Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 148, NWS Philadelphia/Mount Holly

December 11, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Dec 11, 2021, 6:59 PM EST. It was in force for 68 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Dec 11, 2021, 6:59 PM EST (23:59 UTC)
Expired: Dec 11, 2021, 8:07 PM EST
In force: 68 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.0 in
Wind: 49.0 mph

The radar

The Dover AFB radar (KDOX), 66 km from the middle of the area, began a volume at 00:01 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.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 12.0 hours before the alert went out and 148 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 488 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 178 m²/s²
0-3 km storm-relative helicity: 205 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

701 
WHUS51 KPHI 112359
SMWPHI
ANZ430-431-451>455-471-120130-
/O.NEW.KPHI.MA.W.0148.211211T2359Z-211212T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
659 PM EST Sat Dec 11 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  Delaware Bay...
  Coastal waters from Manasquan Inlet NJ to Fenwick Island DE out 20
  nm...
  Outer waters from Manasquan Inlet to Little Egg Inlet NJ out 20 to
  40 nm...

* Until 830 PM EST.

* At 658 PM EST, showers capable of producing waterspouts were
  located along a line extending from 6 nm northwest of Great Egg
  Inlet to near Miah Maull Light to 7 nm south of Slaughter Beach,
  moving northeast at 55 knots.

  HAZARD...Waterspouts and wind gusts to nearly 50 knots.

  SOURCE...Radar.

  IMPACT...Waterspouts can create locally hazardous seas. Small 
           craft could be damaged in briefly higher winds and 
           suddenly higher waves.

* Locations impacted include...
  Atlantic City, Brown Shoal Light, Ship Bottom, Buoy 3fb, Slaughter
  Beach, Cape Henlopen, East Point, Garden State South Reef, Miah
  Maull Light, Great Egg Reef, Brandywine Shoal Light, Ocean City
  Reef, Overfalls Shoal, The Lump, North Beach Haven, Brigantine,
  Little Egg Reef, Atlantic City Reef, Fourteen Foot Bank Light and
  Great Egg Inlet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

Waterspouts can easily overturn boats and create locally hazardous
seas. Seek safe harbor immediately.

&&

LAT...LON 3916 7520 3930 7492 3923 7495 3915 7481
      3924 7477 3931 7485 3944 7465 3938 7464
      3947 7450 3953 7455 3961 7445 3969 7428
      3960 7374 3863 7495 3866 7524 3875 7520
      3876 7530 3883 7529 3890 7536
TIME...MOT...LOC 2358Z 244DEG 54KT 3940 7463 3912 7513 3879 7536 

WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...49KTS

$$

Davis

2 follow-up statements

496 
FZUS71 KPHI 120019
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
719 PM EST Sat Dec 11 2021

ANZ430-120027-
/O.CAN.KPHI.MA.W.0148.000000T0000Z-211212T0130Z/
719 PM EST Sat Dec 11 2021

...THE SPECIAL MARINE WARNING IS CANCELLED...

The affected areas were...
Upper Delaware Bay...

The strongest showers have moved east of the area and no longer pose 
a significant threat to boaters. Strong southerly winds ahead of the 
cold front will continue before shifting west after the cold front 
moves through the region later this evening.

LAT...LON 3886 7525 3916 7491 3915 7481 3924 7477
      3931 7485 3944 7465 3938 7466 3938 7463
      3947 7450 3953 7455 3961 7445 3960 7439
      3969 7427 3960 7374 3863 7495 3866 7524
      3875 7520 3876 7530
TIME...MOT...LOC 0017Z 244DEG 54KT 3951 7434 3923 7484 3890 7507 

$$

ANZ431-451>455-471-120130-
/O.CON.KPHI.MA.W.0148.000000T0000Z-211212T0130Z/
719 PM EST Sat Dec 11 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 830 PM EST...

For the following areas...
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm...
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm...
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm...
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20
nm...
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20
nm...
Delaware Bay waters south of East Point NJ to Slaughter Beach DE...
Waters from Manasquan Inlet NJ to Little Egg Inlet NJ out 20 to 40
nm...

At 717 PM EST, showers capable of producing waterspouts were located
along a line extending from Little Egg Inlet to 8 nm northwest of Sea
Isle City to Brown Shoal Light, moving northeast at 55 knots.

HAZARD...Waterspouts and wind gusts to nearly 50 knots.

SOURCE...Radar indicated.

IMPACT...Waterspouts can create locally hazardous seas. Small craft 
         could be damaged in briefly higher winds and suddenly 
         higher waves.

Locations impacted include...
Atlantic City, Brown Shoal Light, Ship Bottom, Buoy 3fb, Cape
Henlopen, Garden State South Reef, Great Egg Reef, Ocean City Reef,
Overfalls Shoal, The Lump, North Beach Haven, Brigantine, Little Egg
Reef, Atlantic City Reef, Great Egg Inlet, Rehoboth Beach, Cape May
Point, Wildwood, Beach Haven and Garden State North Reef.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

Waterspouts can easily overturn boats and create locally hazardous
seas. Seek safe harbor immediately.

&&

LAT...LON 3886 7525 3916 7491 3915 7481 3924 7477
      3931 7485 3944 7465 3938 7466 3938 7463
      3947 7450 3953 7455 3961 7445 3960 7439
      3969 7427 3960 7374 3863 7495 3866 7524
      3875 7520 3876 7530
TIME...MOT...LOC 0017Z 244DEG 54KT 3951 7434 3923 7484 3890 7507 

WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...49KTS

$$

Davis

883 
FZUS71 KPHI 120107
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
807 PM EST Sat Dec 11 2021

ANZ431-451>455-471-120115-
/O.CAN.KPHI.MA.W.0148.000000T0000Z-211212T0130Z/
807 PM EST Sat Dec 11 2021

...THE SPECIAL MARINE WARNING IS CANCELLED...

The affected areas were... 
Lower Delaware Bay...
Coastal waters from Manasquan Inlet NJ to Fenwick Island DE out 20
nm...
Outer waters from Manasquan Inlet to Little Egg Inlet NJ out 20 to 40
nm...

The showers have moved out of the area and no longer pose a 
significant threat to boaters. Strong southwesterly winds will 
continue for the next couple of hours before turning northwesterly 
as a strong cold front moves across the region. A Gale Warning 
remains in effect through 4 AM Sunday morning.

LAT...LON 3886 7525 3916 7491 3915 7481 3924 7477
      3931 7485 3944 7465 3938 7466 3938 7463
      3947 7450 3953 7455 3961 7445 3960 7439
      3969 7427 3960 7374 3863 7495 3866 7524
      3875 7520 3876 7530
TIME...MOT...LOC 0104Z 244DEG 54KT 3982 7351 3954 7401 3921 7425 

$$

Davis

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 11, 1:11 AM EST	Marine Dense Fog Advisory	PHI		10 hr

Nearby

Special Marine Warnings in New Jersey, 2021 Every special marine warning in 2021

Sources

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