Alert archive / New Jersey / Special Marine Warnings in 2021

Special Marine Warning 147, NWS Philadelphia/Mount Holly

December 6, 2021

NWS Philadelphia/Mount Holly issued this special marine warning at Dec 6, 2021, 7:20 PM EST. It was in force for 47 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
Dec 6, 2021, 7:20 PM EST (00:20 UTC)
Expired
Dec 6, 2021, 8:07 PM EST
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.0 in
Wind
40.0 mph

The radar

The Dover AFB radar (KDOX), 82 km from the middle of the area, began a volume at 00:23 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.3 hours before the alert went out and 177 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, Washington/Dulle, VA at 00:00Z on 2021-12-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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, Washington/Dulle, VA at 00:00Z on 2021-12-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.1939587897117136Sfc1 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
4 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1686 m above ground
0-6 km bulk shear
84 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
90 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

625 
WHUS51 KPHI 070020
SMWPHI
ANZ430-070145-
/O.NEW.KPHI.MA.W.0147.211207T0020Z-211207T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
720 PM EST Mon Dec 6 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 845 PM EST.

* At 718 PM EST, heavy showers were located along a line extending 
  from 22 nm north of Pea Patch Island to near Aberdeen Proving 
  Ground, moving east at 40 knots.

  HAZARD...Wind gusts to 40 knots and an abrupt wind shift to the 
           west northwest.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves.

* Locations impacted include...
  Woodland Beach, Stony Point, Pea Patch Island and Reedy Point. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3961 7562 3974 7557 3972 7544 3969 7544
      3968 7542 3960 7539 3950 7550 3934 7529
      3931 7553 3946 7561 3950 7562
TIME...MOT...LOC 0018Z 268DEG 38KT 3995 7546 3942 7612 

HAIL...0.00IN
WIND...40KTS

$$

Gorse
2 follow-up statements
831 
FZUS71 KPHI 070048
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
748 PM EST Mon Dec 6 2021

ANZ430-070145-
/O.CON.KPHI.MA.W.0147.000000T0000Z-211207T0145Z/
748 PM EST Mon Dec 6 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 845 PM EST...

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

At 747 PM EST, heavy showers were located along a line extending 
from 15 nm northeast of Pea Patch Island to 13 nm west of Woodland 
Beach, moving east at 35 knots.

HAZARD...Wind gusts to 40 knots and an abrupt wind shift to the west 
         northwest.

SOURCE...Radar indicated.

IMPACT...Small craft could be damaged in briefly higher winds and 
         suddenly higher waves.

Locations impacted include...
Woodland Beach, Stony Point, Pea Patch Island and Reedy Point. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3961 7562 3974 7557 3972 7544 3969 7544
      3968 7542 3960 7539 3950 7550 3934 7529
      3931 7553 3946 7561 3950 7562
TIME...MOT...LOC 0047Z 283DEG 34KT 3973 7528 3934 7576 

HAIL...0.00IN
WIND...40KTS

$$

Gorse
113 
FZUS71 KPHI 070107
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
807 PM EST Mon Dec 6 2021

ANZ430-070117-
/O.CAN.KPHI.MA.W.0147.000000T0000Z-211207T0145Z/
807 PM EST Mon Dec 6 2021

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

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

The band of heavy showers will clear the warned area shortly. Also, 
a Gale Warning is now in effect.

LAT...LON 3961 7562 3974 7557 3972 7544 3969 7544
      3968 7542 3960 7539 3950 7550 3934 7529
      3931 7553 3946 7561 3950 7562
TIME...MOT...LOC 0103Z 268DEG 38KT 3974 7505 3935 7553 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 7, 1:56 AM ESTSmall Craft AdvisoryPHI8 hr

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.