Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
1211 PM EDT Wednesday Jul 30 2014
a building area of high pressure over the western Atlantic will push
a warm front towards the region this weekend. Multiple surface waves
will ride northeast along this frontal boundary through this weekend.
High pressure should become dominant again here early next week.
Near term /through tonight/...
no significant change to the early morning forecast. Basically a
much nicer day than yesterday with much less afternoon cloudiness,
warmer temperatures (kapg and kiad and kokx all have a full sun sounding
with 1 degree of 80). If there is a shower...it would be the
Poconos very late in the day.
Tonight...little change to the previous forecast. Showers and
isolated thunderstorms associated with the cool pool in the central PA
mountains this afternoon may reach the Poconos late this evening?
Otherwise...this looks to ME to be another very very nice night
for middle Summer!
Short term /Thursday/...
stronger shortwave interaction with increasing column moisture
and better, not great, instability should lead to widely scattered
showers and isolated thunderstorms...some as early as late morning.
Temperatures should end up being several degrees below normal
with ample cloud cover and scattered shower activity.
Long term /Thursday night through Tuesday/...
no dramatic shifts in the guidance over the past 24 hours though it
is becoming more apparent that there is a split amongst the NCEP vs.
Non-NCEP guidance for this weekend. The dominate feature/driving
force through the end of the work week. Thereafter, the stronger
trough begins to break down with its closed low opening up and
moving off towards the north and east over the weekend. A much more
broad based trough remains overhead through the end of the period.
Friday...deeper moisture advects into the region with ridging
offshore building and heights across the East Coast beginning to
increase. Better instability over the eastern sections of the County Warning Area
with more middle-level impulse activity should lead to even more
scattered convection during the peak heating hours. Weak surface
convergence under a predominant south-southeast flow will aide in
better lift for shower activity along the higher terrain.
Temperatures should again end up cooler than normal.
Saturday - Sunday...upper level jet dynamics come into play more so
than previous days with the right entrance region sitting across the
mid-Atlantic. Offshore ridge continues to build and pushes the
inverted trough closer towards the region, as a warm front of sorts.
Numerous waves move along this baroclinic zone with various degrees
of strength and speed. As stated above there is a split in the
numerical guidance in regards to the timing and location of these
waves. NCEP guidance has a slower approach than the non-NCEP members
and also with their quantitative precipitation forecast fields. Not too prudent to rely on the quantitative precipitation forecast
output still several days away, but the trend may be your
friend...wetter solution for US this weekend. Still lots of
uncertainty to work with though the GFS looks in line with the gefs
while the ec and its ensemble members are in close agreement. We
continue with the chance probability of precipitation given the uncertainty but have added
moderate rain to the forecast with the amount of available moisture
that could be tapped into.
Monday - Tuesday...slight drying trend expected on Monday though not
entirely void of any showers with cold air still aloft with a few
more shortwaves shearing across overhead. High pressure should be
nosing in by Tuesday to allow for better drying. More moisture and
heat advects in and could push temperatures back to normal.
Aviation /16z Wednesday through Sunday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Through 00z this evening. VFR generally scattered clouds at or above 5000ft.
Tonight...VFR. Light or calm wind.
Thursday...mostly VFR ceilings developing with scattered showers and
thunderstorms possible in the afternoon. Local sub-VFR conditions
in showery activity. Medium confidence.
Friday...mostly VFR with scattered showers and thunderstorms
possible during the afternoon. Local sub-VFR conditions in
showery activity. Medium confidence.
Saturday - Sunday...mostly VFR. Possibility for widespread showers
and thunderstorms each day creating MVFR/IFR conditions...some could
be heavy. Medium confidence on possibility, low confidence with
respect to coverage.
announcement: we have posted a new experimental marine observation
program that any mariner can easily use to communicate with the
National Weather Service here in Mount Holly... provided you have internet access. This
can help US fine tune our forecasts...especially if the forecast
is not reflecting the reality at your location. An announcement
will Post in the public information statement and be on
Forecast: expect winds and seas to remain below Small Craft
Advisory through Thursday with winds staying below 15 knots and seas
between 1 and 3 feet. Winds will become southerly this afternoon.
Thursday night - Sunday...sub-sca conditions are expected across
our waters this period.
Dix 88d om through around 3 PM.
near term...drag 1211
short term...drag 1211