Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 63, NWS Philadelphia/Mount Holly

July 9, 1997Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 1997, 5:00 PM EDT for Montgomery County, Pennsylvania. It was in force for 65 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 9, 1997, 5:00 PM EDT (21:00 UTC)
Expired: Jul 9, 1997, 6:05 PM EDT
In force: 65 min
Issued by: NWS Philadelphia/Mount Holly
Area: Whole counties

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 86 km from the middle of the area, began a volume at 21:01 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
Jul 9, 1:15 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.0 hours before the alert went out and 103 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: 189 J/kg
Mixed-layer CIN: -118 J/kg
Mixed-layer LCL: 1364 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 25 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 
TTAA00 KPHL 092100 RRA
SVRPHL
PAC017-091-095-092205-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
500 PM EDT WED JUL 9 1997

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 605 PM EDT FOR PEOPLE IN
THE FOLLOWING LOCATION...

IN  PENNSYLVANIA

   ...NORTHAMPTON COUNTY
   ...MONTGOMERY COUNTY
   ...BUCKS COUNTY
 
AT 455 PM...RADAR SHOWED SEVERE THUNDERSTORMS OVER EASTERN LEHIGH AND
EASTERN BERKS COUNTIES.  THEY WERE MOVING EAST NORTHEAST AT 30 MPH.
THESE STORMS HAVE A HISTORY OF PRODUCING DAMAGING WIND.

THESE ARE DANGEROUS STORMS. MOVE INSIDE A STRONG BUILDING AND DO NOT
STAND NEAR WINDOWS. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON
THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.

DO NOT DRIVE YOUR CAR WHERE WATER COVERS THE ROADWAY. THE WATER MAY
BE DEEPER THAN YOU THINK. IF CAUGHT IN RISING FLOOD WATERS...ABANDON
YOUR CAR QUICKLY AND MOVE TO HIGHER GROUND.

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

FRANKLIN/STAUBER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 3:53 PM EDT	Severe Thunderstorm Warning	PHI	Berks	62 min
Jul 9, 4:49 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh	66 min
Jul 9, 4:53 PM EDT	Severe Thunderstorm Warning	PHI	Berks	32 min
Jul 9, 5:00 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Northampton	65 min
Jul 9, 5:14 PM EDT	Severe Thunderstorm Warning	PHI	Chester	66 min
Jul 9, 6:16 PM EDT	Severe Thunderstorm Warning	PHI	Chester	64 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1997 Every severe thunderstorm warning in 1997

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.