Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

October 15, 2012Chester County, Delaware County, Pennsylvania; New Castle County, Delaware; Cecil County, Kent County, Maryland

NWS Philadelphia/Mount Holly issued this special weather statement at Oct 15, 2012, 2:02 PM EDT for Chester County, Delaware County, Pennsylvania; New Castle County, Delaware; Cecil County, Kent County, Maryland. It was in force for 88 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 15, 2012, 2:02 PM EDT (18:02 UTC)
Expired
Oct 15, 2012, 3:30 PM EDT
In force
88 min
Issued by
NWS Philadelphia/Mount Holly

Counties New Castle County, DE, Cecil County, MD, Kent County, MD, Chester County, PA, Delaware County, PA

The radar

The Dover AFB radar (KDOX), 86 km from the middle of the area, began a volume at 18:04 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.0 hours before the alert went out and 25 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 2012-10-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°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 2012-10-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
181 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.

756 
WWUS81 KPHI 151802
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
202 PM EDT MON OCT 15 2012

DEZ001-002-MDZ008-012-015-NJZ016-017-PAZ067-068-070-151930-
CECIL MD-CHESTER PA-DELAWARE PA-GLOUCESTER NJ-KENT DE-KENT MD-
MONTGOMERY PA-NEW CASTLE DE-QUEEN ANNE'S MD-SALEM NJ-
202 PM EDT MON OCT 15 2012

...SHOWERS AND ISOLATED THUNDERSTORMS WITH HEAVY RAINFALL WILL 
AFFECT MONTGOMERY...DELAWARE...GLOUCESTER...NEW 
CASTLE...CECIL...KENT...CHESTER...QUEEN ANNE'S AND SALEM COUNTIES...

AT 153 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
SHOWERS AND ISOLATED THUNDERSTORMS WITH HEAVY RAIN ALONG A LINE 
EXTENDING FROM 21 MILES NORTH OF BALTIMORE TO 37 MILES SOUTHWEST OF 
BALTIMORE...MOVING NORTHEAST AT 45 MPH. THE SHOWERS WILL BE NEAR 
ROCK SPRINGS AROUND 240 PM...ATGLEN...HOMEVILLE...CONOWINGO AROUND 
245 PM...PARKESBURG...MOUNT VERNON...GLEN ROY...COCHRANVILLE AROUND 
250 PM...ROCK HALL AROUND 255 PM AND SOUTH COATESVILLE AROUND 300 PM.

VERY HEAVY RAIN WILL FALL FROM THE STRONGER SHOWERS...AND WILL CAUSE 
WATER TO POND ON ROADS AND QUICKLY FILL POOR DRAINAGE AREAS. AROUND 
ONE THIRD OF AN INCH WITHIN AN HOUR IS LIKELY TO OCCUR WITH THE 
STRONGER SHOWERS.

THERE ALSO MIGHT BE PEA SIZE HAIL IN DELMARVA AND CHESTER COUNTY 
IN ANY THUNDERSTORMS.

LAT...LON 3932 7619 3942 7601 3952 7599 3954 7607
      3972 7623 3974 7610 3988 7600 4009 7594
      4039 7550 3984 7530 3938 7543 3946 7555
      3950 7556 3948 7558 3937 7551 3932 7543
      3924 7543 3906 7624 3917 7629

$$
 
TFG/KEK

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 15, 4:33 PM EDTSpecial Weather StatementPHIHunterdon, Morris, Somerset, Sussex, Warren87 min
Oct 15, 4:48 PM EDTSpecial Weather StatementPHIMercer, Middlesex, Monmouth87 min
Oct 15, 2:44 PM EDTSpecial Weather StatementPHICarbon, Monroe61 min
Oct 15, 3:25 PM EDTSpecial Weather StatementPHIBucks, Chester, Delaware, Montgomery, Philadelphia80 min
Oct 15, 7:33 PM EDTSpecial Weather StatementPHIKent, Sussex117 min

Nearby

Special Weather Statements in Pennsylvania, 2012Special Weather Statements in Maryland, 2012Special Weather Statements in Delaware, 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.