Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 280504

Area Forecast Discussion
National Weather Service Mount Holly NJ
104 AM EDT SAT MAY 28 2016

A ridge of high pressure across the mid-Atlantic region will maintain
generally fair and warm weather through most of the weekend. Moisture
from the remnants of a tropical system to our south may reach the
area Sunday night and interact with a weak frontal system to produce
showers and thunderstorms. More high pressure and dry but continued
warm weather are expected through the middle of next week.


1230 AM ESTF: No major changes overnight. Temps and dews pretty
close to the hourly projections through midnight. A fair warm
summerlike night with a little more wind on-going than expected
24 hours ago (s-sw 5-10 mph). Patchy stratus/fog expected portions
of e PA toward dawn, particularly near KABE and possibly nw NJ
also. We reset the DIX STA/STP and expect to be in clear air VCP32
for the remainder of the night.

Saturday...Am expecting hottest day of this late May warm spell
and 1-2F warmer than ydy in e PA and interior NJ. Early season
heat wave (Day 3 of the minimum three consecutive 90f or greater
required) is at hand for PHL/PNE/ABE/WRI while other locations
nearby in our CWA have been 89-90F the past two days and today
will be day 3, but cannot officially note them as heat wave
potential inclusive (GED/REG/TTN). So, after any early morning low
clouds/fog/haze...a sunny day with the forecast likely verifying
above any of the warmest available guidance be it bias corrected,
or individual NCEP op MOS, super and national blends. Will discuss
the details in the 3am update. Bottom line...16c at 850 with a
south-southwest wind gusty to 20 mph this afternoon should allow
temps to rise to 1-2F above yesterdays values, at least for e PA
and interior NJ. Heat index 90-95 for NJ and e PA and maybe only
near 90 DE/E MD. may or may not issue advy?

Not anticipating convection this Saturday afternoon even in the
pwat axis of 1.5" near and north of I-78...northern portion of
our CWA. There is no known lift mechanism. Suppose something
isolated can develop but with suppressant ridging at mid levels
(500mb) today and lack of excessive moisture (PWAT of 1.5" for a
570 1000-500mb thickness is not excessive), therefore it seems
difficult to develop afternoon convection.

Max temps again 10-15F above normal.


Fair and not quite as warm as this morning because the PWAT lowers
northward from 1.5 to 1 inch tonight (also means lower dewpoints)
with minimum temps probably 5 to 10F above normal and a light
south to southwest wind. May be hazy with patchy fog expected
late, primarily in the countryside. Any evening showers along and
north of I-80 in NNJ/ne PA quickly end during the evening.


The current summer-like weather pattern over the mid-Atlantic
region is expected to continue through the extended forecast
period. Temperatures will be somewhat above normal and
precipitation will be mainly in the form of convective rain
showers and t-storms. Surface and upper-level features affecting
the area will remain relatively weak. One uncertainty at this time
is how much effect we will see from the tropical/sub-tropical
system now off the SE Atlantic coast.

Moisture from tropical depression 2 NE of the Bahamas is forecast
to move N into the mid-Atlantic on Sunday with an increasing
chance of showers and T-storms by afternoon. Showers and storms
are forecast to continue Sunday night into Monday as a weak
frontal system moves into the area from the NW. PWATS are forecast
to be near 2 inches over the area so some heavy downpours and
possible flooding can be expected. Clouds and precip will result
in milder daytime temps on Monday.

By Tuesday somewhat drier air is expected to push in from the W
and decrease the chances for precip as an upper-level trough moves
by to the N. Daytime temps will recover back into the 80s as there
is not much change in air mass with the with the associated surface
front. Wed and Thu should be mainly fair with high pressure
building in from the N/NE and low-level winds off the cool
Atlantic. Both the latest GFS and ECMWF suggest another frontal
system approaching from the W or NW by next Fri, with increased
chances for precip.


The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12z...VFR with MVFR vsby possible toward 10z in haze or
patchy fog. Small chc IFR stratus fog vcnty KRDG/KABE toward 10z.
Light south to southwest wind.

After 12z...any sub VFR vsby improves to VFR by 15z with only sct
clouds aoa 5000 ft and a south to southwest wind gusty to 18 kt
during mid afternoon. no convection expected at the TAF sites
though not impossible to see an afternoon shower vcnty KABE/KRDG.

Tonight...VFR with possible patchy MVFR vsby in haze or patchy
fog toward 10z sunday. Light south to southwest wind.


Mainly VFR conditions are expected through the period, except
MVFR possible Sunday night thru Monday night in showers and


No marine headlines anticipated through Saturday night.

Winds were gusty 20-30 kt for a time this past Friday evening
(44065 and Weather Flow sites) along the coasts and this drove
seas upward to near 5 ft at 44065. This was stronger than we
expected 24 hours ago. The southerly flow and associated wind
wave are subsiding now.

So in essence, a south to southwest wind occasionally gusty to
near 20 kt through Saturday night with Atlantic waters seas 2-4ft
and De Bay 1-2 Ft.


Winds and seas are expected to remain below SCA criteria during the
Sunday thru Wednesday time frame. Poor visibility is possible
Sunday night through Monday night in showers and thunderstorms.


We`ll be adding considerable information to this section between
4 and 5 am Saturday.




Near Term...Drag 104A
Short Term...Drag 104A
Long Term...AMC
Aviation...AMC/Drag 104A
Marine...AMC/Drag 104A
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