Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 111, NWS Philadelphia/Mount Holly

August 10, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Aug 10, 2021, 8:23 PM EDT. It was in force for 79 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 10, 2021, 8:23 PM EDT (00:23 UTC)
Expired: Aug 10, 2021, 9:42 PM EDT
In force: 79 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 40.0 mph

The radar

The Dover AFB radar (KDOX), 56 km from the middle of the area, began a volume at 00:25 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.

What was reported inside it

Time	Report	Where	Remark
Aug 10, 8:23 PM EDT	TSTM WND DMG	1 Ne Pennsville, NJ	WIRES DOWN NEAR NEW JERSEY AVE. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.4 hours before the alert went out and 154 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: 476 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 1128 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 118 m²/s²
0-3 km storm-relative helicity: 120 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

419 
WHUS51 KPHI 110023
SMWPHI
ANZ430-431-110200-
/O.NEW.KPHI.MA.W.0111.210811T0023Z-210811T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
823 PM EDT Tue Aug 10 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1000 PM EDT.

* At 823 PM EDT, strong thunderstorms were located along a line
  extending from near Pea Patch Island to 11 nm southwest of Woodland
  Beach, moving southeast at 30 knots.

  HAZARD...Wind gusts to 40 knots and small hail.

  SOURCE...Radar.

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

* Locations impacted include...
  Brown Shoal Light, Fourteen Foot Bank Light, Slaughter Beach, East
  Point, Bowers Beach, Woodland Beach, Stony Point, Miah Maull Light,
  Ship John Shoal Light, Brandywine Shoal Light, Reedy Point,
  Fortesque Beach, Sea Breeze, Pea Patch Island, Cross Ledge Light
  and Cape May Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3968 7562 3972 7558 3960 7535 3951 7539
      3943 7534 3946 7520 3927 7513 3929 7506
      3944 7506 3931 7491 3923 7495 3916 7486
      3902 7489 3876 7515 3895 7541 3899 7539
      3918 7547 3923 7561 3930 7554 3940 7561
TIME...MOT...LOC 0023Z 302DEG 28KT 3965 7560 3925 7570 

HAIL...<.75IN
WIND...40KTS

$$

Staarmann

2 follow-up statements

209 
FZUS71 KPHI 110055
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
855 PM EDT Tue Aug 10 2021

ANZ430-431-110200-
/O.CON.KPHI.MA.W.0111.000000T0000Z-210811T0200Z/
855 PM EDT Tue Aug 10 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 1000 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 855 PM EDT, strong thunderstorms were located along a line
extending from 9 nm northeast of Stony Point to near Bowers Beach,
moving southeast at 30 knots.

HAZARD...Wind gusts 34 knots or greater.

SOURCE...Radar indicated.

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

Locations impacted include...
Brown Shoal Light, Fourteen Foot Bank Light, Slaughter Beach, East
Point, Bowers Beach, Woodland Beach, Stony Point, Miah Maull Light,
Ship John Shoal Light, Brandywine Shoal Light, Fortesque Beach, Sea
Breeze, Cross Ledge Light and Cape May Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3948 7561 3960 7535 3951 7539 3943 7534
      3946 7520 3935 7518 3927 7513 3926 7507
      3944 7506 3931 7491 3923 7495 3916 7486
      3902 7489 3876 7515 3895 7541 3899 7539
      3918 7547 3923 7561 3930 7554 3940 7561
TIME...MOT...LOC 0055Z 302DEG 28KT 3952 7533 3912 7543 

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

$$

Staarmann

603 
FZUS71 KPHI 110142
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
942 PM EDT Tue Aug 10 2021

ANZ430-431-110151-
/O.CAN.KPHI.MA.W.0111.000000T0000Z-210811T0200Z/
942 PM EDT Tue Aug 10 2021

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

The affected areas were... 
Delaware Bay...

The thunderstorms have weakened and no longer pose a significant 
threat to boaters. However, rain and gusty winds to around 20 kts 
remain possible.

LAT...LON 3948 7561 3960 7535 3951 7539 3943 7534
      3946 7520 3935 7518 3927 7513 3926 7507
      3944 7506 3931 7491 3923 7495 3916 7486
      3902 7489 3876 7515 3895 7541 3899 7539
      3918 7547 3923 7561 3930 7554 3940 7561
TIME...MOT...LOC 0138Z 302DEG 28KT 3934 7496 3894 7506 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 8:02 PM EDT	Severe Thunderstorm Warning	PHI	Camden, Gloucester	43 min
Aug 10, 8:18 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	42 min
Aug 10, 8:36 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Salem	39 min
Aug 10, 8:43 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	2 hr
Aug 10, 9:07 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Cumberland	23 min
Aug 11, 2:56 PM EDT	Excessive Heat Watch	PHI	Hunterdon, Morris, Warren	12 hr
Aug 11, 5:57 PM EDT	Special Weather Statement	PHI	Sussex	48 min
Aug 11, 6:32 PM EDT	Special Weather Statement	PHI	Morris, Sussex, Warren	28 min
Aug 11, 6:50 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	3 hr
Aug 11, 7:04 PM EDT	Areal Flood Advisory	PHI	Gloucester, Hunterdon, Salem	2 hr
Aug 11, 7:04 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex, Warren	41 min
Aug 11, 7:11 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	49 min
Aug 11, 7:28 PM EDT	Flash Flood Warning	PHI	Morris, Warren	3 hr
Aug 11, 7:45 PM EDT	Special Weather Statement	PHI	Morris	45 min
Aug 11, 7:52 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Camden, Gloucester, Mercer	53 min
Aug 11, 7:57 PM EDT	Special Weather Statement	PHI	Hunterdon, Middlesex, Somerset	48 min
Aug 11, 4:46 PM EDT	Special Weather Statement	PHI	Monroe	44 min
Aug 11, 4:58 PM EDT	Special Weather Statement	PHI	Berks	47 min
Aug 11, 5:20 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	57 min
Aug 11, 5:48 PM EDT	Severe Thunderstorm Warning	PHI	Berks	57 min
Aug 11, 6:16 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Montgomery	44 min
Aug 11, 6:26 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Delaware, Montgomery	49 min
Aug 11, 6:48 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Montgomery, Northampton	42 min
Aug 10, 8:11 PM EDT	Special Weather Statement	PHI	New Castle	34 min
Aug 10, 9:09 PM EDT	Special Weather Statement	PHI	Sussex	36 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.