Scientific Forecaster Discussion
fxus61 kphi 210702
Area forecast discussion
National Weather Service Mount Holly New Jersey
302 am EDT Sat Oct 21 2017
high pressure centered over the area will move offshore later today
but continue to influence our weather into Monday. A cold front
approaching from the west is expected to approach the region on
Tuesday. Low pressure will move along the front Tuesday night
through Wednesday. Another low will affect the area Thursday before
more high pressure builds in for the end of the week.
Near term /until 6 PM this evening/...
early this morning...clear or mostly clear. Calm or light wind.
Patchy fog possible in some of the river valleys toward dawn.
The 1230 am estf lowered some of the mins several degrees in
the Countryside. Lows will have been 0 to 5 above normal.
Today...sunny. Light wind becoming southeast during the afternoon.
High temps similar to or a couple of degrees warmer than ydy.
Used a 50 50 blend of the 00z/21 GFS/NAM except straight warmer
GFS 3 hourly and Max T today, trimmed a degree over i95. Max
temps about 10 to 15f above normal. Looks to ME like 75-59
virtually everywhere i95 corridor northwestward with support
from the 00z/21 ec 2m temp fcst at 18z today. It will be slightly
cooler high terrain. The 72 we're fcstg at kmpo is 5f short of
the record of 77 - 1959. Effective sea breezing along the coast
this aftn with water temps in the 60s...which are still
significantly above normal for this time of year. Max temps
today are fcst generally 10-15f above normal, greatest positive
departures i95 northwestward.
Short term /6 PM this evening through 6 am Sunday/...
clear and nearly calm but patchy fog may form toward dawn Sunday,
especially se of I-95. The 330 am fcst is a 50 50 blend of the
GFS/NAM MOS with Countryside temps lowered 2-3f below the
blended guidance and not much above this mornings mins...ranging
from zero to +10 of normal depending on location.
Long term /Sunday through Friday/...
high pressure will still be in control of the weather for Sunday and
Monday. Moisture will begin to arrive over the area however. This
will result in some cloudiness and areas of fog for Sunday morning
and increasing clouds for Monday. This will likely keep temperatures
a few degrees cooler than Saturday, but readings will still be above
normal for this part of October.
A slow moving front and a upper trough will arrive from the Ohio
Valley Tuesday-Wednesday. As it approaches, it slows, as low
pressure will be deepening across the tenn valley area. The low will
move along the front, just west of our region Tue-Tue night. This
should bring a period of showers and gusty winds to the area. Pops
are mostly in the likely/low categorical range at this time. Quantitative precipitation forecast
thru 12z Wed. Could reach 1/2 to 1 inch over much of the area.
The latest European model (ecmwf) model does have a few spots closer to 2 inches
of quantitative precipitation forecast however. Some of the guidance suggests that some tstms
are also possible. We will not have tstms in the grids at this
point, but will have to consider as we get closer to the event.
Temperatures will be above normal Tuesday, but then fall to
normal Wednesday as the front passes. Pops will decrease back to
chc or slgt chc levels after the front moves offshore.
There will still be a few sct showers around Thu as the upper low
crosses the area. After that, high pressure with drier air is
expected for Fri. Temperatures will be near normal for both of these
Aviation /07z Saturday through Wednesday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Through today...VFR with a few cirrus, especially this afternoon.
Light northwest wind trending northeast later this morning and
then southeast during this afternoon.
Tonight...VFR with some cirrus. The IFR St/fog may develop southeast
of I-95 toward dawn Sunday.
Sunday...a little fog or stratus early...otherwise VFR,
Sunday night and Monday...low clouds and fog are possible from
late Sunday night into Monday morning. Otherwise...mainly VFR.
Monday night through Tuesday night...conditions lowering to
MVFR and IFR in showers. Isolated thunderstorms and moderate to
heavy rain are possible on Tuesday afternoon and Tuesday
evening, along with a south wind gusting around 25 to 30 miles per hour.
Wednesday...conditions improving to VFR.
winds and seas well below Small Craft Advisory criteria through tonight.
Light northwest winds 5-10 kt with a few gusts around 15 kt over the
waters will veer over the next 24 hours, becoming north this morning,
east around midday and then S-southeast late today and tonight.
Seas in our coastal waters of around 2 ft through tonight.
Fog may develop on the coastal waters toward dawn dawn Sunday.
Sunday thru Monday...sub-sca conditions with fair weather.
Monday night...Small Craft Advisory developing on the ocean. Chance of showers.
Tue-Tue night...Small Craft Advisory conditions on the ocean and del Bay. Showers.
Wed-Wed night...Small Craft Advisory on the ocean. Sub-Small Craft Advisory on del Bay. Chc showers.
relative humidity values are likely to drop to around 25% this afternoon but
light winds will limit the risk for a rapid rate of spread of
the values below are the October departures from normal through
the 20th (yesterday).
This climate section will be expanded by 4am as we reevaluate
the month of October temperature projection.
44091 buoy drifted away from its mooring and was recovered. Its
return to service date is unknown.