Alert archive / New Jersey / Special Marine Warnings in 2021
Special Marine Warning 115, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this special marine warning at Aug 20, 2021, 7:25 AM EDT. It was in force for 65 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, 7:25 AM EDT (11:25 UTC)
- Expired
- Aug 20, 2021, 8:30 AM EDT
- In force
- 65 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), 61 km from the middle of the area, began a volume at 11:28 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, 11.4 hours before the alert went out and 91 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
- 1543 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 1030 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 6 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
843
WHUS51 KPHI 201125
SMWPHI
ANZ454-455-475-201230-
/O.NEW.KPHI.MA.W.0115.210820T1125Z-210820T1230Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
725 AM EDT Fri Aug 20 2021
The National Weather Service in Mount Holly NJ has issued a
* Special Marine Warning for...
Coastal waters from Cape May NJ to Fenwick Island DE out 20 nm...
Outer waters from Cape May NJ to Fenwick Island DE out 20 to 40 nm...
* Until 830 AM EDT.
* At 724 AM EDT, a severe thunderstorm capable of producing
waterspouts was located near 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...
Five Fathoms Buoy, Delaware Lightship Buoy 44009, Buoy 2ms and Buoy
4fb.
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 3875 7506 3888 7477 3876 7437
3829 7452
TIME...MOT...LOC 1124Z 234DEG 24KT 3851 7482
WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...>34KTS
$$
CMS2 follow-up statements
230
FZUS71 KPHI 201203
MWSPHI
Marine Weather Statement
National Weather Service Mount Holly NJ
803 AM EDT Fri Aug 20 2021
ANZ454-455-475-201230-
/O.CON.KPHI.MA.W.0115.000000T0000Z-210820T1230Z/
803 AM EDT Fri Aug 20 2021
...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 830 AM EDT...
For the following areas...
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm...
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm...
Waters from Cape May NJ to Fenwick Island DE out 20 to 40 nm...
At 803 AM EDT, a severe thunderstorm capable of producing waterspouts
was located 9 nm south of Five Fathoms Buoy, moving northeast at 20
knots.
HAZARD...Waterspouts and wind gusts 34 knots or greater.
SOURCE...Radar indicated.
IMPACT...Waterspouts can easily overturn boats and create locally
hazardous seas. Small craft could be damaged in briefly
higher winds and suddenly higher waves.
Locations impacted include...
Buoy 4fb, Five Fathoms Buoy and Delaware Lightship Buoy 44009.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to safe harbor until hazardous weather passes.
&&
LAT...LON 3835 7470 3881 7493 3882 7490 3885 7466
3876 7437 3829 7452
TIME...MOT...LOC 1203Z 234DEG 19KT 3862 7462
WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...>34KTS
$$
CMS999
FZUS71 KPHI 201230
MWSPHI
Marine Weather Statement
National Weather Service Mount Holly NJ
830 AM EDT Fri Aug 20 2021
ANZ454-455-475-201239-
/O.EXP.KPHI.MA.W.0115.000000T0000Z-210820T1230Z/
830 AM EDT Fri Aug 20 2021
...THE SPECIAL MARINE WARNING WILL EXPIRE AT 830 AM EDT...
The affected areas were...
Coastal waters from Cape May NJ to Fenwick Island DE out 20 nm...
Outer waters from Cape May NJ to Fenwick Island DE out 20 to 40 nm...
The thunderstorm has moved out of the area and no longer poses a
significant threat to boaters.
LAT...LON 3835 7470 3881 7493 3882 7490 3885 7466
3876 7437 3829 7452
TIME...MOT...LOC 1229Z 234DEG 24KT 3871 7446
$$
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, 8:20 AM EDT | Special Marine Warning | PHI | 55 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.