Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 141, NWS Philadelphia/Mount Holly

October 25, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Oct 25, 2021, 6:03 PM EDT. It was in force for 57 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: Oct 25, 2021, 6:03 PM EDT (22:03 UTC)
Expired: Oct 25, 2021, 7:00 PM EDT
In force: 57 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), 64 km from the middle of the area, began a volume at 22:04 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 12:00Z, 10.1 hours before the alert went out and 163 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: 168 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 959 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 114 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

325 
WHUS51 KPHI 252203
SMWPHI
ANZ430-431-252300-
/O.NEW.KPHI.MA.W.0141.211025T2203Z-211025T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
603 PM EDT Mon Oct 25 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 700 PM EDT.

* At 603 PM EDT, strong thunderstorms were located along a line
  extending from near Woodland Beach to near Bowers Beach to near
  Slaughter Beach, moving north 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, Pea Patch Island, Fourteen Foot Bank
  Light, Slaughter Beach, Bowers Beach, Woodland Beach, Stony Point,
  Miah Maull Light, Ship John Shoal Light, Cross Ledge Light and
  Reedy Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 3964 7561 3968 7552 3958 7550 3953 7546
      3933 7529 3917 7505 3889 7530 3904 7541
      3926 7544 3938 7554 3945 7561 3957 7562
TIME...MOT...LOC 2203Z 183DEG 41KT 3932 7556 3914 7547 3895 7537 

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

$$

JEO

1 follow-up statement

496 
FZUS71 KPHI 252303
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
703 PM EDT Mon Oct 25 2021

ANZ430-431-252313-
/O.EXP.KPHI.MA.W.0141.000000T0000Z-211025T2300Z/
703 PM EDT Mon Oct 25 2021

...THE SPECIAL MARINE WARNING EXPIRED AT 700 PM EDT...

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

The thunderstorms have moved out of the area and no longer pose a
significant threat to boaters.

LAT...LON 3964 7561 3968 7552 3958 7550 3953 7546
      3933 7529 3917 7505 3889 7530 3904 7541
      3926 7544 3938 7554 3945 7561 3957 7562
TIME...MOT...LOC 2303Z 183DEG 41KT 3932 7556 3914 7547 3895 7537 

$$

JEO

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 25, 3:12 AM EDT	Gale Watch	PHI		13 hr
Oct 25, 4:15 PM EDT	Gale Warning	PHI		46 hr
Oct 25, 6:27 PM EDT	Special Weather Statement	PHI	Salem	33 min
Oct 25, 6:33 PM EDT	Severe Thunderstorm Warning	PHI	Salem	42 min
Oct 25, 7:02 PM EDT	Special Weather Statement	PHI	Camden, Gloucester, Salem	43 min
Oct 25, 7:34 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	26 min
Oct 25, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Delaware	48 min
Oct 25, 7:43 PM EDT	Special Weather Statement	PHI	Bucks, Montgomery	47 min
Oct 25, 4:15 PM EDT	Special Weather Statement	PHI	Sussex	30 min
Oct 25, 5:27 PM EDT	Special Weather Statement	PHI	Kent	33 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.