into
Sunday as well.

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

&&

.TIDES/COASTAL FLOODING...
Continued onshore flow will result in water piling up and
unable to drain within tidal waterways. At least minor tidal
flooding is expected for the next several high tide cycles for
portions of our area. Moderate tidal flooding may occur for
portions of our area this weekend.

Coastal Flood Advisories are posted for the New Jersey coast,
Delaware Coast, and part of the Delaware Bay (Cumberland County
in New Jersey and Kent County in Delaware) as at least minor
tidal flooding is expected around high tide through the end of
the weekend. Some guidance indicates moderate flooding may occur
for some locations as early as the Friday morning high tide
cycle. However, confidence in this remains low at this time;
will stick with the advisory for now. A short-fused upgrade may
occur during the next update. Confidence is better for moderate
coastal flooding to occur with high tide cycles this weekend.
Have issued a Coastal Flood Watch as a result to cover the
Saturday and Sunday morning high tide cycles.

For the tidal Delaware River, in general, it looks like water
levels will stay just below advisory thresholds, but will be
watching trends closely.

For the northeastern shore of Maryland, am getting increasingly
concerned that there will be minor flooding over the weekend.
Latest high tide cycle was considerably higher than most
guidance. Will watch trends overnight to see if this low bias
continues.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory until 6 AM EDT Saturday for NJZ012>014-
     020>027.
     Coastal Flood Watch from Saturday morning through Sunday
     afternoon for NJZ012>014-020>027.
     High Risk for Rip Currents from 6 AM EDT Friday through Saturday
     evening for NJZ014-024>026.
DE...Coastal Flood Advisory until 6 AM EDT Saturday for DEZ002>004.
     Coastal Flood Watch from Saturday morning through Sunday
     afternoon for DEZ002>004.
     High Risk for Rip Currents from 6 AM EDT Friday through Saturday
     evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory until 6 PM EDT Saturday for ANZ450>453.
     Small Craft Advisory from 8 AM Friday to 6 PM EDT Saturday for
     ANZ454-455.

&&

$$

SYNOPSIS...Robertson
NEAR TERM...Kruzdlo/Johnson
SHORT TERM...Robertson
LONG TERM...Robertson
AVIATION...Kruzdlo/Johnson/Robertson
MARINE...Kruzdlo/Johnson/Robertson
TIDES/COASTAL FLOODING...