Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPHI 181756
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
156 PM 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 TUESDAY/...
Weak reinforcing cold front moving across the region late this
afternoon with a bit more cold advection and mid-level cloud
cover overspreading the region, and possibly a few sprinkles or
flurries, especially in the Poconos. Dry, colder air mass builds
in behind the front tonight with temps dropping near or below
freezing region-wide, accompanied by a persistent west to
northwest wind, resulting in wind chills deep into the 20s for
most and into the lower teens in the Poconos. Will have some sun
to start on Tuesday, but clouds then increase as warm advection
gets underway ahead of the next system. The combination of the
cold air mass and return of clouds will keep temps down on
Tuesday, with few locations managing to reach 50. Winds will
remain gusty as well much of the day. By late afternoon, there
could be enough warm advection to cause a few flurries or snow
showers to develop in the Poconos, but the air mass should be
too dry elsewhere for any precip.

&&

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

Through Tonight...VFR. Winds W to NW 10-20 kts with gusts to 25
kts rest of today diminishing to 5-10 kts with gusts 10-20 kts
tonight. High confidence.

Tuesday...VFR. Winds W to NW 5-10 kts with gusts 10-20 kts early
increasing to 10-20 kts with gusts to 25 kts in the afternoon.
High confidence.

Outlook...

Wednesday through Friday...VFR overall. A few SHRA or SHSN
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...
SCA through Tuesday with persistent west to northwest winds
10-20 kts with gusts to 30 kts. Seas mainly 2-4 ft.

Outlook...

SCA conditions expected Wednesday 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 over the next few
afternoons could lead to fire weather concerns across our
region. The lack of rainfall during the past week has led to dry
fine fuels over the region, with fine fuel moisture already below
20 percent.

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
further 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 until 6 PM EDT Tuesday for ANZ430-431-
     450>455.

&&

$$

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


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.