424
FXUS61 KPHI 061725
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
125 PM EDT Mon Apr 6 2026

.WHAT HAS CHANGED...
Freeze Watch issued for Tuesday night.

Fire weather concern reduced a bit, especially today, mainly
due to fuel moistures from the weekend rains.

Aviation and Marine discussions have been updated.

&&

.KEY MESSAGES...
1. An elevated risk for fire spread is likely on Tuesday as a
dry airmass will be in place.

2. Chilly temperatures Wednesday morning and Thursday morning
raise frost/freeze concerns where the growing season is
currently active.

&&

.DISCUSSION...
KEY MESSAGE 1...An elevated risk for fire spread is likely on
Tuesday as a dry airmass will be in place.

A period of elevated fire weather conditions is likely Tuesday
as a dry airmass infiltrates the area. On Tuesday morning, a
secondary cold front is forecast to pass through the region.
This will cause dew points to fall into the teens, resulting in
a very dry airmass overhead. MinRH values for Tuesday afternoon
will be in the 25-35% range with northwest winds around 15-20
mph and gusts up to 30-35 mph.

At this time, these conditions will be very close to reaching
Red Flag Warning criteria on Tuesday. While there is high
confidence in meteorological conditions being met for a Red Flag
Warning, rainfall from Sunday may keep 10 hour dead fuel
moistures high enough to offset this threat. Most areas received
around 1/4 to 1/2 of an inch of rainfall, with locally higher
amounts up to 1 inch across southern Delaware and New Jersey. So
far, contacts with our state partner fire agencies have
indicated fuels will not be quite dry enough for a Red Flag
Warning on Tuesday, with a Special Weather Statement being the
most likely issuance. However, we will continue to get feedback
in case fuels dry out excessively fast, resulting in the need
for a warning.

Winds should be lighter on Wednesday, reducing the fire weather
threat.

KEY MESSAGE 2...Chilly temperatures Wednesday morning and
Thursday morning raise frost/freeze concerns where the growing
season is currently active.

Strong Canadian 1040 mb high pressure will settle over New York
State on Wednesday morning before shifting off the New England
coast by Thursday morning. In wake of a cold front on Tuesday, a
reinforcing shot of cold, dry air will arrive Tuesday night and
linger into Wednesday night. Low temperatures will fall into
the low to mid 20s to low to mid 30s for most locales, with
teens in the Poconos by Wednesday morning. Based on coordination
with neighbors, we have decided to start the growing season for
much of the area a few days early, so that in addition to the
Delmarva, frost/freeze headlines may now be issued for most
areas along and south of a line roughly along I-195 and the
east-west PA Turnpike. There is a decent chance (50-60%) for
temperatures at or below freezing on Wednesday morning over
Delmarva as skies will be clear and winds light, with higher
probabilities further north. Therefore, have issued a
widespread freeze watch for all zones now considered active
except the Delaware beaches, where marine influences may keep
temps just above.

Current forecast indicates temperatures Thursday morning will be
a few degrees warmer as the high shifts offshore. However, its
possible that guidance is underdoing the radiational cooling
this night, such that in some better radiative locales, Thursday
morning ends up the colder, while less radiative places end up
with Wednesday morning being colder. In any case, another round
of headlines will be possible, but we`ll cross that bridge when
it gets closer.

A return to more normal temperatures well above freezing comes
by Friday morning, continuing at least through the weekend.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight... VFR expected. Gusty West to Northwest winds
diminishing. SCT to BKN clouds 060-070 most areas into the early
overnight period. High confid.

Tuesday... VFR. Mostly clear skies expected. Gusty Northwest
winds 15 to 20 kts with gusts 25 to perhaps 30 knots expected to
develop after 13Z or 14Z. High confid.

Outlook...

Fair weather with generally VFR conditions are expected during
the midweek to late week time period. The good conditions may
last into Saturday.

&&

.MARINE...
For the rest of today and tonight, we can expect Northwest to
West winds 10 to 15 kts which will decrease overnight as then
back to Southwest overnight. Fair weather.

For Tuesday, a cold front will cross the waters early and a
short period of SCA gusts are possible, but not certain. We did
not issue A SCA at this time. Winds will generally be around 15
kts perhaps a bit higher during the afternoon. Fair weather
expected.

Outlook...

A prolonged period of sub-SCA conditions and Fair weather for
the mid to late week period.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Freeze Watch from late Tuesday night through Wednesday morning
     for PAZ060-070-071-101>104-106.
NJ...Freeze Watch from late Tuesday night through Wednesday morning
     for NJZ013>027.
DE...Freeze Watch from late Tuesday night through Wednesday morning
     for DEZ001>003.
MD...Freeze Watch from late Tuesday night through Wednesday morning
     for MDZ012-015-019-020.
MARINE...None.

&&

$$

DISCUSSION...DeSilva/MJL/RCM
AVIATION...OHara
MARINE...OHara