Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 24, NWS Philadelphia/Mount Holly

May 26, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at May 26, 2021, 7:56 PM EDT. It was in force for 71 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
May 26, 2021, 7:56 PM EDT (23:56 UTC)
Expired
May 26, 2021, 9:07 PM EDT
In force
71 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Dover AFB radar (KDOX), 46 km from the middle of the area, began a volume at 23:58 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, 11.9 hours before the alert went out and 139 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 2021-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 74 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 2021-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 square meters per square second.1939Sfc1 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
74 J/kg
Mixed-layer CIN
-176 J/kg
Mixed-layer LCL
822 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

280 
WHUS51 KPHI 262356
SMWPHI
ANZ430-431-270130-
/O.NEW.KPHI.MA.W.0024.210526T2356Z-210527T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
756 PM EDT Wed May 26 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 930 PM EDT.

* At 756 PM EDT, a strong thunderstorm was located 9 nm southwest of
  Bowers Beach, moving northeast at 25 knots.

  HAZARD...Wind gusts 34 knots or greater.

  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, East Point, Bowers Beach, Miah Maull Light,
  Brandywine 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.

&&

LAT...LON 3928 7513 3926 7507 3929 7506 3932 7507
      3937 7496 3931 7491 3923 7495 3921 7489
      3898 7484 3883 7529 3894 7541 3899 7539
      3903 7546 3909 7547
TIME...MOT...LOC 2356Z 242DEG 25KT 3894 7554 

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

$$

Meola
2 follow-up statements
654 
FZUS71 KPHI 270047
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
847 PM EDT Wed May 26 2021

ANZ430-270057-
/O.CAN.KPHI.MA.W.0024.000000T0000Z-210527T0130Z/
847 PM EDT Wed May 26 2021

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

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

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

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
southern New Jersey...and the adjacent coastal waters.

LAT...LON 3917 7508 3923 7495 3921 7489 3898 7484
      3891 7504 3905 7514
TIME...MOT...LOC 0047Z 242DEG 25KT 3911 7514 

$$

ANZ431-270130-
/O.CON.KPHI.MA.W.0024.000000T0000Z-210527T0130Z/
847 PM EDT Wed May 26 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 930 PM EDT...

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

At 847 PM EDT, a strong thunderstorm was located near Miah Maull
Light, moving northeast at 25 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...
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.

&&

LAT...LON 3917 7508 3923 7495 3921 7489 3898 7484
      3891 7504 3905 7514
TIME...MOT...LOC 0047Z 242DEG 25KT 3911 7514 

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

$$

Meola
599 
FZUS71 KPHI 270107
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
907 PM EDT Wed May 26 2021

ANZ431-270117-
/O.CAN.KPHI.MA.W.0024.000000T0000Z-210527T0130Z/
907 PM EDT Wed May 26 2021

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

The affected areas were... 
Lower 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 1000 PM EDT for
southern New Jersey...and the adjacent coastal waters.

LAT...LON 3917 7508 3923 7495 3921 7489 3898 7484
      3891 7504 3905 7514
TIME...MOT...LOC 0102Z 242DEG 25KT 3918 7498 

$$

Meola

The office that day

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

IssuedProductOfficeCountiesLasted
May 26, 5:27 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer48 min
May 26, 5:34 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Warren41 min
May 26, 5:53 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Hunterdon, Mercer, Middlesex, Monmouth and 2 more67 min
May 26, 6:08 PM EDTSevere Thunderstorm WarningPHIHunterdon, Middlesex, Morris, Somerset31 min
May 26, 6:49 PM EDTSpecial Marine WarningPHI56 min
May 26, 7:04 PM EDTSpecial Marine WarningPHI26 min
May 26, 7:23 PM EDTSpecial Marine WarningPHI97 min
May 26, 3:39 PM EDTSevere Thunderstorm WarningPHIBerks56 min
May 26, 4:10 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh65 min
May 26, 4:46 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery, Northampton44 min
May 26, 4:52 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery38 min
May 26, 5:37 PM EDTSevere Thunderstorm WarningPHIChester53 min
May 26, 6:52 PM EDTSevere Thunderstorm WarningPHIBerks38 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.