Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

August 18, 2011Camden County, Gloucester County, New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 18, 2011, 7:29 AM EDT for Camden County, Gloucester County, New Jersey; 4 counties in Pennsylvania. It was in force for 61 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
Aug 18, 2011, 7:29 AM EDT (11:29 UTC)
Expired
Aug 18, 2011, 8:30 AM EDT
In force
61 min
Issued by
NWS Philadelphia/Mount Holly

Counties Camden County, NJ, Gloucester County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 11:30 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, 11.5 hours before the alert went out and 219 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 2011-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 66 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2011-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
66 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
1883 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
14 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.

672 
WWUS81 KPHI 181129
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
729 AM EDT THU AUG 18 2011

NJZ016>019-027-PAZ068>071-181230-
BUCKS PA-CAMDEN NJ-DELAWARE PA-GLOUCESTER NJ-MONTGOMERY PA-
NORTHWESTERN BURLINGTON NJ-PHILADELPHIA PA-SALEM NJ-
SOUTHEASTERN BURLINGTON NJ-
729 AM EDT THU AUG 18 2011

...STRONG THUNDERSTORMS WILL AFFECT BUCKS...BURLINGTON...CAMDEN...
DELAWARE...GLOUCESTER...MONTGOMERY...PHILADELPHIA AND SALEM
COUNTIES...

AT 727 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 20 MILES SOUTH OF
ALLENTOWN TO 12 MILES WEST OF PHILADELPHIA TO 12 MILES EAST OF 
WILMINGTON...MOVING EAST AT 20 MPH. 

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THESE STORMS. SO FAR, WIND 
GUSTS TO 30 MPH HAVE BEEN OCCURRING WITH THESE STORMS ESPECIALLY 
ALONG THE LEADING EDGE. 

VERY HEAVY RAIN WILL FALL FROM THESE STORMS, AND WILL CAUSE WATER TO 
POND ON ROADS AND GREATLY REDUCE THE VISIBILITIES.

CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS. DO NOT 
SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS, MOVE INDOORS WHEN 
A THUNDERSTORM APPROACHES.

LAT...LON 3970 7476 3963 7539 4001 7544 4002 7542
      4004 7543 4007 7537 4007 7541 4010 7543
      4009 7545 4013 7549 4035 7561 4039 7500
      4005 7470

$$

FORECASTER: GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 4:53 AM EDTSpecial Weather StatementPHIMorris, Somerset, Sussex52 min
Aug 18, 6:35 AM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Hunterdon, Mercer, Morris and 2 more3 hr
Aug 18, 8:16 AM EDTSpecial Weather StatementPHIBurlington, Camden, Gloucester59 min
Aug 18, 8:57 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Monmouth and 1 more3 hr
Aug 18, 3:12 PM EDTFlash Flood WatchPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more29 hr
Aug 18, 3:32 PM EDTSpecial Weather StatementPHIBurlington58 min
Aug 18, 3:50 PM EDTAreal Flood AdvisoryPHIBurlington, Camden51 min
Aug 18, 4:17 PM EDTSpecial Weather StatementPHIMonmouth58 min
Aug 18, 4:55 PM EDTSpecial Weather StatementPHIBurlington65 min
Aug 18, 5:20 PM EDTSevere Thunderstorm WarningPHIBurlington, Monmouth, Ocean33 min
Aug 18, 6:12 PM EDTSpecial Weather StatementPHIMiddlesex63 min
Aug 18, 6:33 PM EDTSpecial Weather StatementPHIMercer57 min
Aug 18, 7:34 PM EDTSpecial Weather StatementPHIMonmouth56 min
Aug 18, 7:37 PM EDTSevere Thunderstorm WarningPHIGloucester, Salem53 min
Aug 18, 7:43 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren62 min
Aug 18, 7:47 PM EDTAreal Flood AdvisoryPHISussex, Warren3 hr
Aug 18, 7:59 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden61 min
Aug 18, 2:57 AM EDTSpecial Weather StatementPHIBerks63 min
Aug 18, 3:53 AM EDTSpecial Weather StatementPHIBerks52 min
Aug 18, 4:48 AM EDTSpecial Weather StatementPHIChester, Montgomery57 min
Aug 18, 5:45 AM EDTSpecial Weather StatementPHIDelaware, Montgomery, Philadelphia60 min
Aug 18, 6:04 AM EDTSpecial Weather StatementPHIBerks, Chester41 min
Aug 18, 9:29 AM EDTAreal Flood AdvisoryPHIDelaware2 hr
Aug 18, 5:30 PM EDTSpecial Weather StatementPHIMonroe60 min
Aug 18, 5:48 PM EDTSevere Thunderstorm WarningPHIChester57 min
Aug 18, 6:18 PM EDTSpecial Weather StatementPHIChester57 min
Aug 18, 6:39 PM EDTSevere Thunderstorm WarningPHIChester66 min
Aug 18, 6:59 PM EDTFlash Flood WarningPHIChester2 hr
Aug 18, 7:14 PM EDTSevere Thunderstorm WarningPHIChester, Delaware50 min
Aug 18, 7:28 PM EDTSpecial Weather StatementPHIChester62 min
Aug 18, 7:31 PM EDTSpecial Weather StatementPHIMonroe59 min
Aug 18, 7:58 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery31 min
Aug 18, 6:04 PM EDTAreal Flood AdvisoryPHICecil116 min
Aug 18, 6:44 PM EDTSpecial Weather StatementPHINew Castle61 min

Nearby

Special Weather Statements in Pennsylvania, 2011Special Weather Statements in New Jersey, 2011Every special weather statement in 2011

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.