Alert archive / New Jersey / Special Marine Warnings in 2021
Special Marine Warning 116, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this special marine warning at Aug 20, 2021, 8:20 AM EDT. It was in force for 55 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
- Aug 20, 2021, 8:20 AM EDT (12:20 UTC)
- Expired
- Aug 20, 2021, 9:15 AM EDT
- In force
- 55 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 0.0 in
- Wind
- 34.0 mph
The radar
The Dover AFB radar (KDOX), 104 km from the middle of the area, began a volume at 12:22 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, 0.3 hours before the alert went out and 133 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.
- Mixed-layer CAPE
- 166 J/kg
- Mixed-layer CIN
- -119 J/kg
- Mixed-layer LCL
- 987 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- -53 m²/s²
- 0-3 km storm-relative helicity
- -29 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.2
The text
As transmitted.
620
WHUS51 KPHI 201220
SMWPHI
ANZ453-454-473-475-201315-
/O.NEW.KPHI.MA.W.0116.210820T1220Z-210820T1315Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
820 AM EDT Fri Aug 20 2021
The National Weather Service in Mount Holly NJ has issued a
* Special Marine Warning for...
Coastal waters from Great Egg Inlet NJ to Cape Henlopen DE out 20
nm...
Outer waters from Great Egg Inlet NJ to Fenwick Island DE out 20 to
40 nm...
* Until 915 AM EDT.
* At 820 AM EDT, severe thunderstorms capable of producing
waterspouts were located along a line extending from Buoy 4fb to 16
nm east of Delaware Lightship Buoy 44009, moving northeast at 25
knots.
HAZARD...Waterspouts and wind gusts 34 knots or greater.
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...
28-Mile Wreck, Deepwater Reef, Five Fathoms Buoy and Buoy 4fb.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to safe harbor until hazardous weather passes.
&&
LAT...LON 3882 7472 3915 7416 3886 7388 3876 7400
3873 7404 3870 7415 3861 7417 3851 7426
3845 7426 3842 7437
TIME...MOT...LOC 1220Z 243DEG 23KT 3880 7461 3851 7436
WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...>34KTS
$$
CMS1 follow-up statement
295
FZUS71 KPHI 201313
MWSPHI
Marine Weather Statement
National Weather Service Mount Holly NJ
913 AM EDT Fri Aug 20 2021
ANZ453-454-473-475-201322-
/O.EXP.KPHI.MA.W.0116.000000T0000Z-210820T1315Z/
913 AM EDT Fri Aug 20 2021
...THE SPECIAL MARINE WARNING WILL EXPIRE AT 915 AM EDT...
The affected areas were...
Coastal waters from Great Egg Inlet NJ to Cape Henlopen DE out 20
nm...
Outer waters from Great Egg Inlet NJ to Fenwick Island DE out 20 to
40 nm...
The thunderstorms have moved out of the area and no longer pose a
significant threat to boaters.
LAT...LON 3882 7472 3915 7416 3886 7388 3876 7400
3873 7404 3870 7415 3861 7417 3851 7426
3845 7426 3842 7437
TIME...MOT...LOC 1312Z 243DEG 23KT 3895 7424 3866 7399
$$
CMSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 8:15 PM EDT | Rip Current Statement | PHI | Atlantic, Cape May, Ocean | 3 days |
| Aug 20, 3:08 AM EDT | Special Weather Statement | PHI | Cumberland | 37 min |
| Aug 20, 3:10 AM EDT | Special Weather Statement | PHI | Atlantic | 35 min |
| Aug 20, 7:25 AM EDT | Special Marine Warning | PHI | 65 min | |
| Aug 20, 8:45 AM EDT | Special Marine Warning | PHI | 60 min | |
| Aug 20, 9:36 AM EDT | Areal Flood Advisory | PHI | Atlantic, Burlington, Cape May, Ocean | 3 hr |
| Aug 20, 3:13 PM EDT | Rip Current Statement | PHI | Monmouth | 60 hr |
| Aug 20, 4:48 PM EDT | Tropical Storm Watch | PHI | Middlesex, Monmouth | 6 hr |
| Aug 20, 6:39 AM EDT | Areal Flood Advisory | PHI | Kent | 8 hr |
| Aug 20, 6:46 AM EDT | Areal Flood Advisory | PHI | Sussex | 3 hr |
| Aug 20, 8:18 AM EDT | Areal Flood Advisory | PHI | Kent, Sussex | 117 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.