Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Mount Holly New Jersey
337 PM EST sun Nov 29 2015

high pressure will build in from eastern Canada tonight and move
offshore on Monday. A warm front to south will move north as a
on Tuesday and Tuesday night. Meanwhile, low pressure across the
plains is expected to track eastward to the Great Lakes Tuesday.
A cold front will move through the Middle- Atlantic States on
Wednesday. As the low lifts into eastern Canada, high pressure
will build in from the west late in the week and into the


Near term /until 6 am Monday morning/...
high pressure builds across New England tonight, nosing its way down the
eastern Seaboard into our area. Any remaining showers or sprinkles across
southern New Jersey and Delaware-Maryland-Virginia will continue to dissipate late this afternoon
into this evening as drier air filters in from the north and any remaining lift
pushes south of the area. The remainder of the night should remain dry as the
high builds down across the area. Clouds will clear from north to south, but
will likely have a difficult time clearing across southern New Jersey and
Delaware-Maryland-Virginia as moisture gets hung up on the southern edge of the high


Short term /6 am Monday morning through 6 PM Monday/...
the high pressure to the north will move offshore of the New England coast
during the day Monday. This will allow cloud cover to build back across the
area, along with the possibility of precipitation. The most likely areas to see
rainfall later during the day would be across southern New Jersey and Delaware-Maryland-Virginia
as an area of vorticity moves into the area as ridging aloft moves across the
area, leading to some enhanced lift and moisture. Precipitation amounts during
the day would be fairly light and only amount to a couple of hundredths of an


Long term /Monday night through Saturday/...
high pressure will move off the new eng CST Monday night and Ely flow
will develop bringing an abundance of clouds and possibly some
drizzle or light rain, mainly over southern areas as a warm front begins to
approach from the S.

There is still a small chance for some freezing rain in our northwestern
zones Monday night if the air mass radiates enough due to cold air damming
and clouds hold off long enough. Confidence remains low on this
happening, but the possibility is there, as model guidance still differs
on frontal timing.

A closed low is forecast to track eastward from the upper Midwest
late Monday night to the Great Lakes on Tuesday and Tuesday night.
Southerly flow aloft ahead of this system will strengthen over the eastern
Continental U.S. During this time. This will produce an overrunning setup over
our region with the west-east oriented front that just moved through our area
positioned just to our south. Expect rain to expand back into our
area late Monday night into Tuesday.

On Tuesday an area of low pressure will eject out of the plains and move
northward toward the Great Lakes before moving eastward. Its attendant cold front will cross
the area Wednesday night. Expect periods of showers from Tuesday night through
Wednesday. While the guidance still differs somewhat on the timing of
heaviest rain and any breaks, it now appears that the precipitation will
linger longer into Wed, and a period of MDT to heavy rain will
likely occur Tuesday night. The GFS wants to bring another round of
MDT/heavy rain, especially for southern and eastern sections Wednesday aftn, while
the European model (ecmwf) does not.

Behind the cfp, high pressure will build in for Wednesday night through the
remainder of the extendd pd, bringing dry weather and near seasonable
temperatures. Overall, not a bad way to start December!


Aviation /20z Sunday through Friday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.

VFR conditions have returned to all taf sites this afternoon as clouds continue
to break and clear out from north to south. VFR conditions are then expected
for the remainder of this evening and overnight, although skies may not become
completely clear for the southern areas.

On Monday, MVFR ceilings are expected to build back across the area from the east
as high pressure to the north pushes offshore of New England and easterly flow
continues to moisten the low levels.

Winds vary from north northwest to north northeast this afternoon, but everyone
will become northeast this evening and overnight. Winds will become easterly
during the day Monday. Speeds are expected to remain 5-10 knots.


Monday night...MVFR ceilings at most terminals during the evening as warm front
approaches. Light rain will gradually expand nwwd. Some terminals
could deteriorate to IFR toward daybreak if steady rain develops.
MDT confidence

Tuesday and Tuesday night...MVFR with periods of IFR in rain likely. Rain
could be heavy at times. Light Ely winds become southerly as a warm front
lifts northward through the region. MDT to high confidence.

Wednesday...MVFR/IFR conditions with showers and cold front most likely late.
Still some uncertainty with respect to timing of cold front and heaviest rain. Low
to MDT confidence.

Wednesday night through Thursday...conds improving to VFR Wednesday night then VFR Thursday.
Westerly winds behind the cold front may occasionally gust to 20 knots
through Thursday morning. High confidence.


we have started the Small Craft Advisory across the far southern Atlantic
waters with this afternoon's forecast as seas at buoy 44009 are teetering
around 5 feet and will continue to rise tonight into Monday and
winds are gusting around 25 knots as well. The Small Craft
Advisory for the rest of the Atlantic waters will with its start
time of 10 PM. Seas will remain above 5 feet through Monday, and
winds could also gust round 25 knots at times on Monday.

Monday night and Tuesday...onshore flow around 15-20 kt, with some gusts
possible to 25 knots. Continue but with seas 4-6 ft, especially over the
southern waters. Confidence is lower further north. The Small Craft Advisory may need to be
extended into this pd, but there could be a lull in the northern waters.

Tuesday night and Wednesday...wind should be below Small Craft Advisory criteria and seas will
be decreasing. Maine flags will likely not be needed or only
needed in the morning. Wind will shift from east or southeast to northwest by late
afternoon as cold front passage occurs.

Wednesday night and Thursday...Post-frontal surge will produce wind that could
gust to Small Craft Advisory criteria during this time.


the WSR-88D located at Fort Dix New Jersey will be down at least until
Monday, November 30. The parts needed to repair the radar are on


Phi watches/warnings/advisories...
New Jersey...none.
Marine...Small Craft Advisory from 10 PM this evening to 6 PM EST
Monday for anz450>453.
Small Craft Advisory until 6 PM EST Monday for anz454-455.


near term...Robertson
short term...Robertson
long term...nierenberg

National Weather Service Glossary of Abbreviations