Alert archive / Pennsylvania / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

May 18, 2011Mercer County, New Jersey; Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this special weather statement at May 18, 2011, 1:01 PM EDT for Mercer County, New Jersey; Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 59 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: May 18, 2011, 1:01 PM EDT (17:01 UTC)
Expired: May 18, 2011, 2:00 PM EDT
In force: 59 min
Issued by: NWS Philadelphia/Mount Holly

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

The radar

The Philadelphia radar (KDIX), 51 km from the middle of the area, began a volume at 17:02 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.

What was reported inside it

Time	Report	Where	Remark
May 18, 1:50 PM EDT	TORNADO	Northeast Philadelphia, PA	CONFIRMED EF-0 IN NORTHEAST PHILADELPHIA NEAR INTERSECTION OF NORTHEAST AVENUE AND RED LION RD.
May 18, 1:55 PM EDT	TSTM WND DMG	Northeast Philadelphia, PA	SEVERAL BUILDINGS DAMAGED IN NORTHEAST PHILADELPHIA

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.0 hours before the alert went out and 122 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: 79 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 561 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 169 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

702 
WWUS81 KPHI 181701
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
101 PM EDT WED MAY 18 2011

NJZ009-010-015-017>019-027-PAZ067>071-181800-
BUCKS PA-CAMDEN NJ-CHESTER PA-DELAWARE PA-GLOUCESTER NJ-HUNTERDON NJ-
MERCER NJ-MONTGOMERY PA-NORTHWESTERN BURLINGTON NJ-PHILADELPHIA PA-
SOMERSET NJ-SOUTHEASTERN BURLINGTON NJ-
101 PM EDT WED MAY 18 2011

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

AT 1258 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 11 MILES SOUTHEAST
OF TRENTON TO 12 MILES EAST OF CAMDEN TO 8 MILES SOUTHWEST OF
CAMDEN...MOVING NORTH AT 35 MPH. THE THUNDERSTORMS WILL BE NEAR
CROSSWICKS...CENTER CITY...YEADON...SHARON HILL AROUND 105 PM...
YARDVILLE-GROVEVILLE...WISSINOMING...TACONY...ROXBOROUGH AROUND 110
PM...MERCERVILLE-HAMILTON SQUARE AND TROUT LAKE AROUND 115 PM.

WIND GUSTS TO 35 MPH ARE POSSIBLE WITH THESE STORMS.

EXPECT INTENSE LIGHTNING FROM THESE STORMS. DO NOT SEEK SHELTER UNDER
TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM
APPROACHES.

LAT...LON 3999 7460 3981 7482 3980 7522 4030 7556
      4043 7511 4060 7477

$$

ROBERTSON

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 4:00 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 4 more	25 hr
May 18, 12:39 PM EDT	Special Weather Statement	PHI	Atlantic, Ocean	66 min
May 18, 2:14 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Somerset	4 hr
May 18, 2:45 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex, Warren	6 hr
May 18, 4:12 PM EDT	River Flood Warning	PHI	Morris	32 hr
May 18, 4:12 PM EDT	River Flood Warning	PHI	Morris	72 hr
May 18, 4:13 PM EDT	River Flood Warning	PHI	Morris, Passaic	36 hr
May 18, 4:34 PM EDT	Flash Flood Warning	PHI	Morris, Sussex, Warren	4 hr
May 18, 1:52 PM EDT	Tornado Warning	PHI	Bucks, Montgomery, Philadelphia	24 min
May 18, 3:05 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery	115 min
May 18, 2:29 PM EDT	Special Weather Statement	PHI	Talbot	61 min
May 18, 2:39 PM EDT	Tornado Warning	PHI	Queen Anne's, Talbot	51 min
May 18, 3:22 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Queen Anne's, Talbot	47 min
May 18, 4:01 PM EDT	Coastal Flood Statement	PHI	Kent, Queen Anne's, Talbot	5 hr

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.