427
FXUS61 KPHI 120545
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
145 AM EDT Wed Jun 12 2024

.SYNOPSIS...
High pressure will be in control through Thursday. A gradual
warming trend is expected for the remainder of this week ahead
of a cold frontal passage on Friday into Friday night. High
pressure will then return on Saturday and build across the
region through early next week with above normal temperatures.

&&

.NEAR TERM /THROUGH TONIGHT/...
Pesky upper low has been slow to clear the region early this
morning, with a few light echoes on radar lingering until after
midnight across northern areas along with plenty of low-mid
clouds. These are slowly dissipating and expect generally
clearing skies through dawn. Some patchy fog may form before
sunrise, most likely across parts of southern NJ and DE where
there was a little rain in the last 24 hours or so, but it
should be pretty minimal. Temps by dawn will be in the 50s for
most, 40s in the coolest Pocono spots and 60ish in the warmest
urban and coastal locales.

For today, upper low will continue pulling away as upper
ridging builds in. There will be a warm front moving across the
region to usher in the warmer air, and it will be accompanied by
mainly mid and high clouds, so not expecting a pure sunny
day... more likely partly to mostly sunny. Regardless, the
return of sun and passing warm front should push temps back to
near 80 for much of the region.

Tonight, ridging and warm advection continues aloft. Thus,
expect temps to stay a few degrees warmer despite less cloud
cover, with upper 50s to low 60s for most.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Quasi-zonal flow will develop through the end of the week with
increasing heights and thicknesses. Another trough axis will
approach and cross through the region by Friday night. At the
surface, high pressure will shift offshore by Thursday but
remain in control through early Friday. A cold front will then
arrive from the north and west on Friday into Friday night.

This pattern will translate to a gradual increase in
temperatures and dewpoints each day along with a dry forecast
until Friday. Highs on Thursday will be in the 80s to around 90
degrees for most inland locations. Temps on Friday will be a bit
warmer with a mix of 80s and low 90s away from the shore,
however with the earlier arrival of the cold front, temps have
trended a bit downward compared to yesterday. Near the shore
temps will mostly be in the 70s to around 80 degrees both days.
While dewpoints will be on the rise, they should top out in the
60s. This will keep heat indices close to the air temperature,
so at this point, it looks like we will remain below Heat
Advisory Criteria on Friday.

With respect to the cold front on Friday and Friday
night...there continues to be support from medium range guidance
that there will at least be some convection around in the
afternoon and evening. Exact convective details remain unclear
especially since we are outside the timeframe of the CAMs.
However, CSU-MLP guidance does have most of our area highlighted
in a 5-14% corridor of severe probs. So, we will need to keep
an eye on Friday`s heat and potential severe weather threats
over the coming days.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The upper trough will depart the region by Saturday giving way
to a large and expansive upper ridge that will build across the
eastern CONUS through early next week. High pressure will be
located near the Great Lakes on Saturday and over the Mid-
Atlantic on Sunday. This will result in near-normal temperatures
for the weekend with mostly sunny skies.

Surface high pressure will shift offshore early next week as
upper ridge builds further resulting in increasing temps through
the middle of next week. This is supported quite well by both
the Climate Prediction Center and most ensemble guidance where
temps may flirt with records. Little in the way of precipitation
is expected other than a stray thunderstorm during the
afternoon.

&&

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

VFR overall expected through tonight. Could be a little BR at
KACY/KMIV early this morning, but odds are not good, so have
left out of TAF for now. Otherwise, winds mainly 5 kts or less
through tonight, from a northerly or westerly direction, except
at KACY where a sea breeze is likely by this afternoon. High
confidence.

Outlook...

Thursday through Thursday night...VFR with mostly clear skies.
No significant weather expected.

Friday through Friday night...Sub-VFR conditions possible with
a chance of thunderstorms during the afternoon and evening.

Saturday through Sunday...VFR with mostly clear skies. No
significant weather expected.

&&

.MARINE...
No marine headlines through tonight. Winds northerly to westerly
generally below 15 kts and seas of 1-2, occasionally up to 3
feet.

Outlook...

Thursday through Friday night...SCA conditions possible
Thursday into Friday due to winds gusting up to 20-25 kt and
seas of 3-5 feet. Fair weather expected through Thursday night
with a chance of thunderstorms on Friday and Friday night.

Saturday through Sunday...No marine headlines expected. Winds
up to 10-15 kt with seas around 2-3 feet. Fair weather.

Rip Currents...

A Low risk for the formation of dangerous rip currents
continues through Thursday. Southerly winds will only have a
small component onshore for most of the coast. Additionally,
expecting more short period, wind driven waves.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...DeSilva/RCM
NEAR TERM...RCM
SHORT TERM...DeSilva/Johnson/Staarmann
LONG TERM...DeSilva/Staarmann
AVIATION...DeSilva/Fitzsimmons/Johnson/RCM
MARINE...DeSilva/Fitzsimmons/Johnson/RCM