Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 64, NWS Philadelphia/Mount Holly

July 1, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 1, 2021, 6:13 PM EDT. It was in force for 92 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 1, 2021, 6:13 PM EDT (22:13 UTC)
Expired: Jul 1, 2021, 7:45 PM EDT
In force: 92 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.0 in
Wind: 50.0 mph

The radar

The Dover AFB radar (KDOX), 106 km from the middle of the area, began a volume at 22:15 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 10.2 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: 1445 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 981 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

531 
WHUS51 KPHI 012213
SMWPHI
ANZ452>455-472-473-475-012345-
/O.NEW.KPHI.MA.W.0064.210701T2213Z-210701T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
613 PM EDT Thu Jul 1 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  
Coastal and outer waters from Little Egg Inlet NJ to Fenwick Island
DE...

* Until 745 PM EDT.

* At 613 PM EDT, severe thunderstorms were located along a line
  extending from Atlantic City Reef to 11 nm east of Five Fathoms
  Buoy to 9 nm west of Chicken Bone, moving east at 40 knots.

  HAZARD...Wind gusts in excess of 50 knots.

  SOURCE...Radar.

  IMPACT...Boats could suffer significant structural damage in high 
           winds. Small craft could capsize in suddenly higher 
           waves.

* Locations impacted include...
  28-Mile Wreck, Five Fathoms Buoy, Buoy 2fb, Atlantic City Reef,
  Deepwater Reef, Delaware Lightship Buoy 44009, Great Egg Reef and
  Atlantic City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3838 7479 3883 7457 3937 7447 3922 7355
      3900 7372 3879 7395 3873 7404 3870 7415
      3861 7417 3851 7426 3831 7427 3822 7431
TIME...MOT...LOC 2213Z 266DEG 39KT 3929 7427 3881 7434 3828 7465 

HAIL...0.00IN
WIND...50KTS

$$

Robertson

2 follow-up statements

743 
FZUS71 KPHI 012301
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
701 PM EDT Thu Jul 1 2021

ANZ452>455-012310-
/O.CAN.KPHI.MA.W.0064.000000T0000Z-210701T2345Z/
701 PM EDT Thu Jul 1 2021

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

The affected areas were...

Coastal waters from Little Egg Inlet NJ to Fenwick Island DE out 20
nm...

The thunderstorms have moved out of the warned area
and no longer pose a significant threat to boaters.

LAT...LON 3835 7469 3886 7431 3929 7400 3922 7355
      3900 7372 3879 7395 3873 7404 3870 7415
      3861 7417 3851 7426 3831 7427 3822 7431
TIME...MOT...LOC 2300Z 258DEG 41KT 3927 7363 3885 7382 3819 7439 

$$

ANZ472-473-475-012345-
/O.CON.KPHI.MA.W.0064.000000T0000Z-210701T2345Z/
701 PM EDT Thu Jul 1 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 745 PM EDT...

For the following areas...
Waters from Cape May NJ to Fenwick Island DE out 20 to 40 nm...
Waters from Great Egg Inlet NJ to Cape May NJ out 20 to 40 nm...
Waters from Little Egg Inlet NJ to Great Egg Inlet NJ out 20 to 40 nm
from 20 to 40 NM...

At 700 PM EDT, severe thunderstorms capable of producing waterspouts
were located along a line extending from 28 nm southeast of Garden
State South Reef to 19 nm southeast of Deepwater Reef to near Chicken
Bone, moving east at 40 knots.

HAZARD...Waterspouts and wind gusts to 40 knots.

SOURCE...Radar indicated.

IMPACT...Waterspouts can easily overturn boats and create locally 
         hazardous seas. Small craft could be damaged in briefly 
         higher winds and suddenly higher waves.

Locations impacted include...
Deepwater Reef.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3835 7469 3886 7431 3929 7400 3922 7355
      3900 7372 3879 7395 3873 7404 3870 7415
      3861 7417 3851 7426 3831 7427 3822 7431
TIME...MOT...LOC 2300Z 258DEG 41KT 3927 7363 3885 7382 3819 7439 

WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...40KTS

$$

Robertson

986 
FZUS71 KPHI 012335
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
735 PM EDT Thu Jul 1 2021

ANZ472-473-475-012345-
/O.EXP.KPHI.MA.W.0064.000000T0000Z-210701T2345Z/
735 PM EDT Thu Jul 1 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 745 PM EDT...

The affected areas were... 

Outer waters from Little Egg Inlet NJ to Fenwick Island DE out 20 to
40 nm...

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

LAT...LON 3835 7469 3886 7431 3929 7400 3922 7355
      3900 7372 3879 7395 3873 7404 3870 7415
      3861 7417 3851 7426 3831 7427 3822 7431
TIME...MOT...LOC 2335Z 266DEG 39KT 3929 7315 3887 7335 3822 7392 

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 8:37 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer	38 min
Jun 30, 8:56 PM EDT	Special Marine Warning	PHI		94 min
Jun 30, 9:05 PM EDT	Special Weather Statement	PHI	Somerset	40 min
Jun 30, 9:21 PM EDT	Special Weather Statement	PHI	Salem	39 min
Jun 30, 9:49 PM EDT	Special Weather Statement	PHI	Monmouth	26 min
Jun 30, 9:51 PM EDT	Special Marine Warning	PHI		60 min
Jul 1, 2:58 AM EDT	Small Craft Advisory	PHI		17 hr
Jul 1, 1:10 PM EDT	Special Weather Statement	PHI	Monmouth	50 min
Jul 1, 1:16 PM EDT	Special Weather Statement	PHI	Atlantic	29 min
Jul 1, 1:28 PM EDT	Special Marine Warning	PHI		62 min
Jul 1, 1:31 PM EDT	Special Weather Statement	PHI	Cumberland	29 min
Jul 1, 4:21 PM EDT	Special Marine Warning	PHI		114 min
Jul 1, 4:27 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Hunterdon, Mercer, Salem and 1 more	48 min
Jul 1, 4:55 PM EDT	Severe Thunderstorm Warning	PHI	Cape May, Cumberland, Salem	80 min
Jul 1, 4:59 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 2 more	46 min
Jul 1, 5:02 PM EDT	Tornado Warning	PHI	Burlington, Mercer	28 min
Jul 1, 5:27 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more	93 min
Jul 1, 5:35 PM EDT	Tornado Warning	PHI	Mercer, Monmouth, Ocean	25 min
Jul 1, 5:40 PM EDT	Special Marine Warning	PHI		65 min
Jul 1, 5:46 PM EDT	Special Marine Warning	PHI		119 min
Jun 30, 8:16 PM EDT	Special Weather Statement	PHI	Bucks, Montgomery	44 min
Jul 1, 2:51 PM EDT	Special Weather Statement	PHI	Chester, Montgomery	39 min
Jul 1, 3:13 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	47 min
Jul 1, 3:23 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	77 min
Jul 1, 3:48 PM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	112 min
Jul 1, 3:50 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	40 min
Jul 1, 4:08 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	52 min
Jul 1, 4:08 PM EDT	Severe Thunderstorm Warning	PHI	Kent	52 min
Jul 1, 4:10 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	94 min
Jul 1, 4:32 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	43 min
Jul 1, 4:57 PM EDT	Tornado Warning	PHI	Kent, Sussex	22 min
Jul 1, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	48 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.