Alert archive / New Jersey / Special Marine Warnings in 2009

Special Marine Warning 21, NWS Philadelphia/Mount Holly

May 29, 2009

NWS Philadelphia/Mount Holly issued this special marine warning at May 29, 2009, 5:03 PM EDT. It was in force for 87 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 29, 2009, 5:03 PM EDT (21:03 UTC)
Expired: May 29, 2009, 6:30 PM EDT
In force: 87 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

The radar

The Dover AFB radar (KDOX), 40 km from the middle of the area, began a volume at 21:06 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.1 hours before the alert went out and 81 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: 4 J/kg
Mixed-layer CIN: -283 J/kg
Mixed-layer LCL: 620 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 58 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, in the capitals the NWS used until 2016.

000 
WHUS51 KPHI 292103
SMWPHI
ANZ430-431-292230-
/O.NEW.KPHI.MA.W.0021.090529T2103Z-090529T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
503 PM EDT FRI MAY 29 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
  DELAWARE BAY WATERS SOUTH OF EAST POINT NJ TO SLAUGHTER BEACH DE
  OVER ATLANTIC COASTAL WATERS...
  DELAWARE BAY WATERS NORTH OF EAST POINT NJ TO SLAUGHTER BEACH DE
  OVER ATLANTIC COASTAL WATERS...
  INCLUDING CAPE HENLOPEN...BRANDYWINE SHOAL LIGHT...BROWN SHOAL
  LIGHT...CAPE MAY POINT...CROSS LEDGE LIGHT...EAST POINT...FORTESQUE
  BEACH...FOURTEEN FOOT BANK LIGHT...MIAH MAULL LIGHT AND SHIP JOHN
  SHOAL LIGHT...

* UNTIL 630 PM EDT

* AT 501 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM...PRODUCING SEVERE WINDS IN EXCESS OF 50 KNOTS 16 NM
  WEST OF CROSS LEDGE LIGHT...OR ABOUT 9 NM WEST OF BOWERS BEACH...
  MOVING EAST AT 25 KNOTS.

* THIS SEVERE THUNDERSTORM WILL BE NEAR
  5 NM SOUTH OF CROSS LEDGE LIGHT BY 540 PM EDT
  2 NM SOUTH OF MIAH MAULL LIGHT BY 545 PM EDT
  3 NM NORTH OF FOURTEEN FOOT BANK LIGHT BY 550 PM EDT
  6 NM NORTH OF BRANDYWINE SHOAL LIGHT BY 555 PM EDT
  6 NM SOUTH OF EAST POINT BY 605 PM EDT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MARINERS CAN EXPECT GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...
AND HEAVY RAINS. BOATERS SHOULD SEEK SAFE HARBOR IMMEDIATELY...UNTIL 
THIS STORM PASSES. FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. 
IF CAUGHT ON THE OPEN WATER STAY BELOW DECK IF POSSIBLE...KEEP AWAY 
FROM UNGROUNDED METAL OBJECTS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW 
JERSEY AND SOUTHEAST PENNSYLVANIA. OTHER INTENSIFYING THUNDERSTORMS WERE
NOTED OVER SOUTHWESTERN SUSSEX COUNTY DELAWARE THAT COULD ALSO MOVE 
INTO THE BAY AFTER 530 PM.

&&

LAT...LON 3940 7544 3935 7537 3935 7533 3930 7531
      3930 7526 3925 7517 3918 7514 3922 7504
      3915 7488 3898 7496 3896 7494 3878 7510
      3878 7515 3884 7524 3893 7532 3901 7533
      3907 7540 3926 7541 3933 7547 3934 7551
TIME...MOT...LOC 2102Z 269DEG 24KT 3909 7558

$$
 
TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
May 29, 5:10 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester	42 min
May 29, 6:16 PM EDT	Special Marine Warning	PHI		119 min
May 29, 7:47 PM EDT	Special Marine Warning	PHI		88 min
May 29, 3:28 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester	62 min
May 29, 3:38 PM EDT	Severe Thunderstorm Warning	PHI	Chester	67 min
May 29, 4:45 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	50 min
May 29, 5:32 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	58 min

Nearby

Special Marine Warnings in New Jersey, 2009 Every special marine warning in 2009

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.