Severe Thunderstorm Warning 161, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
945 PM EDT THU AUG 16 2001

VERY BUSY EVENING HERE WITH SEVERAL SEVERE...AND ONE TORNADIC STORM
ACROSS THE NORTHWEST MTNS...NEAR CLEARFIELD.

MODERATELY STRONG DIRECTIONAL AND SPEED SHEAR IN THE 0-3KM LAYER
CREATED A FAVORABLE ENVIRONMENT FOR SHALLOW TOPPED STORMS WITH
DECENT UPDRAFTS AND GUSTY WINDS. SEVERAL MINI BOW ECHOES IN THE
INITIAL TSRA LINE DURING THE LATE AFTERNOON PRODUCED ISOLATED DAMAGE
ACROSS THE NW MTNS.

THE TSRA THAT PRODUCED A TORNADO TOUCHDOWN NEAR ROCKTON IN NW
CLEARFIELD COUNTY...MAINTAINED MODERATE TO STRONG ROTATION AT THE
0.5 AND 1.5 DEG ELEVATION SCANS FOR OVER AN HOUR ROTATION
DIMINISHED AS IT MOVED INTO NW CLINTON COUNTY AROUND 9 PM.

0-3 KM HELICITY CONTINUES TO INCREASE RAPIDLY TONIGHT BASED ON 18Z
ETA BUFKIT HOURLY PROFILES AT KUNV. VALUES EXCEED 200 M2/S2 AFTER
MIDNIGHT TONIGHT...BUT POTENTIAL FOR TORNADOES WILL DECREASE BASED
ON LESSER UPDRAFT STRENGTH AND SIGNIFICANTLY LOWER CAPE.

PREVIOUS FORECAST WORDING FOR LIKELY TO CATEGORICAL POPS OVER THE
WEST...AND LIKELY POPS LATE TONIGHT IN THE EAST LOOKS FINE BASED ON
RADAR COVERAGE ATTM.

COLD FRONT MOVES ACROSS CENTRAL PENN AROUND 12Z FRIDAY. CHC FOR
SHRA AND TSRA WILL REMAIN UNTIL EARLY AFTERNOON ACROSS THE CENTRAL
SUSQ VALLEY REGION. IMPROVING AND BREEZY CONDITIONS WILL DEVELOP
ELSEWHERE BY LATE FRIDAY MORNING.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AFTERNOON AFD...

WITH LOW/MID LEVEL WINDS BEGINNING TO INCREASE AHEAD OF THE COLD
FRONT...WILL HAVE TO MONITOR CLOSELY FOR SIGNS OF
STRENGTHENING...BUT FOR NOW WILL HANDLE WITH NOWCASTS.

SHORT TERM MODELS REMAINED CONSISTENT WITH NEW RUNS...ALTHOUGH EACH
JUST A BIT STRONGER WITH THE APPROACHING TROUGH.  MAIN DYNAMICS MOVE
ACROSS CENTRAL PA THIS EVENING AND EARLY MORNING...THEN THE DRY SLOT
ENCROACHES LATE TONIGHT INTO FRI MARKING THE BACK EDGE OF PRECIP.
BEFORE THAT HAPPENS THE REGION WILL HAVE TO DEAL WITH SHOWERS/
THUNDERSTORMS IN MOST PLACES TONIGHT.  WITH STRONG 850/500MB
CORRELATED JETS...THE POTENTIAL FOR STRONG WINDS MIXING DOWN TO THE
SURFACE WILL CONTINUE MAINLY THIS EVENING FOR THE WESTERN HALF OF
THE CWA.  WILL MENTION THIS IN THE ZONES.

BY SUNRISE...PRECIP SHOULD BE OVER FOR THE WEST...WHILE A CHANCE
WILL CONTINUE MAINLY THROUGH THE MORNING IN THE EAST.  SPC CONTINUES
A SLIGHT RISK JUST EAST OF THE CWA TOMORROW...AND BELIEVE THIS LOOKS
PRETTY GOOD AS PRECIP WILL MOVE EAST BEFORE THE BEST HEATING KICKS
IN.

IN THE EXTENDED...NEXT BATCH OF MOISTURE ARRIVES AHEAD OF A TROUGH
CURRENTLY DROPPING INTO THE UPPER PLAINS.  THIS WILL BRING A CHANCE
OF SHOWERS/THUNDERSTORMS SAT NIGHT THROUGH SUN NIGHT BEFORE LIFTING
BACK TO THE NORTH.  AFTER THAT...A RUN OF DRY DAYS AND SEASONAL
WEATHER.

.CTP...NONE.

LAMBERT

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE STATE COLLEGE PA
625 PM EDT THU AUG 16 2001

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

0405 PM    8 SW COUDERSPORT          PA   WIND DAMAGE
08/16/01   POTTER                         6 TO 8 TREES DOWN...REPORTED
                                          BY COUNTY EMA

0432 PM    2 WEST RENOVO             PA   WIND DAMAGE
08/16/01   CLINTON                        TREES BLOWN DOWN ALONG ROUTE
                                          120...REPORTED BY COUNTY EMA

0518 PM    LOCK HAVEN                PA   WIND DAMAGE
08/16/01   CLINTON                        POWER LINES BLOWN DOWN IN
                                          TOWN...REPORTED BY COUNTY EMA

LAMBERT