Alert archive / Pennsylvania / Special Weather Statements in 2015

Special Weather Statement, NWS Philadelphia/Mount Holly

August 4, 20154 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 4, 2015, 12:45 AM EDT for 4 counties in 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: Aug 4, 2015, 12:45 AM EDT (04:45 UTC)
Expired: Aug 4, 2015, 1:45 AM EDT
In force: 60 min
Issued by: NWS Philadelphia/Mount Holly

Counties Bucks County, PA, Chester County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 86 km from the middle of the area, began a volume at 04:47 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, 4.8 hours before the alert went out and 216 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1050 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1110 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 173 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.5

Open this sounding in Storm Lab

The text

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

301 
WWUS81 KPHI 040445
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1245 AM EDT TUE AUG 4 2015
 
PAZ060-070-071-101>106-040545-
BERKS-WESTERN CHESTER-WESTERN MONTGOMERY-PHILADELPHIA-EASTERN
MONTGOMERY-LOWER BUCKS-EASTERN CHESTER-DELAWARE-UPPER BUCKS-
1245 AM EDT TUE AUG 4 2015

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTHWESTERN
HUNTERDON...NORTHWESTERN MERCER...NORTHEASTERN DELAWARE...
NORTHEASTERN CHESTER...BUCKS...SOUTHEASTERN BERKS...SOUTHEASTERN
LEHIGH...CENTRAL PHILADELPHIA AND MONTGOMERY COUNTIES...

AT 1244 AM EDT...A LINE OF STRONG THUNDERSTORMS WAS ALONG A LINE
EXTENDING FROM NEAR GILBERTSVILLE TO NEAR CHESTER SPRINGS TO NEAR
MARSHALLTON...AND MOVING EAST AT 40 MPH.

WIND GUSTS UP TO 50 MPH ARE POSSIBLE WITH THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
PHILADELPHIA...WEST CHESTER...NORRISTOWN...POTTSTOWN...
PHOENIXVILLE...LANSDALE...WEST NORRITON...EAST NORRITON...
COATESVILLE...QUAKERTOWN...PERKASIE...DOYLESTOWN...DOWNINGTOWN...
CONSHOHOCKEN...HATBORO...SOUDERTON...BEDMINSTER...AMBLER...
COLLEGEVILLE AND ROYERSFORD.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
CAUSE LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4010 7577 4039 7571 4043 7550 4042 7549
      4044 7546 4052 7507 4045 7507 4042 7506
      4040 7496 4034 7494 4032 7492 4023 7491
      3999 7509 3993 7586
TIME...MOT...LOC 0444Z 258DEG 34KT 4029 7562 4012 7566 3993 7573 
$$

HEAVENER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 2:07 AM EDT	Special Weather Statement	PHI	Hunterdon, Mercer, Middlesex, Somerset	53 min
Aug 4, 2:30 AM EDT	Special Weather Statement	PHI	Morris, Warren	60 min
Aug 4, 2:56 AM EDT	Special Weather Statement	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	64 min
Aug 4, 3:33 AM EDT	Special Marine Warning	PHI		57 min
Aug 4, 3:36 AM EDT	Special Weather Statement	PHI	Morris	24 min
Aug 4, 4:12 AM EDT	Special Weather Statement	PHI	Gloucester	63 min
Aug 4, 4:20 AM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	33 min
Aug 4, 5:25 AM EDT	Special Weather Statement	PHI	Monmouth	65 min
Aug 4, 10:53 AM EDT	Rip Current Statement	PHI	Cape May	4 hr
Aug 4, 12:06 AM EDT	Special Weather Statement	PHI	Chester	54 min
Aug 4, 1:23 AM EDT	Special Weather Statement	PHI	Berks	37 min
Aug 4, 1:31 AM EDT	Severe Thunderstorm Warning	PHI	Berks	44 min
Aug 4, 1:42 AM EDT	Special Weather Statement	PHI	Carbon	48 min
Aug 4, 1:54 AM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	50 min
Aug 4, 5:18 AM EDT	Special Weather Statement	PHI	Kent, Queen Anne's	57 min
Aug 4, 5:37 AM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	34 min
Aug 4, 6:11 PM EDT	Special Weather Statement	PHI	Sussex	64 min
Aug 4, 6:20 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	20 min

Nearby

Special Weather Statements in Pennsylvania, 2015 Every special weather statement in 2015

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.