Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

August 19, 2011Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 19, 2011, 12:02 AM EDT for Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 58 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 19, 2011, 12:02 AM EDT (04:02 UTC)
Expired: Aug 19, 2011, 1:00 AM EDT
In force: 58 min
Issued by: NWS Philadelphia/Mount Holly

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 108 km from the middle of the area, began a volume at 04:02 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 4.0 hours before the alert went out and 203 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: 27 J/kg
Mixed-layer CIN: -177 J/kg
Mixed-layer LCL: 1773 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 34 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.

094 
WWUS81 KPHI 190402
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1202 AM EDT FRI AUG 19 2011

DEZ001-MDZ008-PAZ067-070-190500-
CECIL MD-CHESTER PA-DELAWARE PA-NEW CASTLE DE-
1202 AM EDT FRI AUG 19 2011

...STRONG THUNDERSTORMS WILL AFFECT CECIL...CHESTER...DELAWARE AND
NEW CASTLE COUNTIES...

AT 1155 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 13 MILES SOUTHWEST
OF LANCASTER TO 22 MILES NORTHWEST OF BALTIMORE...MOVING EAST AT 20
MPH. THE THUNDERSTORMS WILL BE NEAR MOUNT VERNON...HOMEVILLE AROUND
1245 AM...CONOWINGO AND RICHARDSMERE AROUND 100 AM.

VERY HEAVY RAINFALL WILL OCCUR OVER AREAS THAT RECEIVED HEAVY RAINS
EARLIER. BE ALERT FOR THE POSSIBILITY OF LOCALIZED FLOODING.

THIS LINE MAY EVENTUALLY CAUSE CONSIDERABLE POOR DRAINAGE FLOODING 
AS IT MOVES TOWARD THE PHILADELPHIA WILMINGTON URBAN CORRIDOR.
 

LAT...LON 3973 7615 3978 7607 3987 7601 3992 7601
      4000 7598 4004 7546 3944 7573 3945 7601
      3946 7602 3953 7599 3955 7603 3954 7607
      3956 7610 3969 7623 3972 7624

$$

FORECASTER: DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 8:11 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	64 min
Aug 18, 8:26 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	112 min
Aug 18, 8:31 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer	59 min
Aug 18, 8:48 PM EDT	Special Weather Statement	PHI	Warren	57 min
Aug 18, 8:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	57 min
Aug 18, 8:59 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex, Warren	61 min
Aug 18, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Morris, Somerset, Warren	57 min
Aug 18, 9:53 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cape May, Cumberland, Salem	67 min
Aug 18, 9:57 PM EDT	Severe Thunderstorm Warning	PHI	Morris	43 min
Aug 19, 12:19 AM EDT	Special Marine Warning	PHI		26 min
Aug 19, 12:19 AM EDT	Special Weather Statement	PHI	Cape May	41 min
Aug 19, 12:50 AM EDT	Special Weather Statement	PHI	Cumberland, Salem	40 min
Aug 19, 1:14 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 1 more	3 hr
Aug 19, 1:31 AM EDT	Special Weather Statement	PHI	Cumberland, Gloucester, Salem	59 min
Aug 19, 2:28 AM EDT	Special Weather Statement	PHI	Camden, Cumberland, Gloucester, Salem	47 min
Aug 19, 2:48 AM EDT	Special Weather Statement	PHI	Monmouth, Ocean	57 min
Aug 19, 3:06 AM EDT	Areal Flood Advisory	PHI	Atlantic, Cape May, Cumberland	114 min
Aug 19, 3:21 AM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth, Ocean	114 min
Aug 19, 6:24 AM EDT	Special Weather Statement	PHI	Mercer, Middlesex	36 min
Aug 19, 6:37 AM EDT	Special Weather Statement	PHI	Middlesex	23 min
Aug 19, 1:34 PM EDT	Special Marine Warning	PHI		41 min
Aug 19, 2:39 PM EDT	Special Marine Warning	PHI		96 min
Aug 19, 3:23 PM EDT	Special Marine Warning	PHI		67 min
Aug 19, 4:05 PM EDT	Special Weather Statement	PHI	Camden	55 min
Aug 19, 4:15 PM EDT	Special Marine Warning	PHI		90 min
Aug 19, 4:29 PM EDT	Severe Thunderstorm Warning	PHI	Warren	61 min
Aug 19, 4:32 PM EDT	Areal Flood Advisory	PHI	Sussex, Warren	2 hr
Aug 19, 4:38 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	67 min
Aug 19, 4:42 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	4 hr
Aug 19, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Sussex, Warren	78 min
Aug 19, 5:27 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	111 min
Aug 19, 5:29 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	50 min
Aug 19, 5:47 PM EDT	Special Marine Warning	PHI		118 min
Aug 19, 5:49 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	104 min
Aug 19, 5:59 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Morris, Somerset	80 min
Aug 19, 6:14 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Salem	65 min
Aug 19, 6:24 PM EDT	Severe Thunderstorm Warning	PHI	Morris	28 min
Aug 19, 6:54 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth	31 min
Aug 18, 8:08 PM EDT	Special Weather Statement	PHI	Berks	67 min
Aug 19, 4:00 AM EDT	Areal Flood Warning	PHI	Delaware	4 hr
Aug 19, 1:46 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	59 min
Aug 19, 2:35 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	70 min
Aug 19, 2:38 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	3 hr
Aug 19, 2:57 PM EDT	Flash Flood Warning	PHI	Carbon, Monroe	3 hr
Aug 19, 3:47 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	58 min
Aug 19, 4:52 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	53 min
Aug 19, 5:35 PM EDT	Severe Thunderstorm Warning	PHI	Chester	55 min
Aug 19, 5:39 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	3 hr
Aug 19, 5:42 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery	48 min
Aug 19, 5:45 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	3 hr
Aug 18, 8:35 PM EDT	Special Weather Statement	PHI	Queen Anne's	55 min
Aug 19, 1:00 AM EDT	Special Weather Statement	PHI	Cecil	45 min
Aug 19, 1:44 AM EDT	Special Weather Statement	PHI	Cecil, Kent, Queen Anne's	61 min
Aug 19, 4:09 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's	66 min
Aug 19, 4:42 PM EDT	Severe Thunderstorm Warning	PHI	Caroline	63 min
Aug 19, 4:53 PM EDT	Areal Flood Advisory	PHI	Caroline, Cecil, Kent, Queen Anne's	5 hr
Aug 19, 6:18 PM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	3 hr
Aug 19, 6:21 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	69 min
Aug 19, 6:34 PM EDT	Areal Flood Advisory	PHI	Caroline	2 hr
Aug 19, 1:20 PM EDT	Special Weather Statement	PHI	Kent, Sussex	85 min
Aug 19, 1:42 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	63 min
Aug 19, 2:09 PM EDT	Areal Flood Advisory	PHI	Sussex	92 min
Aug 19, 2:33 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	7 hr
Aug 19, 2:53 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	52 min
Aug 19, 2:59 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	61 min
Aug 19, 3:13 PM EDT	Special Weather Statement	PHI	Sussex	92 min
Aug 19, 3:53 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	5 hr
Aug 19, 4:23 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	82 min

Nearby

Special Weather Statements in Pennsylvania, 2011 Special Weather Statements in Maryland, 2011 Every 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; radar from the NEXRAD Level II archive.