Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

September 22, 2012Delaware County, Philadelphia County, Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 22, 2012, 7:02 PM EDT for Delaware County, Philadelphia County, Pennsylvania; New Castle County, Delaware. It was in force for 58 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
Sep 22, 2012, 7:02 PM EDT (23:02 UTC)
Expired
Sep 22, 2012, 8:00 PM EDT
In force
58 min
Issued by
NWS Philadelphia/Mount Holly

Counties New Castle County, DE, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 23:02 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 12:00Z, 11.0 hours before the alert went out and 213 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 12:00Z on 2012-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 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 12:00Z on 2012-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 175 square meters per square second.19395878Sfc1 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
34 J/kg
Mixed-layer CIN
-233 J/kg
Mixed-layer LCL
877 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
175 m²/s²
0-3 km storm-relative helicity
158 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.

177 
WWUS81 KPHI 222302
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
702 PM EDT SAT SEP 22 2012

DEZ001-MDZ008-NJZ016>019-PAZ067-068-070-071-230000-
CAMDEN NJ-CECIL MD-CHESTER PA-DELAWARE PA-GLOUCESTER NJ-MONTGOMERY PA-
NEW CASTLE DE-NORTHWESTERN BURLINGTON NJ-PHILADELPHIA PA-SALEM NJ-
702 PM EDT SAT SEP 22 2012

...STRONG THUNDERSTORMS WILL AFFECT BURLINGTON...CAMDEN...CECIL...
CHESTER...DELAWARE...GLOUCESTER...MONTGOMERY...NEW CASTLE...
PHILADELPHIA AND SALEM COUNTIES...

AT 658 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 13 MILES EAST OF
WEST CHESTER TO 7 MILES NORTH OF NEWARK TO 7 MILES SOUTH OF NEWARK...
MOVING NORTHEAST AT 35 MPH. THE THUNDERSTORMS WILL BE NEAR MORRIS
PARK...ROXBOROUGH AROUND 715 PM...NORTHEAST PHILADELPHIA...ROCKLEDGE
AROUND 730 PM...WISSINOMING...TACONY AROUND 745 PM...WESTVILLE AND
BROOKLAWN AROUND 800 PM.

BE PREPARED FOR RAPIDLY CHANGING WEATHER AND MOVE INDOORS AT THE
FIRST SIGN OF THREATENING WEATHER. THIS LINE SHALL AFFECT PHILADELPHIA
AND CAMDEN.

KIDX DOPPLER RADAR HAS BEEN CONSISTENTLY SHOWING WINDS OF AROUND 40 MPH
WITH THIS LINE AND A COUPLE OF MESONET SITES IN CHESTER COUNTY HAD WIND
GUSTS TO THIS LEVEL. 

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

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 3982 7581 4003 7540 4010 7503 4007 7497
      4005 7498 4006 7494 4005 7491 3981 7498
      3950 7582

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 22, 3:51 AM EDTSmall Craft AdvisoryPHI34 hr
Sep 22, 5:26 AM EDTRip Current StatementPHIAtlantic, Cape May, Monmouth, Ocean15 hr
Sep 22, 6:19 PM EDTSpecial Weather StatementPHIWarren56 min
Sep 22, 6:46 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Sussex, Warren74 min
Sep 22, 7:39 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester66 min
Sep 22, 7:52 PM EDTSpecial Weather StatementPHISomerset38 min
Sep 22, 5:11 PM EDTSpecial Weather StatementPHIChester64 min
Sep 22, 6:02 PM EDTSpecial Weather StatementPHIChester, Delaware88 min
Sep 22, 6:14 PM EDTSpecial Weather StatementPHILehigh61 min
Sep 22, 7:22 PM EDTSpecial Weather StatementPHINew Castle53 min
Sep 22, 6:30 PM EDTSpecial Weather StatementPHICecil60 min

Nearby

Special Weather Statements in Pennsylvania, 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.