Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 21, NWS State College, PA

May 7, 1999Bedford County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at May 7, 1999, 8:00 PM EDT for Bedford County, Pennsylvania. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: May 7, 1999, 8:00 PM EDT (00:00 UTC)
Expired: May 7, 1999, 8:30 PM EDT
In force: 30 min
Issued by: NWS State College, PA
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Bedford County, PA

The radar

The Sterling radar (KLWX), 127 km from the middle of the area, began a volume at 00:03 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.0 hours before the alert went out and 135 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: 863 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 958 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 278 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 5.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCTP 080002 RRA
SVRCTP
PAC009-080030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
800 PM EDT FRI MAY 7 1999

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN BEDFORD COUNTY.

* UNTIL 830 PM EDT.

* AT 755 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 12 MILES SOUTH OF RAINSBURG...OR ABOUT 10 MILES
  NORTHEAST OF CUMBERLAND...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  CHANEYSVILLE AT 810 PM EDT. 
  RAINSBURG AND INGLESMITH AT 815 PM EDT.

LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE IN 
THE PATH OF T2HE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A 
SUBSTANTIAL SHELTER.

.END/ NICOSIA/FITZGERALD

LAT...LON 3987 7875 3960 7862 3968 7842 3973 7838
          4000 7824

The office that day

Everything else NWS State College, PA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 8, 5:14 PM EDT	Severe Thunderstorm Warning	CTP	Lycoming, Tioga	61 min
May 8, 5:14 PM EDT	Severe Thunderstorm Warning	CTP	Union	61 min
May 8, 5:32 PM EDT	Severe Thunderstorm Warning	CTP	Northumberland, Snyder	58 min
May 8, 5:32 PM EDT	Severe Thunderstorm Warning	CTP	Columbia, Montour	58 min
May 8, 5:44 PM EDT	Severe Thunderstorm Warning	CTP	Sullivan	61 min
May 8, 6:07 PM EDT	Severe Thunderstorm Warning	CTP	Columbia	53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1999 Every severe thunderstorm warning in 1999

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.