Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 51, NWS Philadelphia/Mount Holly

June 21, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Jun 21, 2021, 10:01 PM EDT. It was in force for 29 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 21, 2021, 10:01 PM EDT (02:01 UTC)
Expired
Jun 21, 2021, 10:30 PM EDT
In force
29 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), 55 km from the middle of the area, began a volume at 02:04 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, 2.0 hours before the alert went out and 153 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 2021-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1131 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 00:00Z on 2021-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 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
1131 J/kg
Mixed-layer CIN
-101 J/kg
Mixed-layer LCL
1172 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
165 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

546 
WHUS51 KPHI 220201
SMWPHI
ANZ430-431-220230-
/O.NEW.KPHI.MA.W.0051.210622T0201Z-210622T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
1001 PM EDT Mon Jun 21 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1030 PM EDT.

* At 1000 PM EDT, a strong thunderstorm was located near Ship John
  Shoal Light, moving east at 40 knots.

  HAZARD...Wind gusts 34 knots or greater and small hail.

  SOURCE...Radar.

  IMPACT...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,
  Bowers Beach, Woodland Beach, Miah Maull Light, Ship John Shoal
  Light and Cross Ledge Light.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

&&

LAT...LON 3945 7533 3943 7534 3943 7530 3946 7520
      3935 7518 3930 7512 3927 7513 3922 7491
      3896 7529 3910 7547 3918 7547 3920 7554
      3946 7556
TIME...MOT...LOC 0200Z 263DEG 38KT 3926 7544 

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

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 8:13 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren62 min
Jun 21, 8:31 PM EDTSpecial Marine WarningPHI59 min
Jun 22, 11:46 AM EDTSpecial Marine WarningPHI44 min
Jun 22, 12:51 PM EDTSpecial Marine WarningPHI114 min
Jun 22, 1:25 PM EDTSpecial Marine WarningPHI65 min
Jun 22, 1:47 PM EDTSpecial Marine WarningPHI118 min
Jun 22, 2:27 PM EDTSpecial Marine WarningPHI93 min
Jun 22, 3:05 PM EDTSmall Craft AdvisoryPHI15 hr
Jun 22, 3:26 PM EDTSpecial Marine WarningPHI68 min
Jun 21, 9:28 PM EDTSpecial Weather StatementPHIKent47 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.