Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 97, NWS Philadelphia/Mount Holly

July 21, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 21, 2021, 3:48 PM EDT. It was in force for 57 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 21, 2021, 3:48 PM EDT (19:48 UTC)
Expired: Jul 21, 2021, 4:45 PM EDT
In force: 57 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 40.0 mph

The radar

The Philadelphia radar (KDIX), 56 km from the middle of the area, began a volume at 19:51 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

Brookhaven, NY (KOKX), launched 12:00Z, 7.8 hours before the alert went out and 111 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: 130 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 1495 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

979 
WHUS51 KPHI 211948
SMWPHI
ANZ450-451-212045-
/O.NEW.KPHI.MA.W.0097.210721T1948Z-210721T2045Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  
Coastal waters from Sandy Hook to Little Egg Inlet NJ out 20 nm...

* Until 445 PM EDT.

* At 347 PM EDT, a severe thunderstorm was located near Silverton,
  moving northeast at 35 knots.

  HAZARD...Wind gusts to 40 knots and large hail.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves. Large hail could result in 
           structural damage.

* Locations impacted include...
  Sea Girt Reef, Shark River Reef, Point Pleasant Beach, Axel Carlson
  Reef, Belmar and Manasquan Inlet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

Frequent lightning is occurring with this storm. If caught on the
open water, stay below deck if possible and keep away from ungrounded
metal objects.

&&

LAT...LON 4036 7383 4013 7367 4012 7369 4002 7408
      4027 7405 4028 7404 4037 7386
TIME...MOT...LOC 1947Z 242DEG 35KT 4008 7415 

HAIL...>.75IN
WIND...40KTS

$$

Gorse

1 follow-up statement

670 
FZUS71 KPHI 212015
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
415 PM EDT Wed Jul 21 2021

ANZ450-451-212045-
/O.CON.KPHI.MA.W.0097.000000T0000Z-210721T2045Z/
415 PM EDT Wed Jul 21 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 445 PM EDT...

For the following areas...
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20
nm...
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm...

At 415 PM EDT, a severe thunderstorm was located over Sea Girt Reef,
moving east at 20 knots.

HAZARD...Wind gusts 34 knots or greater and large hail.

SOURCE...Radar indicated.

IMPACT...Small craft could be damaged in briefly higher winds and 
         suddenly higher waves. Large hail could result in 
         structural damage.

Locations impacted include...
Sea Girt Reef, Shark River Reef, Point Pleasant Beach, Axel Carlson
Reef, Belmar and Manasquan Inlet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 4036 7383 4013 7367 4012 7369 4002 7408
      4027 7405 4028 7404 4037 7386
TIME...MOT...LOC 2015Z 250DEG 20KT 4015 7397 

HAIL...>.75IN
WIND...>34KTS

$$

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 11:09 AM EDT	Special Weather Statement	PHI	Morris	36 min
Jul 21, 12:41 PM EDT	Special Weather Statement	PHI	Ocean	34 min
Jul 21, 12:46 PM EDT	Special Marine Warning	PHI		89 min
Jul 21, 12:51 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Ocean	39 min
Jul 21, 12:53 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	67 min
Jul 21, 1:28 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic	47 min
Jul 21, 1:43 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	49 min
Jul 21, 2:10 PM EDT	Special Marine Warning	PHI		95 min
Jul 21, 2:13 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	47 min
Jul 21, 2:35 PM EDT	Special Marine Warning	PHI		55 min
Jul 21, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	26 min
Jul 21, 3:04 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	56 min
Jul 21, 3:16 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	44 min
Jul 21, 3:27 PM EDT	Severe Thunderstorm Warning	PHI	Camden, Gloucester	33 min
Jul 21, 3:43 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	47 min
Jul 21, 3:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	42 min
Jul 21, 3:57 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Salem	33 min
Jul 21, 4:04 PM EDT	Special Marine Warning	PHI		56 min
Jul 21, 4:17 PM EDT	Special Marine Warning	PHI		58 min
Jul 21, 4:50 PM EDT	Special Marine Warning	PHI		55 min
Jul 21, 5:07 PM EDT	Special Marine Warning	PHI		23 min
Jul 21, 5:09 PM EDT	Special Marine Warning	PHI		66 min
Jul 21, 5:24 PM EDT	Special Marine Warning	PHI		46 min
Jul 21, 5:31 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	29 min
Jul 21, 5:52 PM EDT	Special Marine Warning	PHI		53 min
Jul 21, 1:08 PM EDT	Special Weather Statement	PHI	Lehigh	37 min
Jul 21, 1:11 PM EDT	Special Weather Statement	PHI	Northampton	34 min
Jul 21, 1:27 PM EDT	Severe Thunderstorm Warning	PHI	Berks	48 min
Jul 21, 2:03 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	42 min
Jul 21, 2:14 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Delaware, Montgomery	19 min
Jul 21, 2:41 PM EDT	Special Weather Statement	PHI	Montgomery	49 min
Jul 21, 2:48 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	42 min
Jul 21, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	38 min
Jul 21, 5:59 PM EDT	Special Weather Statement	PHI	Berks	31 min
Jul 21, 4:50 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	25 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.