Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 10, NWS Philadelphia/Mount Holly

April 21, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Apr 21, 2021, 2:40 PM EDT. It was in force for 55 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 21, 2021, 2:40 PM EDT (18:40 UTC)
Expired: Apr 21, 2021, 3:35 PM EDT
In force: 55 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 49.0 mph

The radar

The Philadelphia radar (KDIX), 34 km from the middle of the area, began a volume at 18:40 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.

What was reported inside it

Time	Report	Where	Remark
Apr 21, 2:41 PM EDT	TSTM WND DMG	2 Se Leisure Village Ea, NJ	GARDEN SHED BLOWN OVER, SECTION OF VINYL FENCE BROUGHT DOWN, AND SHINGLES BLOWN OFF HOUSE. TIME ESTIMATED FROM RADAR. SOCIAL MEDIA.
Apr 21, 2:43 PM EDT	HAIL 0.25	1 Ese Manahawkin, NJ
Apr 21, 2:44 PM EDT	HAIL 0.25	1 N Seaside Heights, NJ
Apr 21, 2:45 PM EDT	HAIL 0.25	Barnegat, NJ

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.7 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.

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: 1427 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 206 m²/s²
0-3 km storm-relative helicity: 201 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

213 
WHUS51 KPHI 211840
SMWPHI
ANZ450-451-470-471-212015-
/O.NEW.KPHI.MA.W.0010.210421T1840Z-210421T2015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
240 PM EDT Wed Apr 21 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  
Coastal and outer waters from Sandy Hook to Little Egg Inlet NJ...

* Until 415 PM EDT.

* At 240 PM EDT, strong thunderstorms were located along a line
  extending from Sandy Hook to 9 nm west of Ship Bottom, moving east
  at 40 knots.

  HAZARD...Wind gusts to nearly 50 knots and small hail.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves.

* Locations impacted include...
  Ocean Gate, Sea Girt Reef, Ship Bottom, Atlantic Highlands,
  Barnegat Light Reef, Monmouth Beach, Sea Bright, Axel Carlson Reef,
  Silverton, Harvey Cedars, Forked River, Fair Haven, Lavallette,
  Barnegat Light, Garden State North Reef, Shark River Reef, Point
  Pleasant Beach, Belmar, Seaside Park and Manasquan Inlet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 4044 7398 4026 7365 4004 7346 3957 7361
      3961 7437 3970 7426 3982 7427 3990 7420
      3993 7425 3996 7425 4000 7420 4020 7411
      4024 7405 4027 7405 4031 7412 4042 7406
      4040 7398
TIME...MOT...LOC 1840Z 259DEG 40KT 4047 7398 3970 7437 

HAIL...<.75IN
WIND...49KTS

$$

Davis

1 follow-up statement

507 
FZUS71 KPHI 211935
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
335 PM EDT Wed Apr 21 2021

ANZ450-451-470-471-211944-
/O.CAN.KPHI.MA.W.0010.000000T0000Z-210421T2015Z/
335 PM EDT Wed Apr 21 2021

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

The affected areas were... 

Coastal and outer waters from Sandy Hook to Little Egg Inlet NJ...

The thunderstorms have weakened and no longer pose a significant 
threat to boaters. However, a Gale Warning is now in affect for the 
affected waters, and gale force winds are expected to continue.

A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
central and southern New Jersey...and the adjacent coastal waters.

LAT...LON 4044 7398 4026 7365 4004 7346 3957 7361
      3961 7437 3970 7426 3982 7427 3990 7420
      3993 7425 3996 7425 4000 7420 4020 7411
      4024 7405 4027 7405 4031 7412 4042 7406
      4040 7398
TIME...MOT...LOC 1933Z 259DEG 40KT 4058 7322 3981 7361 

$$

JEO

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 8:48 PM EDT	Freeze Watch	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	7 hr
Apr 21, 3:26 AM EDT	Freeze Warning	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	30 hr
Apr 21, 12:25 PM EDT	Severe Thunderstorm Warning	PHI	Warren	50 min
Apr 21, 12:51 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	21 min
Apr 21, 12:55 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	27 min
Apr 21, 1:10 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Salem	50 min
Apr 21, 1:17 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris, Somerset, Sussex	58 min
Apr 21, 1:28 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	36 min
Apr 21, 1:30 PM EDT	Special Marine Warning	PHI		60 min
Apr 21, 1:43 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Morris, Somerset	33 min
Apr 21, 1:58 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Monmouth, Ocean	62 min
Apr 21, 2:02 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Monmouth, Ocean	43 min
Apr 21, 2:03 PM EDT	Special Weather Statement	PHI	Cumberland	27 min
Apr 21, 2:17 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cumberland, Gloucester, Salem	43 min
Apr 21, 2:28 PM EDT	Special Weather Statement	PHI	Middlesex, Monmouth	47 min
Apr 21, 2:30 PM EDT	Special Marine Warning	PHI		60 min
Apr 21, 2:38 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	37 min
Apr 21, 2:43 PM EDT	Special Weather Statement	PHI	Cape May	32 min
Apr 21, 2:50 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Ocean	40 min
Apr 21, 3:02 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic	28 min
Apr 21, 3:07 PM EDT	Special Marine Warning	PHI		53 min
Apr 21, 12:03 PM EDT	Special Weather Statement	PHI	Chester, Lehigh	42 min
Apr 21, 12:17 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	43 min
Apr 21, 12:54 PM EDT	Special Weather Statement	PHI	Delaware	36 min
Apr 21, 1:23 PM EDT	Severe Thunderstorm Warning	PHI	Kent	37 min
Apr 21, 2:09 PM EDT	Special Weather Statement	PHI	Sussex	36 min
Apr 21, 2:18 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	42 min
Apr 21, 2:47 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	16 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.