Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 76, NWS Philadelphia/Mount Holly

July 9, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 9, 2021, 12:25 AM EDT. It was in force for 95 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: Jul 9, 2021, 12:25 AM EDT (04:25 UTC)
Expired: Jul 9, 2021, 2:00 AM EDT
In force: 95 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), 76 km from the middle of the area, began a volume at 04:28 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 00:00Z, 4.4 hours before the alert went out and 98 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: 440 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 675 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 336 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

499 
WHUS51 KPHI 090425
SMWPHI
ANZ431-453>455-473-475-090600-
/O.NEW.KPHI.MA.W.0076.210709T0425Z-210709T0600Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
1225 AM EDT Fri Jul 9 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  Lower Delaware Bay...
  Coastal and outer waters from Great Egg Inlet NJ to Fenwick Island
  DE...

* Until 200 AM EDT.

* At 1224 AM EDT, scattered thunderstorms capable of producing 
  waterspouts were located along a line extending from near Fenwick 
  Island to 8 nm east of Jackspot Reef, moving north at 35 knots.

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

  SOURCE...Radar.

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

* Locations impacted include...
  Overfalls Shoal, Five Fathoms Buoy, Fenwick Island, Buoy 4fb, Cape
  May Reef, Cape Henlopen, Rehoboth Beach, Bethany Beach, Cape May
  Point, Delaware Lightship Buoy 44009, Buoy 2ms and Indian River
  Inlet Bridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Thunderstorms can produce sudden waterspouts. Waterspouts can easily
overturn boats and create locally hazardous seas. Seek safe harbor
immediately.

&&

LAT...LON 3845 7503 3845 7510 3851 7511 3852 7513
      3881 7514 3897 7495 3874 7407 3872 7408
      3870 7415 3861 7417 3851 7426 3831 7427
      3822 7432
TIME...MOT...LOC 0424Z 195DEG 35KT 3843 7499 3807 7458 

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

$$

BAH

1 follow-up statement

935 
FZUS71 KPHI 090529
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
129 AM EDT Fri Jul 9 2021

ANZ431-453>455-473-475-090600-
/O.CON.KPHI.MA.W.0076.000000T0000Z-210709T0600Z/
129 AM EDT Fri Jul 9 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 200 AM EDT...

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...
Delaware Bay waters south of East Point NJ to Slaughter Beach DE...
Waters from Cape May NJ to Fenwick Island DE out 20 to 40 nm...
Waters from Great Egg Inlet NJ to Cape May NJ out 20 to 40 nm...

At 128 AM EDT, thunderstorms capable of producing waterspouts were 
located along a line extending from near Buoy 2ms to 15 nm north of 
Chicken Bone, moving east at 10 knots.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Overfalls Shoal, Five Fathoms Buoy, Buoy 4fb, Cape May Reef, Cape
Henlopen, Rehoboth Beach, Cape May Point and Buoy 2ms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Thunderstorms can produce sudden waterspouts. Waterspouts can easily
overturn boats and create locally hazardous seas. Seek safe harbor
immediately.

&&

LAT...LON 3870 7514 3881 7514 3897 7495 3874 7407
      3872 7408 3870 7415 3861 7417 3851 7426
      3839 7427
TIME...MOT...LOC 0528Z 272DEG 11KT 3885 7478 3849 7436 

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

$$

BAH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 10:25 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland	7 hr
Jul 8, 11:02 PM EDT	Special Marine Warning	PHI		88 min
Jul 8, 11:59 PM EDT	Areal Flood Advisory	PHI	Salem	5 hr
Jul 9, 12:07 AM EDT	Special Marine Warning	PHI		53 min
Jul 9, 12:08 AM EDT	Areal Flood Advisory	PHI	Atlantic, Camden, Gloucester	6 hr
Jul 9, 1:34 AM EDT	Special Marine Warning	PHI		86 min
Jul 9, 1:49 AM EDT	Special Marine Warning	PHI		26 min
Jul 9, 2:05 AM EDT	Areal Flood Advisory	PHI	Burlington, Monmouth, Ocean	8 hr
Jul 9, 2:50 AM EDT	Tornado Warning	PHI	Atlantic, Cape May, Cumberland	25 min
Jul 9, 2:53 AM EDT	Special Marine Warning	PHI		68 min
Jul 9, 3:38 AM EDT	Tornado Warning	PHI	Atlantic, Burlington, Ocean	18 min
Jul 9, 3:51 AM EDT	Special Marine Warning	PHI		84 min
Jul 9, 4:08 AM EDT	Gale Warning	PHI		3 hr
Jul 9, 4:41 AM EDT	Tornado Warning	PHI	Monmouth, Ocean	34 min
Jul 9, 4:44 AM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex	5 hr
Jul 9, 4:54 AM EDT	Areal Flood Advisory	PHI	Morris, Somerset	5 hr
Jul 9, 4:58 AM EDT	Special Marine Warning	PHI		39 min
Jul 9, 5:34 PM EDT	Areal Flood Advisory	PHI	Sussex, Warren	2 hr
Jul 9, 6:19 PM EDT	Severe Thunderstorm Warning	PHI	Salem	41 min
Jul 9, 6:24 PM EDT	Special Marine Warning	PHI		66 min
Jul 9, 6:50 PM EDT	Areal Flood Advisory	PHI	Gloucester, Salem	2 hr
Jul 9, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland, Gloucester, Salem	63 min
Jul 9, 7:17 PM EDT	Severe Thunderstorm Warning	PHI	Camden, Gloucester	23 min
Jul 9, 7:39 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Sussex, Warren	2 hr
Jul 9, 7:43 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Camden, Cape May, Cumberland, Gloucester, Salem	62 min
Jul 9, 7:46 PM EDT	Areal Flood Advisory	PHI	Atlantic, Camden, Cumberland, Gloucester, Salem	108 min
Jul 9, 5:17 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	43 min
Jul 9, 6:55 PM EDT	Special Weather Statement	PHI	Carbon	35 min
Jul 9, 7:07 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	3 hr
Jul 9, 7:31 PM EDT	Special Weather Statement	PHI	Northampton	29 min
Jul 8, 10:19 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	5 hr
Jul 8, 11:37 PM EDT	Tornado Warning	PHI	Sussex	23 min
Jul 8, 11:59 PM EDT	Tornado Warning	PHI	Sussex	12 min
Jul 9, 12:04 AM EDT	Tornado Warning	PHI	Sussex	26 min
Jul 9, 12:11 AM EDT	Tornado Warning	PHI	Sussex	35 min
Jul 9, 12:28 AM EDT	Tornado Warning	PHI	Sussex	17 min
Jul 9, 4:54 PM EDT	Special Weather Statement	PHI	New Castle	66 min

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.