Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 89, NWS Philadelphia/Mount Holly

July 17, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 17, 2021, 8:46 PM EDT. It was in force for 59 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 17, 2021, 8:46 PM EDT (00:46 UTC)
Expired: Jul 17, 2021, 9:45 PM EDT
In force: 59 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.0 in
Wind: 40.0 mph

The radar

The Dover AFB radar (KDOX), 44 km from the middle of the area, began a volume at 00:48 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 00:00Z, 0.8 hours before the alert went out and 137 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: 1997 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 1118 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

126 
WHUS51 KPHI 180046
SMWPHI
ANZ430-431-180145-
/O.NEW.KPHI.MA.W.0089.210718T0046Z-210718T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
846 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  Delaware Bay...

* Until 945 PM EDT.

* At 845 PM EDT, a strong thunderstorm was located over Bowers Beach,
  moving northeast at 35 knots.

  HAZARD...Wind gusts to 40 knots.

  SOURCE...Radar.

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

* Locations impacted include...
  Fortesque Beach, Brown Shoal Light, Fourteen Foot Bank Light,
  Slaughter Beach, Cape Henlopen, East Point, Bowers Beach, Miah
  Maull Light, Brandywine Shoal Light and Cross Ledge Light.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 3932 7516 3929 7512 3927 7513 3926 7507
      3931 7506 3935 7494 3923 7495 3915 7481
      3920 7477 3924 7477 3923 7474 3878 7510
      3879 7531 3883 7529 3894 7541 3899 7539
      3903 7546 3918 7547 3919 7550 3924 7551
TIME...MOT...LOC 0045Z 246DEG 37KT 3902 7542 

HAIL...0.00IN
WIND...40KTS

$$

NC

1 follow-up statement

164 
FZUS71 KPHI 180125
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
925 PM EDT Sat Jul 17 2021

ANZ430-431-180145-
/O.CON.KPHI.MA.W.0089.000000T0000Z-210718T0145Z/
925 PM EDT Sat Jul 17 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 945 PM EDT...

For the following areas...
Delaware Bay waters north of East Point NJ to Slaughter Beach DE...
Delaware Bay waters south of East Point NJ to Slaughter Beach DE...

At 924 PM EDT, a severe thunderstorm was located over Brandywine
Shoal Light, moving east at 25 knots.

HAZARD...Wind gusts in excess of 50 knots and small hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Fortesque Beach, Brown Shoal Light, Fourteen Foot Bank Light,
Slaughter Beach, Cape Henlopen, East Point, Bowers Beach, Miah Maull
Light and Brandywine Shoal Light.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3903 7546 3927 7513 3926 7507 3931 7506
      3935 7494 3923 7495 3916 7482 3920 7477
      3924 7477 3923 7474 3881 7509 3878 7510
      3879 7531 3883 7529 3894 7541 3899 7539
TIME...MOT...LOC 0124Z 258DEG 25KT 3903 7513 

HAIL...<.75IN
WIND...50KTS

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:00 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer, Monmouth	45 min
Jul 17, 8:09 PM EDT	Flash Flood Warning	PHI	Mercer, Somerset	4 hr
Jul 17, 8:35 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	40 min
Jul 17, 8:36 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean, Somerset	54 min
Jul 17, 8:53 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth	3 hr
Jul 17, 9:25 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	2 hr
Jul 17, 9:27 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Jul 17, 9:30 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	29 min
Jul 17, 9:36 PM EDT	Flash Flood Warning	PHI	Camden, Gloucester, Salem	2 hr
Jul 17, 9:44 PM EDT	Special Marine Warning	PHI		61 min
Jul 17, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Salem	42 min
Jul 17, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	54 min
Jul 17, 10:22 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	23 min
Jul 17, 10:27 PM EDT	Special Weather Statement	PHI	Burlington, Camden	33 min
Jul 17, 10:38 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	16 min
Jul 17, 10:43 PM EDT	Flash Flood Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	79 min
Jul 17, 10:47 PM EDT	Special Marine Warning	PHI		118 min
Jul 17, 10:51 PM EDT	Special Marine Warning	PHI		114 min
Jul 17, 11:07 PM EDT	Special Weather Statement	PHI	Middlesex	38 min
Jul 17, 11:08 PM EDT	Areal Flood Warning	PHI	Hunterdon	12 hr
Jul 17, 11:11 PM EDT	Special Weather Statement	PHI	Monmouth, Ocean	34 min
Jul 17, 11:20 PM EDT	Special Marine Warning	PHI		115 min
Jul 17, 11:26 PM EDT	Areal Flood Warning	PHI	Somerset	10 hr
Jul 18, 2:41 AM EDT	Areal Flood Warning	PHI	Mercer	4 hr
Jul 18, 3:48 AM EDT	River Flood Warning	PHI	Mercer	3 hr
Jul 18, 9:08 AM EDT	Areal Flood Warning	PHI	Somerset	2 hr
Jul 18, 11:03 AM EDT	River Flood Warning	PHI	Middlesex, Somerset	88 min
Jul 17, 8:44 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	82 min
Jul 17, 8:57 PM EDT	Severe Thunderstorm Warning	PHI	Chester	48 min
Jul 17, 9:15 PM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	2 hr
Jul 17, 8:40 PM EDT	Special Weather Statement	PHI	Kent	35 min
Jul 17, 10:36 PM EDT	Special Weather Statement	PHI	Kent	24 min
Jul 17, 10:54 PM EDT	Areal Flood Advisory	PHI	Kent	48 min
Jul 17, 10:55 PM EDT	Severe Thunderstorm Warning	PHI	Kent	50 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.