Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 87, NWS Philadelphia/Mount Holly

July 14, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 14, 2021, 7:03 PM EDT. It was in force for 61 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 14, 2021, 7:03 PM EDT (23:03 UTC)
Expired
Jul 14, 2021, 8:04 PM EDT
In force
61 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Philadelphia radar (KDIX), 49 km from the middle of the area, began a volume at 23:03 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, 11.1 hours before the alert went out and 117 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 2021-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1588 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.193958Sfc1 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
1588 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
506 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted.

863 
WHUS51 KPHI 142303
SMWPHI
ANZ450-150030-
/O.NEW.KPHI.MA.W.0087.210714T2303Z-210715T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
703 PM EDT Wed Jul 14 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 830 PM EDT.

* At 702 PM EDT, strong thunderstorms were located along a line
  extending from Sandy Hook Bay to 7 nm west of Belmar, moving east
  at 15 knots.

  HAZARD...Wind gusts 34 knots or greater.

  SOURCE...Radar.

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

* Locations impacted include...
  Sea Girt Reef, Leonardo, Shark River Reef, Belmar, Atlantic
  Highlands, Monmouth Beach, Sea Bright, Sandy Hook Reef, Fair Haven,
  Manasquan Inlet and Point Pleasant Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4025 7364 4014 7367 4001 7374 4010 7402
      4011 7409 4012 7410 4012 7411 4020 7411
      4024 7405 4027 7405 4032 7413 4035 7414
      4042 7406 4040 7398 4044 7398
TIME...MOT...LOC 2302Z 290DEG 16KT 4044 7405 4023 7418 

HAIL...0.00IN
WIND...>34KTS

$$

CMS
1 follow-up statement
843 
FZUS71 KPHI 150004
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
804 PM EDT Wed Jul 14 2021

ANZ450-150014-
/O.CAN.KPHI.MA.W.0087.000000T0000Z-210715T0030Z/
804 PM EDT Wed Jul 14 2021

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

The affected areas were... 

Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm...

The thunderstorms have weakened and no longer pose a significant
threat to boaters.

LAT...LON 4025 7364 4014 7367 4001 7374 4010 7402
      4011 7409 4012 7410 4012 7411 4020 7411
      4024 7405 4027 7405 4032 7413 4035 7414
      4042 7406 4040 7398 4044 7398
TIME...MOT...LOC 0002Z 290DEG 16KT 4035 7372 4014 7385 

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 3:42 PM EDTSpecial Weather StatementPHIMorris18 min
Jul 14, 5:47 PM EDTSpecial Marine WarningPHI43 min
Jul 14, 5:54 PM EDTSpecial Weather StatementPHIOcean51 min
Jul 14, 6:41 PM EDTSpecial Weather StatementPHIMonmouth34 min
Jul 14, 7:03 PM EDTSevere Thunderstorm WarningPHIMonmouth42 min
Jul 14, 7:24 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth36 min
Jul 14, 7:26 PM EDTAreal Flood AdvisoryPHIMiddlesex, Monmouth2 hr
Jul 14, 7:37 PM EDTFlash Flood WarningPHIMonmouth3 hr

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.