Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

July 31, 2011Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 31, 2011, 10:00 PM EDT for Chester County, Pennsylvania. It was in force for 60 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
Jul 31, 2011, 10:00 PM EDT (02:00 UTC)
Expired
Jul 31, 2011, 11:00 PM EDT
In force
60 min
Issued by
NWS Philadelphia/Mount Holly

County Chester County, PA

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.0 hours before the alert went out and 159 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 2011-08-01Temperature 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 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2011-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3062 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
73 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.

454 
WWUS81 KPHI 010200
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1000 PM EDT SUN JUL 31 2011

PAZ067-010300-
CHESTER PA-
1000 PM EDT SUN JUL 31 2011

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

AT 958 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 9 MILES NORTH OF LANCASTER...MOVING SOUTHEAST AT
25 MPH. THE THUNDERSTORM WILL BE NEAR HOMEVILLE...ATGLEN AROUND 1045
PM...MOUNT VERNON AND OXFORD AROUND 1100 PM.

VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM.

LAT...LON 3978 7607 3985 7603 3987 7601 3992 7601
      3993 7600 3999 7599 4003 7595 4011 7594
      4005 7586 3976 7579 3973 7611 3974 7613

$$

HAYES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 10:13 PM EDTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset62 min
Jul 31, 10:58 PM EDTSpecial Weather StatementPHIMorris62 min
Aug 1, 1:49 AM EDTSpecial Marine WarningPHI56 min
Aug 1, 1:50 AM EDTSpecial Weather StatementPHIMonmouth55 min
Aug 1, 1:35 PM EDTSpecial Weather StatementPHIMorris, Sussex, Warren3 hr
Aug 1, 2:11 PM EDTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Gloucester, Ocean94 min
Aug 1, 2:44 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem29 min
Aug 1, 4:09 PM EDTSpecial Weather StatementPHICamden66 min
Aug 1, 5:06 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Gloucester69 min
Aug 1, 5:50 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester, Salem70 min
Aug 1, 6:03 PM EDTSpecial Marine WarningPHI57 min
Aug 1, 6:16 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Gloucester59 min
Aug 1, 6:17 PM EDTAreal Flood AdvisoryPHICamden, Gloucester3 hr
Aug 1, 6:20 PM EDTSevere Thunderstorm WarningPHIGloucester, Salem46 min
Aug 1, 6:47 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cumberland, Gloucester, Salem73 min
Aug 1, 7:01 PM EDTAreal Flood AdvisoryPHIAtlantic, Cumberland, Gloucester, Salem119 min
Aug 1, 7:07 PM EDTSpecial Marine WarningPHI83 min
Aug 1, 7:12 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland59 min
Aug 1, 7:17 PM EDTSpecial Marine WarningPHI118 min
Aug 1, 3:14 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe51 min
Aug 1, 3:46 PM EDTSpecial Weather StatementPHIBerks89 min
Aug 1, 4:00 PM EDTSevere Thunderstorm WarningPHIBerks75 min
Aug 1, 4:33 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Delaware, Montgomery, Philadelphia87 min
Aug 1, 4:39 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh42 min
Aug 1, 5:11 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia2 hr
Aug 1, 5:37 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Philadelphia53 min
Aug 1, 4:07 PM EDTSpecial Weather StatementPHICecil53 min
Aug 1, 4:46 PM EDTSevere Thunderstorm WarningPHICecil48 min
Aug 1, 5:12 PM EDTSevere Thunderstorm WarningPHICecil, Kent, Queen Anne's78 min
Aug 1, 6:12 PM EDTAreal Flood AdvisoryPHIKent, Queen Anne's2 hr
Aug 1, 6:41 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's, Talbot18 min
Aug 1, 7:31 PM EDTSpecial Weather StatementPHICaroline, Cecil, Kent, Queen Anne's119 min
Aug 1, 7:46 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's38 min
Aug 1, 3:15 PM EDTSpecial Weather StatementPHISussex45 min
Aug 1, 3:38 PM EDTSevere Thunderstorm WarningPHISussex37 min
Aug 1, 3:59 PM EDTFlash Flood WarningPHISussex4 hr

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.