Norristown, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

722
FXUS61 KPHI 230558
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
158 AM EDT Fri May 23 2025

.SYNOPSIS...
Low pressure will continue to slide to the northeast and will track
into New England on Friday. At the same time, high pressure will
begin to build into our region on Friday and remain in place through
Monday. Low pressure will move out of the Ohio Valley on Tuesday and
track offshore Wednesday into Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
A few lingering showers near the coast at this hour, but
otherwise, we are in a lull, precipitation wise, until a short
wave trough digging on the back side of the big upper level low
arrives this afternoon/evening. Rain with this round is expected
to be less widespread and more showery than what we have seen
the last few days.

Pressure gradient will tighten by mid day, so wind gusts up to
25 mph will be possible through the day.

Thanks to dry air advection with the northwesterly flow and
clearing skies, temperatures overnight will be able to drop
into the 40s for most of the area.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
The low pressure system responsible for our recent rain will track
into New England on Friday and remain near Newfoundland Saturday and
Sunday. As a result, we`ll only keep a small chance of showers going
across our far NW zones as embedded short waves rotate through this
area. We`ll see a good amount of sun on Saturday across the region,
especially south of the PA Turnpike and 195 in NJ. I feel like a
broken record, but it will be breezy once again on Saturday in the W
to NW flow.

More sun is expected on Sunday with a bit less wind. We could see
more clouds on Monday, especially across our southern zones, but
winds look light right now.

Temperatures will run below normal through the weekend. Highs on
Saturday will mainly be in the 60s, except 50s across the Southern
Poconos and NW NJ. On Sunday, expect 60s to lower 70s. For those of
you heading down the shore, even with surf temps in the upper 50s
right now, you`ll see similar temps compared to inland locales with
the west winds. Overnight lows will mainly be in the 40s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The period begins with surface high pressure in play. And it looks
like it will hang around through Monday and very likely into
Tuesday.

As the high breaks down, a low pressure system will move out of the
Ohio Valley on Tuesday and track offshore Wednesday into Thursday.
This will provide the region, especially our southern counties, with
the next widespread shot of rain.

As for temperatures through the period, confidence is high that
they`ll remain at or below normal.

&&

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

Through 12Z...Mostly MVFR or IFR ceilings through 12Z. Some
visibility restrictions in fog also possible, but expect
ceilings to be the controlling factor. Winds generally light and
variable. After 09Z, winds will start to shift to northwesterly
up to 10 kt. With this wind shift we could start to see ceilings
improve.

Today...ceilings improve quickly by 15Z. Prevailing VFR for the
remainder of the day with the exception of potential for brief
restrictions with showers generally between 18 and 22Z.
Northwesterly winds around 10 kt gusting up to 20 kt.

Tonight...VFR conditions expected with light (less than 10kt)
northwesterly winds.

Outlook...

Saturday...Mainly VFR. Can`t rule out MVFR conditions in a
brief shower.

Sunday and Monday...Mainly VFR conditions expected.

Tuesday...Mainly VFR early. MVFR or IFR later in the day with rain
moving in.

&&

.MARINE...
Small Craft Advisories remain in effect for the ocean waters through
tonight. Although winds will diminish this evening, seas will remain
elevated. Seas currently average 8 to 11 feet, and seas will
diminish to 3 to 4 feet by daybreak. NE winds 15 to 20 kt with gusts
up to 25 kt will diminish to 10 to 15 kt by this evening, then will
turn W by daybreak. Once the SCA ends, conditions will remain just
below SCA criteria through Friday.

On Friday, W winds will range from 10 to 15 kt with gusts up to 20
kt.

VSBY restrictions in showers through tonight.

Outlook...

Friday night and Saturday...There`s a chance seas could touch 5 ft
or winds gust to 25 kts, but confidence is on the lower side right
now. So not issuing a SCA attm. But at the very least, conditions
will be approaching SCA conditions.

Saturday night through Monday...Sub-SCA conditions expected.

Tuesday...Sub-SCA conditions expected at least the first half the
day. Seas will ramp up later in the day in advance of our next
system. A SCA may be needed later in the day on Tuesday, more so
Tuesday evening.

Rip Currents...

Friday and Saturday...While winds will be offshore coming out of
the west around 10-20 mph, an 8-10 second period, with multiple
swell groups and breaking waves of 2-4 feet will result in a
MODERATE risk for development of rip currents at all beaches.

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

&&

.TIDES/COASTAL FLOODING...
Coastal Flood Advisories have been allowed to expire. Once we
get to Friday, flow shifts to off shore and thus the risk for
tidal flooding on subsequent high tide cycles decreases for the
ocean and tidal Delaware Bay.

Some guidance suggests some minor flooding within the tidal
Delaware River, particularly on Friday, but confidence was not
high enough to issue further advisories. Higher water levels
could also be a result of freshwater runoff, similar to what
happened last week.

Some spotty minor tidal flooding is possible with the overnight
high tide cycle along the Chesapeake Bay, with the tidal flood
threat decreasing in subsequent high tide cycles.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 AM EDT early this morning for
     ANZ450>455.

&&

$$

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