Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 181124
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
724 AM EDT Mon Mar 18 2024

.SYNOPSIS...
A reinforcing cold front moves through the region today.
Several upper level disturbances and cold fronts will pass
through the region this week as surface high pressure builds to
the west. Developing low pressure approaches for the end of the
week and weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
An upper trough to the west of our area will push east today
and move offshore tonight. High pressure builds across the area
thru the period. Overall, a dry forecast today as west to
northwest winds increase over the area. Cooler and much drier
air will continue to arrive today and then winds will diminish
tonight. We have undercut much of the dew point guidance with
dew points dropping in to the teens or low 20s by this
afternoon. Winds will increase to 10 to 15 mph with gusts to 25
mph. Sky cover will be mostly sunny early, but then increasing
clouds for the afternoon, especially for North/West areas. Highs
will be close to normal with upper 40s/low 50s in many areas.

For tonight, the upper trough crosses the area and high
pressure ridges in from the Ohio Valley. After some evening
clouds, skies will become mostly clear. Cold temperatures are
expected with readings dropping to the mid/upper 20s for the N/W
areas to near freezing across Philly metro and Delmarva. Winds
will be West to Northwest around 5 mph.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A deep upper trough will encompass the Northeast, Mid-Atlantic,
and Great Lakes for the Short Term period. Several disturbances
will push weak cold fronts through the region Tuesday
afternoon, then again on Wednesday afternoon and evening.
Canadian high pressure then builds into the Northern Plains and
western Great Lakes Wednesday night.

Conditions will mostly be dry on Tuesday, although Lake Effect
streamers will develop off of Lake Erie and may dip down into
the southern Poconos Tuesday afternoon. A gusty westerly flow of
15 to 20 mph with gusts as high as 30 mph will be in place, and
cold air advection will keep temperatures generally in the 40s
to around 50, which are 5 to 10 degrees below normal for this
time of the year.

By Wednesday, some weak warm air advection will allow
temperatures to climb by a few degrees compared to Tuesday.
Another cold front will pass through the region late Wednesday
and Wednesday night as low pressure passes north of the region.
This may touch off some more rain showers down to the I-95
corridor and snow showers in the southern Poconos. QPF will be
minimal.

A gusty west flow will turn northwest Wednesday night with
speeds 15 to 25 mph with 25 to 35 mph gusts.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
High pressure passes north of the region Thursday through
Friday. Cold air advection redevelops on Thursday with
potentially the coldest day of the week with highs in the low to
mid 40s. Northwest winds will continue to range from 15 to 25
mph with 25 to 35 mph gusts, though a few peak gusts could reach
40 mph.

With high pressure moving offshore Friday, return flow sets up
and temperatures begin to warm back up to normal levels for the
end of the week and weekend.

Unsettled conditions on tap for the upcoming weekend as
developing low pressure looks to take a run at the Mid-Atlantic
and Northeast. However, there is much uncertainty among the
models as to the track the low will take. Will follow the NBM
and cap PoPs at chance.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

.Rest of Today...VFR expected. Mostly high clouds early then
increasing Cu/Sc clouds for the late morning and into the
afternoon. Northwest to West winds increasing to 10 to 15 kts
with gusts to 25 kts. High confid.

.Tonight...VFR expected. Decreasing clouds and winds. Northwest
to West winds 5 to 10 knots. High confid.

Outlook...

Tuesday through Friday...VFR overall. A few SHRA or SHSN
Tuesday afternoon, and again Wednesday afternoon and evening
could result in brief sub-VFR conditions. A prolonged period of
W-NW winds will range from 15 to 20 kt with 25 to 35 kt gusts.

&&

.MARINE...
Low pressure moving along the front to the south will move
offshore early today. High pressure builds in later today and
tonight. Winds will increase thru the day as colder air arrives
across the waters. We`ll probably remain below SCA much of today
but some gusts around 20 kts are possible early this morning.
Late this afternoon and for tonight, SCA winds and seas are
expected to develop. SCA will be issued with the 330 AM fcst.
Fair weather is expected today and tonight.

Outlook...

SCA continues into Tuesday, and SCA conditions expected through
Thursday with persistent W-NW winds. Gales are possible from
time to time, especially Wednesday or Wednesday night.
Conditions could subside below SCA levels Friday.

&&

.FIRE WEATHER...
Lowering humidity levels and increasing winds this afternoon
could lead to fire weather concerns across our region. The lack
of rainfall during the past week has led to dry fuels over the
region. After coordination with the fire weather partners later
this morning, the fire weather products will be updated and
there is a possibility of an SPS being issued.

A few rain or snow showers are possible across the Poconos from
time to time this week. Aside from that, dry conditions on tap.
Although most of the area is above normal for precipitation
since March 1, it has been a week since the last significant
rainfall, and no significant rainfall is expected this week.

Min RH values this week will generally range from 25 to 35
percent, and stronger westerly flow occurs over the area as well
with winds generally 15 to 20 mph with gusts 25 to 30 mph.

The day of highest concern looks to be Thursday, where surface
dew points drop into the upper single digits to low teens. Min
RH values may be as low as 20 to 25 percent, and west to
northwest winds could gust as high as 30 to 35 mph. By then, it
will be almost 2 weeks since the last significant rainfall.

Depending on how fast and how efficiently fine fuels dry out
will add to possible concerns for the rapid spread of any fires
that may develop.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 PM EDT
     Tuesday for ANZ430-431-450>455.

&&

$$

SYNOPSIS...MPS
NEAR TERM...OHara/RCM
SHORT TERM...MPS
LONG TERM...MPS
AVIATION...MPS/OHara/RCM
MARINE...MPS/OHara
FIRE WEATHER...PHI


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