Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

May 7, 20114 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at May 7, 2011, 4:29 PM EDT for 4 counties in Pennsylvania. It was in force for 91 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 7, 2011, 4:29 PM EDT (20:29 UTC)
Expired
May 7, 2011, 6:00 PM EDT
In force
91 min
Issued by
NWS Philadelphia/Mount Holly

Counties Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 85 km from the middle of the area, began a volume at 20:32 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

Brookhaven, NY (KOKX), launched 12:00Z, 8.5 hours before the alert went out and 217 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, Brookhaven, NY at 12:00Z on 2011-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 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, Brookhaven, NY at 12:00Z on 2011-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
9 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
1218 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
104 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.

427 
WWUS81 KPHI 072029
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
429 PM EDT SAT MAY 7 2011

PAZ060-061-067>071-072200-
BERKS PA-BUCKS PA-CHESTER PA-DELAWARE PA-LEHIGH PA-MONTGOMERY PA-
PHILADELPHIA PA-
429 PM EDT SAT MAY 7 2011

...SHOWERS AND ISOLATED THUNDERSTORMS WITH STRONG WIND GUSTS WILL 
AFFECT PARTS OF DELAWARE...PHILADELPHIA...CHESTER...MONTGOMERY... 
BERKS...LEHIGH AND BUCKS COUNTIES...

AT 423 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
SHOWERS WITH STRONG WIND GUSTS ALONG A LINE EXTENDING FROM 5 MILES
SOUTHEAST OF ALLENTOWN TO 9 MILES SOUTHEAST OF READING...MOVING 
SOUTHEAST AT 30 MPH. A WIND GUST OF 37 MPH OCCURRED AT READING 
REGIONAL AIRPORT. THE SHOWERS AND ISOLATED THUNDERSTORMS WILL BE 
NEAR RICHLANDTOWN...PLEASANT VALLEY...CEDARVILLE...SOUTH POTTSTOWN 
AROUND 435 PM...GLENMOORE...TRUMBAUERSVILLE...SANATOGA...QUAKERTOWN 
AROUND 440 PM...PUGHTOWN AND SPRING MOUNT AROUND 445 PM.

WIND GUSTS TO 40 MPH ARE LIKELY AND MAYBE EVEN SOME SMALL HAIL ARE 
POSSIBLE WITH THE STRONGEST SHOWERS. TEMPERATURES WILL ALSO DROP 
AROUND TEN DEGREES AS THE SHOWERS MOVE THROUGH.

LAT...LON 4021 7599 4063 7541 4061 7539 4058 7541
      4054 7535 4056 7530 4036 7495 4032 7493
      4030 7487 4024 7484 4021 7478 3985 7528
      3985 7531 3984 7537 4014 7590

$$
 
TFG

The office that day

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

IssuedProductOfficeCountiesLasted
May 6, 9:54 PM EDTSpecial Marine WarningPHI96 min
May 7, 3:00 PM EDTSpecial Weather StatementPHISussex90 min
May 7, 3:11 PM EDTSpecial Weather StatementPHIWarren64 min
May 7, 5:20 PM EDTSpecial Weather StatementPHICamden, Hunterdon, Mercer, Somerset85 min
May 7, 6:52 PM EDTSpecial Marine WarningPHI53 min
May 7, 12:03 PM EDTSpecial Weather StatementPHIMonroe57 min
May 7, 1:13 PM EDTSpecial Weather StatementPHICarbon, Monroe92 min
May 6, 9:17 PM EDTSpecial Weather StatementPHIKent, Queen Anne's58 min

Nearby

Special Weather Statements in Pennsylvania, 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.