Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 166, NWS Philadelphia/Mount Holly

August 11, 2004Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2004, 4:04 PM EDT for Bucks County, Pennsylvania. It was in force for 41 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 11, 2004, 4:04 PM EDT (20:04 UTC)
Expired: Aug 11, 2004, 4:45 PM EDT
In force: 41 min
Issued by: NWS Philadelphia/Mount Holly
Area: Counties, with a storm outline in the text

County Bucks County, PA

The radar

The Philadelphia radar (KDIX), 87 km from the middle of the area, began a volume at 20:05 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 11, 12:55 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.1 hours before the alert went out and 199 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: 1077 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 599 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 112004
SVRPHI
PAC017-112045-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
403 PM EDT WED AUG 11 2004

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA.

* UNTIL 445 PM EDT

* AT 400 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  QUAKERTOWN...OR ABOUT 14 MILES SOUTHEAST OF BETHLEHEM...AND MOVING
  NORTHEAST AT 30 MPH.

IF YOU SEE THREATENING WEATHER...HEAD INDOORS IMMEDIATELY.

 
LAT...LON 4053 7507 4047 7507 4046 7508 4041 7506
      4034 7527 4036 7530 4049 7538 4056 7522
      4055 7516 4056 7511

$$

TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 2:21 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	54 min
Aug 11, 2:40 PM EDT	Severe Thunderstorm Warning	PHI	Chester	95 min
Aug 11, 3:12 PM EDT	Tornado Warning	PHI	Chester	78 min
Aug 11, 5:09 PM EDT	Special Marine Warning	PHI		81 min
Aug 11, 5:25 PM EDT	Severe Thunderstorm Warning	PHI	Berks	65 min
Aug 11, 5:28 PM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	32 min
Aug 11, 5:37 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	53 min
Aug 11, 5:56 PM EDT	Severe Thunderstorm Warning	PHI	Montgomery	34 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2004 Every severe thunderstorm warning in 2004

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.