Severe Thunderstorm Warning 186, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1155 AM EST WED NOV 9 2005

.SHORT TERM (REST OF TODAY)...

SEVERE THUNDERSTORM WATCH 855 JUST ISSUED FOR THE NORTHWEST PENN
MTNS AND ADJACENT PORTIONS OF NE OHIO/WRN NEW YORK UNTIL 7 PM EST
THIS EVENING.

UPDATED ZFP AND WEATHER GRIDS SENT TO REFLECT THIS WATCH.

&&

.PREVIOUS DISCUSSION...
(ISSUED 1133 AM EST WED NOV 9 2005)

SHORT TERM (REST OF TODAY THROUGH THURSDAY)...

ACTIVE CONVECTIVE WEATHER IN STORE FOR THIS AFTERNOON AND EARLY
EVENING...AS A POTENT COLD FRONT APPROACHES FROM THE OHIO
VALLEY...ACCOMPANIED BY A STRONG LOW TO MID LEVEL WIND FIELD AND
EXTREMELY HIGH 0-3KM HELICITY 400+ M2/S2.

STRONG 850 MB COLD ADVECTION THIS EVENING WILL HELP TRANSPORT DOWN
A GUSTY WEST WIND...THAT WILL CONTINUE THROUGH MUCH OF THURSDAY.

A FAIRLY WELL-ALIGNED 290 DEG BOUNDARY LAYER FLOW AND 850 MB TEMPS
OF NEAR -5 C THURSDAY WILL COMBINE WITH A PRONOUNCED MID LEVEL
THERMAL TROUGH TO BRING NUMEROUS MORNING SNOW SHOWERS AND PERHAPS
A MINOR ACCUMULATION OF AN INCH OR SO TO THE NW MTNS.

PREVIOUS DISCUSSION...
(ISSUED 237 AM EST WED NOV 9 2005)

SHORT TERM (TODAY)...
SFC HI CENTERED OVR SRN QUEBEC EARLY THIS MORNING...WITH RESULTANT COOL
AIR DAMMING EVIDENT ALL THE WAY DOWN TO THE LOWER SUSQ. RIVER
VALLEY. MEANWHILE...WARM FRONT CONTS TO LIFT TOWARDS ERN OHIO WITH
A SUBSTANTIAL ZONE OF SHOWERS WITH EMBEDDED LIGHTNING APPROACHING
SOUTHWEST PA BORDER WITH BOTH OH AND WV. MUCH OF THIS SHOULD HOLD
TOGETHER AND CROSS MOST OF WESTERN AND CENTRAL PORTIONS OF MY CWA
THIS MORNING AND EARLY THIS AFTERNOON...AHEAD OF SHARP COLD FRONT
THAT WILL LIKELY NOT PASS UNTIL THE 6-10 PM TIMEFRAME (FROM W TO
E).

MAIN CONCERN TODAY IS FOR SEVERE WEATHER THREAT...AND NO CHANGES
TO THE OVERRIDING THINKING THAT COOL AIR DAMMING WILL EFFECTIVELY
PUT THE KABASH ON MOST OF THIS CONCERN ACROSS THE CENTRAL AND
EASTERN SECTIONS. FAR WEST WILL BE A DIFFERENT STORY WHERE WIND
DAMAGE IS MOST LIKELY FROM A PROBABLY SQUALL LINE THAT IS EXPECTED
TO DEVELOP AHEAD OF THE FRONT THIS AFTERNOON INTO EARLY THIS EVENING.
HOWEVER...DAY 1 CONVECTIVE OUTLOOK PLACES ALL OF MY COUNTIES IN
SLIGHT RISK FOR THIS AFTERNOON AND EVENING...AS SHALLOW
COOL/STABLE AIR DUE TO DAMMING IS EXPECTED TO MIX OUT IN THE FAST
FLOW AHEAD OF THE FRONT LATER TODAY.

LONG TERM (TONIGHT THROUGH TUESDAY)...
COLD FRONT BLASTS THROUGH THE REGION THIS EVENING...FOLLOWED BY
SHARPLY COLDER AIR FOR THE OVERNIGHT AND ESPECIALLY ON THURSDAY...
WITH SNOW SHOWERS EXPECTED ON THU IN THE TYPICAL DOWNWIND
LOCATIONS OF THE NORTHWEST MOUNTAINS AND LAURELS (NO ACCUMULATION
EXPECTED HOWEVER).

COOL CONDS WILL PREVAIL INTO FRIDAY AS MODERATE NORTHWEST FLOW AND
VERY COOL AND UNSTABLE BOUNDARY LAYER WILL PROMOTE ADDITIONAL LAKE
EFFECT SNOW SHOWERS...AT LEAST UNTIL FRIDAY NIGHT OR SATURDAY WHEN
THE SURFACE RIDGE AXIS BUILDS ACROSS PA AND EFFECTIVELY SHUTS
THINGS OFF. MODERATING TEMPS AND DRY CONDS EXPECTED FOR THE
REMAINDER OF THIS COMING WEEKEND...ALTHOUGH A STORM SYSTEM LIFTING
INTO THE CENTRAL LAKES BY SUNDAY EVENING WILL SPREAD SHOWEVER INTO
THE OHIO VALLEY LATE IN THE DAY. FRONTAL ZONE ASSOCIATED WITH THIS
SYSTEM WILL SHEAR OUT ACROSS THE STATE...KEEPING CLOUDS AND AT
LEAST SLIGHT CHANCE OF SHOWER IN THE PICTURE EARLY NEXT WEEK.
A MUCH STRONGER FRONT WILL LIKELY ARRIVE TUE NIGHT...BRINGING
ANOTHER WINTRY PREVIEW AS AN ICIER BLAST OF AIR TRANSCENDS UPON
CENTRAL PA WEDNESDAY AFTERNOON.

AVIATION...
A WILD DAY IN STORE FOR C PA TODAY. WINDS WILL BE ON THE INCREASE
THIS MORNING...MAY NEED LLWS ON 12Z PACKAGE. CIGS AND VISIBILITIES
NOT BAD YET...BUT EXPECT WIDESPREAD MVFR AND EVEN IFR CONDITONS
LATER THIS MORNING...AS WARM FRONT MOVES IN. ALSO HISTORY OF
ELEVATED CONVECTION WITH WARM FRONT.

COMBINATION OF STRONG SHEAR AND DYNAMICS...ALONG WITH TAP INTO
DEWPOINTS IN THE UPPER 50S TO LOWER 60S...AND THERMAL RIDGE BEHIND
MOISTURE RIDGE WOULD SUPPORT SEVERE WEATHER...PERHAPS EVEN
TORNADOES...AS COLD FRONT MOVES IN JUST AFTER PEAK HEATING. SYSTEM
DOES NOT QUITE HAVE THE SAME SETUP AS THE ONE ON SUNDAY. THIS SYSTEM
HAS MORE POTENTIAL. LIMITING FACTOR WILL BE THAT SOME AREAS MAY NOT
GET INTO THE WARM SECTOR...SUSPECT AREAS N AND E OF IPT...BUT WINDS
FIELDS ARE ABNORMALLY STRONG...THUS WARM AIR COULD MAKE IT ALL THE
WAY TO THE NY BORDER. WATER VAPOR LOOP SHOWS DARKENING OVER THE
UPPER PLAINS...SYSTEM SHOULD CONTINUE TO DEEPEN QUICKLY TODAY.

VERY STRONG DRY INTRUSION THIS EVENING BEHIND FRONT...VFR CONDITIONS
SHOULD PREVAIL FOR THE MOST PART. SOME SC BY THU MORNING ACROSS THE
MTS. COLD ENOUGH FOR SNOW SHOWERS ON THU...BUT SHEAR WILL LIMIT
ACTIVITY IN THE EARLY PART OF THE DAY.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH 855 IN EFFECT FOR THE NORTHWEST PENN
MTNS UNTIL 00Z THURS. &&

SHORT TERM...LAMBERT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
322 AM EST WED NOV 9 2005

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066-100830-
WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD-
NORTHERN CENTRE-SOUTHERN CENTRE-CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN-
JUNIATA-SOMERSET-BEDFORD-FULTON-FRANKLIN-TIOGA-NORTHERN LYCOMING-
SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR-
NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-
CUMBERLAND-ADAMS-YORK-LANCASTER-
322 AM EST WED NOV 9 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT
A COLD FRONT WILL MOVE ACROSS THE REGION LATER THIS AFTERNOON AND
EVENING. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS...WITH
WIND DAMAGE BEING THE MAIN SEVERE WEATHER THREAT...ACCOMPANYING
THE FRONT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1115 AM EST WED NOV 9 2005

PAZ004-091815-
WARREN-
1115 AM EST WED NOV 9 2005

...STRONG THUNDERSTORMS WILL AFFECT MAINLY THE NORTHERN PART WARREN
COUNTY BETWEEN 1145 PM AND 1 PM...

AT 1112 AM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES NORTH OF
RIPLEY NEW YORK...SOUTHWEST ALONG THE LAKE ERIE SHORELINE TO NEAR
ASHTABULA OHIO...MOVING EAST AT 45 MPH. THE THUNDERSTORMS
WILL BE NEAR COLUMBUS AROUND 1215 PM...BEAR LAKE AROUND 1220
PM...SPRING CREEK...LOTTSVILLE AROUND 1225 PM...SUGAR GROVE AROUND
1230 PM...GARLAND AROUND 1235 PM AND YOUNGSVILLE AROUND 1240 PM.

WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS.

ALSO...OCCASIONAL...DANGEROUS CLOUD TO GROUND LIGHTNING WILL BE
OCCURRING.

SEEK SHELTER INDOORS...PREFERABLY INSIDE A STURDY BUILDING...IF
THREATENING WEATHER APPROACHES.

FORECASTER: LAMBERT

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
111 PM EST WED NOV 9 2005

PAZ005-006-010>012-017-091945-
CAMERON-CLEARFIELD-ELK-MCKEAN-NORTHERN CLINTON-POTTER-
111 PM EST WED NOV 9 2005

...STRONG THUNDERSTORMS WILL AFFECT THE COUNTIES OF
MCKEAN...CLEARFIELD...CAMERON...POTTER...ELK AND CLINTON THROUGH
245 PM EST...

AT 107 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
AREA OF STRONG THUNDERSTORMS MOVING RAPIDLY EAST ACROSS THE
NORTHWEST MOUNTAINS OF PENNSYLVANIA...WITH THE LEADING EDGE ALONG A
LINE EXTENDING FROM 11 MILES EAST OF WARREN TO 4 MILES SOUTHEAST OF
RIDGWAY TO 9 MILES WEST OF DUBOIS...MOVING NORTHEAST AT 50 MPH.

THE THUNDERSTORMS WILL BE NEAR TREASURE LAKE...MOUNT JEWETT AROUND
120 PM...PENFIELD...LEWIS RUN...KINZUA BRIDGE STATE PARK...CYCLONE
AROUND 125 PM...TRUMAN...SMETHPORT...REW AND PARKER DAM STATE PARK
AROUND 130 PM.

WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE
STORMS...ALONG WITH OCCASIONAL...DANGEROUS CLOUD TO GROUND LIGHTNING.

FORECASTER: LAMBERT