Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

August 3, 2011Berks County, Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 3, 2011, 9:02 PM EDT for Berks County, Bucks County, Montgomery County, Pennsylvania. 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
Aug 3, 2011, 9:02 PM EDT (01:02 UTC)
Expired
Aug 3, 2011, 10:00 PM EDT
In force
58 min
Issued by
NWS Philadelphia/Mount Holly

Counties Berks County, PA, Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 01:06 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, 1.0 hours before the alert went out and 227 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 2011-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 127 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 00:00Z on 2011-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 square meters per square second.193958Sfc1 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
127 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
866 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

098 
WWUS81 KPHI 040102
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
902 PM EDT WED AUG 3 2011

NJZ009-015-PAZ060>062-067>071-040200-
BERKS PA-BUCKS PA-CHESTER PA-DELAWARE PA-HUNTERDON NJ-LEHIGH PA-
MERCER NJ-MONTGOMERY PA-NORTHAMPTON PA-PHILADELPHIA PA-
902 PM EDT WED AUG 3 2011

...THUNDERSTORMS WILL AFFECT BERKS...BUCKS...CHESTER...DELAWARE... 
HUNTERDON ...LEHIGH...MERCER...MONTGOMERY...NORTHAMPTON AND 
PHILADELPHIA COUNTIES...

AT 854 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
EMBEDDED THUNDERSTORMS WITHIN A LINE OF HEAVIER SHOWERS EXTENDING 
FROM 6 MILES EAST OF ALLENTOWN TO 7 MILES SOUTHWEST OF ALLENTOWN TO 
16 MILES NORTHWEST OF READING...MOVING SOUTHEAST AT 30 MPH. THE 
THUNDERSTORMS WILL BE NEAR REVERE...FERNDALE AROUND 915 
PM...PIPERSVILLE...OTTSVILLE AROUND 930 PM...LUMBERVILLE...NEW HOPE 
AROUND 945 PM...AMBLER AND WARMINSTER HEIGHTS AROUND 1000 PM.

A PERIOD OF HEAVY RAINFALL WILL OCCUR THAT COULD PRODUCE ONE HALF 
INCH TO 1 INCH OF RAIN WITHIN AN HOURS TIME. BE ALERT FOR THE 
POSSIBILITY OF LOCALIZED FLOODING.

LAT...LON 4055 7561 4069 7532 4020 7475 4007 7504
      4001 7576 4049 7633

$$

FORECASTER:  DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 8:53 PM EDTSpecial Weather StatementPHISussex52 min
Aug 3, 9:53 PM EDTSpecial Weather StatementPHIMercer52 min
Aug 3, 10:33 PM EDTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Gloucester, Hunterdon, Mercer and 3 more117 min
Aug 4, 12:18 AM EDTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Ocean and 1 more117 min
Aug 4, 3:55 AM EDTCoastal Flood AdvisoryPHIAtlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more11 hr
Aug 3, 8:11 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh, Northampton64 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.