Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 11, NWS Philadelphia/Mount Holly

April 9, 2001Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 9, 2001, 8:09 PM EDT for Bucks County, Pennsylvania. It was in force for 36 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 9, 2001, 8:09 PM EDT (00:09 UTC)
Expired
Apr 9, 2001, 8:45 PM EDT
In force
36 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Bucks County, PA

What was reported inside it

TimeReportWhereRemark
Apr 9, 8:15 PM EDTThunderstorm Wind 63 MTrumbauersville, PA
Apr 9, 8:45 PM EDTThunderstorm Wind 60 EWoodbourne, PA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

IssuedProductOfficeLasted
Apr 9, 7:00 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.2 hours before the alert went out and 198 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 2001-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2001-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 136 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1601 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
136 m²/s²
0-3 km storm-relative helicity
202 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.

000 
WUUS51 KPHI 100010
SVRPHL
PAC017-029-091-100045-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
809 PM EDT MON APR 9 2001

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 845 PM EDT.

* AT 804 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SEVERE THUNDERSTORMS... 4 MILES NORTH OF POTTSTOWN...MOVING EAST AT
  60 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SOUDERTON...COLLEGEVILLE...KING OF PRUSSIA...QUAKERTOWN AT 815 PM.
  LANSDALE...CHALFONT...PERKASIE...DUBLIN AT 820 PM.
  AMBLER...DOYLESTOWN AT 825 PM.

FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER
RADIO...YOUR LOCAL RADIO OR TELEVISION STATION...OR YOUR CABLE
TELEVISION OUTLET.
$$

LAT...LON 4057 7522 4004 7598 3979 7580 4030 7497

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 9, 8:02 PM EDTSevere Thunderstorm WarningPHIChester43 min
Apr 9, 8:09 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery36 min
Apr 9, 8:37 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia38 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2001Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.