Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

September 11, 2011Mercer County, New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 11, 2011, 10:52 PM EDT for Mercer County, New Jersey; 4 counties in Pennsylvania. It was in force for 83 min. 2 reports 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: Sep 11, 2011, 10:52 PM EDT (02:52 UTC)
Expired: Sep 12, 2011, 12:15 AM EDT
In force: 83 min
Issued by: NWS Philadelphia/Mount Holly

Counties Mercer County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 64 km from the middle of the area, began a volume at 02:53 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
Sep 11, 11:15 PM EDT	TSTM WND DMG	Drexel Hill, PA	TREE LIMBS DOWN.
Sep 11, 11:15 PM EDT	HAIL 0.88	Hainesport, NJ

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 2.9 hours before the alert went out and 209 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: 30 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 549 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 84 m²/s²
0-3 km storm-relative helicity: 122 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.

417 
WWUS81 KPHI 120252
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1052 PM EDT SUN SEP 11 2011

NJZ009-015-018-019-PAZ068>071-120415-
BUCKS PA-CAMDEN NJ-DELAWARE PA-HUNTERDON NJ-MERCER NJ-MONTGOMERY PA-
NORTHWESTERN BURLINGTON NJ-PHILADELPHIA PA-
1052 PM EDT SUN SEP 11 2011

...STRONG THUNDERSTORMS WILL AFFECT BUCKS...BURLINGTON...CAMDEN...
DELAWARE...HUNTERDON...MERCER...MONTGOMERY AND PHILADELPHIA
COUNTIES...

AT 1048 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
STRONG THUNDERSTORMS EXTENDING FROM 18 MILES SOUTHEAST OF ALLENTOWN 
TO 8 MILES EAST OF WEST CHESTER...MOVING EAST AT 15 MPH. THE 
THUNDERSTORMS WILL BE NEAR BEDMINSTER...OTTSVILLE AROUND 1100 
PM...PIPERSVILLE...TINICUM TOWNSHIP AROUND 1115 
PM...LUMBERVILLE...BYRAM AROUND 1130 PM...STOCKTON...SERGEANTSVILLE 
AROUND 1145 PM...SAND BROOK AND AUDUBON PARK AROUND MIDNIGHT.

OTHER STRONG THUNDERSTORMS WERE MOVING NORTHEAST THROUGH THE 
PHILADELPHIA METRO AREA. 

VERY HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THESE STORMS.

EXPECT DANGEROUS CLOUD TO GROUND LIGHTNING FROM THESE STORMS.

LAT...LON 4034 7465 4032 7463 3983 7486 3983 7510
      3988 7515 3985 7525 3983 7538 3985 7560
      3992 7556 3998 7545 4004 7543 4007 7537
      4007 7541 4012 7548 4049 7531 4049 7479
      4037 7473 4038 7463

$$

MPD

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 10:44 PM EDT	Areal Flood Advisory	PHI	Salem	107 min
Sep 11, 11:02 PM EDT	Areal Flood Advisory	PHI	Salem	103 min
Sep 11, 11:05 PM EDT	Special Weather Statement	PHI	Salem	85 min
Sep 11, 11:10 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland, Gloucester, Salem	65 min
Sep 11, 11:15 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Monmouth, Ocean	60 min
Sep 12, 12:17 AM EDT	Special Weather Statement	PHI	Ocean	58 min
Sep 12, 12:24 AM EDT	Severe Thunderstorm Warning	PHI	Ocean	66 min
Sep 12, 12:34 AM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Salem	56 min
Sep 12, 1:29 AM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Cumberland, Ocean	61 min
Sep 12, 1:33 AM EDT	Special Marine Warning	PHI		117 min
Sep 12, 11:05 AM EDT	Coastal Flood Statement	PHI	Burlington, Camden, Gloucester	6 hr
Sep 12, 2:15 PM EDT	Special Weather Statement	PHI	Sussex	60 min
Sep 12, 3:59 PM EDT	Special Weather Statement	PHI	Morris	91 min
Sep 11, 8:19 PM EDT	Flash Flood Warning	PHI	Berks	3 hr
Sep 11, 8:46 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Sep 11, 9:00 PM EDT	Flash Flood Warning	PHI	Chester	3 hr
Sep 11, 9:14 PM EDT	Flash Flood Warning	PHI	Berks, Chester, Montgomery	110 min
Sep 11, 9:14 PM EDT	Special Weather Statement	PHI	Berks, Chester, Lehigh, Montgomery	61 min
Sep 11, 9:24 PM EDT	Severe Thunderstorm Warning	PHI	Chester	51 min
Sep 11, 9:34 PM EDT	Special Weather Statement	PHI	Philadelphia	41 min
Sep 11, 9:54 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	51 min
Sep 11, 9:56 PM EDT	Flash Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Sep 11, 10:25 PM EDT	Special Weather Statement	PHI	Philadelphia	65 min
Sep 11, 10:29 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	46 min
Sep 11, 10:08 PM EDT	Special Weather Statement	PHI	Cecil	67 min
Sep 12, 12:46 AM EDT	Special Weather Statement	PHI	Kent	59 min

Nearby

Special Weather Statements in Pennsylvania, 2011 Special Weather Statements in New Jersey, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.