Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPHI 211615
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1215 PM EDT Mon Sep 21 2020

.SYNOPSIS...
Sprawling high pressure over the Northeast will persist through
tonight before becoming reestablished in the central and
southern Appalachians by midweek. A weak cold front will move
through the Northeast Thursday night and into Friday. High
pressure will build back into the region next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Clear skies expected into the afternoon and also tonight.
Temperatures have risen into the low to the mid 60s as winds
have become gusty as times with mixing to around 900mb. The
decent mixing and a tightening pressure gradient between the
high pressure to our north and Hurricane Teddy off shore winds
over the waters and especially right along the shoreline could
certainly be quite breezy with gusts up to 30 mph possible.

Tonight should feel like a wash rinse repeat cycle with lows
forecast once again to fall into the upper 30s to low 40s under
longwave radiational cooling albeit slightly warmer than the
past two evenings. 925mb temps are on average about a 0.5-1C
warmer for tonight compared to last night. Patchy frost will
likely develop in some of the shelter valley locales of the
Poconos and Lehigh Valley. Enjoy your day!

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Broad high pressure continues to dominate the region through
the middle of the week. Expect the surface high to gradually
retrograde to the south and eventually crest over the
Appalachian Mountains by Wednesday. This leads to a modest
warmer trend with highs anticipated on Tuesday to be in the low
70s and by Wednesday temps should warm into the mid to upper
70s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
High pressure will still be in place Thursday however aloft the
ridge starts to break down. The impacts of Teddy moving towards
Nova Scotia and a shortwave cutoff low from the remnants of Beta
will start to push the surface high pressure system off to our
north and east. The question will be how far north the upper
level shortwave pushes as some of the guidance indicates the
potential for some rain to move into the region Friday into
Saturday. Most of the guidance however keeps the rainfall to our
south so the forecast will indicate a slight chance of showers
but not much higher. Temperatures will continue the warming
trend from Wednesday with highs in the upper 70s to near 80 with
overnight lows in the 60s.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

This afternoon...VFR. NE winds increasing to 10-15 kt with
15-20 kt gusts, expect a few kt higher at KACY. High confidence.

Tonight...VFR. Light NE winds. High confidence.

Outlook...

Tuesday thru Thursday...VFR. SKC much of the time.

&&

.MARINE...
Small Craft Advisory conditions remain in place on the ocean
waters through Tuesday. NE winds will range from 15-20 kt with
gusts to 25 kt possible. Main issue will be the seas, which will
continue to be elevated in the 8- 12 feet range. Winds will be
slightly lower during the rest overnight hours increasing once
again this afternoon.

For Delaware Bay, NE winds continue to gust up to 25kts this
morning at both Brandywine and Lewes so I`ve hoisted an SCA
through today with the expectation that winds will continue
around 20 to 25kts with choppy waters through the morning before
eventually relaxing back to 10 to 20kts.

Outlook...

SCA conditions on the ocean into Wednesday with the swells and
influence from tropical system Teddy remaining but diminishing.
Conditions will remain sub-SCA after that thru the end of the
week. Fair weather much of the week with the next chance of
showers expected later next weekend. Rough surf expected Monday
night into Tuesday.

Rip currents...

There remains a high risk for the development of dangerous rip
currents through Monday for all of the Atlantic beaches of New
Jersey and Delaware, with a very long-period swell of 5 to 8
feet expected in the surf zone through the period. Breaking
waves are likely to be dangerous, causing localized beach
erosion as well. A high surf advisory is in effect through
Monday night. The elevated rip- current risk will likely last
through at least Tuesday, with high surf expected to subside by
then.

&&

.TIDES/COASTAL FLOODING...
Widespread minor flooding is occurring for Atlantic, Cape May
and Sussex DE as northeasterly onshore flow continues with
building seas associated with Teddy.

No flooding is currently expected on the eastern shore of Chesapeake
Bay, and only spotty minor flooding is currently forecast for
the tidal Delaware River and upper portions of Delaware Bay
through Monday. Spotty minor flooding is anticipated for today`s
high tide cycle as well for coastal locales of Ocean, Monmouth
and Burlington counties in NJ.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...High Rip Current Risk through Tuesday evening for NJZ014-
     024>026.
     High Surf Advisory until 6 AM EDT Tuesday for NJZ014-024>026.
     Coastal Flood Advisory until 4 PM EDT this afternoon for
     NJZ022>025.
DE...High Rip Current Risk through Tuesday evening for DEZ004.
     High Surf Advisory until 6 AM EDT Tuesday for DEZ004.
     Coastal Flood Advisory until 4 PM EDT this afternoon for
     DEZ003-004.
MD...None.
MARINE...Small Craft Advisory until 8 PM EDT Wednesday for ANZ450>455.
     Small Craft Advisory until 6 PM EDT this evening for ANZ430-
     431.

&&

$$
Synopsis...CMS/Deal
Near Term...Deal/PO.
Short Term...Deal
Long Term...O`Hara
Aviation...Deal/PO
Marine...MPS/O`Hara
Tides/Coastal Flooding...WFO PHI



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.