Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
1222 PM 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/...
As the warm front lifts northward this afternoon, a short
wave/vorticity impulse will lift through the area as well. We can
see the area of rainfall associated with these features
approaching from the south. This rainfall will spread northward across
the area this afternoon, with periods of moderate rainfall
possible. Mesoscale models indicate the highest rainfall amounts
close to 1/4th of an inch will be across central and eastern New Jersey
We should see some additional warming occur today but not too
much. Temperatures are expected to range from the middle/upper 40s
across the northern zones to the middle/upper 50s across the
southern zones, and low 50s in between.
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 /17z Tuesday through Saturday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy, and surrounding areas.
Today...IFR/LIFR conditions will continue through the day. Light
rain/drizzle early will be replaced by more steady rainfall,
moderate at times, later this morning into the afternoon. Winds
will remain east to northeast around 5-10 knots, with some
stronger winds and gusting near 20 knots along the coast.
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
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.
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.
November was a top 10 warmest month for many of our climate
Phl #2 at 53.2 plus 5.6 normal 47.6
period of record GOES back to 1874
Ilg #6 at 50.8 plus 4.2 normal 46.6
period of record GOES back to 1917
Abe #3 at 48.0 plus 5.3 normal 42.7
period of record GOES back to 1922
Allentown also will have had a trace of snow for the month which is
below the monthly normal of 0.7 inches. A trace in November is
not unusual, having occurred in 2009 and 2013, both of which ended
up big Winters with around 59.8 and 68.1 inches of snow
respectively including big february's of 3 foot monthly snowfall.
In addition, Allentown had the 7th driest November on record.
The driest november's for Allentown are
2012 and 1946 both 1.00
Acy 8 at 51.1 plus 4.3 normal 46.8
period of record GOES back to 1874
Marine...Small Craft Advisory until 5 am EST Wednesday for anz450>455.