Bear, Delaware 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

059
FXUS61 KPHI 112021
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
321 PM EST Wed Dec 11 2024

.SYNOPSIS...
Strengthening low pressure across the area and an approaching
cold front will result in widespread heavy rainfall and blustery
conditions today. The cold front will push offshore tonight ushering
in much colder and drier air, along with continued breezy conditions
Thursday. High pressure returns into the weekend with gradually
moderating temperatures. Another weak system may impact the area
Sunday into Monday.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 3 PM, an elongated area of developing low pressure was
centered over eastern PA into upstate NY with a cold front
associated with it extending southward into Virginia through the
Carolinas. Quite a large swath of rain with this system really
covering pretty much the entire eastern seaboard. Generally, the
rainfall rates and amounts haven`t been too heavy across the area
yet but it`s really over the next few hours that we expect heavier
elements of showers to move through with a continuing threat for
some embedded thunderstorms as the precipitation becomes more
convective. This will occur as the low continues to strengthen
while moving north and east into western New England. This will
drag a cold front through the region west to east through the
mid to late afternoon with it expected to be offshore by 7 PM
this evening. PWATs are continuing to increase as warm, moist
air advects north ahead of the cold front and will top off near
1.5 to 1.7 inches which is very high for this time of year. In
addition, there`s also even some instability, especially near
the coastal plain. Further, we have a southerly LLJ of around 60
knots at 850 mb. The limiting factor though in terms of the
really strong winds reaching the surface has been a low level
inversion. Nevertheless, expect it to remain rainy and gusty
this afternoon with a Wind Advisory remaining in effect for the
coastal plain until 9 PM. And as the inversion should weaken
some this afternoon, looking at some gusts within the Advisory
area of 45 to 50+ mph with locally even stronger winds possible
if convection can mix down some of the higher winds above the
boundary layer. The Storm Prediction Center continues to
highlight the area essentially along and east of the I-95
corridor in a MARGINAL risk for severe thunderstorms with a
SLIGHT risk closer to the coast. Meanwhile the Weather
Prediction Center continues to highlight a MARGINAL risk for
excessive rainfall. Biggest threat in terms of excessive rain
looks to be urban, small stream and poor drainage type flooding.


As mentioned above, the cold front should be off the coast by around
7 PM or so with rapidly falling temperatures and strong WNW winds in
its wake. The rain will still linger for a few hours or so behind
the front with it even ending as some snow in the Poconos (any
accumulation will be very minor, if any). Otherwise, expect WNW
winds 15 to 25 gusting 35 to 45 mph through this evening behind the
front with some peak gusts to around 50 mph possible. Expect all
precip to have ended by 11 PM or so with skies clearing out and
winds starting to diminish some overnight. By morning, expect lows
mostly in the upper 20s to low 30s.

For Thursday, strong low pressure will be continuing to pull away
from the region as it lifts north through eastern Canada. Meanwhile,
high pressure will build into the Ohio Valley through the day. This
set up will keep a good gradient in place much of the day so expect
west winds generally around 15 gusting at times 20 to 30
mph...especially from around late morning through mid afternoon.
Otherwise, it will be a much colder day under mainly clear to partly
cloudy skies with highs mainly in the 30s to low 40s. However with
the wind chill factored in, it will feel a good 10+ degrees colder
than this.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
Cold air will deepen across the area Thursday as strong high
pressure moves towards the area from the upper Great Lakes region.
The upper trough will continue over the area, but gradually flatten
into Friday. Skies will be mainly clear thru the period with gusty
winds Thursday. Temperatures will be well below normal with highs
Thu in the 20s for the NW areas and low/mid 30s for metro
Philadelphia and much of NJ. Highs will be in the low 40s for
Delmarva and south NJ. Highs on friday will be a few degrees cooler
than Thursdays. Lows will be in the teens and low 20s for Fri/Sat
mornings.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The weekend will start off dry and colder than normal as the strong
high pressure continues across the area before retreating into New
England by evening. An onshore flow develops across our area once
the high moves away. Temperatures will continue cool with a cold
Saturday morning yielding to a slightly below normal temps for the
daytime hours. Readings will eventually top out in the upper 30s/low
40s for the northern/western parts of the CWA while low/mid 40s will
be more common for the S/E areas.

The onshore flow and increasing moisture will create more unsettled
weather for Sunday and into the upcoming week. An upper short wave
and weak surface low for Sunday will be followed by another system
for later Monday and Tuesday. These features will create chances for
rains Sun/Sun night (likely pops) and more clouds and chances for
rains Mon/Tue. Temperatures for the Sun-Tue period will be above
normal, so p-type will be rain for the area with perhaps a few
flakes for the higher elevations far NW. Highs will be in the 40s
N/W Sunday and low 50s S/E. By Monday, 50s will be expected for
highs across all areas.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

This afternoon...Many sites have seen a reprieve the past several
hours with MVFR or even brief VFR. However as a cold front
approaches and eventually moves through west to east by later this
afternoon expect showers to become heavier with lowering conditions
back to IFR likely. Embedded thunderstorms remain possible but
confidence not high enough to include in the TAF. Ahead of the
front, expect southerly winds increasing to around 15 gusting up to
30 knots, except up to 40 knots at ACY. The front should clear the I-
95 TAF sites by around 22z and the coastal plain by around 23z or
so. Moderate confidence overall.

Tonight...Rain ends from west to east and conditions improve to VFR
from 02Z to 05Z. Winds shift to the west at 15 to 20 kt with 25 to
35 kt gusts. Moderate confidence.

Thursday...VFR. West winds around 15 gusting 20 to 30 knots.
High confidence.


Outlook...

Thursday night... VFR expected. Gusty W/NW winds expected.

Friday thru Sat night... VFR expected.

Sunday... Lower CIGs and VSBYs possible with rain developing.

&&

.MARINE...

A Gale Warning is up for all waters through tonight as sustained
winds of 25-35 kt and gusts up to 45 kt are expected. Seas around 8
to 12 feet. Periods of rain and low visibility on the waters through
this evening along with the potential for some embedded
thunderstorms.

Winds will diminish back down to Small Craft Advisory levels by
around dawn Thursday with these conditions continuing through the
day. Otherwise, fair weather for Thursday.

Outlook...

Sub-SCA conditions Thu night thru Sat night. SCA flags are
possible again Sunday. Rain expected Sunday.

&&

.HYDROLOGY...
Today`s system is bringing a widespread 1-2+ inches of rain with
rain falling heavy at times this afternoon, tapering off early
this evening. Given low stream levels lead into the event, and
most of the area still being in moderate to extreme drought,
flooding concerns should mainly be confined to urban and poor
drainage areas. A MARGINAL (1/4) risk for excessive rainfall is
in place from the Weather Prediction Center, which is about
right given the limiting factors mentioned above. However one
other thing that will have to be watched is the snowmelt to our
north because this, combined with the rainfall, will cause the
mainstem Delaware River to see rises to half to three-quarter
bankful over the next couple of days. Other mainstem rivers will
also see rises, but no flooding is expected.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Wind Advisory until 9 PM EST this evening for NJZ013-014-
     020>027.
DE...Wind Advisory until 9 PM EST this evening for DEZ002>004.
MD...Wind Advisory until 9 PM EST this evening for MDZ015-019-020.
MARINE...Gale Warning until 6 AM EST Thursday for ANZ430-431-450>455.

&&

$$

SYNOPSIS...Staarmann
NEAR TERM...Fitzsimmons/Hoeflich
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...Fitzsimmons/Hoeflich/OHara
MARINE...Fitzsimmons/Hoeflich/OHara
HYDROLOGY...