Area Forecast Discussion
Issued by NWS Mt. Holly, NJ-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KPHI 201351
Area Forecast Discussion
National Weather Service Mount Holly NJ
951 AM EDT FRI MAY 20 2016
High pressure will remain over the region today bringing beautiful
weather. A low pressure system developing over the southeastern
states will move toward the North Carolina/Virginia border by
early Saturday and then offshore. It will then move northeastward
off the coast. 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. Improving weather
with warmer temperatures is expected by midweek.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --After looking at current temps, the 00z and 06z Bufkit soundings,
and upper air soundings adjacent to the CWA, I trimmed afternoon
highs by a degree a two.
Great looking day ahead with lots of sun, little wind,
comfortable humidities, and at or slightly above normal temps.
High pressure extended from the eastern Great Lakes to the Middle
Atlantic region early this morning. The air mass will drift to the
east and off the coast today.
The high is expected to bring a mostly sunny sky for today. A light
northerly wind is forecast to become southerly by late in the day.
The sea and bay breeze fronts should work their way well inland with
little resistance from the synoptic flow.
Maximum temperatures are expected to favor the middle and upper 70s
in our forecast area. Readings will be a bit cooler than that in the
elevated terrain of the Poconos and northwestern New Jersey and
along the immediate coast.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
The high will continue to move out to sea tonight. Meanwhile, an
area of low pressure is forecast to move up the Ohio River Valley
with another low progressing northeastward along the coast of the
As the areas of low pressure approach our region, we are
anticipating and increase in high, then mid level clouds tonight.
Rain is forecast to begin moving into parts of southeastern
Pennsylvania and the upper Delmarva toward daybreak.
The wind should become light and variable for much of tonight.
However, it is expected to begin settling into the east on the
coastal plain late tonight with speeds increasing to 5 to 10 mph.
The thickening and lowering cloud cover should keep temperatures
from falling much below the upper 40s and lower 50s in our region.
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Low pres will move from near the NC/VA brdr offshore then newd on
Sat. This will bring widespread rain to the area, especially for
srn and ern portions. The rain will begin to taper off sat eve but
will linger into sun mrng for at least portions of the area. Rain
cud be hvy at times from the aftn into erly eve.
The guid still differs on Sun with the GFS and NAM/WRF being
drier than the ECMWF. Regardless, there is likely to be a t least
a dry pd in the mrng, if not longer. Any precip in the aftn would
be in the form of instability shwrs with the upr low overhead.
There is still considerable uncertainty for the early portion of
next week. With high pres at the sfc and an upr low, it is a bit
of an interesting fcst. It is, of course, difficult to fcst
completely dry conds under an upr low. At the same time the mdls
have been going back and forth and tend to overdo things on the
wrn side of an upr low. The day runs have been dry or drier and
then the night runs come in wetter. For now, will keep at least
some low pops for Mon and Tue, but am not making any major changes
to what has been fcst the last few days.
We finally kick the upper low out on Wed, which looks like it
could be the nicest day of the week under sfc high pres and
Then, low pres moves acrs the plains into ern Canada and its
assocd approaches from the w on Thu. This will increase precip
chcs for the latter half of Thu.
Temps will finally become more seasonal and be above nrml by the
end of the pd, which is something we have not been able to say
much in May. Sat will be the coolest day of the pd under ely flow
and abundant cloud cover and rain. Then there will be a warming
trend with temps into the 80s! by the end of the pd.
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
VFR conditions are expected for today and tonight.
We are anticipating a mostly sunny sky for today followed by an
increase in high and mid level clouds tonight. Ceilings should
remain above 8000 feet through daybreak on Saturday even as an area
of rain approaches from the southwest at that time.
A light northerly wind this morning is forecast to become southerly
this afternoon. The New Jersey sea breeze front is expected to reach
KACY early in the afternoon before making its way to the lower
Delaware Valley in the evening. The bay breeze will likely impact
KILG with a 160 or 170 degree wind around 8 to 12 knots for much of
the afternoon and evening. The wind should become light and variable
at our TAF sites for much of tonight before settling into the east
at KPHL and points to the east and south toward morning.
Sat...widespread ra expected acrs the region. VFR conds erly will
rapidly deteriorate to mvfr and ifr. Rain may be heavy at times
durg the aftn and eve, especially from KPHL and to the south and
east. high confidence.
Sun through Mon...Pds of shra with mvfr. Low to moderate
Tue...Mainly VFR conditions expected. A few shra may move through
the region. Low confidence of shra potential.
High pressure is forecast to pass off the coast today before moving
farther out to sea tonight. Low pressure should begin to approach
from the Carolinas late tonight.
A northerly wind this morning is expected to become southeast to
south during the afternoon and evening. The wind should back toward
the east late tonight. Wind speeds are forecast to be less than 15
knots through the period. Wave heights on our ocean waters should
favor the 2 to 3 foot range with wave heights on Delaware Bay
remaining 2 feet or less.
Sat through Sun...low pressure will move newd from nr the NC/VA
brdr up the cst. seas and wind will steadily increase 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 should easily reach the 7 to 8 ft range by Sat
night and will remain elevated will build and begin to exceed 5
feet by Sat aftn. Seas will remain elevated through Sun.
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 Sat aftn and night. sca will be needed everywhere,
and there the gale watch will remain in place over the srn waters
for now. mdl guid still differs on gale potential. however it is
also psbl that the gale watch cud be needed further n.
Mon thru Tue...No marine headlines are expected.
RIP CURRENTS: The Surf Zone Forecast begins for the season this
morning. Based on the expected wind, wave and swell conditions we
are anticipating a low risk for the development of dangerous rip
currents for today along the New Jersey shore and at the Delaware
The Surf Zone Forecast 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 this 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