Area Forecast Discussion
Issued by NWS Mt. Holly, NJ
FXUS61 KPHI 300126
Area Forecast Discussion
National Weather Service Mount Holly NJ
926 PM EDT WED JUN 29 2016
High pressure will remain the dominant weather feature through
Friday. A cold front will approach from the west on Friday,
crossing the region Friday evening and then moving offshore
through Saturday morning. High pressure will then build in from
the west for the weekend. A warm front will move into the area on
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
High pressure was centered over the Great Lakes and the Ohio
River Valley this evening. The high will continue building
We are anticipating a mostly clear sky overnight with a light and
variable wind. Temperatures are expected to drop into the upper
50s and lower 60s in most of our forecast area.
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
Sunny to start then sct cu form during the afternoon...possibly
broken for a time from PHL south and west. Cirrus becomes
noticeable to the south and west of PHL during the afternoon.
Light north to northwest wind early in the day turns southerly
during the afternoon with a definite southeast sea breeze
component along the coasts. The sea breeze probably develops
FCST Basis: a 50 50 blend of the 12z/29 gfs/nam mos.
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Mdls differ with the amt of moisture/precip Thu night. The GFS is
more robust, bringing at least some precip to the region. The
ECMWF confines precip, mainly to srn areas, while the NAM is
basically dry. For now, will keep some low pops and see what
happens. WPC is going twd the drier soln, so it would seem that
any precip chcs would be on the lower side and the GFS is
A cdfnt approaches from the w on Fri and precip chcs increase in
the aftn along with tstm probs. Moisture increase and dewpts creep
back into the mid 60s. CAPE is decent and LIs are more than
adequate on Fri. There is virtually no wind shear, however. But we
are in that time of year where it doesn`t take much for a
The cdfnt moves thru Fri night and high pres moves in for Sat
into Sun bringing genly dry wx. A wmfnt, extending ewd from low
pres in the plains cud bring precip to the Delmarva and srn areas
by Sun night.
The high then re-exerts itself for Mon, but low precip chcs still
exist over the extreme S. By Tue, the aforementioned low
approaches the region and there is considerable diffs between the
GFS and ECMWF. The GFS is stronger and wetter durg this timeframe.
Also important is the posn of a wmfnt, which the EC would have
over the Delmarva while the GFS is further N. Obviously, the Tue
fcst is low confidence attm.
Temps look to be nr nrml.
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
VFR conditions are expected through the TAF period under a mostly
clear sky. The wind should be light and variable overnight. It is
expected to settle into the west and southwest for Thursday around
4 to 8 knots.
Thu night through Fri...VFR conds genly expected Thu night,
though a few shra can not be ruled out that cud reduce cigs/vsbys.
The better chc of MVFR/IFR is on Fri aftn in tsra as cdfnt
approaches. Moderate confidence.
Sat thru Mon...Mainly VFR Conds expected. A few shra/tsra extreme
s on Mon. High confidence.
Winds and seas should remain below SCA criteria today through
Thursday. Any gusts for the most part under 18 kt.
RIP CURRENTS...We are forecasting a LOW risk for Thursday, but it
may border on moderate during the afternoon if a strong and more
onshore wind develops. Am expecting a near 3 ft ese swell of about
7 seconds. Local Ocean County beaches may experience more frequent
or stronger rip currents.
Thu night through Mon...Winds and seas are expected to remain
below SCA criteria. Gusty winds possible late Thursday or Friday
in the vicinity of any thunderstorms.
At this time...the outlook for the formation of dangerous rip
currents will probably vary daily from low to moderate through
Barring a highly unexpected rain event prior to 1 AM Friday,
Allentown will have recorded its 10th driest June on record (1.87
inches). Records date back to 1922. Normal for the entire month of
June at Allentown is 4.31 inches. The record lowest for June is
still 0.34 inches, set in 1949.
Otherwise, what you see today on monthly departures is pretty
close to what June will end up both for temperature departures and
rainfall deficits. The rainfall deficits received helpful
reduction the past two days, and hopefully we receive additional
assistance from mother nature on Friday.
A review of the past 7 days of rainfall still shows below normal
over most of northern NJ and ne PA except a narrow east-west swath
between I80 and I78.
June temperature departures continues 1-2 degrees above normal
ABE RDG TTN PHL, near normal ACY ILG and a bit below normal at GED
Lance prepared the following for your use:
The following table lists the number of days w/temperatures at or
above 90 degrees so far for the meteorological summer and spring
seasons compared to normal.
SITE Actual # Normal # Departure
---- --------- --------- ---------
ACY 5 4.5 + 0.5
PHL 8 6.4 + 1.6
ILG 3 4.4 - 1.4
ABE 6 3.0 + 3.0
In terms of the June 2016 monthly climate (as of 6/28) at our big
four long term sites, temperatures have been above normal and
precipitation below normal, except Wilmington, with slightly above
The following table lists: the normal average vs. June 2016
average temperature and the resultant departure from normal.
SITE TEMPERATURE (F) PRECIPITATION (IN)
---- ------------------ ---------------------
ACY 70.6 VS. 70.8 +0.2 2.90 VS 2.31 -0.59
PHL 73.0 VS. 74.0 +1.0 3.19 VS 1.87 -1.32
ILG 72.0 VS. 72.1 +0.1 3.62 VS 3.69 +0.06
ABE 68.9 VS. 71.1 +2.2 4.01 VS 1.87 -2.14
note: the above data represent the month through June 28.