Alert archive / Pennsylvania / Special Weather Statements in 2012

Special Weather Statement, NWS Philadelphia/Mount Holly

August 10, 20124 states

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 10, 2012, 8:43 AM EDT for 4 states. It was in force for 92 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 10, 2012, 8:43 AM EDT (12:43 UTC)
Expired: Aug 10, 2012, 10:15 AM EDT
In force: 92 min
Issued by: NWS Philadelphia/Mount Holly

Counties Kent County, DE, New Castle County, DE, Caroline County, MD, Gloucester County, NJ, Hunterdon County, NJ, Salem County, NJ, Sussex County, NJ, Warren County, NJ, Bucks County, PA, Delaware County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 92 km from the middle of the area, began a volume at 12:44 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.

What was reported inside it

Time	Report	Where	Remark
Aug 10, 9:30 AM EDT	TSTM WND DMG	Greensboro, MD	TREES DOWN

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 0.7 hours before the alert went out and 188 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: 279 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 652 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

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

646 
WWUS81 KPHI 101243 CCA
SPSPHI

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
843 AM EDT FRI AUG 10 2012

DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>009-016>018-021-PAZ055-
061-062-067>071-101415-
BUCKS PA-CAMDEN NJ-CAROLINE MD-CECIL MD-CHESTER PA-CUMBERLAND NJ-
DELAWARE PA-GLOUCESTER NJ-HUNTERDON NJ-INLAND SUSSEX DE-KENT DE-
KENT MD-LEHIGH PA-MONROE PA-MONTGOMERY PA-MORRIS NJ-NEW CASTLE DE-
NORTHAMPTON PA-PHILADELPHIA PA-QUEEN ANNE'S MD-SALEM NJ-SUSSEX NJ-
TALBOT MD-WARREN NJ-
843 AM EDT FRI AUG 10 2012

...SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN AND LOCALIZED WIND 
GUSTS...

AT 836 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
SHOWERS AND THUNDERSTORMS ALONG A LINE EXTENDING FROM 25 MILES WEST 
OF NEWTON TO 50 MILES SOUTHWEST OF GEORGETOWN...MOVING NORTHEAST AT 
30 MPH. OTHER WIDELY SCATTERED STORMS WERE DEVELOPING AHEAD OF THE 
LINE. 

THE MAIN LINE OF SHOWERS AND THUNDERSTORMS WILL BE NEAR TRAPPE AND 
CORDOVA AROUND 845 AM...CARNEYS POINT AND WERRY LAKE AROUND 900 
AM...ERWINNA AND COLLINGDALE AROUND 915 AM...KENSINGTON AND NEWTON 
AROUND 930 AM...AND GLASSBORO AND WISSINOMING AROUND 945 AM.

VERY HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL POOR DRAINAGE AREAS. DO NOT DRIVE 
THROUGH FLOOD WATERS, THE WATER MAY BE DEEPER THAN YOU THINK IT IS.

THE HEAVY RAIN WILL ALSO CAUSE REDUCED VISIBILITY. IF YOU WILL BE 
DRIVING THIS MORNING, BE SURE TO LEAVE PLENTY OF ROOM BETWEEN YOUR 
VEHICLE AND THE ONE AHEAD OF YOU.

THE STRONGEST STORMS WILL GENERATE WIND GUSTS TO 40 MPH. 

FREQUENT 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 3868 7576 3867 7594 3857 7603 3864 7616
      3866 7616 4116 7531 4125 7513 4115 7514
      4109 7502 4136 7469 4129 7455 4000 7506
      3990 7502 3953 7519 3938 7543 3948 7558
      3904 7536 3855 7552 3846 7569

$$

MPD

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 10:51 PM EDT	Special Weather Statement	PHI	Sussex	54 min
Aug 10, 4:00 AM EDT	Small Craft Advisory	PHI		50 hr
Aug 10, 8:41 AM EDT	Special Weather Statement	PHI	Gloucester, Hunterdon, Salem, Sussex, Warren	94 min
Aug 10, 9:08 AM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Cumberland, Gloucester, Hunterdon, Mercer and 5 more	3 hr
Aug 10, 10:05 AM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more	115 min
Aug 10, 10:19 AM EDT	Special Marine Warning	PHI		86 min
Aug 10, 10:33 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 8 more	4 hr
Aug 10, 10:51 AM EDT	Special Marine Warning	PHI		84 min
Aug 10, 10:58 AM EDT	Special Marine Warning	PHI		62 min
Aug 10, 11:41 AM EDT	Special Marine Warning	PHI		2 hr
Aug 10, 12:10 PM EDT	Special Weather Statement	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Morris and 2 more	80 min
Aug 9, 8:24 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	66 min
Aug 9, 9:24 PM EDT	Special Weather Statement	PHI	Monroe	96 min
Aug 9, 10:05 PM EDT	Special Weather Statement	PHI	Berks	55 min
Aug 9, 10:09 PM EDT	Areal Flood Advisory	PHI	Monroe	98 min
Aug 9, 10:25 PM EDT	Flash Flood Warning	PHI	Monroe	83 min
Aug 10, 7:40 AM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Chester, Lehigh, Monroe, Montgomery and 1 more	3 hr
Aug 10, 8:55 AM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	65 min
Aug 10, 10:14 AM EDT	Severe Thunderstorm Warning	PHI	Sussex	61 min

Nearby

Special Weather Statements in Pennsylvania, 2012 Special Weather Statements in New Jersey, 2012 Special Weather Statements in Delaware, 2012 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.