Alert archive / Pennsylvania / Tornado Warnings in 1999

Tornado Warning 7, NWS State College, PA

July 30, 1999York County, Pennsylvania

NWS State College, PA issued this tornado warning at Jul 30, 1999, 7:32 PM EDT for York County, Pennsylvania. It was in force for 28 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
Jul 30, 1999, 7:32 PM EDT (23:32 UTC)
Expired
Jul 30, 1999, 8:00 PM EDT
In force
28 min
Issued by
NWS State College, PA
Area
Whole counties

County York County, PA

What was reported inside it

TimeReportWhereRemark
Jul 30, 7:35 PM EDTThunderstorm WindYork, PAA roof was blown off a home on Gay Street. .
Jul 30, 7:50 PM EDTHail 2.5Seven Vlys, PAHail the size of peaches fell in Seven Valleys, Jocobus, Glen Rock and Shrewsbury.

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 12:00Z, 11.5 hours before the alert went out and 122 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 12:00Z on 1999-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1233 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 12:00Z on 1999-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
1233 J/kg
Mixed-layer CIN
-113 J/kg
Mixed-layer LCL
1423 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
14.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCTP 302337
TORCTP
PAC133-310000-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
732 PM EDT FRI JUL 30 1999

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Jul 30, 1:45 PM EDT, 5 hours 47 minutes earlier.

Area forecast discussion, Jul 30, 1:45 PM EDT, 5 hours 47 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
145 PM EDT FRI JUL 30 1999

...WRK ZONES BY 250 PM...

...ZONES BY 355 PM...

...CHANGES...

WILL KEEP FCST CLOSE TO WHAT WE HAVE NOW...BUT UP TEMPS TONIGHT...GIVEN
WHAT DEWPOINTS ARE ALREADY.

MOST LIKELY WILL HAVE A MENTION OF STORMS EARLY TONIGHT FOR EASTERN
AREAS...MAYBE WESTERN AREAS.

WILL ADD CHC POPS FOR LATE WED.

...DISC...

WARM FRONT FROM C NY...SOUTHWARD TO E PA.  CONVECTION DID FIRE OVER
SW NY AND DROP SE...AS EXPECTED.  ONE THING I DID NOT EXPECT WAS THAT
ACTION COULD GET INTO LOWER SUSQUEHANNA VLY THIS AM.

ANYWAY...LEADING EDGE OF THE HIGHER DEWPOINTS WORKING IN FROM THE
WEST.  LIKE IN 1995...THEY CAN COME UP HIGH...EVEN WITH W FLOW.
WAS THINKING ABOUT A HEAT ADVISORY FOR SE PORTION OF CWA...FOR TODAY
INTO SAT...AS WAS CONCERN THAT FCST DEWPOINTS WERE TOO LOW...BUT
WILL HOLD OFF FOR NOW...BUT WILL KEEP AN EYE ON THIS.

WOULD LIKE TO SEE MORE OF A CAP. WHILE BEST CHC WILL BE EASTERN
AREAS...ACCAS NOTED TO THE WEST.  AIRMASS QUITE UNSTABLE AT 12Z.
DECIDED ON AM PACKAGE NOT TO PUT STORMS IN NW AREAS THIS AFT.

NOT REAL CONCERN ABOUT SEVERE...BUT WILL HAVE TO WATCH FOR ANY STORM
THAT CAN FIRE NEAR ANY LAKE BREEZE...AS THEY COULD DROP SE AND FIRE
OFF MORE STORMS...AS WAS THE CASE IN 1995...GIVEN THE EXTREMELY HIGH
DEWPOINTS TO THE W.

MY THOUGHTS FROM THE AM DISC...ABOVE...ARE STILL IN LINE WITH
WHAT I SEE.

DEWPOINTS IN THE EXTREME RANGE CONTINUE TO ADVECT EASTWARD.
FWC DEWPOINT FCST TOO LOW THIS AFT.  AIRMASS IS BARELY CAPPED
OFF TO THE WEST.  CAP JUST HOLDS IT DOWN TILL IT IS MORE DANGEROUS
ANYWAY.  AIRMASS JUST LIKE A CAN OF GAS...IF MOTHER NATURE THROWS
A MATCH IN IT...WATCH OUT.  CURRENT CONCERN IS THE LAKES AREA...
CONVECTION FIRING FAST OVER ONTARIO...COULD DROP SE ALONG TROUGH
LINE INTO N PA.

ANYWAY...LOOKS LIKE FRONT MOVES IN SUNDAY.  N PA...ESP. NW PA...
COULD GET CLIPPED LATE SAT NIGHT BY ANYTHING THAT DROPS SE FROM
SOUTHERN CANADA...W NY ETC.

SAT AFT...STILL NOT CLEAR CUT...MODELS HINT AT A WEAKNESS OVER THE
OHIO VLY...LIKE A SECORDARY WARM FRONT...MOST LIKELY THE LEADING
EDGE OF THE EXTREME DEWPOINTS.  COULD TOUCH OFF A STORM DURING THE
AFTERNOON HOURS.  WILL LEAVE OUT OF THE FCST...EXCEPT FOR JST AREA
...AS IT IS ALREADY IN FCST.

ETA IS FASTER...AND DROPS PRESSURE FAST...AS LOW MOVES DOWN
THE ST. LAWRENCE RIVER VLY.

WILL NOT GO TOO FAST WITH PCPN AND >FROPA.

.CTP...NONE.

MARTIN

In the hours before

Local storm report, Jul 30, 2:28 PM EDT, 5 hours 4 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
228 PM EDT FRI JUL 30 1999

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

0220 PM    MANSFIELD                 PA   1.5 INCH HAIL
07/30/99   TIOGA                          PING PONG BALL SIZE HAIL
Local storm report, Jul 30, 6:05 PM EDT, 1 hour 27 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
605 PM EDT FRI JUL 30 1999

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

0220 PM    MANSFIELD                 PA   1.5 INCH HAIL
07/30/99   TIOGA                          PING PONG BALL SIZE HAIL

0325 PM    MANSFIELD                 PA   1.0 INCH HAIL
07/30/99   TIOGA                          QUARTER SIZE HAIL

0341 PM    MONTOURSVILLE             PA   .75 INCH HAIL
07/30/99   LYCOMING                       DIME SIZE HAIL

0350 PM    WILLIAMSPORT              PA   1.0 INCH HAIL
07/30/99   LYCOMING                       QUARTER SIZE HAIL

0405 PM    MONTGOMERY                PA   1.5 INCH HAIL
07/30/99   LYCOMING                       QUARTER SIZE HAIL

0434 PM    WARRENSVILLE              PA   1.75 INCH HAIL
07/30/99   LYCOMING                       GOLF BALL SIZE HAIL

0455 PM    WILLIAMSPORT              PA   1.75 INCH HAIL
07/30/99   LYCOMING                       GOLF BALL SIZE HAIL

0500 PM    MONTGOMERY                PA   1.75 INCH HAIL
07/30/99   LYCOMING                       GOLF BALL SIZE HAIL

0528 PM    SELINSGROVE               PA   1.75 INCH HAIL
07/30/99   SNYDER                         GOLF BALL SIZE HAIL

0530 PM    NEW COLUMBIA              PA   1.75 INCH HAIL
07/30/99   UNION                          GOLF BALL SIZE HAIL

0500 PM    MILTON                    PA   .75 INCH HAIL
07/30/99   NORTHUMBERLAND                 DIME SIZE HAIL

LA CORTE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 1:59 PM EDTSevere Thunderstorm WarningCTPTioga61 min
Jul 30, 2:57 PM EDTSevere Thunderstorm WarningCTPTioga63 min
Jul 30, 3:40 PM EDTSevere Thunderstorm WarningCTPLycoming80 min
Jul 30, 3:50 PM EDTSevere Thunderstorm WarningCTPNorthumberland55 min
Jul 30, 3:56 PM EDTSevere Thunderstorm WarningCTPUnion64 min
Jul 30, 4:02 PM EDTSevere Thunderstorm WarningCTPTioga58 min
Jul 30, 4:19 PM EDTSevere Thunderstorm WarningCTPDauphin, Perry71 min
Jul 30, 4:36 PM EDTSevere Thunderstorm WarningCTPNorthumberland, Snyder69 min
Jul 30, 4:52 PM EDTSevere Thunderstorm WarningCTPLycoming, Union83 min
Jul 30, 5:32 PM EDTSevere Thunderstorm WarningCTPDauphin58 min
Jul 30, 6:00 PM EDTSevere Thunderstorm WarningCTPSnyder, Union60 min
Jul 30, 6:17 PM EDTSevere Thunderstorm WarningCTPJuniata, Perry73 min
Jul 30, 6:24 PM EDTSevere Thunderstorm WarningCTPDauphin66 min
Jul 30, 7:05 PM EDTSevere Thunderstorm WarningCTPYork55 min
Jul 30, 7:23 PM EDTSevere Thunderstorm WarningCTPCumberland67 min

Nearby

Tornado Warnings in Pennsylvania, 1999Every tornado warning in 1999Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.