Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
1239 PM EST Wednesday Nov 25 2015
strengthening high pressure over the northeastern United States will
crest to the south of Newfoundland late Thursday or Friday. A cold
front will cross our region Saturday followed by high pressure
influencing the area Sunday. Organizing low pressure over the
Midwest states may bring some unsettled weather to our region early
Near term /until 6 PM this evening/...
today...sunny (few cirrus and sc). Temperatures maybe 3 degrees warmer than
yesterday (near normal) with the wind turning light east or
Not critical to the forecast but you may notice..for those with
home barometers..the surface pressure quite high, near 30.75
inches by days end.
Forecast basis: blended 00z/25 GFS/NAM weighted more heavily to
the warmer GFS.
Have increased temperatures a tad as some areas are already at or within
a degree of fcsted highs and with full sunshine see no reason why
they wont exceed them. Otherwise, made a few minor tweaks to forecast.
Short term /6 PM this evening through 6 am Thursday/...
other than some possible thin cirrus, it will be clear "most" of the
night and frosty again (except not the coasts). There will be a
subtle change...persistent southeast flow in the boundary layer will be
increasing the relative humidity below 3500 feet and actually there should be some
mixing of the wind overnight...possibly to 15 miles per hour along the New Jersey
coast...especially from kacy northward to Raritan Bay. Elsewhere
the light wind may actually Bend back to northeast.
Am also expecting a deck of SC to develop sometime after 4 am
(ecmwf is not that interested in the SC option) along the coasts...
especially the New Jersey coast. There may also be some patchy Countryside
fog elsewhere...mainly in excessively radiative cooled areas which
is basically vicinity kfwn-kptw slot.
Adjusted some of the Countryside temperatures lower using the new
06z GFS mavmos.
Forecast basis: blended 00z/25 GFS/NAM weighted more heavily to the
colder values of the available 00z/25 NCEP MOS guidance. Then added
my recently Standard radiative lowering by 2-3f in the kfwn- kptw
slot and also The Pine Barrens of New Jersey though am not as confident of
full radiative cooling there because of a possible stirring of the
Long term /Thursday through Tuesday/...
a fairly quiet and mild start to the long term for Thanksgiving day
and Friday as strong departing high pressure will continue to
influence the middle Atlantic Seaboard. A southeasterly onshore flow
will be felt across the region both days, and other than a little
patchy morning fog in more favored areas Thursday and Friday, dry
weather is expected with a mix of sun and clouds. Daytime temperatures both
days will be running well above normal, some 10 to 12 degrees above
late November averages, with highs ranging from the 50s across the
north to the lower and middle 60s from the Delaware valley to
central/southern New Jersey and the Delaware-Maryland-Virginia.
By Saturday morning, a cold front is forecast to be crossing our
area. Moisture looks to be fairly limited with this boundary, but we
have kept some low chance probability of precipitation for showers as the front passes from
northwest to southeast through the forecast area. Maximum temperatures
overall will be about ten degrees cooler as compared to Friday, and
our northwest zones may have falling temperatures into Saturday afternoon
as the cooler air filters in behind the cold front. Saturday's highs
are expected to range from the 40s across the north to the lower and
middle 50s across the south.
More uncertainty exists with the rest of the extended part of the
forecast as an area of high pressure stretching across the Great
Lakes region is expected to influence our weather Sunday. Meanwhile
to our southwest over the lower Ohio Valley, an organizing low
pressure system may send some showers our way from late Sunday into
Monday, followed by another area of low pressure developing south of
the Great Lakes into Tuesday. As mentioned there is a good deal of
uncertainty with the timing and extent of showers across our area as
there are noticeable differences in model solutions between the GFS,
ECMWF, and others regarding the strength of the high pressure to our
north and also the strength and track of organizing low pressure
across the Ohio Valley/Great Lakes. The GFS overall is a much drier
solution as compared to the European model (ecmwf) which eventually develops a much
stronger low pressure that tracks into eastern Canada, with a
trailing cold front affecting our region late Tuesday. For now, we
blended in the latest wpc and superblend guidance with continuity
for temperatures/winds/pops for the latter part of the long term period.
Temperatures look to be running around normal for the Monday and
Tuesday timeframe as we close out November and start December.
Aviation /18z Wednesday through Monday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Today...VFR. Mainly high clouds. East to southeast wind 10 kts or less.
Tonight...VFR clear or scattered cirrus. Then a deck of broken ceilings
somewhere between 2000-3500 feet should develop along the coasts
sometime after 09z/26. Small chance patchy fog elsewhere in the
Countryside toward 10z...mainly the extra radiative areas of northwest New Jersey
and east central PA. Light east or northeast wind except southeast
gusts to 15 knots possible along the New Jersey coast.
Thursday and Friday...mainly VFR conditions are expected. Some
patchy fog may develop, especially early Friday morning, and some
lower ceilings may also develop during Friday with southeast,
Friday night and Saturday...some brief sub-VFR conditions possible
in showers as a cold front crosses the area.
Sunday...mainly VFR conditions. Slight chance for some showers,
especially across the southern terminals.
no headlines. Good weather for the mariner. Light north to northeast
wind becoming southeast this afternoon with gusts increasing to 15
knots and persisting tonight. A long period swell of 2 feet persists on
the Atlantic waters throughout.
Thursday...sub-advisory conditions are expected.
Friday and Saturday...a Small Craft Advisory may need to be
considered for the Atlantic coastal waters as seas may increase into
the 5 to 7 foot range. Wind gusts may also approach 25 knots for a
time later Saturday.
Sunday...winds and seas below Small Craft Advisory levels are expected.
the following locations may experience near record warmth Friday
November 27, presuming there is considerable sunshine from midday-
early afternoon Onward with a south to southwest wind of around 10
miles per hour. All guidance is now in agreement favoring a very nice day
for the first big shopping day after Thanksgiving...after any
early morning clouds/fog and mex/ece MOS almost identical to each
Of the records below...it appears kmpo is least likely to
approach, holding in the 50s.
Record highs for Friday November 27
kabe 62 -1988 and 1959
krdg 65- 2011
kmpo 60- 2006 and 1984
kacy 69- 1981
November is projecting and probably locked to be a top 10 warmest
month for at least portions, if not all of our forecast area.
This mornings reevavluation includes all climate data through the
24th, and then projected lows and highs from our National Weather Service Mount Holly
database of November 25 through the 30th. Unless something remarkable
occurs that we and the models are not foreseeing, there should be
very little slippage in the projections below. In other words, we
Post with above average confidence that these numbers should be
close, probably within 4 tenths accuracy either side.
The only change in monthly average and associated ranking was
Atlantic City (radiational cold at pomona)
Phl #3 at 52.8 plus 5.2 normal 47.6 por 1874
Ilg #7 at 50.7 plus 4.1 normal 46.6 por 1917
Ilg has missing monthly data between the late 1890s and 1917 so
we know the database is useful back through 1917.
Abe #5 at 47.7 plus 5.0 normal 42.7 por 1922
Acy tied #9 at 50.9 plus 4.1 normal 46.8 por 1874