Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
321 am EDT sun Aug 30 2015
high pressure will slide over the eastern U.S. Through the work week
leading to a mostly hot and dry pattern. A weak cold front may slide
into our region on Thursday. A low off shore and a high to our
northeast may provide some cooler conditions for next weekend.
Near term /until 6 PM this evening/...
hi pressure will remain over the region today and slowly
move eastward. As it does, both cloud cover and moisture will increase.
A shortwave will approach from the west during the afternoon hours and this feature
could trigger a shower or tstm, mainly for northern and western areas, so will
continue very low probability of precipitation in these locations. However, the overall air mass
is very dry, so it wouldn't be surprising if nothing happened either.
Temperatures will be a bit warmer than Saturday and Delaware points will creep up as
Short term /6 PM this evening through 6 am Monday/...
any isolated showers or thunderstorms will come to an end and then
expect just a pcldy sky with gradually increasing dew pts, as the
high remains the dominant weather feature as we close out August and
Long term /Monday through Saturday/...
some shifts in tracks and timing with the latest model runs, but
the main story remains the high sliding over the region for much
of the work week.
Monday through Wednesday...may see a few lingering showers or
thunderstorms Monday morning as an upper level short wave trough
moves further away from the region, but otherwise precipitation
chances through this period are very slim. Should see a modest
warming trend from Monday into Tuesday as the ridge axis slides
overhead, thus leading to increasing 1000-500 mb thicknesses for
the region. Even with this high amplitude ridge though, highs
should stay well below records, and heat index values should stay
in the lower to middle 90s.
Thursday...a bit more uncertainty in this period, specifically
with the evolution of the weak cold front. Some models are now
stalling this front well north of the region, or showing the
temperature gradient almost disappear completely by the time it
reaches our region. For now though, have stayed close to the
previous forecast for both temperatures and precipitation chances,
as the upper level short wave trough could provide enough lift and
focus for convection even without the front, and still think there
is a chance the front will reach the area given that the models
tend to underestimate how far south fronts will propagate in the
Friday through Saturday...stayed relatively close to the previous
forecast as there are some large differences among the long range
models in this period. The GFS shows steady on shore flow as a
surface high develops to our northwest. Meanwhile, the European model (ecmwf) shows
a vertically stacked, and nearly stationary, low to our southeast.
Either solution though does look to bring a cooling trend through
Aviation /07z Sunday through Thursday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
VFR conds will be the rule through the taf pd, with hi pressure
in control. A weak disturbance will move through during the late afternoon
hours and could touch off a stray rain showers or thunderstorms and rain mainly for krdg or
kabe. However, overall chances are very low and, therefore, will not
be mentioned in the tafs. Otherwise, expect a SW wind to develop y
late morning generally 10 kts or less. Wind will then decrease after
Monday through Wednesday...VFR conditions expected though
localized MVFR conditions with fog possible each morning.
Thursday...mostly VFR conditions. Isolated thunderstorms
no marine flags are anticipated through the near and short term
periods. Seas will generally be in the 2 to 4 feet range. Wind will generally be
SW in the 10 to 15 knots range with gusts as high as 20 knots.
Monday through Thursday...winds and seas should stay well below
Small Craft Advisory criteria. Water temperatures are above
a moderate risk will be maintained in New Jersey once again
today, as we will have 24-4 feet seas, SW wind that could gust as high
as 20 knots and southeast swell. We will still be influenced by the nearly
full moon as well and have long periods...around 10 seconds. In
Delaware, the risk remains low.