Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 28, NWS Philadelphia/Mount Holly

June 3, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jun 3, 2021, 5:55 PM EDT. It was in force for 65 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
Jun 3, 2021, 5:55 PM EDT (21:55 UTC)
Expired
Jun 3, 2021, 7:00 PM EDT
In force
65 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
34.0 mph

The radar

The Dover AFB radar (KDOX), 37 km from the middle of the area, began a volume at 21:59 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, 9.9 hours before the alert went out and 130 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 12:00Z on 2021-06-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 126 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2021-06-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 square meters per square second.193958Sfc1 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
126 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
573 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

347 
WHUS51 KPHI 032155
SMWPHI
ANZ430-431-032300-
/O.NEW.KPHI.MA.W.0028.210603T2155Z-210603T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
555 PM EDT Thu Jun 3 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 700 PM EDT.

* At 554 PM EDT, a severe thunderstorm capable of producing
  waterspouts was located 7 nm southwest of Slaughter Beach, moving
  northeast at 45 knots.

  HAZARD...Waterspouts, wind gusts 34 knots or greater, and small 
           hail.

  SOURCE...Radar.

  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...
  Brown Shoal Light, Fourteen Foot Bank Light, Slaughter Beach, Cape
  Henlopen, East Point, Bowers Beach, 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 3944 7537 3936 7518 3932 7512 3927 7513
      3926 7507 3931 7506 3926 7494 3923 7495
      3921 7488 3905 7483 3893 7498 3863 7523
      3872 7524 3875 7520 3876 7530 3883 7529
      3894 7541 3899 7539 3903 7546 3919 7550
TIME...MOT...LOC 2154Z 218DEG 44KT 3882 7542 

WATERSPOUT...POSSIBLE
HAIL...<.75IN
WIND...>34KTS

$$

Davis
2 follow-up statements
661 
FZUS71 KPHI 032236
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
636 PM EDT Thu Jun 3 2021

ANZ430-431-032300-
/O.CON.KPHI.MA.W.0028.000000T0000Z-210603T2300Z/
636 PM EDT Thu Jun 3 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 700 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 635 PM EDT, a severe thunderstorm capable of producing waterspouts
was located over East Point, moving northeast at 45 knots.

HAZARD...Waterspouts, wind gusts to nearly 50 knots, and small hail.

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...
Fortesque Beach, Sea Breeze, Fourteen Foot Bank Light, East Point,
Miah Maull Light, Ship John Shoal Light, Cross Ledge Light and Cape
May Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3944 7537 3936 7518 3932 7512 3927 7513
      3926 7507 3931 7506 3926 7494 3923 7495
      3921 7488 3905 7483 3893 7498 3920 7546
TIME...MOT...LOC 2235Z 218DEG 44KT 3922 7501 

WATERSPOUT...POSSIBLE
HAIL...<.75IN
WIND...49KTS

$$

Davis
980 
FZUS71 KPHI 032252
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
652 PM EDT Thu Jun 3 2021

ANZ430-431-032302-
/O.EXP.KPHI.MA.W.0028.000000T0000Z-210603T2300Z/
652 PM EDT Thu Jun 3 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 700 PM EDT...

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

The thunderstorm has moved out of the area and no longer poses a
significant threat to boaters.

A Severe Thunderstorm Watch remains in effect until 900 PM EDT for
central Delaware...southern New Jersey...and the adjacent coastal
waters.

LAT...LON 3944 7537 3936 7518 3932 7512 3927 7513
      3926 7507 3931 7506 3926 7494 3923 7495
      3921 7488 3905 7483 3893 7498 3920 7546
TIME...MOT...LOC 2252Z 218DEG 44KT 3938 7485 

$$

Davis

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 3, 9:37 AM EDTFlash Flood WatchPHIBurlington, Camden, Gloucester, Salem12 hr
Jun 3, 6:33 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland, Salem42 min
Jun 3, 7:07 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more38 min
Jun 3, 7:09 PM EDTFlash Flood WarningPHICamden, Gloucester, Salem2 hr
Jun 3, 7:13 PM EDTAreal Flood AdvisoryPHIBurlington, Hunterdon, Mercer, Middlesex, Somerset3 hr
Jun 3, 7:52 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean38 min
Jun 3, 3:02 PM EDTSpecial Weather StatementPHIBerks43 min
Jun 3, 3:54 PM EDTSpecial Weather StatementPHIBerks36 min
Jun 3, 5:14 PM EDTSevere Thunderstorm WarningPHIBerks, Chester27 min
Jun 3, 5:20 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Delaware, Montgomery, Philadelphia3 hr
Jun 3, 5:59 PM EDTFlash Flood WarningPHIBerks, Chester108 min
Jun 3, 6:19 PM EDTFlash Flood WarningPHIBerks, Chester, Montgomery115 min
Jun 3, 5:33 PM EDTSpecial Weather StatementPHISussex42 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.