Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 52, NWS Philadelphia/Mount Holly

June 22, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jun 22, 2021, 11:46 AM EDT. It was in force for 44 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
Jun 22, 2021, 11:46 AM EDT (15:46 UTC)
Expired
Jun 22, 2021, 12:30 PM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
34.0 mph

The radar

The Dover AFB radar (KDOX), 78 km from the middle of the area, began a volume at 15:45 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, 3.8 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-pSkew-T log-p diagram, Wallops Is Stn, VA at 12:00Z on 2021-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1075 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2021-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.193958Sfc1 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
1075 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1069 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

430 
WHUS51 KPHI 221546
SMWPHI
ANZ452>454-472-473-221630-
/O.NEW.KPHI.MA.W.0052.210622T1546Z-210622T1630Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
1146 AM EDT Tue Jun 22 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  
Coastal waters from Little Egg Inlet NJ to Cape Henlopen DE out 20
nm...
Outer waters from Little Egg Inlet to Cape May NJ out 20 to 40 nm...

* Until 1230 PM EDT.

* At 1145 AM EDT, a severe thunderstorm capable of producing 
  waterspouts was located just east of Cape May, moving northeast at 
  45 knots.

  HAZARD...Waterspouts, wind gusts 34 knots or greater, and small 
           hail.

  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...
  Atlantic City, Buoy 2fb, Atlantic City Reef, Buoy 3fb, Great Egg
  Inlet, Great Egg Reef, Ocean City Reef, Wildwood, The Lump, 28-
  Mile Wreck, Cape May Reef, Sea Isle City, Buoy 2ms and Wildwood
  Reef.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3921 7469 3940 7449 3916 7401 3877 7483
      3890 7498
TIME...MOT...LOC 1545Z 239DEG 45KT 3891 7475 

WATERSPOUT...POSSIBLE
HAIL...<.75IN
WIND...>34KTS

$$

JEO
1 follow-up statement
916 
FZUS71 KPHI 221624
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
1224 PM EDT Tue Jun 22 2021

ANZ452>454-472-473-221634-
/O.EXP.KPHI.MA.W.0052.000000T0000Z-210622T1630Z/
1224 PM EDT Tue Jun 22 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 1230 PM EDT...

The affected areas were... 

Coastal waters from Little Egg Inlet NJ to Cape Henlopen DE out 20
nm...
Outer waters from Little Egg Inlet to Cape May NJ out 20 to 40 nm...

The thunderstorm has weakened and no longer poses a significant
threat to boaters.

LAT...LON 3921 7469 3940 7449 3916 7401 3877 7483
      3890 7498
TIME...MOT...LOC 1624Z 239DEG 45KT 3915 7424 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 8:13 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren62 min
Jun 21, 8:31 PM EDTSpecial Marine WarningPHI59 min
Jun 21, 10:01 PM EDTSpecial Marine WarningPHI29 min
Jun 22, 12:51 PM EDTSpecial Marine WarningPHI114 min
Jun 22, 1:25 PM EDTSpecial Marine WarningPHI65 min
Jun 22, 1:47 PM EDTSpecial Marine WarningPHI118 min
Jun 22, 2:27 PM EDTSpecial Marine WarningPHI93 min
Jun 22, 3:05 PM EDTSmall Craft AdvisoryPHI15 hr
Jun 22, 3:26 PM EDTSpecial Marine WarningPHI68 min
Jun 21, 9:28 PM EDTSpecial Weather StatementPHIKent47 min

Nearby

Special Marine Warnings in New Jersey, 2021Every 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.