Area Forecast Discussion
Issued by NWS Mt. Holly, NJ-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KPHI 191954
Area Forecast Discussion
National Weather Service Mount Holly NJ
354 PM EDT THU MAY 19 2016
High pressure will build into the region tonight and influence our
weather through Friday. A low pressure system will develop over the
southeastern United States late Friday, crossing to the south and
east of our area over the weekend. Surface high pressure will then
build across the region early in the week but unsettled weather will
remain due to an upper level low across the Mid-Atlantic.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --Remainder of this afternoon...Partly to mostly sunny. There might
be a couple of late day showers in NJ (dewpoints look too dry in
PA which are below guidance) with a leftover cool pool aloft and
modest low level moisture trying to initiate a low top convective
release. However, other than the nearby KEWR shower of a little
earlier this afternoon, have withdrawn the showers from the
forecast. Light south to southeast winds along the coasts and
light west to northwest inland. isolated gusts 20 kt.
Tonight...Clear with radiational cooling in the countryside as high
pressure slides eastward overhead. Any daytime cumulus is forecast
to dissipate this evening. Evening light nw winds west of I-95 and
light south-southwest winds over SE NJ, DE and MD eshore, all become
west to northwest during the night and become nearly calm everywhere.
Radiated low temps several degrees below 12z/19 GFS/NAM MOS guidance
most of the area countryside in NJ and PA. These lows are several
degrees below normal in the countryside.
Patchy fog is in the forecast the typical spots of northern and
coastal NJ but probably not a big deal. Used UPS cross over tool.
Otherwise this forecast was a 50 50 blend of 12z/19 GFS/NAM
-- End Changed Discussion --
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
-- Changed Discussion --Sunny and pleasant. Light north to northwest winds during the
morning turn southwest interior during the late afternoon when
cirrus starts arriving, and south to southeast along the coasts.
This forecast was nearly identical to the previous forecast.
Raised the 50 50 blended 12z/19 GFS/NAM guidance by a degree
(upper 70s I-95 corridor). These max temps are several degrees
above normal away from the waters influence.
-- End Changed Discussion --
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Friday night should be most quiet as high pressure shifts offshore
and moves to the east. Clouds will increase from the south to the
north as low pressure organizes across the southeastern United
The aforementioned low pressure system will move to the northeast
through Saturday, passing to the south and east of the area late
Saturday into Sunday. Rain associated with this system will push in
from south and spread northward through Saturday. PWAT values in the
1.5-2.0 range indicate that heavy rain is possible, especially
across the Delmarva and Southern New Jersey on Saturday. As we head
into Saturday night, the rain should be starting to lighten up,
especially across our western areas. However, light showers may
continue through Saturday night.
At the surface, high pressure will make its way into the from the
west on Sunday. The wrench in the forecast is a pesky upper level
low that will reside over the eastern US, keeping us in more of an
unsettled pattern for the start of the work week. There will likely
be breaks in any precipitation that does develop but we are not
likely to see much sun during this time.
Tuesday is when things start to look up a bit. The upper level low
starts to break down and then shifts to the east. A few lingering
showers are possible but expect the region to start clearing out as
we head into the middle of the week.
Some differences in the models exist from Tuesday onward in how the
surface high is positioned. The ECMWF keeps the high just to our
south while the GFS has it breaking down, allowing for a few
shortwaves to cross the region. What they do agree on is warmer air
making its way into the region leading to above normal temperatures
for the latter part of the week.
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
Remainder of this afternoon...VFR sct-bkn clouds aoa 7000 ft.
Isolated afternoon showers possible, vicinity KTTN but chances
too small to add to the TAF at this time.
Light generally north or northwest wind backing to west or southwest
later in the day except southeast to south sea breezes along the
coasts including KACY and KMIV progressing northwestward slowly
but probably not reaching I95.
Tonight...VFR clear. winds Becoming light west to northwest during
the night or calm.
Friday...VFR. Clear to start then some cirrus late in the day.
Light northwest to north wind becoming southwest interior late in
the day and south to southeast coastal areas during the afternoon.
Friday night...VFR conditions are expected with increasing
cloudiness from south to north. Showers may start to impact the
southern terminals late.
Saturday...Showers will start to spread northward through the area
on Saturday. VFR conditions will rapidly deteriorate to MVFR, with
IFR conditions possible. Rain may be heavy at times, especially from
KPHL and to the south and east.
Sunday through Monday...Showers continue through Sunday and Monday
with VFR/MVFR conditions expected.
Tuesday...Mainly VFR conditions expected. A few showers may move
through the region but confidence is low at this time.
-- End Changed Discussion --
No marine headlines through Friday.
Water temperatures are generally a little below normal...mid 50s.
Southeast to south wind, max gusts under 20 kt, turning west to
northwest during the night and Friday morning with max gusts under
15 kt. Southerly sea breezes developing during the afternoon.
Friday night...Sub-advisory conditions are expected to continue
across the area waters.
Saturday through Sunday...low pressure will move up the southeast US
coast and pass to the south and east of the area. As the low makes
it way towards the area, seas and winds will start to increase. Seas
will build and begin to exceed 5 feet by Saturday afternoon. Seas
will remain elevated through Sunday evening.
East winds ahead of the low will tun to the northeast by Saturday
afternoon, increasing through this time. Wind gusts will increase
and gale force gusts remain possible, especially across our southern
ocean zones Saturday afternoon and night. At the very least a Small
Craft Advisory will be needed. A Gale Warning may be needed for a
stretch of time Saturday afternoon and Saturday night. For now, we
have issued a Gale Watch for Saturday for our 3 southernmost ocean
Monday...Any lingering higher seas should subside in the wake of the
departing low. Winds are expected to remain around 10 knots out
of the north-northeast with gusts up to 20 knots.
Tuesday...Sub-advisory conditions are expected to continue across
the area waters.
RIP CURRENTS: The Surf Zone forecast begins Friday morning and it
will have a news headline on our homepage. It should also be
accompanied by a probable debut of the Experimental National Beach
Forecast page (if not Friday afternoon, then certainly early next
week). You will be able to click the beach located umbrella and
comprehensive beach localized forecast information including beach
specific forecasts, the surf zone forecast, ultraviolet index, rip
current preparedness/safety information for beaches within our
forecast area. DIX and DOX live radar will be posted on the right
side as well as a Rip Current recognition video, and Lightning
Safety tips. Comments on the page will be welcome.
We expect that we will need to adjust the density of the beaches
All this will be tied together in a social media announcement
sometime late Friday morning.
Ultimately for beach goers maximum enjoyment and safety...swimming
within vision of lifeguards is a best practice. Rip currents come
and go, tending to repeat only near jetties and piers, particularly
the incident side of the swell. Rip currents may be a little stronger
when the tide cycle is in the lower half of its cycle. Most rip
current fatalities are male, under 40 and unguarded beaches.
Water temperatures are currently a little below normal, mid 50s.
MARINE...Gale Watch from Saturday morning through Saturday evening for
Near Term...Drag 355
Short Term...Drag 355