Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
1151 am EDT Monday Aug 31 2015
high pressure will build over our region through middle week. A weak
cold front should slide south through our region Thursday into
Friday. This weekend, high pressure will reside along the eastern
New England coast, providing a little relief from the heat.
Near term /until 6 PM this evening/...
the sprinkles from earlier this morning have mostly dissipated.
Partly to mostly cloudy skies remain across the area through
today. A weak surface trough across the area, combined with weak
short wave/vorticity impulse moving across the area through this
afternoon may help create a few isolated showers, so we'll keep a
slight chance of showers across the northern and western areas,
but have expanded the showers farther to the east. Would not be
suprised to see an isolated lightning strike or two. There is also
a large area of precipitation to our south across Virginia that is
slowly moving northeast. The current expectation is that if this
area holds together through the afternoon that it will remain to
our south. If it does move a little farther northward, it would
likely mainly affect southern Delaware and the adjacent coastal
With at least to some partial sunshine, temperatures today should
be close to what they were Sunday.
Short term /6 PM this evening through 6 am Tuesday/...
behind the fropa, surface high pressure builds back in and expect a
clearing sky and generally light wind.
Long term /Tuesday through Sunday/...
Tuesday and Wednesday...upper level ridge axis slides over the
region. As a result, thicknesses increase and should see
temperatures a few degrees higher than today. With the ridge axis
overhead on Tuesday, synoptic scale subsidence should inhibit any
showers from developing. A few models show an embedded upper
level short wave trough digging southeast over the region
Wednesday, which could be enough for isolated convective
initiation, primarily west of the fall line.
Thursday and Friday...still considerable model disagreement and
continuity on the timing and evolution of the cold front which may
be sliding into the region through this period. At this point,
think the faster (with the front arriving late Thursday or
Thursday night) and further south (moving completely south of the
region) solutions are the most likely given the large meridional
component of the upper level pattern. That being said, I didn't go
quite as low with high temperatures each day as the GFS and ECMWF,
given the still large model disagreements.
Saturday through Sunday...once the front slides south, the next
question will be where the surface high stalls. At this point, it
is looking likely that it will be far enough off shore to lead to
on shore flow for our region, providing further relief from the
heat, and possibly some light precipitation.
Aviation /16z Monday through Friday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
VFR conds are expected once again. A weak cold front will approach from
the northwest during the afternoon. It may touch off a stray shwr, mainly north and
W, but for the most part it is expected to be dry. Probability of precipitation are too
low to include in the forecasts.
Do not expect much of a wind shift behind it. Wind should be generally out of
the SW and will increase and become gusty in spots this afternoon. Gusts
could reach about 15 kt, before subsiding overnight, to below 5 kts
or less in most areas.
Tuesday...VFR conditions expected.
Wednesday...localized MVFR conditions with br possible in the
morning, and isolated thunderstorms possible near kabe and krdg in
the afternoon. Otherwise...VFR conditions expected.
Thursday through Friday...increasing chances for showers and
thunderstorms across the region. Also possible for widespread fog
to develop north of a cold front if it moves into our region.
no marine flags are anticipated through the near and short term
periods. Seas will generally be around 3. Wind will generally be SW in the 10
to 15 knots range with gusts as high as 20 knots.
Tuesday through Thursday...winds and seas should stay well
below Small Craft Advisory criteria. Water temperatures are above
Friday...seas could approach 5 feet, especially late in the day on
Friday and wind gusts near 20 knots are possible.
a moderate risk will be maintained in New Jersey once again today, as we
will have seas around 3 ft, SW wind that could gust as high as 20
knots and S swell. We will still be influenced by the nearly full
moon as well and have long periods...around 9 seconds. In
Delaware, the risk remains low.