Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 280114

Area Forecast Discussion
National Weather Service Mount Holly NJ
914 PM EDT Thu Apr 27 2017

A cold front will move across the area late tonight and early
on Friday. 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


A frontal boundary extended across western Pennsylvania and
West Virginia this evening. The feature will progress to the
east and it should pass through our region late tonight and
early on Friday. The showers and thunderstorms with and ahead of
the front should continue to weaken during the night as they
encounter low level stable air. When the precipitation reaches
our region it should be mostly in the form of light rain
showers. However, some elevated instability will exist and there
may be isolated thunderstorms, as well.

A light south to southwest wind is expected tonight. The wind
direction is forecast to become west in the wake of the front.

Minimum temperatures are anticipated to range from the middle
50s to the lower 60s.


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.

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
possible thunderstorms.

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.


The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Conditions were VFR at all eight of our TAF sites at 0100Z.
That should continue to be the case for much of the night at
KRDG, KPHL, KILG, KMIV and KACY until a front approaching from
the west brings MVFR ceilings and scattered showers and isolated
thunderstorms between about 0600Z and 1200Z. The chance for
thunder is too low to include in the TAFs.

The persistent southeast flow may bring some MVFR or IFR
ceilings to KTTN, KPNE and KABE before 0600Z, then the chance
for showers will be the same as at our other five TAF sites late
tonight with the low ceilings continuing until a short time
after the front passes.

The frontal boundary is anticipated to move across our TAF
sites between about 0900Z and 1100Z with conditions improving to
VFR for Friday with only scattered cloud cover expected from
mid morning onward.

A south to southwest wind around 4 to 8 knots is expected to
shift to the west around 6 to 10 knots with the arrival of the


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 tonight into Friday
morning on the Atlantic Coastal waters, generally ranging from 5
to 6 feet. A few gusts near or above 20 kt are possible this
evening. The Small Craft Advisory will be extended until 1:00 PM


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.


**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 1994
59.4 2017?  projected tied warmest ever
58.5 1921
58.4 2010
57.9 1941

ABE normal 49.9 POR 1922

56.8 projecting record
56.4 1941
54.7 1994

ACY normal 51.7 POR 1874

57.2 projecting record
56.3 2010
56.1 2011


MARINE...Small Craft Advisory for hazardous seas until 1 PM EDT
     Friday for ANZ450>455.



Near Term...Iovino
Short Term...Muccilli
Long Term...Muccilli
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