Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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591
FXUS61 KPHI 270937
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
537 AM EDT FRI MAY 27 2016

.SYNOPSIS...
High pressure off the middle Atlantic coast will settle over our
region through the weekend, gradually giving way to a cold front,
that is expected to move through our area Tuesday. Canadian high
pressure is expected to settle over our region by mid week, while
a persistent area of low pressure lurks off the southeast coast.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
535 AM ESTF: Showers in northwest NJ were moving ene and dying
rapidly. they should be all in our county warning area (CWA) by
630 am. PWAT is building and so slow moving showers means
torrents. Hamburg in Berks County earlier had 0.4 inches,
Rieglesville in Hunterdon County .34, Clinton in Hunterdon County
0.21, Stewartsville in Warren County 0.22,  KABE .14,  KXLL 0.27

Today...Confidence on where and when any showers and tstms is below
average. Thinking mainly north of I-78 and mainly this afternoon.
PWAT of 1.7 inches and slow ene movement at 15 to 20 kt could
mean the issuance of flood advisories for poor drainage street
flooding this afternoon in a few locations...maybe Morris County
is the focus?

Otherwise very warm and more humid with a potential for D2 of 90F
temps at KABE/KPHL/KPNE/KTTN/KACY/KGED/KESN. Depends on how much
sunshine and how much non marine influenced flow. Best chance for
90F temps is near and north of I-78 possibly extending down to
KPHL? Airmass is as warm as ydy with higher dewpoints. More cloud
cover may make it more difficult to maximize heat potential but
for now we have issued 90F Philly north. This again is above all
available NCEP guidance which includes the Super and National
blends which yesterday were biased low with respect to reality.
EC also indicates says about the same as ydy. This would mean max
temps 10 to 15F above normal.

Max heat index today...roughly in the lower 90s...or about 5 to 6f
warmer than yesterday...because of the higher dewpoints.

South to southwest wind with afternoon gusts 15 mph.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
Any late day convection should diminish and end by midnight.
Otherwise fair and mild. Looks like haze and/or patchy fog early
tomorrow morning with the fog in your typical spots...northwest NJ
and also vcnty KRDG and KMIV. Min temps about 10 to 15F above
normal.

Forecast basis: a 50 50 blend of the 00z/27 GFS/NAM MOS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
The main story will continue to be above average temperatures
thru Sunday with high temperatures near 90 degrees, as well as
uncomfortable humidity levels into early next week. Temps will
remain above average into the middle of next week

The main uncertainty will be the interaction between an approaching
cold front early next week and an early season tropical/sub-tropical
system modeled to develop in the Bahamas. The models continue the
trend of drawing a plume of moisture northward along the east coast,
with PW values nearing 2.00 inches, or 2 to 3 Standard Deviations
above normal by Monday. With the approach of a cool front and
weak steering currents aloft, there is the potential for heavy
downpours on Monday. Otherwise, there is a chance of diurnally
driven showers and thundershowers Saturday and Sunday. For
Saturday, this activity should be focused northwest of I-95,
while Delmarva may see an increase in activity by late Sunday.

A cold frontal passage is anticipated Tuesday, with a drying
trend for Wednesday and Thursday. But with low pressure off the
southeast US coast, this front may get hung up close to our
region, which would lead to a more pessimistic forecast.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Early this morning through 12z...VFR with showers NNJ weakening
and ending ending by 11z. Light south to southwest wind.

After 12z...VFR with sct-bkn aoa 5000 ft. South to southwest wind
gusting around 15-18 kt during the afternoon. Chance of a shower
or tstm but not in the TAFS till more convinced of nearby passage
of any convection. For now we have prob30 of a mdt afternoon
shower in KRDG and KABE.

Tonight...VFR. Any evening convection diminishes and ends early
and am thinking mostly north of our TAF sites. Patchy 1SM fog
possible near 09z vcnty KMIV...otherwise a bit hazy early
Saturday morning. Light south to southwest wind.

OUTLOOK...

Predominantly VFR during the day through the period, with MVFR
possible Sunday night thru Monday night.

&&

.MARINE...
No marine headlines through tonight.

Southerly flow persists...at times gusty to 15 or 20 kt. Seas generally
1-3 ft. More conservative NWPS wave heights were used for this 330AM
forecast.

OUTLOOK...
Winds and seas are expected to remain below SCA criteria during
the Saturday thru Tuesday time frame. Some maritime fog is
possibleSunday night.

RIP CURRENTS: Issued low risk for the formation of dangerous rip
currents except for Monmouth County - moderate. Gusty southerly
winds to 20 mph late in the day may enhance the rip current risk
elsewhere along the NJ coast.

Warmer than normal temperatures, appears to be one part of the
recipe for heightened surf zone danger. Another part: unguarded
beaches. Be smart and safe. Unless you`re an accomplished
swimmer... unguarded beach swimming is ill advised.

The water temperatures were still only in the lower 60s southern
NJ and Delaware Atlantic coasts, and the upper 50s along much of
the northern NJ coast.

&&

.CLIMATE...
The record maximum temperature today at allentown is 91, set in
1991 and 1965. It should be near record this afternoon. All other
record maximum temperatures in our county warning area (CWA) for
May 27 appear out of reach.

&&

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

&&

$$
Synopsis...Franck
Near Term...Drag 538
Short Term...Drag 538
Long Term...Franck
Aviation...Drag/Franck 538
Marine...Drag/Franck
Climate...538



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