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
322
FXUS61 KPHI 280726
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
326 AM EDT Tue Mar 28 2017

.SYNOPSIS...
Weak low pressure will move across the Middle Atlantic region today
and then offshore tonight. Large high pressure will build across the
area Wednesday and then move east of the area by Friday morning. A
low and its associated fronts will push across our region Friday and
remain into Saturday. More high pressure will be over the area
Sunday and into Monday. Another disturbance may affect the area Next
Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
317 AM ESTF: sct tstms in NJ should exit northeastward this
morning by daybreak. Torrents of rain in stronger cells with
possibly very small hail.

Not expanding advisories posted last evening at this time.

It is possible that the Dense Fog Advisory may need to be
expanded westward in the 6 am fcst, but confidence on how
widespread it will be, is low, at this time.

Today...Murky again. Mostly cloudy. Fog and scattered showers
especially north of the boundary this morning then possibly a
tstm on the Delmarva this aftn where best mlcape of less than
800J. Weak speed shear so svr not expected. PWAT 1.25 so brief
torrents of rain possible in any shower.

Pls follow later PHI discussions and those of SPC regarding SVR
potential.

FCST basis: 50 50 blended 00z/28 GFS/NAM MOS.Temps were modified
downward using the 2m temps from HRRR and NAM. Still, the
temperature forecast remains a concern with the placement of the
eastward- extending warm front again a complicating factor.
Errors in these values are likely given timing of the rain
cooling factor and where skies may thin to allow a little sun.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
Any remaining showers end from west to east with a slightly
faster modeled end to the rain than 24 hours ago.

There could be some patchy fog, especially early at night in
the still moist boundary layer with a light north wind
increasing a bit late at night and trending northwest.

FCST Basis was a 50 50 blend of the 00z/28 GFS/NAM MOS.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A rather steady progression of disturbances in the extended period
with a 2 day (or so) return period. Fair weather is expected for
much of Wednesday and Thursday as high pressure across Canada ridges
southward across the area. Temperatures will be close to normal with
highs in the mid/upper 50s south and low/mid 50s north. Lows will be
in the mid/upper 30s north and low 40s south. It will be dry and
breezy Wednesday, but with wet ground conditions, fire weather
hazards will probably not be a big concern.

The first of two disturbances in the long term will affect much of
the area for much of Friday and Saturday. Low pressure will move up
the Ohio Valley Friday and then off the VA Tidewater area Saturday.
Our region will remain on the cooler nrly part of the system.
Occasional showers should occur much of the time. Depending on what
computer model, the rains could begin Thu night. Temperatures should
remain near or a little below normal thru the period. A couple
snowflakes across the highest elevations of the southern Poconos are
possible.

Fair weather returns over the region for Sunday and persist into
Monday as high pressure to the north ridges across the area.
Temperatures will be a little above normal with upper 50s to low 60s
for highs in most areas. Another disturbance may approach for Tue
with the latest EC model having a soaker system across the area and
the GFS much slower with the low and a fair weather day for Tue. We
just have chc pops for now.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Through 12z...variable conditions with generally MVFR vsby
gradually deteriorating to IFR conds in st/fog by 12z with
scattered showers and isolated tstms. light wind, mostly east
or northeast at the TAF locations.

After 12z...IFR variable MVFR conds in st/fog scattered showers
and a generally light east to northeast wind.

Tonight...MVFR/IFR conditions possible in showers and fog early...
becoming VFR late. Light north winds will become north to northwest
overnight around 10 knots.

OUTLOOK...

wed/thu...VFR expected. Gusty north winds Wed.
fri/sat...lower cigs/vsbys expected. Showers.

&&

.MARINE...
Dense Fog Advisory continues for the New Jersey coastal waters
north of Little Egg. Areas south may also develop dense fog
this morning, but it is less certain at this time.

Winds/seas will be under advisory criteria through Tonight.

Scattered showers/isolated thunderstorms through today, with
showers ending this evening.

OUTLOOK...

wed...sub-sca conditions.
wed night/thu morning...low end sca near the nj coastal waters.
thu afternoon thru fri...sub-sca expected. Showers fri. fri
night thru sat...sca possible. showers.

&&

.EQUIPMENT...
KNEL appears to be reading 10F too warm the past several days.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Dense Fog Advisory until 10 AM EDT this morning for NJZ013-014-
     020-026.
DE...None.
MD...None.
MARINE...Dense Fog Advisory until 10 AM EDT this morning for ANZ450-451.

&&

$$
Synopsis...O`Hara
Near Term...Drag
Short Term...Drag
Long Term...O`Hara
Aviation...Drag/O`Hara
Marine...Drag/O`Hara
Equipment...



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