Alert archive / New Jersey / Areal Flood Warnings in 2020

Areal Flood Warning 57, NWS Philadelphia/Mount Holly

December 24, 20205 counties in New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Dec 24, 2020, 11:48 PM EST for 5 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 15 hr. 10 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Dec 24, 2020, 11:48 PM EST (04:48 UTC)
Expired
Dec 25, 2020, 2:54 PM EST
In force
15 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 89 km from the middle of the area, began a volume at 04:49 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Dec 25, 12:15 AM ESTFLOOD3 Wsw Cloverhill, NJTHE NESHANIC RIVER AT REAVILLE (REAN4) REACHED FLOOD STAGE AT 1215 AM, CRESTING AT 9.28 FEET AT 400 AM.
Dec 25, 1:00 AM ESTFLOOD1 Sw Wrightstown Twp, PANESHAMINY CREEK AT PENNS PARK (PEPP1) REACHED FLOOD STAGE AT 100 AM, CRESTING AT 15.65 FEET AT 715 AM.
Dec 25, 1:34 AM ESTFLOOD2 S Jamison, PAFLOODING ON STATE HIGHWAY 263 NEAR THE HERITAGE CREEK GOLF CLUB. TIME BASED ON DISPATCH REPORT.
Dec 25, 2:15 AM ESTFLOOD2 Sse Village Shires, PANESHAMINY CREEK AT LANGHORNE (LNGP1) REACHED FLOOD STAGE AT 215 AM, CRESTING AT 11.40 FEET AT 1045 AM.
Dec 25, 3:15 AM ESTFLOOD2 W Stanton, NJTHE SOUTH BRANCH RARITAN RIVER AT STANTON (STTN4) REACHED FLOOD STAGE AT 315 AM, CRESTING AT 8.26 FEET AT 430 AM. IT FELL BELOW FLOOD STAGE AND THEN RETURNED ABOVE FLOOD STAGE AT 1230 PM, CRESTING AT 8.13 FEET AT 230 PM.
Dec 25, 3:15 AM ESTFLOODReadington, NJROUTE 22 WEST IS CLOSED NEAR MERCK DRIVE DUE TO ROADWAY FLOODING.
Dec 25, 4:00 AM ESTFLOOD1 Ese Branchburg Twp, NJTHE NORTH BRANCH RARITAN RIVER AT SOUTH BRANCH (SBRN4) REACHED FLOOD STAGE AT 400 AM, CRESTING AT 10.10 FEET AT 1100 AM (MODERATE FLOOD).
Dec 25, 7:00 AM ESTFLOOD1 Ne High Bridge, NJTHE SOUTH BRANCH RARITAN RIVER AT HIGH BRIDGE (HBRN4) REACHED FLOOD STAGE AT 700 AM, CRESTING AT 10.25 FEET AT 900 AM.
Dec 25, 7:23 AM ESTHEAVY RAIN 1.58Readington, NJ
Dec 25, 1:30 PM ESTFLOODManville, NJTHE RARITAN RIVER AT MANVILLE (MNVN4) REACHED FLOOD STAGE AT 130 PM, CRESTING AT 14.68 FEET AT 445 PM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 4.8 hours before the alert went out and 179 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2020-12-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2020-12-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 682 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
784 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
682 m²/s²
0-3 km storm-relative helicity
727 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

698 
WGUS41 KPHI 250448
FLWPHI

BULLETIN - EAS ACTIVATION REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
1148 PM EST Thu Dec 24 2020

NJC019-021-027-035-041-PAC017-251045-
/O.NEW.KPHI.FA.W.0057.201225T0448Z-201225T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
1148 PM EST Thu Dec 24 2020

The National Weather Service in Mount Holly has issued a

* Flood Warning for...
  Northwestern Mercer County in central New Jersey...
  Southwestern Morris County in northern New Jersey...
  Somerset County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Warren County in northwestern New Jersey...
  Eastern Bucks County in southeastern Pennsylvania...

* Until 545 AM EST.

* At 1148 PM EST, Doppler radar and automated rain gauges indicated 
  heavy rain due to thunderstorms. Flooding is ongoing or expected 
  to begin shortly in the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen.

Some locations that may experience flooding include...
  Easton, Somerville, Bridgewater, Ewing, Middlesex, Bound Brook, 
  Manville, Hackettstown, Byram, Washington, Mendham, and Flemington.

This includes the following highways...
	Pennsylvania Turnpike between exits 349 and 352.
	Interstate 78 in New Jersey between mile markers 0 and 42.
	Interstate 80 in New Jersey between mile markers 1 and 20.
	Interstate 295 in New Jersey between mile markers 72 and 76.
	Interstate 287 in New Jersey between mile markers 11 and 32.

Additional rainfall amounts of 0.5 to 1.5 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4067 7518 4069 7520 4075 7520 4079 7511
      4085 7509 4086 7505 4098 7513 4090 7477
      4070 7442 4067 7445 4065 7440 4058 7451
      4011 7495 4021 7513 4040 7502 4043 7506
      4050 7506 4057 7509 4056 7516 4061 7520

$$

CMS
5 follow-up statements
239 
WGUS81 KPHI 250713
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
213 AM EST Fri Dec 25 2020

NJC019-021-027-035-041-PAC017-251045-
/O.CON.KPHI.FA.W.0057.000000T0000Z-201225T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
213 AM EST Fri Dec 25 2020

...FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM EST EARLY THIS 
MORNING FOR NORTHWESTERN MERCER, SOUTHWESTERN MORRIS, SOMERSET, 
HUNTERDON, WARREN, AND EASTERN BUCKS COUNTIES...

At 213 AM EST, gauge reports indicated several streams and creeks 
are near or above flood stage across the warning area. Additionally, 
local law enforcement has reported flooding in portions of Bucks, 
Hunterdon, and Somerset Counties. Flooding is expected to continue 
for several more hours.

For South Branch Raritan River at Stanton:
At 2:00am the stage was 7.44 feet.
Flood Stage is 8 feet.

For Neshanic River at Reaville:
At 2:00am the stage was 8.71 feet.
Flood Stage is 6.5 feet.

For Lamington River 1.2 NW Pottersville:
At 1:15am the stage was 3.73 feet.
Flood Stage is 4.5 feet.

For Spruce Run at Glen Gardner:
At 2:00am the stage was 6.32 feet.
Flood Stage is 7 feet.

For South Branch Raritan River at High Bridge:
At 1:45am the stage was 9.3 feet.
Flood Stage is 10 feet.

For Lamington River at Burnt Mills:
At 2:00am the stage was 9.88 feet.
Flood Stage is 11 feet.

For Middle Brook at Burnt Mills:
At 1:00am the stage was 8.69 feet.
Flood Stage is 9.5 feet.

This includes the following highways...
	Pennsylvania Turnpike between exits 351 and 352.
	Interstate 78 in New Jersey between mile markers 0 and 42.
	Interstate 80 in New Jersey near mile marker 1...and
	between mile markers 5 and 20.
	Interstate 295 in New Jersey between mile markers 73 and 76.
	Interstate 287 in New Jersey between mile markers 12 and 32.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4067 7518 4069 7520 4075 7520 4079 7511
      4085 7509 4086 7505 4098 7513 4090 7477
      4070 7442 4067 7445 4065 7440 4058 7451
      4011 7495 4021 7513 4040 7502 4043 7506
      4050 7506 4057 7509 4056 7516 4061 7520

$$

CMS
968 
WGUS41 KPHI 250926
FLWPHI

BULLETIN - EAS ACTIVATION REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
426 AM EST Fri Dec 25 2020

NJC019-021-027-035-041-PAC017-251700-
/O.EXT.KPHI.FA.W.0057.000000T0000Z-201225T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
426 AM EST Fri Dec 25 2020

The National Weather Service in Mount Holly has extended the

* Flood Warning for...
  Northwestern Mercer County in central New Jersey...
  Southwestern Morris County in northern New Jersey...
  Somerset County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Warren County in northwestern New Jersey...
  Eastern Bucks County in southeastern Pennsylvania...

* Until noon EST Friday.

* At 426 AM EST, gauge reports indicated several rivers, creeks, and 
  streams are in flood across the warning area. Flooding will 
  continue for several more hours.

For South Branch Raritan River at Stanton:
At 4:15am the stage was 8.23 feet.
Flood Stage is 8 feet.
...
For North Branch Raritan River at South Branch:
At 4:00am the stage was 8.01 feet.
Flood Stage is 8 feet.
...
For North Branch Raritan River at Raritan:
At 4:15am the stage was 8.04 feet.
Flood Stage is 10 feet.
...
For Neshanic at Reaville:
At 4:15am the stage was 9.28 feet.
Flood Stage is 6.5 feet.
...
For Neshaminy Creek at Penns Park:
At 4:01am the stage was 15.59 feet.
Flood Stage is 13 feet.
...
For North Branch Raritan River at North Branch:
At 4:15am the stage was 11.34 feet.
Flood Stage is 12.3 feet.
...
For Middle Brook at Burnt Mills:
At 4:00am the stage was 7.27 feet.
Flood Stage is 9.5 feet.
...
For Neshaminy Creek at Langhorne:
At 3:15am the stage was 9.65 feet.
Flood Stage is 9 feet.
...
For South Branch Raritan River at High Bridge:
At 3:45am the stage was 9.48 feet.
Flood Stage is 10 feet.
...
For Lamington River at Burnt Mills:
At 4:15am the stage was 10.46 feet.
Flood Stage is 11 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4067 7518 4069 7520 4075 7520 4079 7511
      4085 7509 4086 7505 4098 7513 4090 7477
      4070 7442 4067 7445 4065 7440 4058 7451
      4011 7495 4021 7513 4040 7502 4043 7506
      4050 7506 4057 7509 4056 7516 4061 7520

$$

CMS
573 
WGUS81 KPHI 251311
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
811 AM EST Fri Dec 25 2020

NJC019-021-027-035-041-PAC017-251700-
/O.CON.KPHI.FA.W.0057.000000T0000Z-201225T1700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
811 AM EST Fri Dec 25 2020

...FLOOD WARNING REMAINS IN EFFECT UNTIL NOON EST TODAY FOR 
NORTHWESTERN MERCER, SOUTHWESTERN MORRIS, SOMERSET, HUNTERDON, 
WARREN, AND EASTERN BUCKS COUNTIES...

At 811 AM EST, gauge reports indicated flooding of several rivers, 
creeks, and streams in the warning area. The South Branch Raritan 
River at High Bridge is now in flood, and the North Branch Raritan 
River at South Branch has reached moderate flood stage. Flooding is 
expected to continue for several more hours.

For South Branch Raritan River at Stanton:
At 8:00am the stage was 7.48 feet.
Flood Stage is 8 feet.

For North Branch Raritan River at South Branch:
At 7:00am the stage was 9.16 feet.
Flood Stage is 8 feet.

For North Branch Raritan River at Raritan:
At 7:45am the stage was 9.2 feet.
Flood Stage is 10 feet.

For Neshanic at Reaville:
At 8:00am the stage was 7.61 feet.
Flood Stage is 6.5 feet.

For Neshaminy Creek at Penns Park:
At 8:01am the stage was 15.58 feet.
Flood Stage is 13 feet.

For North Branch Raritan River at North Branch:
At 7:15am the stage was 12.11 feet.
Flood Stage is 12.3 feet.

For Neshaminy Creek at Langhorne:
At 7:15am the stage was 11.18 feet.
Flood Stage is 9 feet.

For South Branch Raritan River at High Bridge:
At 7:45am the stage was 10.15 feet.
Flood Stage is 10 feet.

For Lamington River at Burnt Mills:
At 7:45am the stage was 10.4 feet.
Flood Stage is 11 feet.

For Musconetcong River at Bloomsbury:
At 7:15am the stage was 5.04 feet.
Flood Stage is 6 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4067 7518 4069 7520 4075 7520 4079 7511
      4085 7509 4086 7505 4098 7513 4090 7477
      4070 7442 4067 7445 4065 7440 4058 7451
      4011 7495 4021 7513 4040 7502 4043 7506
      4050 7506 4057 7509 4056 7516 4061 7520

$$

CMS
751 
WGUS41 KPHI 251659
FLWPHI

BULLETIN - EAS ACTIVATION REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
1159 AM EST Fri Dec 25 2020

NJC019-021-027-035-041-PAC017-252300-
/O.EXT.KPHI.FA.W.0057.000000T0000Z-201225T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
1159 AM EST Fri Dec 25 2020

The National Weather Service in Mount Holly has extended the

* Flood Warning for...
  Northwestern Mercer County in central New Jersey...
  Southwestern Morris County in northern New Jersey...
  Somerset County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Warren County in northwestern New Jersey...
  Eastern Bucks County in southeastern Pennsylvania...

* Until 600 PM EST Friday.

* At 1159 AM EST, several gauges across the warned area were above 
  flood stage or approaching flood stage.

For North Branch Raritan River at South Branch:
At 11:00am the stage was 10.1 feet.
Flood Stage is 8 feet.
...
For North Branch Raritan River at Raritan:
At 11:15am the stage was 9.29 feet.
Flood Stage is 10 feet.
...
For Neshanic at Reaville:
At 11:45am the stage was 5.68 feet.
Flood Stage is 6.5 feet.
...
For Neshaminy Creek at Penns Park:
At 11:30am the stage was 13.97 feet.
Flood Stage is 13 feet.
...
For North Branch Raritan River at North Branch:
At 11:15am the stage was 11.46 feet.
Flood Stage is 12.3 feet.
...
For South Branch Raritan River at High Bridge:
At 10:45am the stage was 10.16 feet.
Flood Stage is 10 feet.
...
For Lamington River at Burnt Mills:
At 11:45am the stage was 8.15 feet.
Flood Stage is 11 feet.
...
For Musconetcong River at Bloomsbury:
At 11:15am the stage was 5.15 feet.
Flood Stage is 6 feet.
...
For Pequest River at Pequest:
At 11:15am the stage was 4.33 feet.
Flood Stage is 6 feet.




PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most 
flood deaths occur in vehicles.

&&

LAT...LON 4067 7518 4069 7520 4075 7520 4079 7511
      4085 7509 4086 7505 4098 7513 4090 7477
      4070 7442 4067 7445 4065 7440 4058 7451
      4011 7495 4021 7513 4040 7502 4043 7506
      4050 7506 4057 7509 4056 7516 4061 7520

$$

Kruzdlo
867 
WGUS81 KPHI 251954
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
254 PM EST Fri Dec 25 2020

NJC019-021-027-035-041-PAC017-252004-
/O.CAN.KPHI.FA.W.0057.000000T0000Z-201225T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Morris NJ-Somerset NJ-Warren NJ-Bucks PA-
254 PM EST Fri Dec 25 2020

...FLOOD WARNING IS CANCELLED FOR NORTHWESTERN MERCER, SOUTHWESTERN 
MORRIS, SOMERSET, HUNTERDON, WARREN, AND EASTERN BUCKS COUNTIES...

This multi-county Flood Warning has been cancelled. Please refer to 
specific River Flood Warnings for the Neshaminy and Raritan.

LAT...LON 4067 7518 4069 7520 4075 7520 4079 7511
      4085 7509 4086 7505 4098 7513 4090 7477
      4070 7442 4067 7445 4065 7440 4058 7451
      4011 7495 4021 7513 4040 7502 4043 7506
      4050 7506 4057 7509 4056 7516 4061 7520

$$

Kruzdlo

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this areal flood warning went out at Dec 24, 11:10 PM EST, 38 minutes earlier.

Area forecast discussion, Dec 24, 11:10 PM EST, 38 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
1110 PM EST Thu Dec 24 2020

.SYNOPSIS...
A strong and complex storm will affect the region tonight and
into Friday. This storm will weaken and move away over the weekend
as high pressure builds over the area. Another low will cross
north of the area Monday causing a cold front to cross our region.
More high pressure is expected for the middle of next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Winds continue to escalate quickly. Expanded the high wind
warning to include New Castle (ILG has already had gusts above
50 kt), Salem, Gloucester, Camden and all of Burlington County.

Center of the 500 mb closed low is over IL now, with the trough
axis extending all the way down to the Gulf. There are two
surface lows, one centered over Quebec, the secondary low
has lifted all the way into western MD/PA from the Carolinas
just over the past few hours. The cold front currently over
western PA is expected to rapidly sweep east as we go through
the night.

Southerly flow should increase through the evening. As mentioned
above though, it is slightly behind schedule. Dew points are
already in the 50s, and could get close to 60 F just ahead of
the front. This will yield PWATs between 1.3-1.5 inches, which
is over 300% of normal for this time of the year. Heavier rain
will move into the western zones by early this evening, and then
several rounds of heavy rain will affect the region into the
overnight.

Storm total QPF forecast remains about what the forecast had previously
had, which is generally 1-2 inches throughout, and the highest amounts
will be in the Lehigh Valley, southeast Pennsylvania, and northern
New Jersey. For the southern Poconos, storm total rainfall will
average 3-4 inches. Up to 2 inches is possible for the New Jersey
coast. For more on the flooding potential, please see the Hydrology
section below.

Winds between 925 mb-850 mb will average 70-90 kt tonight, and
with heavy rain and a tight pressure gradient, a good deal of
those winds will mix down, especially along the coastal areas.
Even back towards southeast Pennsylvania, the LLJ will average
50-70 kt winds. The High Wind Warnings and Wind Advisories
remain in effect for most of the areas, but will make one
change. Currently expecting 60-70 mph winds along the barrier
island of New Jersey and into coastal portions of mainland New
Jersey, as well into Sussex county, Delaware. Will upgrade from
Wind Advisory to a High Wind Warning there. For the rest of the
region, maximum wind gusts will range from 45-55 mph.

With the warm and humid air spreading into the region, surface
instability parameters remain fairly low, but MUCAPE values are
projected to be from 100-200 J/kg, but as much as 500 J/kg in
portions of southern New Jersey. 0-6 km Bulk Shear will range
from 70-80 kt. SPC Day 1 outlook has the southern half of the
forecast area in a Marginal risk for severe weather, and several
stronger cells, or even broken line segments may form and that
would mix down the damaging wind gusts mentioned above. NAM-3km
showing a squall line developing, and this is reflected in the
HRRR as well. Will go ahead and add a chance for thunder to the
southern half of the forecast area. That could mix down
damaging winds that are stronger than forecast in the Wind
Advisory and High Wind Warning areas.

The heaviest of the rain should be just offshore by the time this
period ends. Temps this evening and into most of the night
will remain warm, generally in the 50s and low 60s.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
The bulk of the rain ends fairly abruptly Friday morning, and models
continue to indicate a dry slot sliding up the coast. CAA will be
underway in the morning as low pressure departs and a cold front
works its way through the region. Temps drop off even further during
the day as a stronger cold front passes through in the afternoon. As
the cold air surges east, temps will drop during the day, but
probably not below freezing until towards the evening. With the
passage of the front, as well as with the strong shortwave energy
approaching from the west, cannot rule out scattered rain and/or
snow showers into the afternoon hours. The high temperature for the
day will likely occur between midnight-2am.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
The upper pattern continues to remain fairly amplified and
progressive during the long term part of the forecast.

The system from the near/short term parts of the forecast will
continue to exit off to the northeast Fri night/Sat leaving only
some scattered snow showers across the higher elevations of the
Southern Poconos and northwest NJ for the evening Friday. The
coldest of the airmass will be settling across the area, so below
normal temps and a chilly wind will be over the region. Lows Fri
night will be in the teens/low 20s over the northern areas and
mostly low/mid 20s for Delmarva, srn NJ and metro Philadelphia. Wind
chills will take about ten degrees off these air temperature values.

Saturday and Sunday both looks dry at this point with high pressure
settling across the region. Temperatures will be cold Saturday but
moderate back close to normal by Sunday.

Another low and upper air feature will pass north of the region
Monday with high pressure building in again Tuesday. While
widespread precipitation is not expected with the system Monday, a
couple scattered rain/snow showers will accompany the trailing
fronts. Temperatures will reach the 40s regionwide Monday, but then
drop back below normal (mostly 30s) Tuesday following a cold front.

After a fair weather day Wednesday, most forecast models are showing
another potent low developing across the middle part of the country
and tracking towards the Great Lakes later Wed/Thu. This
patters kinda looks like the present system, perhaps weaker with
a maturing cyclone and strong cold front to cross the MIddle
Atlantic perhaps later Thu into Friday. Too early for specifics,
but it could get very warm preceding the system and this is
reflected in out high temps for Thu being in the 50s for many
areas. We will go along with the NBM guidance for now with chc
pops for Wed night/Thu/Thu night.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Through tonight... Conditions will continue to deteriorate from west
to east through this evening, due both to lower ceilings and
visibility restrictions in rain. For most of the overnight
hours, mainly IFR or low end MVFR is expected with rain, which
could be heavy at times. Rain may begin to diminish by late in
the night from west to east. South- southeast winds will
continue to increase overnight, with speeds of 20 to 25 kt and
gusts of 35 to 45 kt expected in most areas, a little higher
near MIV and ACY. LLWS will continue although the increasing
surface winds will mitigate it somewhat, especially near and
west of PHL where winds aloft will not be as strong. Surface
winds should turn more southerly with time and become more
southwest during the predawn hours, with speeds also beginning
to decrease during the predawn hours. Moderate confidence on the
overall pattern, but low confidence on the timing.

Friday... Mainly MVFR to begin the day with ceilings of 1000 to
2000 ft lingering even after the rain pulls away, which should
occur from west to east between 12z and 15z. MVFR should
continue for most of the morning and likely into the early
afternoon. Low clouds may begin to lift and/or scatter out by
mid to late afternoon, which could allow VFR conditions to
develop. Winds will be southwest shifting to west-southwest at
10 to 15 kt with gusts to 20 kt, except a little stronger near
the coast. Moderate confidence.

Outlook...

Fri night thru Sun night...VFR expected. Gusty winds Fri night
and Saturday.

Mon/Mon night...Mostly VFR. Scattered showers mostly N/W.

Tue...VFR expected.

&&

.MARINE...
Tonight...Winds this evening will quickly ramp up to Storm Force on
all waters, and will expand the Storm Warning to include upper DE
Bay. Sustained winds of 35-45 kts are expected with gusts of 50-60
kt are expected with the passage of low pressure. Visibility
restrictions likely in heavy rain and fog. Seas across the ocean
waters will build to 10-20 feet.

Friday...Winds abruptly shift to the west early, and decease to 20-
30 kt with 30-40 kt gusts. Going into midday, conditions lower to
SCA levels and should remain at SCA levels through the
afternoon.

Outlook...

Fri night thru Saturday...SCA conditions continuing on the
waters diminishing late. Fair weather.

Sat night thru Sunday night...sub-SCA expected. Fair.

Monday thru Tue...SCA expected. Scattered showers Mon mostly north.

Tue night into Wed...sub-SCA expected. Fair.

&&

.HYDROLOGY...
A widespread 1-3" of rain will fall with 2-4" in the southern
Poconos. There is about an inch of liquid equivalent in the snowpack
across interior portions of southeast Pennsylvania and northern New
Jersey. This snowpack should rapidly melt into tonight due to the
combination of the warm temps and heavy rain. Flooding will develop
on the smaller smaller streams and creeks, and there will be rises
on the mainstem rivers. In addition, urban and poor drainage
flooding is likely to develop. A Flood Watch remains in effect for
all of southeast Pennsylvania and northern New Jersey.

After the rain ends Friday morning, is is likely that rises on area
rivers and streams will continue into Friday afternoon and Friday
night. Several forecast points, including along the Macopin,
Raritan, Passaic, and Schuylkill Rivers will approach and may go
over minor flood stage, and the Millstone River at Blackwell Mills
is expected to crest at moderate flood stage.

&&

.TIDES/COASTAL FLOODING...
Update: a coastal flood advisory has been issued for Kent County
MD as Tolchester is now expected to be above advisory levels
with the high tide overnight.

A strong southerly wind is expected for tonight. As a result, the
most susceptible locations in our region for any tidal flooding will
be our counties on the eastern shore of Chesapeake Bay, areas around
Barnegat Bay in New Jersey, and areas around Little Assawoman Bay in
southeastern Delaware.

The strong southerly flow is forecast to continue until about 3:00
to 5:00 AM on Chesapeake Bay. As of mid afternoon, the surge had
built to about 1 foot on parts of the lower bay. The astronomical
high tides will be running particularly low as we move away from the
first quarter moon phase. As a result, it will take a surge of 2.5
to 3.0 feet to cause even spotty minor tidal flooding in the
counties of Talbot, Caroline, and Queen Anne's. We will
forecast that scenario for now, and we will continue to monitor
trends on Chesapeake Bay. The high tide works its way northward
through our counties on the eastern shore between about midnight
and 5:00 AM, so we still have a little time in case we find
that we need to issue an advisory.

The southerly flow is anticipated to persist until around daybreak
of the oceanfront. The usual situation in this type of pattern is
that water becomes trapped in Little Assawoman Bay in southeastern
Delaware, and in Barnegat Bay in New Jersey. It seems likely that we
will eventually need a Coastal Flood Statement for those areas at
some point from late tonight into Friday.

Our remaining tidal areas in New Jersey and Delaware, and those
along Delaware Bay and the tidal Delaware River should experience no
more than some spotty minor tidal flooding. The more significant
flood potential will come from the heavy rainfall.

&&

.EQUIPMENT...
Data quality errors at the KDOX radar site are making the
reflectivity and radar estimated precipitation look worse than
it actually is. Technicians are aware of the issue and working
to resolve it.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch through Friday morning for PAZ054-055-060>062-070-
     071-101>106.
     Wind Advisory until 7 AM EST Friday for PAZ054-055-060>062-070-
     071-101>106.
NJ...Flood Watch through Friday morning for NJZ001-007>010-012-015.
     Wind Advisory until 7 AM EST Friday for NJZ001-007>010-012-015.
     High Wind Warning until 7 AM EST Friday for NJZ013-014-016>027.
DE...Flood Watch through Friday morning for DEZ001.
     High Wind Warning until 7 AM EST Friday for DEZ001>004.
MD...Wind Advisory until 7 AM EST Friday for MDZ012-015-019-020.
     Coastal Flood Advisory until 6 AM EST Friday for MDZ012.
MARINE...Storm Warning until 7 AM EST Friday for ANZ430-431-450>455.

&&

Synopsis...CMS/O'Hara
Near Term...Johnson/MPS
Short Term...MPS
Long Term...O'Hara
Aviation...Johnson/O'Brien/O'Hara
Marine...MPS/O'Hara
Hydrology...WFO PHI
Tides/Coastal Flooding...WFO PHI
Equipment...WFO PHI
Hazardous weather outlook, Dec 24, 11:12 PM EST, 36 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
1112 PM EST Thu Dec 24 2020

NJZ001-007>010-012-015-PAZ054-055-060>062-070-071-101>106-260415-
Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Carbon-
Monroe-Berks-Lehigh-Northampton-Delaware-Philadelphia-
Western Chester-Eastern Chester-Western Montgomery-
Eastern Montgomery-Upper Bucks-Lower Bucks-
1112 PM EST Thu Dec 24 2020

...WIND ADVISORY IN EFFECT UNTIL 7 AM EST FRIDAY...
...FLOOD WATCH IN EFFECT THROUGH FRIDAY MORNING...

This Hazardous Weather Outlook is for central New Jersey, northern
New Jersey, northwest New Jersey, east central Pennsylvania,
northeast Pennsylvania and southeast Pennsylvania.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.
   Wind Advisory.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.
   Wind Advisory.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

MDZ012-260415-
Kent MD-
1112 PM EST Thu Dec 24 2020

...WIND ADVISORY IN EFFECT UNTIL 7 AM EST FRIDAY...
...COASTAL FLOOD ADVISORY IN EFFECT UNTIL 6 AM EST FRIDAY...

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory.
   Coastal Flood Advisory.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

MDZ015-019-020-260415-
Queen Annes-Talbot-Caroline-
1112 PM EST Thu Dec 24 2020

...WIND ADVISORY IN EFFECT UNTIL 7 AM EST FRIDAY...

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ002>004-NJZ013-014-016>027-260415-
Kent-Inland Sussex-Delaware Beaches-Western Monmouth-
Eastern Monmouth-Salem-Gloucester-Camden-Northwestern Burlington-
Ocean-Cumberland-Atlantic-Cape May-Atlantic Coastal Cape May-
Coastal Atlantic-Coastal Ocean-Southeastern Burlington-
1112 PM EST Thu Dec 24 2020

...HIGH WIND WARNING IN EFFECT UNTIL 7 AM EST FRIDAY...

This Hazardous Weather Outlook is for central Delaware, southern
Delaware, central New Jersey and southern New Jersey.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   High Wind Warning.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   High Wind Warning.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ001-260415-
New Castle-
1112 PM EST Thu Dec 24 2020

...HIGH WIND WARNING IN EFFECT UNTIL 7 AM EST FRIDAY...
...FLOOD WATCH IN EFFECT THROUGH FRIDAY MORNING...

This Hazardous Weather Outlook is for northern Delaware.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   High Wind Warning.
   Flood Watch.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   High Wind Warning.
   Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

ANZ430-431-450>455-260415-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
1112 PM EST Thu Dec 24 2020

...STORM WARNING IN EFFECT UNTIL 7 AM EST FRIDAY...

This Hazardous Weather Outlook is for Atlantic coastal waters and
Delaware Bay Waters.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Storm Warning.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Storm Warning.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

In the hours before

Local storm report, Dec 24, 11:29 PM EST, 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1129 PM EST THU DEC 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1019 PM     NON-TSTM WND DMG 1 NNE WEST FREEHOLD     40.26N 74.29W
12/24/2020                   MONMOUTH           NJ   DEPT OF HIGHWAYS

            DOWNED TREE ON US 9 SOUTHBOUND AREA OF NJ 33
            BUSINESS (FREEHOLD TWP) 1 RIGHT LANE OF 4
            LANES CLOSED.

&&

NC
Local storm report, Dec 24, 11:30 PM EST, 18 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1130 PM EST THU DEC 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1117 PM     NON-TSTM WND DMG CONCORDVILLE            39.89N 75.52W
12/24/2020                   DELAWARE           PA   DEPT OF HIGHWAYS

            TREE DOWN ON US ROUTE 1 SOUTHBOUND BETWEEN
            THORNTON ROAD AND CONCORD ROAD. ALL LANES
            CLOSED.

&&

STAARMANN
Local storm report, Dec 24, 11:32 PM EST, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1132 PM EST THU DEC 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1118 PM     FLOOD            1 E FRICKS              40.31N 75.22W
12/24/2020                   BUCKS              PA   DEPT OF HIGHWAYS

            FLOODING ON ROUTE 152 NEAR CREEK ROAD.

&&

NC
Local storm report, Dec 24, 11:36 PM EST, 12 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1136 PM EST THU DEC 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1116 PM     NON-TSTM WND DMG CONCORDVILLE            39.89N 75.52W
12/24/2020                   DELAWARE           PA   DEPT OF HIGHWAYS

            TREE DOWN ON US-01 NEAR THE INTERSECTION
            WITH CONCORD ROAD.

&&

NC
Local storm report, Dec 24, 11:38 PM EST, 10 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1138 PM EST THU DEC 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1130 PM     NON-TSTM WND DMG NORRISTOWN              40.11N 75.34W
12/24/2020                   MONTGOMERY         PA   PUBLIC

            ROOF SHINGLES BLOWN OFF HOME IN NORRISTOWN.

&&

NC
Local storm report, Dec 24, 11:45 PM EST, 3 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1145 PM EST THU DEC 24 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1110 PM     NON-TSTM WND DMG 2 E HAMMONTON           39.63N 74.77W
12/24/2020                   ATLANTIC           NJ   TRAINED SPOTTER

            ELECTRIC POLE DOWN WITH SPARKING WIRES AT
            MAIN AND PLEASANTVILLE ROAD IN HAMMONTON.

&&

NC

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 24, 8:39 PM ESTAreal Flood AdvisoryPHICumberland, Gloucester, Salem6 hr
Dec 24, 9:08 PM ESTCoastal Flood AdvisoryPHIBurlington, Camden14 hr
Dec 24, 9:16 PM ESTAreal Flood AdvisoryPHIHunterdon, Warren3 hr
Dec 24, 9:38 PM ESTAreal Flood WarningPHICamden14 hr
Dec 24, 11:10 PM ESTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Salem4 hr
Dec 25, 12:00 AM ESTAreal Flood WarningPHIMiddlesex, Somerset6 hr
Dec 25, 12:03 AM ESTCoastal Flood StatementPHIOcean12 hr
Dec 25, 1:37 AM ESTAreal Flood AdvisoryPHIMorris, Sussex, Warren10 hr
Dec 25, 1:56 AM ESTAreal Flood WarningPHIBurlington, Camden7 hr
Dec 25, 2:05 AM ESTRiver Flood WarningPHIHunterdon, Somerset4 hr
Dec 25, 3:22 AM ESTGale WarningPHI6 hr
Dec 25, 3:22 AM ESTSmall Craft AdvisoryPHI51 hr
Dec 25, 5:43 AM ESTAreal Flood AdvisoryPHIMercer, Middlesex, Somerset3 hr
Dec 25, 7:25 AM ESTRiver Flood WarningPHIMorris, Passaic37 hr
Dec 25, 11:27 AM ESTAreal Flood WarningPHISussex, Warren16 hr
Dec 25, 12:17 PM ESTRiver Flood WarningPHIMiddlesex, Somerset9 hr
Dec 25, 12:53 PM ESTCoastal Flood StatementPHIBurlington, Ocean4 hr
Dec 25, 2:11 PM ESTRiver Flood WarningPHIMiddlesex, Somerset7 hr
Dec 25, 2:12 PM ESTRiver Flood WarningPHISomerset20 hr
Dec 25, 2:26 PM ESTRiver Flood WarningPHIHunterdon, Somerset3 hr
Dec 25, 6:25 PM ESTRiver Flood WarningPHIMorris21 hr
Dec 24, 8:47 PM ESTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia6 hr
Dec 24, 10:09 PM ESTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton6 hr
Dec 24, 10:21 PM ESTAreal Flood WarningPHIBucks14 hr
Dec 24, 10:30 PM ESTRiver Flood WarningPHIDelaware10 hr
Dec 24, 11:26 PM ESTRiver Flood WarningPHIChester13 hr
Dec 24, 11:54 PM ESTAreal Flood WarningPHILehigh, Monroe, Northampton12 hr
Dec 25, 12:36 AM ESTRiver Flood WarningPHIMontgomery13 hr
Dec 25, 12:53 AM ESTAreal Flood WarningPHIChester6 hr
Dec 25, 12:59 AM ESTRiver Flood WarningPHIChester, Montgomery, Philadelphia21 hr
Dec 25, 2:28 AM ESTRiver Flood WarningPHIBucks15 hr
Dec 25, 3:29 AM ESTAreal Flood WarningPHIBerks6 hr
Dec 25, 3:33 AM ESTRiver Flood WarningPHIChester, Delaware17 hr
Dec 25, 4:00 AM ESTRiver Flood WarningPHILehigh, Northampton16 hr
Dec 25, 4:31 AM ESTAreal Flood WarningPHICarbon, Lehigh, Monroe, Northampton7 hr
Dec 25, 4:53 AM ESTRiver Flood WarningPHIBerks, Montgomery9 hr
Dec 25, 6:32 AM ESTRiver Flood WarningPHIMontgomery, Philadelphia7 hr
Dec 25, 7:28 AM ESTRiver Flood WarningPHIMonroe10 hr
Dec 25, 12:13 PM ESTAreal Flood WarningPHICarbon, Monroe9 hr

Nearby

Areal Flood Warnings in New Jersey, 2020Areal Flood Warnings in Pennsylvania, 2020Every areal flood warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.