Area Forecast Discussion
Issued by NWS Mt. Holly, NJ-- Remove Highlighting --
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FXUS61 KPHI 272046
Area Forecast Discussion
National Weather Service Mount Holly NJ
446 PM EDT Thu Apr 27 2017
A cold front will move across the area tonight into Friday
morning. A backdoor cold front will move across the area
Saturday into Saturday night. This front will remain to our
south on Sunday, then return as a warm front on Sunday night.
Another cold front is expected on Monday night, with a secondary
front or surface trough Tuesday. Another cold front is possible
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
The majority of the low clouds from this morning have since
eroded, with the exceptions being portions of the NJ coastline
due to persistent low level southeasterly flow and across the
terrain of NEPA and NWNJ. Continued erosion is expected through
the remainder of the afternoon. At the same time mid to high
clouds will also be streaming overhead out ahead of a low
pressure system ejecting through the Great Lakes. Highs this
afternoon will range from the low 70s across NEPA/NWNJ to low
80s south, except stuck in the 60s along the immediate
Tonight, the trailing cold front associated with Great Lakes
low will push eastward, crossing the area between midnight and
sunrise. There will be some scattered showers along the front,
along with the possibility of a few elevated thunderstorms. Not
expecting any severe threat as any instability will not be
surface based. Models also showing the potential for
redevelopment of some low clouds and fog potential across
portions of northern NJ and into northeastern PA. Elsewhere,
played down fog threat as low level southerly flow out ahead of
the front should inhibit more widespread formation. Lows drop
into the mid 50s to low 60s by morning.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
Warm and mostly sunny day expected once front clears the region
on Friday. Should see highs at or above 80 degrees for most
locations, except along the immediate shoreline and the higher
elevations of the Poconos.
A frontal wave will be moving along a stationary front off to
the northwest of the area late Friday night and into Saturday
morning. This may touch off a few showers or an isolated
thunderstorm Friday night into Saturday morning. As it moves
northeastward into New England, strong surface high pressure
will build in behind it, pushing the frontal boundary southward
towards and through the area Saturday night. Out ahead of it
though on Saturday, expecting warm temperatures with highs in
the 80s along with the chance for a few showers/thunderstorms.
SPC has placed part of the area in Marginal Risk for severe
thunderstorms on Saturday.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Much of the area will then be on the cool side of the boundary
on Sunday with northeast low level flow. This will keep
temperatures much cooler than on Saturday with highs from 65-70F
for most locations, except across portions of Delaware and
eastern Maryland where they may try to remain on the warmer side
of the boundary. Uncertainty still remains on its position.
Chances for additional showers also exist, but thunder threat
much lower with stable low levels.
Front will then traverse back northward over the region Sunday
night into Monday out ahead of a low pressure system pushing
through the Great Lakes. This will lead to the redevelopment of
southerly flow and rebounding temperatures. Highs Monday should
reach back into the 70s to near 80F. The cold front then pushes
across the area late Monday and Monday night with showers and
Cyclonic flow aloft develops behind the front for Tuesday and
Wednesday with a few secondary cold fronts possible. Most areas
remain dry, but some instability showers in the colder air aloft
are possible, especially across the Poconos and NW NJ. Highs
from the 60s to low 70s and lows in the 40s and 50s.
The next organized system will then be developing across the
lower Mississippi Valley during the middle of next week and will
push towards the region by late in the week with the next chance
of more widespread precipitation.
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
This Afternoon...Lingering IFR at ACY and MVFR at TTN will
gradually improve to VFR during the remainder of the afternoon
hours. Winds generally S/SE around 10 knots, with some gusts to
Tonight...After 03Z, low clouds may move back in over the
region, mainly ACY/ABE/TTN, although potential does exist at
other sites. In addition, showers and isolated thunderstorms
will approach from the west. There is low confidence though on
if individual TAF sites will be affected and the timing.
Southerly winds tonight shift west late after frontal passage.
Friday...VFR develops at all TAF sites with west/northwest
Friday night...VFR early. Patchy fog and low CIGS may develop
Saturday...Becoming VFR during the morning, although chances
exist for a few showers and thunderstorms. Conditions may
temporarily be reduced with any showers/storms.
Saturday night-Sunday night...Low clouds and fog may develop
overnight Saturday and continue into Sunday night leading to
reduced conditions. Small chance of showers and thunderstorms.
Conditions may temporarily be reduced with any showers.
Monday...Low conditions in the morning, becoming VFR during the
day. A chance of showers thunderstorms during the day, with
more likely showers and thunderstorms overnight. Lower
conditions possible during the day with any showers or storms,
more likely lower conditions overnight. Gusty southwest winds
around 25 knots.
Elevated seas are expected to continue today and tonight on the
Atlantic Coastal waters, generally ranging from 5 to 6 feet. A
few gusts near or above 20 kt are possible this evening.
Friday...Winds expected to remain below advisory levels, but
seas may remain elevated to advisory levels.
Friday night-Sunday night...Seas may approach 5 feet at times,
and winds may gust near 20 knots, but conditions expected to
remain below advisory levels.
Monday...Winds likely to gust 25-30 knots, and seas likely to
exceed 5 feet as well leading to Small Craft Advisory
conditions. A period of Gale conditions is also possible.
Though some of the guidance is depicting minor coastal flooding
with the evening high tides today and tomorrow, we are not
expecting any coastal flooding as astronomical tides will start
to decrease, and by tonight, winds will be shifting to off
-- Changed Discussion --**Record or number 2 warmest April on record expected**
Presuming our forecast temps these last 4 days of April are
accurate, we are assured of a top 2 warmest April on record in
much of our forecast area. Sunday is probably the critical day
for determining record or not.
Below: April projected within the top April average temps, the
normal for April and the period of record (POR).
This includes todays high and low temperatures through 4 PM.
PHL normal 54.0 POR 1874
59.4 2017? projected tied warmest ever
ABE normal 49.9 POR 1922
56.8 projecting record
ACY normal 51.7 POR 1874
57.2 projecting record
-- End Changed Discussion --
MARINE...Small Craft Advisory for hazardous seas until 6 AM EDT Friday