Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 80, NWS State College, PA

May 31, 1998Franklin County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at May 31, 1998, 10:19 PM EDT for Franklin County, Pennsylvania. It was in force for 56 min. 2 reports came from 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, with what was reported inside it.

The facts

Issued
May 31, 1998, 10:19 PM EDT (02:19 UTC)
Expired
May 31, 1998, 11:15 PM EDT
In force
56 min
Issued by
NWS State College, PA
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Franklin County, PA

The radar

The Sterling radar (KLWX), 103 km from the middle of the area, began a volume at 02:19 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

TimeReportWhereRemark
May 31, 10:30 PM EDTHail 0.75Mercersburg, PA
May 31, 10:50 PM EDTHail 0.75Greencastle, 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.3 hours before the alert went out and 108 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, Washington/Dulle, VA at 00:00Z on 1998-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3110 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 1998-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 203 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
3110 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1063 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
203 m²/s²
0-3 km storm-relative helicity
277 m²/s²
Significant tornado parameter
3.0
Supercell composite
18.2

Open this sounding in Storm Lab

The text

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

492 
WUUS01 KCTP 010221 RRA
SVRCTP
PAC055-010315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1019 PM EDT SUN MAY 31 1998

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

   * SEVERE THUNDERSTORM WARNING FOR...
     FRANKLIN COUNTY IN PENNSYLVANIA
     INCLUDING WAYNESBORO...GREENCASTLE...FAYETTEVILLE AND
     CHAMBERSBURG

   * UNTIL 1115 PM EDT

   * AT 1017 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
     A SEVERE THUNDERSTORM 9 MILES SOUTHWEST OF MERCERSBURG...OR
     ABOUT 17 MILES WEST OF GREENCASTLE...MOVING EAST AT 45 MILES PER
     HOUR.

   * SEVERE THUNDERSTORM WILL BE...
     5 MILES SOUTH OF MERCERSBURG AT 1025 PM EDT
     3 MILES SOUTHWEST OF GREENCASTLE AT 1035 PM EDT
     3 MILES NORTHWEST OF WAYNESBORO AT 1045 PM EDT
     6 MILES NORTHEAST OF ROUZERVILLE AT 1100 PM EDT
     17 MILES EAST OF ROUZERVILLE AT 1115 PM EDT

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY 
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST 
OFFICE IN STATE COLLEGE PA.

IF YOU SEE SEVERE WEATHER APPROACHING...SEEK SHELTER IMMEDIATELY.

LA CORTE
LAT...LON 3979 7801 3968 7817 3973 7747 4026 7769

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS State College, PA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 31, 3:00 PM EDT, 7 hours 19 minutes earlier.

Area forecast discussion, May 31, 3:00 PM EDT, 7 hours 19 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
3 PM EDT SUN MAY 31 1998

...MESOSCALE AND CONVECTIVE DISCUSSION...

STRONG CELLS HAVE AT LEAST TEMPORARILY EXITED NRN PART OF STATE
WITH SOME REPORTED HAIL AROUND 3/4 DIAMETER. MESO ANAL SHOWS OUTFLOW
BOUNDARY SLIDING SE THRU NRN PA...AS A QUIET FEATURE SO FAR. OF
CONCERN IS STRONG CONFLUENT ZONE AND AXIS OF HIGH MOISTURE SETTING
UP OVER SUSQ VALLEY. SFC WINDS ARE GUSTING OUT OF THE SOUTH HELPING
POOL DEWPOINTS NEAR 70 RESULTING IN SFC BASED CAPES NEARING 3000
J/KG. MODEL OUTPUT AND MESO ANAL FROM PSU SUGGEST CAP IS WEAKEST IN
THIS AREA. SATELLITE TIMING SUGGESTS WE ARE ABOUT AN HOUR AWAY FROM
NRN OUTFLOW BOUNDARY SWEEPING INTO THIS CONFLUENT ZONE. HARD TO SAY
IF THIS WILL TRIGGER ACTIVITY OR IF CELLS JUST DECIDE TO FORM IN
WHAT APPEARS TO BE A FAVORABLE ENVIRONMENT.

OTHERWISE IT APPEARS AS IF MAIN ACTION WILL BE LATER IN THE
AFTERNOON AND EVENING AS OHIO VALLEY CONVECTION SWINGS EAST INTO THE
REGION. 18Z SFC ANAL SHOWS STARK WIND SHIFT ASSOC WITH COLD
FRONT/SQUALL LINE. MODELS SHOW STRONG UPPER SUPPORT IN THE FORM OF
A POTENT LOBE OF HIGH PV AIR SLIDING EAST ACCOMPANYING A COUPLED
UPPER JET FEATURE. THE RETREATING RIGHT ENTRANCE REGION OF THE NRN
BRANCH IS MADE TO CREATE A BULLS EYE OF STRONG DIVERGENCE OVER MUCH
OF PA BY 00Z. MODEL SEEMS TO BE USING GENERATED CONVECTIVE PRECIP TO
TIGHTEN UPPER HGHT FIELD WHICH IN TURN RESULTS IN SIGNIFICANT
INTENSIFICATION OF THE JET STREAK AND ITS DIVERGENCE FIELD. BOTTOM
LINE IS STAGE IS BEING SET FOR LATE DAY ROUND OF SEVERE CONVECTION.
RIGHT NOW SHEAR IN LOW LEVELS SUPPORTS POSSIBLE ROTATING
THUNDERSTORMS...BUT MODEL OUTPUT FROM MESO ETA AND BUFKIT SOUNDINGS
SUGGEST WE LOSE HELICITY RAPIDLY LATER IN THE DAY AND EVENING. THIS
LEANS TWD THREAT CHANGING FROM SUPERCELLS TO BOW ECHOES AND MAINLY
STRAIGHT LINE WINDS.

LA CORTE

In the hours before

Local storm report, May 31, 7:45 PM EDT, 2 hours 34 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PENNSYLVANIA
745 PM EDT SUN MAY 31 1998

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION.d...

0630 PM    3S BRADFORD               PA   TORNADO
05/31/98   MCKEAN                         REPORTED BY EMA

0730 PM                              PA   WIND DAMAGE
05/31/98   ELK                            TREES DOWN COUNTYWIDE

OSTUNO
Special weather statement, May 31, 9:27 PM EDT, 52 minutes before
PAZ004>006-010>012-017-018-010140-

SPECIAL WEATHER STATEMENT- TORNADO WATCH CANCELLATION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
927 PM EDT SUN MAY 31 1998

THE TORNADO WATCH IS NO LONGER IN EFFECT FOR WARREN...MCKEAN...
POTTER...ELK...CAMERON...CLEARFIELD...CENTRE... AND NORTHERN
CLINTON COUNTY.  THE COLD FRONT IS USHERING COOLER...DRIER AIR INTO
THE REGION ENDING THE SEVERE WEATHER THREAT.  NO MORE SEVERE
WEATHER IS EXPECTED TONIGHT IN THE ABOVE NAMED COUNTIES.

HEAD
Special weather statement, May 31, 9:27 PM EDT, 52 minutes before
PAZ004>006-010>012-017-018-010140-

SPECIAL WEATHER STATEMENT- TORNADO WATCH CANCELLATION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
927 PM EDT SUN MAY 31 1998

THE TORNADO WATCH IS NO LONGER IN EFFECT FOR WARREN...MCKEAN...
POTTER...ELK...CAMERON...CLEARFIELD...CENTRE... AND NORTHERN
CLINTON COUNTY.  THE COLD FRONT IS USHERING COOLER...DRIER AIR INTO
THE REGION ENDING THE SEVERE WEATHER THREAT.  NO MORE SEVERE
WEATHER IS EXPECTED TONIGHT IN THE ABOVE NAMED COUNTIES.

HEAD
Local storm report, May 31, 10:10 PM EDT, 9 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PENNSYLVANIA
1010 PM EDT SUN MAY 31 1998

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0835 PM    7W SALISBURY              PA   1 INCH HAIL
05/31/98   SOMERSET                       QUARTER SIZED HAIL.

0845 PM    SALISBURY                 PA   TORNADO
05/31/98   SOMERSET                       HOUSES AND TRAILERS
                                          DAMAGED OR DESTROYED.
                                          MANY INJURIES REPORTED.

0914 PM    MUNCY                     PA   62 MPH TSTM GUST
05/31/98   LYCOMING

0930 PM    MILLVILLE                 PA   61 MPH TSTM GUST
05/31/98   COLUMBIA
Local storm report, May 31, 10:10 PM EDT, 9 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PENNSYLVANIA
1010 PM EDT SUN MAY 31 1998

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0835 PM    7W SALISBURY              PA   1 INCH HAIL
05/31/98   SOMERSET                       QUARTER SIZED HAIL.

0845 PM    SALISBURY                 PA   TORNADO
05/31/98   SOMERSET                       HOUSES AND TRAILERS
                                          DAMAGED OR DESTROYED.
                                          MANY INJURIES REPORTED.

0914 PM    MUNCY                     PA   62 MPH TSTM GUST
05/31/98   LYCOMING

0930 PM    MILLVILLE                 PA   61 MPH TSTM GUST
05/31/98   COLUMBIA
Special weather statement, May 31, 10:10 PM EDT, 9 minutes before
PAZ004>006-010>012-017-018-010140-

SPECIAL WEATHER STATEMENT- TORNADO WATCH EXPIRATION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1010 PM EDT SUN MAY 31 1998

THE TORNADO WATCH IS NO LONGER IN EFFECT FOR CENTRAL PENNSYLVANIA.

THE WATCH HAS BEE ALLOWED TO EXPIRE IN THE FOLLOWING COUNTIES...

TIOGA... LYCOMING... SULLIVAN... UNION... NORTHUMBERLAND...
MONTOUR... COLUMBIA... SCHUYLKILL... CAMBRIA... BLAIR...
HUNTINGDON... JUNIATA... MIFFLIN... SNYDER... SOMERSET... BEDFORD...
FULTON... FRANKLIN... PERRY... CUMBERLAND... ADAMS... YORK...
DAUPHIN... LEBANON... AND LANCASTER.

THE STRONGEST STORMS HAVE SHIFTED EAST OF THE AREA. MORE SHOWERS AND
THUNDERSTORMS MOVING THROUGH THE LAUREL HIGHLANDS MAY CAUSE BRIEFLY
HEAVY RAIN AND STRONG WINDS THROUGH MIDNIGHT...BUT THE THREAT FOR
SEVERE WEATHER HAS DIMINISHED FOR MOST OF THE REGION.

LA CORTE

The office that day

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

IssuedProductOfficeCountiesLasted
May 31, 8:10 PM EDTTornado WarningCTPLebanon35 min
May 31, 8:12 PM EDTTornado WarningCTPClinton, Potter78 min
May 31, 8:22 PM EDTTornado WarningCTPSomerset38 min
May 31, 8:24 PM EDTSevere Thunderstorm WarningCTPCentre91 min
May 31, 8:24 PM EDTSevere Thunderstorm WarningCTPLycoming91 min
May 31, 8:45 PM EDTTornado WarningCTPBedford, Somerset60 min
May 31, 8:56 PM EDTSevere Thunderstorm WarningCTPLancaster, York34 min
May 31, 9:01 PM EDTSevere Thunderstorm WarningCTPColumbia, Montour, Northumberland, Union89 min
May 31, 9:01 PM EDTSevere Thunderstorm WarningCTPSullivan89 min
May 31, 9:32 PM EDTTornado WarningCTPBedford28 min
May 31, 9:45 PM EDTSevere Thunderstorm WarningCTPCambria, Somerset60 min
May 31, 9:45 PM EDTSevere Thunderstorm WarningCTPBlair60 min
May 31, 9:46 PM EDTSevere Thunderstorm WarningCTPFulton29 min
May 31, 10:24 PM EDTSevere Thunderstorm WarningCTPBedford66 min
May 31, 10:39 PM EDTTornado WarningCTPBedford66 min
May 31, 10:48 PM EDTSevere Thunderstorm WarningCTPHuntingdon62 min
May 31, 10:52 PM EDTSevere Thunderstorm WarningCTPFulton38 min
May 31, 11:32 PM EDTSevere Thunderstorm WarningCTPFranklin48 min
May 31, 11:36 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland64 min
May 31, 11:47 PM EDTSevere Thunderstorm WarningCTPDauphin, York93 min
Jun 1, 12:09 AM EDTSevere Thunderstorm WarningCTPLancaster76 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1998Every severe thunderstorm warning in 1998

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.