Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
940 PM EST Wednesday Nov 25 2015
high pressure will continue to strengthen as it builds over the
northeastern United States, cresting to the south of Newfoundland
late Thursday. A cold front front will cross the region on Saturday
followed by high pressure on Sunday. Low pressure will build across
the midwestern United States bringing unsettled weather to the
region early next week.
Near term /until 6 am Thursday morning/...
the surface high continues to build northeast. This will keep
benign weather and increasing temperatures over the area for the
Thanksgiving Holiday. Clear skies will lead to prime radiational
cooling conditions. As such, there could be some patchy fog around
sunrise, primarily in the Lehigh Valley and Pine barrens area.
Short term /6 am Thursday morning through 6 PM Thursday/...
a broad surface ridge will remain over the area with good southwesterly flow
as everyone sits down for Turkey. Clouds will continue to increase
and we will likely end up with a mostly cloudy day. However, the
southwesterly flow will cause temperatures to be about 10 degrees above normal.
Long term /Thursday night through Wednesday/...
high pressure will shift to the south of Newfoundland by late
Thursday and we should see a shift in the flow across our region.
The flow will become more southeasterly and we will see moisture
increasing across our area. With low level moisture increasing and
a moderate airmass in place, we will likely see some patchy fog
develop Thursday night into Friday morning. The airmass will remain
warm and we should see temperatures remain well above normal for
Friday. Expect highs from the 50s up into the middle 60s across the
Low pressure will cross well to our north across Canada with the
trailing cold front reaching our area late Friday into Saturday. The
front should reach our northern and western areas late Friday night
or early Saturday and some light showers look to accompany the
front. There still does not seem to be a lot of moisture associated
with the frontal passage so it doesn't look like Saturday will be a
complete washout. However, there may be enough moisture around for a
few showers to be a little bit steadier and we may continue to see
off and on showers through the day as the front sags to the
southeast. Overall, not expecting rainfall amounts to exceed one
half of an inch with this front. Temperatures on Saturday will much
cooler than Friday as the air behind the front taps into some of the
colder air seeping down from Canada. Temperatures will range from
the middle to upper 40s across the north to middle to upper 50s (may even
near 60) across the south. Expect a much coder night over the region
as well as temperatures respond to the air entering the area. One
limiting factor may be the amount of cloud cover we retain, which
may allow temperatures to remain a smidgen higher than the guidance shows.
Overall, expect lows to range from the upper 20s north to the lower
40s across the south.
Moving beyond the frontal passage becomes pretty jumbled as the
models struggle to get a grasp on what happens once the front moves
through. We should a brief return to high pressure on Sunday as
the high starts to build across the north of our area. However, the
models show that the front may never fully clear the area, stalling
across the Delaware-Maryland-Virginia. The stalled boundary looks like it would act as
means of transport for moisture, keeping eh chance for some showers
across the southern areas. As a low pressure system develops to our
west, we may see the boundary push north a bit, which would bring a
slight chance or chance of showers across the remainder of the
region. This low looks to be suppressed by the high on several
models and kind of gets squashed out by Tuesday. Yet another low
pressure system will develop over the Midwest or Ohio Valley and
start to move across the Great Lakes and across to the north of our
forecast area. Timing, location, and strength all differ at this
time and we will need to monitor to see if the models become more
aligned over the next several runs. With all of this said, we will
likely see a period of cloudier skies and showers possible through
midweek. With colder temperatures reaching into our northern zones,
we may see some the rain mix with or changeover to snow at times.
Aviation /03z Thursday through Monday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg,kmiv, kacy and surrounding areas.
Mostly VFR conditions are expected through the taf period. There
could be some patchy fog near 12z. The highest risk will be at
kmiv, kabe, and krdg, however, even at these locations it seems
unlikely, so have not mentioned it in the tafs at this time.
In addition, middle level clouds around 3000 to 4000 feet above ground level could
move in after 15z. At this point, expect VFR conditions, but
ceilings may briefly lower into MVFR category.
Winds will be mostly southeasterly but shifting to more southerly
by 18z. However, through out the taf period, expect wind speeds to
remain below 10kt.
Thursday night and Friday...mainly VFR conditions expected.
Patchy fog possible through early Friday morning. Low clouds remain
possible in the southeast flow.
Friday night and Saturday...a cold front will cross the region
Saturday with MVFR/IFR conditions possible in showers. Clearing from
northwest to southeast and return to VFR expected later in the day.
Sunday and Monday...mainly VFR conditions expected. A slight chance
for some showers, mainly across the southern terminals.
with strong high pressure to the NE and the ridge over the
area, no marine headlines are anticipated through the near and short
term periods. Seas will generally be 2-3 feet, possibly reaching 4 feet in the S
by the end of the period. Wind will mainly be southeast gusting as high as 15
Thursday night and Friday...sub-advisory conditions are expected.
Friday night and Saturday...increasing waves on the ocean may build
to 5 to 7 feet with a Small Craft Advisory likely needed. North to
northwest winds may gust up near 25 knots late Saturday.
Sunday and Monday...winds and waves are expected to fall below Small
Craft Advisory criteria Sunday with a period of sub-advisory
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 other.
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