Area Forecast Discussion
Issued by NWS Mt. Holly, NJ-- Remove Highlighting --
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FXUS61 KPHI 181932
Area Forecast Discussion
National Weather Service Mount Holly NJ
332 PM EDT Tue Oct 18 2016
High pressure will remain over the Southeast coast before moving
into the western Atlantic waters into the end of the week.
Meanwhile, a weak cold front will approach the region on
Wednesday, pass through on Wednesday night, and then will return
to the north as a warm front on Thursday. Low pressure developing
over the Ohio Valley will pass to the north on Friday, dragging a
strong cold front through the region. High pressure then builds in
from the south as low pressure deepens to the north over the
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Record high temps have been reached or tied in some areas today.
High pres will remain off the cst tonight and will gradually move
ewd as a cdfnt approaches from the w. Another unseasonably warm
night is in store, with lows higher than the normal highs in many
Dry wx is expected with the warm swly flow.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Another very warm day is in store, possibly the warmest yet. The
aforementioned cdfnt will be making its way from w to e from mrng
thru the aftn. The only caveat on temps is if there are too many
clouds to suppress temps.
The fropa looks to be dry with any precip holding off until after
the end of the pd, despite lowering and thickening clouds.
Temps should make it into the 80s in most areas.
.LONG TERM /THURSDAY THROUGH TUESDAY/...
A prolonged period of unsettled weather on tap for the middle to
the end of the week.
Cold front works its way through the region Wednesday night. Not
sure how far south that front will actually go, as it may get hung
up across central NJ and southern PA before stalling out. That
front then returns to the north as a warm front on Thursday.
Meanwhile, a deepening upper level trough will dig into the
central U.S. on Thursday, and primary low pressure will develop
over the Ohio Valley during that time. That low will track to the
north and east, passing through western NY/PA as it lifts into
eastern Canada on Friday.
As that trough approaches, it will become negatively tilted, and
models indicating the potential for secondary low pressure
development off the Mid-Atlantic coast. In addition, a weak
tropical low currently east of the Caribbean Islands will track to
the north, and that aforementioned secondary low may tap into and
merge with the tropical low. Models keep this system over the
western Atlantic waters
As the primary low lifts into Canada, it will drag a strong cold
front through the region Friday and Friday night.
As a result, scattered showers will develop Wednesday night with
the approach of the initial cold front, and then showers will
increase and become more widespread on Thursday and Friday. Cannot
rule out a rumble of thunder, especially on Friday, but it is too
soon to include in the forecast at this time.
Over the weekend, low pressure over eastern Canada will intensify
as high pressure strengthens over the Southeast U.S. The pressure
gradient will tighten between those 2 systems over the Northeast
and Mid-Atlantic, and can expect gusty W-NW winds for the region.
Upper trough remains over the area, and with several shortwaves
diving into the base of the trough, some showers are possible, but
no strong signal for showers yet.
Trough continues to depart for the start of the new week as high
pressure builds in from the west.
Well above normal temps on tap to close out the work week, and
then temps fall below normal for the weekend and new week.
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
VFR conds are expected for the remainder of the day into erly
tonight with high pres and swly flow. Once again tonight, there is
the potential for low clouds and fog.
However, a cdfnt will be approaching from the w durg the mrng
hours and this front cud stir things up enough to keep cigs and
vsbys from getting too low. For now, will maintain MVFR thru about
13Z. After that VFR conds will prevail.
Wind will genly be swly today around 10 kts or slightly higher
this aftn before becoming light overnight. SW flow will return Wed
mrng, but the wind will become more wly then nwly durg the mrng
and aftn hours behind the fropa with speeds genly in the 5 to 10
Wednesday night...Mainly VFR, but some showers possible, which
could lower conditions to MVFR at least.
Thursday through Friday night...Showers developing on Thursday,
becoming more widespread into Friday, tapering off Friday night.
MVFR conditions likely, with the chance for IFR and lower.
Saturday through Sunday...Mainly VFR. NW winds with 25-35 KT
We will keep the SCA in effect as prev issued acrs the nrn waters
for increasing wind and seas, but it will be marginal. Acrs the
srn waters there will be an increase as well, but conds shud
remain below sca criteria. After this SCA comes down Wed mrng, no
additional marine flags are anticipated.
Wednesday through Friday afternoon...Forecast winds and seas
below SCA criteria.
Friday night through Sunday...A strong cold front passes across
the waters Friday night. Tight pressure gradient develops over the
weekend with winds gusting to at least 30 KT with the potential
for gale force wind gusts.
Here are the record high temperatures for today (10/18) and
Wednesday (10/19)...and across southern portions of the area on
TUE OCT 18 WED OCT 19 THU OCT 20
Mount Pocono, PA 84 in 1908 80 in 1963 75 in 1963
Reading, PA 85 in 1908 84 in 1963 80 in 1947/1953/1969
Allentown, PA 81 in 1963 82 in 1963 78 in 1936
Trenton, NJ 82 in 1908 83 in 1963 80 in 1969
Philadelphia, PA 85 in 1908 80 in 1947 80 in 1916/1938
Atlantic City, NJ 83 in 1908 80 in 1991 85 in 1987
Wilmington, DE 81 in 1938 81 in 1963 82 in 1969
Georgetown, DE 81 in 1996 81 in 1953 83 in 1953
Thursday is dependent on sunshine. For now, no records but this
could change in future forecasts. We`ve left the records in this
section since it could be near record in a few locations,
especially south of Philly.
Monthly averages are projecting 3 degrees or so above normal, ranking
a top 15 warmest October for PHL/ABE. This is stated with the usual
mid month uncertainty. What we do know is that the warmth of this
week will virtually lock in an above normal month, especially
since the pattern for the last week of October does not indicate
any lengthy period of below normal temperatures.
MARINE...Small Craft Advisory until 7 AM EDT Wednesday for ANZ450>452.