Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 69, NWS Philadelphia/Mount Holly

July 6, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 6, 2021, 9:37 PM EDT. It was in force for 113 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 6, 2021, 9:37 PM EDT (01:37 UTC)
Expired: Jul 6, 2021, 11:30 PM EDT
In force: 113 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), 46 km from the middle of the area, began a volume at 01:39 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 00:00Z, 1.6 hours before the alert went out and 121 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: 1647 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 876 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

309 
WHUS51 KPHI 070137
SMWPHI
ANZ450-451-470-471-070330-
/O.NEW.KPHI.MA.W.0069.210707T0137Z-210707T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
937 PM EDT Tue Jul 6 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 1130 PM EDT.

* At 936 PM EDT, severe thunderstorms were located along a line
  extending from Atlantic Highlands to 7 nm southwest of Cliffwood
  Beach to 25 nm southwest of South Amboy, moving southeast at 25
  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...
  Ocean Gate, Sea Girt Reef, Leonardo, Atlantic Highlands, Monmouth
  Beach, Sea Bright, Axel Carlson Reef, Silverton, Fair Haven,
  Lavallette, Shark River Reef, Point Pleasant Beach, Belmar, Seaside
  Park, Manasquan Inlet, Pine Beach and Sandy Hook Reef.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Boaters should seek safe harbor immediately until these storms pass.
Wind gusts to 40 knots, large hail, high waves, dangerous lightning,
and heavy rain are possible with these storms.

&&

LAT...LON 4044 7398 4026 7365 3994 7337 3987 7333
      3988 7354 3989 7417 3993 7425 3996 7425
      4000 7420 4020 7411 4024 7405 4027 7405
      4032 7413 4036 7413 4042 7406 4040 7398
TIME...MOT...LOC 0136Z 298DEG 26KT 4042 7402 4035 7434 4030 7479 

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

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 8:03 PM EDT	Special Weather Statement	PHI	Burlington, Ocean	42 min
Jul 6, 8:11 PM EDT	Special Marine Warning	PHI		82 min
Jul 6, 8:24 PM EDT	Special Marine Warning	PHI		2 hr
Jul 6, 8:29 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	46 min
Jul 6, 8:37 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Monmouth, Morris, Somerset	53 min
Jul 6, 8:50 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	40 min
Jul 6, 9:04 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Somerset	41 min
Jul 6, 9:10 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset and 1 more	2 hr
Jul 6, 9:29 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset	61 min
Jul 6, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	57 min
Jul 6, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	39 min
Jul 6, 10:50 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	2 hr
Jul 6, 10:54 PM EDT	Special Weather Statement	PHI	Burlington	51 min
Jul 6, 11:11 PM EDT	Special Weather Statement	PHI	Burlington	19 min
Jul 6, 11:30 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Ocean	45 min
Jul 6, 11:39 PM EDT	Special Marine Warning	PHI		66 min
Jul 6, 11:55 PM EDT	Special Weather Statement	PHI	Monmouth	50 min
Jul 7, 12:01 AM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	71 min
Jul 7, 12:10 AM EDT	Special Marine Warning	PHI		95 min
Jul 7, 11:19 AM EDT	Tropical Storm Watch	PHI	Atlantic, Burlington, Cape May, Monmouth, Ocean	18 hr
Jul 7, 3:32 PM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more	42 hr
Jul 6, 8:16 PM EDT	Special Weather Statement	PHI	Lehigh	29 min
Jul 6, 10:08 PM EDT	Special Weather Statement	PHI	Philadelphia	37 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.