Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

July 4, 2012Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 4, 2012, 11:37 PM EDT for Montgomery County, Pennsylvania. It was in force for 38 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 4, 2012, 11:37 PM EDT (03:37 UTC)
Expired
Jul 5, 2012, 12:15 AM EDT
In force
38 min
Issued by
NWS Philadelphia/Mount Holly

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 93 km from the middle of the area, began a volume at 03:37 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 00:00Z, 3.6 hours before the alert went out and 221 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 00:00Z on 2012-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1802 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, Brookhaven, NY at 00:00Z on 2012-07-05The 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
1802 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1100 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
189 m²/s²
Significant tornado parameter
0.7
Supercell composite
3.9

Open this sounding in Storm Lab

The text

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

009 
WWUS81 KPHI 050337
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1137 PM EDT WED JUL 4 2012

PAZ068-069-050415-
BUCKS PA-MONTGOMERY PA-
1137 PM EDT WED JUL 4 2012

...A STRONG THUNDERSTORM WILL AFFECT BUCKS AND MONTGOMERY COUNTIES...

AT 1135 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 13 MILES SOUTH OF ALLENTOWN...MOVING SOUTHEAST AT
30 MPH. THE THUNDERSTORM WILL BE NEAR SELLERSVILLE...SPRING MOUNT...
SCHWENKSVILLE AROUND 1145 PM...SOUDERTON...HARLEYSVILLE...TELFORD...
SILVERDALE AROUND 1150 PM...HATFIELD...KULPSVILLE AND FRICKS AROUND
1155 PM.

DOWNPOURS WILL OCCUR WITH THESE STORMS...AND WILL CAUSE WATER TO 
POND ON ROADS FOR A TIME. WIND GUSTS UP TO 40 MPH AND SMALL HAIL ARE 
POSSIBLE.

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 4015 7504 4006 7539 4037 7559 4038 7559
      4043 7550 4042 7548 4045 7545 4048 7541

$$

FORECASTER: GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 10:23 PM EDTSpecial Weather StatementPHIMercer37 min
Jul 4, 10:52 PM EDTSpecial Weather StatementPHIOcean38 min
Jul 4, 11:01 PM EDTSevere Thunderstorm WarningPHIOcean29 min
Jul 4, 11:14 PM EDTSpecial Weather StatementPHIMercer46 min
Jul 5, 12:08 AM EDTSpecial Weather StatementPHIBurlington, Mercer37 min
Jul 5, 12:34 AM EDTSpecial Weather StatementPHIBurlington, Ocean41 min
Jul 5, 12:35 AM EDTSpecial Weather StatementPHIBurlington, Ocean40 min
Jul 5, 1:00 AM EDTSpecial Marine WarningPHI51 min
Jul 5, 1:15 AM EDTSpecial Weather StatementPHIAtlantic, Ocean60 min
Jul 5, 1:39 AM EDTSpecial Weather StatementPHICape May, Cumberland66 min
Jul 5, 4:28 AM EDTExcessive Heat WatchPHIAtlantic, Cape May, Cumberland, Salem24 hr
Jul 5, 3:53 PM EDTCoastal Flood StatementPHIAtlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more9 hr
Jul 4, 9:18 PM EDTSpecial Weather StatementPHICarbon, Monroe57 min
Jul 4, 10:37 PM EDTSpecial Weather StatementPHIBerks, Lehigh38 min
Jul 4, 11:07 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh27 min
Jul 4, 11:45 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery28 min
Jul 5, 1:34 AM EDTSpecial Weather StatementPHILehigh56 min
Jul 5, 1:41 AM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Carbon, Lehigh, Montgomery, Northampton34 min
Jul 5, 6:49 PM EDTSpecial Weather StatementPHIKent41 min
Jul 5, 7:28 PM EDTSpecial Weather StatementPHIKent, Queen Anne's47 min
Jul 5, 7:36 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's39 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.