Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 74, NWS Philadelphia/Mount Holly

July 8, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jul 8, 2021, 11:02 PM EDT. It was in force for 88 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 8, 2021, 11:02 PM EDT (03:02 UTC)
Expired
Jul 9, 2021, 12:30 AM EDT
In force
88 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.0 in
Wind
49.0 mph

The radar

The Dover AFB radar (KDOX), 76 km from the middle of the area, began a volume at 03:02 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, 3.0 hours before the alert went out and 98 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, Wallops Is Stn, VA at 00:00Z on 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 440 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 00:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.19395878Sfc1 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
440 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
675 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
336 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.3

Open this sounding in Storm Lab

The text

As transmitted.

273 
WHUS51 KPHI 090302
SMWPHI
ANZ431-453>455-473-475-090430-
/O.NEW.KPHI.MA.W.0074.210709T0302Z-210709T0430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
1102 PM EDT Thu Jul 8 2021

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  Lower Delaware Bay...
  Coastal and outer waters from Great Egg Inlet NJ to Fenwick Island
  DE...

* Until 1230 AM EDT.

* At 1100 PM EDT, scattered thunderstorms capable of producing 
  waterspouts were located along a line extending from near Fenwick 
  Island to 7 nm southeast of Jackspot Reef, moving north at 25 
  knots.

  HAZARD...Waterspouts and wind gusts to nearly 50 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...
  Overfalls Shoal, Five Fathoms Buoy, Fenwick Island, Buoy 4fb, Cape
  May Reef, Cape Henlopen, Rehoboth Beach, Bethany Beach, Cape May
  Point, Delaware Lightship Buoy 44009, Buoy 2ms and Indian River
  Inlet Bridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Thunderstorms can produce sudden waterspouts. Waterspouts can easily
overturn boats and create locally hazardous seas. Seek safe harbor
immediately.

&&

LAT...LON 3845 7503 3845 7510 3851 7511 3852 7513
      3881 7514 3897 7495 3874 7407 3872 7408
      3870 7415 3861 7417 3851 7426 3832 7427
      3822 7432
TIME...MOT...LOC 0300Z 190DEG 25KT 3842 7503 3803 7462 

WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...49KTS

$$

BAH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 10:25 PM EDTAreal Flood AdvisoryPHICape May, Cumberland7 hr
Jul 8, 11:59 PM EDTAreal Flood AdvisoryPHISalem5 hr
Jul 9, 12:07 AM EDTSpecial Marine WarningPHI53 min
Jul 9, 12:08 AM EDTAreal Flood AdvisoryPHIAtlantic, Camden, Gloucester6 hr
Jul 9, 12:25 AM EDTSpecial Marine WarningPHI95 min
Jul 9, 1:34 AM EDTSpecial Marine WarningPHI86 min
Jul 9, 1:49 AM EDTSpecial Marine WarningPHI26 min
Jul 9, 2:05 AM EDTAreal Flood AdvisoryPHIBurlington, Monmouth, Ocean8 hr
Jul 9, 2:50 AM EDTTornado WarningPHIAtlantic, Cape May, Cumberland25 min
Jul 9, 2:53 AM EDTSpecial Marine WarningPHI68 min
Jul 9, 3:38 AM EDTTornado WarningPHIAtlantic, Burlington, Ocean18 min
Jul 9, 3:51 AM EDTSpecial Marine WarningPHI84 min
Jul 9, 4:08 AM EDTGale WarningPHI3 hr
Jul 9, 4:41 AM EDTTornado WarningPHIMonmouth, Ocean34 min
Jul 9, 4:44 AM EDTAreal Flood AdvisoryPHIMercer, Middlesex5 hr
Jul 9, 4:54 AM EDTAreal Flood AdvisoryPHIMorris, Somerset5 hr
Jul 9, 4:58 AM EDTSpecial Marine WarningPHI39 min
Jul 9, 5:34 PM EDTAreal Flood AdvisoryPHISussex, Warren2 hr
Jul 9, 6:19 PM EDTSevere Thunderstorm WarningPHISalem41 min
Jul 9, 6:24 PM EDTSpecial Marine WarningPHI66 min
Jul 9, 6:50 PM EDTAreal Flood AdvisoryPHIGloucester, Salem2 hr
Jul 9, 6:57 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem63 min
Jul 9, 7:17 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester23 min
Jul 9, 7:39 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Sussex, Warren2 hr
Jul 9, 7:43 PM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Cape May, Cumberland, Gloucester, Salem62 min
Jul 9, 7:46 PM EDTAreal Flood AdvisoryPHIAtlantic, Camden, Cumberland, Gloucester, Salem108 min
Jul 9, 5:17 PM EDTSevere Thunderstorm WarningPHIChester, Delaware43 min
Jul 9, 6:55 PM EDTSpecial Weather StatementPHICarbon35 min
Jul 9, 7:07 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh, Monroe, Northampton3 hr
Jul 9, 7:31 PM EDTSpecial Weather StatementPHINorthampton29 min
Jul 8, 10:19 PM EDTAreal Flood AdvisoryPHIKent, Sussex5 hr
Jul 8, 11:37 PM EDTTornado WarningPHISussex23 min
Jul 8, 11:59 PM EDTTornado WarningPHISussex12 min
Jul 9, 12:04 AM EDTTornado WarningPHISussex26 min
Jul 9, 12:11 AM EDTTornado WarningPHISussex35 min
Jul 9, 12:28 AM EDTTornado WarningPHISussex17 min
Jul 9, 4:54 PM EDTSpecial Weather StatementPHINew Castle66 min

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.