Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

July 15, 2012Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 15, 2012, 9:16 PM EDT for Chester County, Pennsylvania. It was in force for 59 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 15, 2012, 9:16 PM EDT (01:16 UTC)
Expired
Jul 15, 2012, 10:15 PM EDT
In force
59 min
Issued by
NWS Philadelphia/Mount Holly

County Chester County, PA

The radar

The Dover AFB radar (KDOX), 116 km from the middle of the area, began a volume at 01:19 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, 1.3 hours before the alert went out and 171 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 2012-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 652 joules per kilogram.LCLLFCEL10008507005003002001001 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 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.1939Sfc1 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
652 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
1264 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
119 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.

980 
WWUS81 KPHI 160116
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
916 PM EDT SUN JUL 15 2012

DEZ001-PAZ067-160215-
CHESTER PA-NEW CASTLE DE-
916 PM EDT SUN JUL 15 2012

...A STRONG THUNDERSTORM WILL AFFECT CHESTER AND NEW CASTLE
COUNTIES...

AT 913 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 18 MILES NORTHWEST OF NEWARK...MOVING EAST AT 30
MPH. THE THUNDERSTORM WILL BE NEAR TOUGHKENAMON...WEST GROVE AROUND
930 PM...KENNETT SQUARE...ASHLAND AROUND 945 PM AND TALLEYVILLE
AROUND 1000 PM.

WIND GUSTS TO 50 MPH ARE POSSIBLE WITH THIS STORM.

LAT...LON 3983 7602 3985 7603 3990 7599 3991 7559
      3989 7558 3987 7560 3986 7560 3985 7558
      3984 7558 3984 7556 3977 7553 3974 7605
      3979 7606

$$

HAYES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 15, 8:04 PM EDTSpecial Weather StatementPHIAtlantic56 min
Jul 15, 8:11 PM EDTSpecial Weather StatementPHIGloucester, Salem64 min
Jul 15, 8:35 PM EDTSpecial Weather StatementPHIMercer, Middlesex, Monmouth55 min
Jul 15, 8:39 PM EDTSpecial Marine WarningPHI66 min
Jul 15, 8:58 PM EDTSpecial Weather StatementPHIBurlington, Camden62 min
Jul 15, 9:00 PM EDTSpecial Weather StatementPHIBurlington60 min
Jul 15, 9:21 PM EDTSpecial Weather StatementPHIMercer54 min
Jul 15, 9:33 PM EDTSpecial Weather StatementPHIMiddlesex, Monmouth57 min
Jul 15, 9:45 PM EDTSpecial Marine WarningPHI60 min
Jul 15, 9:52 PM EDTSpecial Weather StatementPHIOcean68 min
Jul 15, 9:55 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Mercer, Monmouth, Ocean80 min
Jul 15, 10:14 PM EDTSpecial Marine WarningPHI79 min
Jul 15, 10:51 PM EDTSpecial Weather StatementPHIAtlantic, Camden, Gloucester, Salem54 min
Jul 15, 11:25 PM EDTSpecial Weather StatementPHIAtlantic, Ocean65 min
Jul 16, 3:35 AM EDTHeat AdvisoryPHIBurlington, Hunterdon, Middlesex, Monmouth, Morris, Ocean and 3 more62 hr
Jul 15, 8:27 PM EDTSpecial Weather StatementPHIChester, Montgomery, Philadelphia63 min
Jul 15, 8:30 PM EDTSevere Thunderstorm WarningPHIChester45 min
Jul 15, 8:08 PM EDTSpecial Weather StatementPHINew Castle67 min
Jul 16, 4:32 PM EDTSpecial Weather StatementPHISussex88 min

Nearby

Special Weather Statements in Pennsylvania, 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.