Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
341 am EST Tuesday Dec 1 2015
a warm front will lift through our region today. By tomorrow night,
a cold front will slide through our region, before the large low
pressure system lifts to the northeast. After that, high pressure
should build in through the remainder of the week and into the
Near term /until 6 PM this evening/...
a warm front will lift through our area today. As the front makes it
way through, we will continue to see periods of rain across the
region. In addition to the increased moisture and warmth, we have a
shortwave moving through the region this morning/afternoon which may
enhance the precipitation causing it to become moderate to heavy at
Temperatures have been warming all night and with the exception of a
very few spot locations in the higher terrain, we are above the
freezing mark in the forecast area. Another good thing has been the
increasing dew points in these areas. With that said, the threat for
any potential freezing rain has ended and we have changed everything
over to plain rain in the forecast for today.
We should see some additional warming occur today but not too much.
Temperatures are expected to range from the low/middle 40s across the
northern zones to the upper 50s across the southern zones.
Short term /6 PM this evening through 6 am Wednesday/...
periods of rain/fog will continue through the night although the
intensity may lighten up some as the shortwave exits to the east and
the warm front pushes to the north of the area. We might even see a
lull in the precipitation or more of a change to some very light rain or
drizzle. With light winds and a very moist low level of the
atmosphere, we may see some fog develop through the overnight
With cloudy skies remaining across the region, we won't see too much
of a change with the overnight temperatures. Lows will range from
around 40 across the northern zones to the lower 50s across the
Long term /Wednesday through Monday/...
once the main low pressure system begins to lift away from our
region on Thursday, the remainder of the long term is relatively
quiet as a high builds over the region.
Wednesday...more of what we'll see in the near and short term, as
the region remains in the warm sector, with rain expected to
continue through the day. Model soundings do indicate meager cape
values, so could see a shift back from a stratiform event to a
more convective event. In addition...model soundings show precipitable water
values above one inch which is above the 90th percentile of normal
for this time of year. Still, mean wind speeds will be quite high,
so think the heavy rain threat is limited.
Wednesday night and Thursday...cold front sweeps through the
region Wednesday evening, which should translate into an abrupt
end to the precipitation for most locations as dry air advection becomes
a major factor behind the front. The one exception is in the
Poconos and northwest NJ, where the westerly and northwesterly flow may
result in some orgraphically enhanced precipitation. For now though, it
appears any lingering precipitation in these areas would be either light
rain or drizzle as the middle levels will dry out quickly (and
temperatures, even in the highest elevations, should stay above
freezing through this period).
Friday through Monday...a surface high will slowly slide east out
of the central U.S. Through this time resulting in a dry pattern.
Should see a very modest warming trend through this period as the
1000 to 500 mb thickness increases as the upper level ridge
Aviation /09z Tuesday through Saturday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy, and surrounding areas.
Today...mainly IFR conditions exist at the terminals with
intermittent returns to MVFR at times. With an easterly flow across
the region, expect ceilings and visibilities to largely remain
IFR,possibly drop to LIFR at times, through much of the day. Periods
of rain with fog are expected to continue through today. Easterly
winds will continue through today. A period of stronger winds this
morning will gradually relax through the afternoon. Winds along the
coast will be a bit stronger with gusts up to 20 knots at kacy
Tonight...IFR or lower conditions will remain possible through
tonight with periods of rain continuing through tonight. Winds will
lighten up this evening, becoming around 5 knots or less overnight.
Wednesday and Wednesday night...starting as IFR with low
ceilings and rain, but slowly improving through the day into
Wednesday evening. By late Wednesday night conditions should return
to VFR. Abrupt shift to westerly winds possible with the cold front
on Wednesday night.
Thursday through Saturday...mostly VFR conditions expected.
the Small Craft Advisory on the lower Delaware Bay has been
A Small Craft Advisory remains in effect for the ocean waters
through 6am Wednesday.
Winds will continue to gust in the northeast to east flow through
this morning across the area waters with a weakening trend through
the day. Although the winds will drop below 25 knots by this
afternoon, the seas will remain above 5 feet. Seas are expected to
remain elevated through today. Once the winds subside enough, the
Small Craft Advisory will likely need to be changed over to a small
craft for hazardous seas.
Wednesday... winds and seas should stay below Small Craft Advisory criteria through
the day. There may be some reductions in visibility due to the rain.
Wednesday night through Thursday night...behind the cold front that
will push through Wednesday night, wind gusts of 25 to 30 knots are
expected on the Bay and the ocean waters. There is a small chance
for a few gusts to 35 knots on the ocean waters on Thursday morning.
Through this period waves near 5 feet are expected on both the ocean
waters and the Lower Bay. Winds and seas should slowly subside
Friday and Saturday...winds and seas should stay below Small Craft Advisory criteria.
Marine...Small Craft Advisory until 5 am EST Wednesday for anz450>455.