Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
413 am EDT sun Jul 24 2016
high pressure will remain in control over the area until a weak
cold front approaches the from the northwest by late tonight. This
front will push across the area Monday. High pressure will return
for the middle part of the week. Another front may affect the area
Thursday into next weekend.
Near term /until 6 PM this evening/...
a frontal boundary will continue to sink just to our south early
today, with drier air moving into the region from the north as high
pressure north of the area weakens as it tries to move across the
area. Temperatures today will continue to be hot with most places
reaching the low to mid 90s. With the lower humidity, even with the
high temperatures, the heat index values will not reach much more
than the actual air temperature, except across the far south where
the humidity will be the highest. The excessive heat warning for
the Philadelphia Metro areas will remain in effect as heat index
values will hover near criteria today and certainly get there
We should be precipitation free today as drier air moves in behind
the frontal boundary an no short wave/vorticity impulses are
expected through the daytime hours.
Short term /6 PM this evening through 6 am Monday/...
the evening will start off precipitation free, but as we go through
the night, the frontal boundary to our south will begin lifting
northward, while a short wave/vorticity impulse approaches from the
west. This short wave is expected to interact with the lifting
frontal boundary and create isolated/scattered showers or
thunderstorms during the overnight hours. The best chance for any
precipitation overnight looks to be the northern two-thirds of the
There could also be some patchy fog north of the lifting warm
frontal boundary overnight with a warm and moistening airmass moving
Long term /Monday through Saturday/...
the main impact will be the heat and humidity for the early part of
the week. Expect high temperatures in the mid to upper 90s across
the area Monday. This, combined with a very humid airmass will push
heat index values above 100 degrees for most of the area. A weak
cold front will push across the region late Monday and Monday night.
This will spark off the next round of showers and thunderstorms with
the potential for some to become severe.
This cold front will slide to our south by Tuesday, bringing some
slight moderation in temperatures and humidity levels. Still expect
temperatures in the lower to mid 90s with heat indexes that approach
100. Much of the area should stay dry Tuesday and Wednesday, with
just extreme southern New Jersey and the Delmarva with the threat of
thunder due to the proximity to the stalled frontal boundary
lingering across the mid-Atlantic. The slight downward trend of heat
and humidity levels will continue on Wednesday with temperatures
generally staying in the lower 90s.
The front starts to approach back from the south as a warm front by
Wednesday night into Thursday. A couple of weak waves of low
pressure may develop and then ride up along this boundary giving US
a couple of chances for shower and thunderstorm development for the
latter part of the week. There does not look to be much in the way
of a pattern chance into next weekend, so expect the warm, humid and
unsettled weather to continue through the end of the week and next
Aviation /08z Sunday through Thursday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
There is some patchy light fog this morning, mainly at miv and other
rural areas, but this will lift and burn off around/shortly after
sunrise. The rest of the day will be VFR. It is possible that some
patchy fog could develop again overnight tonight into Monday
morning. Also, there is a chance for isolated/scattered showers or
thunderstorms overnight tonight.
Winds are light and variable at many locations this morning, but
where they have a direction, they are more northwest and will likely
become north to northeast later this morning. Winds are expected to
become more south to southwest during by midday as high pressure
weakens as it tries to move across the area.
Outlook... VFR much of the time. Scattered (mostly) late
afternoon and evening showers and thunderstorms may limit
cigs/vsbys at times through the period. The best chance for this
will be Monday afternoon and evening and then again on Thursday.
sub-Small Craft Advisory conditions will continue today and tonight
across the area. There is a chance of showers or thunderstorms late
tonight into Monday morning.
mostly a period of sub-sca conditions expected. Scattered
showers and thunderstorms will create locally higher winds and seas
through the period. Best chance for this will be Monday afternoon
and evening and Thursday.
record high temperatures today through Thursday are below.
Site 24th 25th 26th 27th 28th
---- ---- ---- ---- ---- ----
Phl... 98-2011 96-1899 101-1892 101-1940 100-1941
Abe... 95-1999 95-1999 98-1940 98-1955 97-1949
Acy... 100-2011 99-2010 96-2011 99-2005 98-1999
Ilg... 98-2011 96-1987 99-1894 100-1894 101-1894
Ttn... 98-1910 97-1999 99-1892 100-1894 101-1894
Ged... 99-2011 99-2010 97-2012 98-2005 99-1949
Ridge... 96-2010 96-1999 99-1940 98-1955 99-1941
Mpo... 91-1914 90-1999 89-1949 91-1955 93-1949
PA...heat advisory from 11 am to 6 PM EDT Monday for paz060>062-101-
Excessive heat warning until 6 PM EDT Monday for paz070-071-
New Jersey...heat advisory from 11 am to 6 PM EDT Monday for njz001-007>010-
Excessive heat warning until 6 PM EDT Monday for njz015-
Delaware...heat advisory from 11 am to 6 PM EDT Monday for dez002>004.
Excessive heat warning until 6 PM EDT Monday for dez001.
Maryland...heat advisory from 11 am to 6 PM EDT Monday for mdz008-012-015-