Area Forecast Discussion
Issued by NWS Mt. Holly, NJ
FXUS61 KPHI 201953
Area Forecast Discussion
National Weather Service Mount Holly NJ
353 PM EDT WED JUL 20 2016
A weak front will push through the Delmarva tonight. Then, high
pressure will build into the area Thursday night and Friday. A
cold front will cross the region and dissipate Friday night into
Saturday. Strong high pressure will then re-establishes itself
into next week, but another cold front will slowly approach from
the northwest by Tuesday.
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
High pressure will build over the region tonight. This will result
in clear skies with light winds. Temperatures will likely cool off
fairly quickly this evening with lows in the Pine Barrens and in
valleys across northwestern portions of the region. Temperatures
will likely fall a few degrees below what model guidance is showing
for tonight in those areas. Some patchy fog can not be ruled out for
a hour or two just before sunrise. However, it would be very shallow
dissipating rapidly by sunrise. Will leave fog out of the grids at
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
High pressure will gradually move offshore. It will still be close
enough for another mostly sunny day across the region. This will
also mean a change to more southwesterly winds which will increase
the heat and humidity. Modeled boundary layer temperatures and
statistical data show highs right around or just under 90 for most
of the region on Thursday. An afternoon seabreeze could also occur
as well, cooling the shore off by a few degrees.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
High pres and heat will be the main wx features thru the extendd
pd. thu night starts dry with high pres off the cst. fri am will
remain dry, but durg fri a cdfnt will approach from the w and
cross the region durg fri aftn and eve. expect shwrs and tstms to
develop, especially n and w. ltst guid suggests less areal
coverage, but there is some disagreement as to how far s the tstms
may actually reach. spc has the nrn 2/3s of the area in mrgnl risk
on fri with gusty wind and hail being the greatest risks in an
increasingly hot and moist ams.
by sat, the heat really gets turned up and continues into mon and
psbly tue. a cdfnt will cross the area mon night, but will likely
not do much to cool things down on mon as they will area too late
in the day. shwrs and tstms will accompany the front. temps shud
easily hit the mid 90s Sat thru Tue, with heat index values
around 100 degrees Sat and sun and 105 degrees on Mon, then 95 to
100 on Tue. Heat headline will likely be needed for at least a
portion of this period and may be initiated as soon as Thursday.
The guid differs by a few degrees Sun and Mon and the dew points
can make a world of difference but no matter how you look at it is
going to be hot and uncomfortable.
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
VFR through Thursday. Two main points of discussion. First, A narrow
window for patchy fog is present from about 09-10z Thursday morning
just before sunrise. Right now fog formation is not likely given the
available data but it can not be ruled out. A Seabreeze could form
and change the wind direction for a short window in the afternoon
around 19z potentially impacting ILG and ACY. Winds will be under 10
knots, more variable tonight then from the southwest on Thursday.
Thu night...VFR. High confidence.
Fri-Fri night...Generally VFR. A chance of shra/tsra, especially
n and w which may briefly lead to MVFR/IFR. Gusty southwest winds
15-20 knots. CFP. Mdt to high confidence.
Sat-Sun...VFR. High Pressure. High Confidence.
Mon...Mainly VFR. A cdfnt will approach from the W durg the day
and could trigger some shra/tsra durg the aftn, which cud lead to
some MVFR/IFR, especially n and w. Moderate confidence.
Seas are expected to remain around 2 feet through Thursday. Any wind
gusts will be under 15 knots more variable tonight then from the
southwest on Thursday.
Thu night...No marine headlines anticipated.
Fri-Fri night...SCA conds psbl with increasing winds ahead of an
approaching cold front.
Sat-Mon...No marine headlines anticipated.
RIP CURRENTS... The risk for the formation of dangerous rip
currents through Thursday will be low at the DE and NJ beaches,
but very localized moderate rips are possible, especially along
the NJ coast.
We have had some reports of upwelling along the coast, where
temperatures have dropped into the 50s and 60s.