Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 65, NWS Philadelphia/Mount Holly

July 4, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 4, 2021, 5:39 PM EDT. It was in force for 66 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 4, 2021, 5:39 PM EDT (21:39 UTC)
Expired
Jul 4, 2021, 6:45 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
34.0 mph

The radar

The Philadelphia radar (KDIX), 44 km from the middle of the area, began a volume at 21:40 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.7 hours before the alert went out and 189 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, Brookhaven, NY at 12:00Z on 2021-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Brookhaven, NY at 12:00Z on 2021-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
519 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

339 
WHUS51 KPHI 042139
SMWPHI
ANZ451-042245-
/O.NEW.KPHI.MA.W.0065.210704T2139Z-210704T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
539 PM EDT Sun Jul 4 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 645 PM EDT.

* At 539 PM EDT, a strong thunderstorm was located near Beach Haven,
  moving southeast at 10 knots.

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

  SOURCE...Radar.

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

* Locations impacted include...
  Beach Haven, North Beach Haven, Garden State South Reef, Little Egg
  Reef and Ship Bottom.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

Report severe weather to the Coast Guard or the National Weather
Service.

&&

LAT...LON 3945 7420 3955 7443 3957 7442 3958 7440
      3960 7440 3967 7430 3964 7406
TIME...MOT...LOC 2139Z 297DEG 10KT 3960 7434 

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

$$

MPS
2 follow-up statements
851 
FZUS71 KPHI 042158
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
558 PM EDT Sun Jul 4 2021

ANZ451-042245-
/O.CON.KPHI.MA.W.0065.000000T0000Z-210704T2245Z/
558 PM EDT Sun Jul 4 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 645 PM EDT...

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

At 558 PM EDT, a strong thunderstorm was located over Beach Haven,
moving southeast at 10 knots.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Beach Haven, Little Egg Reef and North Beach Haven. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

Report severe weather to the Coast Guard or the National Weather
Service.

&&

LAT...LON 3954 7414 3945 7420 3954 7441 3962 7426
      3955 7412
TIME...MOT...LOC 2158Z 316DEG 12KT 3954 7429 

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

$$

MPS
062 
FZUS71 KPHI 042235
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
635 PM EDT Sun Jul 4 2021

ANZ451-042245-
/O.EXP.KPHI.MA.W.0065.000000T0000Z-210704T2245Z/
635 PM EDT Sun Jul 4 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 645 PM EDT...

The affected areas were... 

Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20
nm...

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

LAT...LON 3954 7414 3945 7420 3954 7441 3962 7426
      3955 7412
TIME...MOT...LOC 2235Z 297DEG 10KT 3949 7417 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 1:25 AM EDTDense Fog AdvisoryPHIHunterdon, Warren7 hr
Jul 4, 3:01 PM EDTSpecial Weather StatementPHIOcean29 min
Jul 4, 3:02 PM EDTSpecial Weather StatementPHIBurlington28 min
Jul 4, 3:04 PM EDTSpecial Weather StatementPHIOcean26 min
Jul 4, 3:28 PM EDTSpecial Weather StatementPHIBurlington32 min
Jul 4, 4:05 PM EDTSpecial Weather StatementPHIBurlington25 min
Jul 4, 4:39 PM EDTSpecial Weather StatementPHIOcean36 min
Jul 4, 5:38 PM EDTSpecial Weather StatementPHIOcean37 min
Jul 4, 6:23 PM EDTSpecial Weather StatementPHIAtlantic37 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.