Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 148, NWS Philadelphia/Mount Holly

July 27, 2004Bucks County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 27, 2004, 9:39 PM EDT for Bucks County, Philadelphia County, Pennsylvania. It was in force for 36 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
Jul 27, 2004, 9:39 PM EDT (01:39 UTC)
Expired
Jul 27, 2004, 10:15 PM EDT
In force
36 min
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

Counties Bucks County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 56 km from the middle of the area, began a volume at 01:42 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

Brookhaven, NY (KOKX), launched 00:00Z, 1.7 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-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2004-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 99 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2004-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 195 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
99 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
458 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
195 m²/s²
0-3 km storm-relative helicity
242 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 280139 CCA
SVRPHI
PAC017-101-280215-

BULLETIN - EAS ACTIVATION REQUESTED...CORRECTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
936 PM EDT TUE JUL 27 2004

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA.
  NORTHEASTERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA.

* UNTIL 1015 PM EDT

* AT 935 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED OVER NORTHEASTERN
  PHILADELPHIA...AND MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  LEVITTOWN BY 945 PM EDT...

LAT...LON 4004 7519 3999 7513 4017 7480 4022 7487

$$

CORRECTION TO DELINEATE AREAS OF COUNTIES.

JRP

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 9:37 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia38 min
Jul 27, 10:44 PM EDTFlash Flood WarningPHIBerks, Chester, Delaware, Montgomery, Philadelphia4 hr
Jul 28, 2:28 AM EDTFlash Flood WarningPHIBerks, Chester, Delaware, Montgomery, Philadelphia3 hr
Jul 28, 7:00 PM EDTFlash Flood WarningPHIMontgomery2 hr
Jul 28, 7:10 PM EDTSevere Thunderstorm WarningPHIBucks50 min
Jul 28, 7:21 PM EDTFlash Flood WarningPHIBucks114 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2004Every 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.