Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 61, NWS Philadelphia/Mount Holly

July 9, 1997Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 1997, 4:53 PM EDT for Berks County, Pennsylvania. It was in force for 32 min. 1 report 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: Jul 9, 1997, 4:53 PM EDT (20:53 UTC)
Expired: Jul 9, 1997, 5:25 PM EDT
In force: 32 min
Issued by: NWS Philadelphia/Mount Holly
Area: Whole counties

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 139 km from the middle of the area, began a volume at 20:56 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.

What was reported inside it

Time	Report	Where	Remark
Jul 9, 5:00 PM EDT	Thunderstorm Wind 55	Mohnton, 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.

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, 8.9 hours before the alert went out and 106 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 092053 RRA
SVRPHL
PAC011-092125-

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 525 PM EDT FOR PEOPLE IN
THE FOLLOWING LOCATION...

IN  PENNSYLVANIA

   ...BERKS COUNTY
 
AT 450 PM...RADAR SHOWED A SEVERE THUNDERSTORM JUST SOUTH OF READING.
IT WAS MOVING EAST NORTHEAST AT 30 MPH.

ANOTHER SEVERE THUNDERSTORM OVER YORK COUNTY MAY AFFECT BERKS COUNTY
LATER THIS EVENING.

THIS IS A DANGEROUS STORM. 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, 5:00 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Northampton	65 min
Jul 9, 5:00 PM EDT	Severe Thunderstorm Warning	PHI	Montgomery	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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.