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000
FXUS61 KPHI 271603
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1203 PM EDT Mon Jun 27 2022

.SYNOPSIS...
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A cold front will cross the region this afternoon bringing
numerous showers and thunderstorms to the area. Seasonably cool
and dry high pressure will arrive in the wake of the front on
Tuesday before dissipating into Wednesday. Dry conditions and
fair weather is then expected to continue through Friday with
warming temperatures and increasing humidity as the week
progresses. A slow-moving cold front will move into the the
region on Saturday and linger through Sunday resulting in
unsettled weather for the holiday weekend with showers and
thunderstorms likely.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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Forecast remains mostly on track. Cold front approaching from
the NW is helping convection start to intensify now that CAPE
has begun to increase with insolation. Expect showers and storms
to expand across the region, especially S/E of PHL, over the
next few hours before heading off the coast late this
afternoon/early this evening. That said, CAPE and shear look
insufficient for significant severe weather, but PW`s near 2"
look to produce some isolated heavy rainfall totals.
Fortunately, the most at risk is the coatal plain where, for the
most part, soils will be able to absorb it better. Highs today
won`t go much higher than presently, while lows tonight with the
cooler air moving in will be down into the 50s and 60s, notably
cooler than this past morning.
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&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
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Zonal flow will prevail in the wake of a departing shortwave
trough on Tuesday. A mid-level trough axis will eject eastward
out of the Great Lakes region early Wednesday passing across the
area later in the day. At the surface, seasonably cool and dry
high pressure will settle across the region on Tuesday and then
dissipate into Wednesday with a Bermuda high remaining offshore.

Temperatures Tuesday and Tuesday night will be on the order of
5-8 degrees below normal along with dewpoints in the mid 50s
making for a rather pleasant early summer day. Winds will be
from the northwest around 5-10 mph becoming calm overnight.
Decidedly the pick of the week.

On Wednesday, southwesterly flow will begin advecting warmer
air into the area rebounding temperatures to near normal.
Dewpoints will still be in the mid to upper 50s, so it will
still be a pretty nice and seasonable day overall under mostly
sunny skies. The trough axis passing across the area during the
late afternoon and evening could result in a rouge shower near
or north of I-78, but the antecedent conditions will be rather
dry. Thinking this activity would be nothing more than a few
sprinkles (if anything at all), thus we do not have any
precipitation chances mentioned in the forecast.
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&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
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Thursday and Friday will see a gradual warming trend as 500 mb
heights begin to increase with ridging building into the area.
Highs on Thursday will be in the mid to upper 80s, with an
outside chance for 90 in the urban corridor. Friday will be a
bit warmer, with higher confidence in temperatures over 90
degrees. 850 mb temperatures are expected to be a bit higher
compared to Thursday, likely sitting in the 17-20C range. Still
looking dry overall for these two days, however with Bermuda
high pressure sitting offshore, moisture will increase as we
progress through the end of the week. Dewpoints will gradually
rise, eventually getting into the upper 60s by Friday. Ridging
will flatten out by late Friday as the weekend turns unsettled.

The holiday weekend pattern will turn active as a mid-level
trough and surface cold front approach the region. Atmospheric
moisture will increase further, with PWATs getting into the 1.5
to 2 inch range. With some instability in place as well, there
will be a chance for some thunderstorms. Slight chance PoPs come
into the forecast for far northwestern zones on Saturday
morning, with chance to likely PoPs coming in for parts of the
region during the afternoon. Guidance continues to hint at a
rather slow progression of the front (which typically stall out
across our area in these setups), which will likely keep active
and unsettled weather through Sunday as well. The GFS remains
the most progressive solution with the front clearing the area
by Sunday morning, but this is an outlier and thus the Sunday
forecast continues to maintain likely PoPs as well. A
slower/stalling frontal boundary would set us up for a potential
excessive rainfall event given the high PWats, so this period
will need to be monitored closely for any potential holiday
weekend impacts.
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&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
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The following discussion is for KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY and surrounding areas.

This afternoon...Intervals of MVFR CIGs. SHRA with scattered
TSRA with MVFR VSBYs. Conditions improve to VFR from west to
east late. SW winds around 10 kt, becoming W through the
afternoon. Moderate confidence.

Tonight...VFR. NW winds 5 to 10 kt. High confidence.

Outlook...

Tuesday through Thursday...VFR. Winds northwesterly on Tuesday will
become west to southwesterly for Wednesday and Thursday around 5-10
kts. Light to calm winds at night. High confidence.

Friday...VFR. South to southwesterly winds 10-15 kts. High
confidence.
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&&

.MARINE...
A tight pressure gradient forms between high pressure off the
Eastern Seaboard and an approaching cold front. SW winds will
increase to 15 to 20 kt with gusts to 25 kt through the day
along with seas building to 4 to 5 ft. Small Craft Advisory
remains in effect through late afternoon. VSBY restrictions in
showers and scattered thunderstorms. Winds turn NW tonight at 10
to 20 kt. Seas diminishing to 2 to 4 ft.

Outlook...

Tuesday...Sub-advisory conditions expected. Initially northerly
winds will shift to the south around 5-10 kts. Seas 2-3 feet. Fair
weather.

Wednesday through Thursday...Sub-advisory conditions expected. South
to southwesterly winds 10-15 kts. Seas 2-3 feet. Fair weather.

Friday...Winds and seas building to near advisory criteria,
especially into the afternoon. Southerly winds 15-20 kts with gusts
up to 25 kts and seas 3-5 feet. Fair weather.

Rip Currents...

SW winds will range from 15 to 20 mph today before turning NW
tonight. However, there will be a New Moon on Tuesday. As a result,
there is a MODERATE risk for the development of dangerous rip
currents at New Jersey beaches today and a LOW risk at Delaware
beaches. With high pressure building in from the west, there is a
LOW risk for the development of dangerous rip currents at New Jersey
and Delaware beaches on Tuesday.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 4 PM EDT this afternoon for
     ANZ450>455.

&&

$$
Synopsis...Staarmann
Near Term...MPS
Short Term...Staarmann
Long Term...Hoeflich/Staarmann
Aviation...MPS/Staarmann
Marine...MPS/Staarmann