Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

August 3, 2012Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 3, 2012, 2:39 PM EDT for Chester County, Pennsylvania. It was in force for 66 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 3, 2012, 2:39 PM EDT (18:39 UTC)
Expired
Aug 3, 2012, 3:45 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 125 km from the middle of the area, began a volume at 18:39 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, 6.7 hours before the alert went out and 54 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, Phillips Aaf/Abe, MD at 12:00Z on 2012-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1112 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, Phillips Aaf/Abe, MD at 12:00Z on 2012-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 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
1112 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
961 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
37 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.

567 
WWUS81 KPHI 031839
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
239 PM EDT FRI AUG 3 2012

PAZ067-031945-
CHESTER PA-
239 PM EDT FRI AUG 3 2012

...A STRONG THUNDERSTORM WILL AFFECT CHESTER COUNTY...

AT 235 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 17 MILES WEST OF WEST CHESTER...MOVING NORTHEAST
AT 10 MPH. THE THUNDERSTORM WILL BE NEAR PARKESBURG AROUND 255 PM...
SOUTH COATESVILLE AROUND 325 PM...MODENA...COATESVILLE AROUND 330 PM
AND THORNDALE AROUND 345 PM.

VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL POOR DRAINAGE AREAS.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM.

EXPECT FREQUENT...DANGEROUS CLOUD TO GROUND LIGHTNING FROM THIS 
STORM WITH SMALL HAIL ALSO POSSIBLE.

LAT...LON 3988 7595 3994 7599 4009 7580 3992 7564
      3983 7592

$$

FORECASTER: HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 3:38 PM EDTSpecial Weather StatementPHIBurlington67 min
Aug 3, 4:17 PM EDTSevere Thunderstorm WarningPHICumberland, Salem58 min
Aug 3, 4:21 PM EDTSpecial Marine WarningPHI84 min
Aug 3, 4:35 PM EDTSpecial Weather StatementPHIMonmouth55 min
Aug 3, 4:45 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean60 min
Aug 3, 5:12 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester63 min
Aug 3, 5:35 PM EDTSpecial Weather StatementPHIMercer55 min
Aug 3, 5:42 PM EDTSpecial Weather StatementPHIMercer63 min
Aug 3, 5:46 PM EDTAreal Flood AdvisoryPHIGloucester101 min
Aug 3, 5:55 PM EDTSpecial Weather StatementPHIBurlington65 min
Aug 3, 6:20 PM EDTAreal Flood AdvisoryPHIBurlington, Mercer2 hr
Aug 3, 6:23 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer43 min
Aug 3, 4:15 PM EDTSpecial Weather StatementPHIDelaware60 min
Aug 3, 7:33 PM EDTSpecial Weather StatementPHIBucks57 min
Aug 3, 2:58 PM EDTSpecial Weather StatementPHISussex62 min
Aug 3, 3:57 PM EDTSpecial Weather StatementPHINew Castle63 min
Aug 3, 4:14 PM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Aug 3, 4:58 PM EDTSevere Thunderstorm WarningPHINew Castle40 min
Aug 3, 5:24 PM EDTSpecial Weather StatementPHICecil66 min

Nearby

Special Weather Statements in Pennsylvania, 2012Every special weather statement in 2012

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.