Area forecast discussion
National Weather Service Mount Holly New Jersey
545 am EDT Thursday Jun 20 2013
Synopsis...
high pressure in place across the northeast and Middle Atlantic States
will slowly progress east and offshore through today. This high
pressure will remain nearby through Friday providing more pleasant
weather. Over the weekend, an increasing southwesterly flow will
develop across our region, bringing increasing heat and humidity
into the middle of next week.
&&
Near term /until 6 PM this evening/...
early this morning through 9 am...fair weather...patchy high based SC
mostly snj while St/SC develops vicinity kphl-kilg southwestward into North Maryland and
much of West Virginia. Any Countryside patchy fog will be evaporated by
7am as the boundary layer warms. Light wind.
Today...a beautiful day with high based scattered SC... 6000-7000 feet.
Cooling sea breezes. 50/50 blended 00z/20 NCEP GFS-NAM MOS guidance
should verify maximum temperatures in the interior of the lower 80s.
Dewpoints were primarily the warmer GFS MOS. Winds..Max g this
afternoon 15 knots out of the south-southwest except southeast along the coast where sea
breezes begin by late morning.
European model (ecmwf) maximum temperature (80 phl) is the coolest of the European model (ecmwf)-NCEP converted
MOS and the 00z/20 NCEP MOS.
&&
Short term /6 PM this evening through 6 am Friday/...
fair very nice weather continues with radiational cooling again. Low temperatures
a tad milder than those of this early Thursday morning. Patchy
fog possible toward dawn in the Countryside. 50/50 blended 00z/20
NAM/GFS MOS guidance except mostly the warmer GFS dewpoints. Light
south wind.
&&
Long term /Friday through Wednesday/...
the start of the long term will feature quiet and dry weather as an
area of high pressure is forecast to shift southeastward from Canada
into our region during Friday, with a continued relatively zonal
flow aloft. This set-up will keep ample sunshine in place for
another day, with near average late June maximum temperatures and
comfortable humidity levels, as dewpoints hold in the 50s. The
trend, however, through the remainder of the long term will be for
increasing warmth and humidity day-by-day across the middle Atlantic as
surface high pressure gradually shifts southeast and offshore during
Saturday, with middle-level ridging also taking shape. While Saturday
will still be a fairly pleasant day overall, remaining precipitation-free
with maximum temperatures still holding to the lower to middle 80s for
much of the area, the return southwesterly flow around the periphery
of the high pressure increases Sunday, as does the middle-level
ridging. This will bring increasing low level moisture across the
region, with dewpoints back into the middle and even upper 60s from
Sunday through early next week. In addition, model guidance also
shows several shortwaves progressing through the middle level flow
aloft through this period which will yield a daily chance for a few
scattered shwrs/T-storms. We have kept the precipitation potential at this
point in the slight chance to low chance range, as the convective
activity looks to be diurnal in nature and widely scattered at
best.
With regards to temperatures in the latter portion of the extended,
we took a blend of wpc guidance with continuity, with above average
temperatures expected Sunday through Wednesday. The warmest days at
this time look to be Monday through Wednesday, with temperatures
peaking from the upper 80s to low 90s for much of the region with a
noticeable rise in humidity. While we do not anticipate reaching
criteria for heat related headlines at this time, this will be a
noticeable change in airmass by early next week across the region,
and we have made a mention in our hazardous weather outlook.
&&
Aviation /10z Thursday through Monday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Through 13z...VFR patchy clouds near 7000 feet in snj. Any patchy fog
in the Countryside near 10z New Jersey/de/E Maryland evaporates by 11z. Light
wind. There is an area of St/SC developing vicinity kphl-kilg into North
Maryland and West Virginia that we're monitoring. At this hour...0940z...we're
not factoring this an air travel pblm for kphl.
After 13z...VFR scattered clouds at or above 6000 feet. SW wind with any gusts
under 15kt except southeast sea-Bay breezes developing kacy-kmiv-kilg by
afternoon.
Tonight...VFR clear. Light south wind. Patchy fog possible in the
Countryside after 06z/21.
Outlook...
Friday and Saturday...early morning MVFR possible in fog/haze,
otherwise VFR conditions expected.
Sunday and Monday...mostly VFR conditions; although, MVFR or lower
is possible in early fog/haze or afternoon/evening shwrs/T-storms.
&&
Marine...
no headlines through tonight. A persistent 2 feet southeast swell of 6 to 8
second on the ocean waters. Mainly south wind g under 15kt.
Outlook...
surface high pressure remaining nearby from Friday into early next
week will yield sub-Small Craft Advisory conditions for our coastal waters and
Delaware Bay. Winds will mainly be southerly through the weekend,
becoming more southwesterly by Monday. Seas are expected to be in
the 2 to 3 foot range for our coastal waters, with 1 to 2 foot seas
into Delaware Bay.
&&
Rip currents...
water temperatures along our New Jersey and Delaware coasts are near or a
bit above normal as of June 19.
Risk rip current formation projection the next several days is
generally low. If the swell increases to 3 feet on Friday as modeled
by the 00z/20 GFS ww3...then we would see a moderate risk for the
formation of rip currents. There is doubt whether the 2 feet southeast swell
can build to a 3 feet swell.
Even if we assign a low risk...that doesn't mean no risk. It just
means that odds favor less than usual formation of dangerous rip
currents. We still need to be wary and alert and have a safety
plan in mind should a problem develop.
&&
Climate...
it appears June temperatures will average above normal...departures
increasing maybe a few tenths of a degree from where they were through
June 19. That range is from near 0 at kmpo to near plus 1f most other
stations and nearly plus 2f at kged. This assessment was based
only on the GFS statistical data from 12z/29 and 00z/20 cycles.
So while the excessive warmth of Spring 2012 was not repeatable
this season...we are still running a slightly warmer than normal
April-June 2013.
&&
Equipment...
tphl is ots and its rts will probably not occur prior to 12z/20.
&&
Phi watches/warnings/advisories...
PA...none.
New Jersey...none.
Delaware...none.
Maryland...none.
Marine...none.
&&
$$
Synopsis...Kline
near term...drag 544a
short term...drag 544a
long term...Kline
aviation...drag/Kline 544a
marine...drag/Kline 544a
rip currents...544a
climate...544a
equipment...
