Severe Thunderstorm Warning 9, NWS State College, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1047 PM EDT WED MAY 21 2014

.SYNOPSIS...

A SLOW MOVING WARM FRONT OVER CENTRAL PENNSYLVANIA WILL LIFT
TO THE NORTH AND EAST TONIGHT. A COLD FRONT WILL PUSH THROUGH THE
STATE THURSDAY. THE EXTENDED FORECAST WILL FEATURE A GRADUAL
WARMING TREND BEGINNING THIS WEEKEND...DESPITE SOME SHOWERS
LINGERING SATURDAY IN THE POST- FRONTAL NORTHWEST FLOW.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...

AS WAS ADVERTISED BY AN EARLIER VERSION OF THE HRRR...A STRING OF
CONVECTION HAS DEVELOPED AND IS SLIDING SOUTH THROUGH THE
NORTHERN MOUNTAINS. IT'S A LITTLE EARLIER THAN PREDICTED...BUT
THE GENERAL LINEAR ORGANIZATION IS A DECENT MATCH. THE APPROACH OF
THE MAIN MID LEVEL SHORTWAVE ASSOCIATED WITH THE FRONTAL SYSTEMIS
PROVIDING JUST ENOUGH WARM ADVECTION AND LARGE SCALE LIFT TO KEEP
ACTIVITY GOING AND MAKE FOR ANOTHER NIGHT OF NOCTURNAL FIREWORKS.

AS YET THERE IS NO INDICATION WE WILL SEE THE KIND OF HEAVY
DOWNPOURS WE SAW LAST NIGHT AS THE DEEPEST MOISTURE HAS POOLED OFF
TO THE SOUTH OF THE AREA...AND THE LINE IS MOVING NEARLY NORMAL
TO ITS ORIENTATION...LIMITING RESIDENCE TIME FOR THE RAINS OVER
ANY ONE AREA.

WILL HAVE TO WATCH THE NWRN ZONES WHERE HEAVY RAIN DEVELOPED LATE
LAST NIGHT AND RESULTED IN SERIOUS FLOODING IN AND AROUND RIDGWAY.

HAVE ALLOWED THE FLOOD WARNING FOR ELK COUNTY AND THE FLOOD WATCH
TO BOTH EXPIRE AS WATERS ARE RECEDING IN THE AREAS AFFECTED BY
EARLIER RAINS.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
SFC COLD FRONT PUSHES ACROSS THE CENTRAL AND EASTERN ZONES DURING
THE MIDDAY AND AFTERNOON HOURS. A RATHER POTENT UPPER SHORT WAVE
MOVING SE FROM THE UPPER GLAKES WILL HELP TO STRENGTHEN THE
ASSOCIATED 300 MB JET...WITH ITS LEFT EXIT REGION HELPING TO
ENHANCE LARGE SCALE LIFT AND THE CONVECTIVE THREAT ACROSS THE
EASTERN HALF OF PENN DURING THE PEAK HEATING OF THE DAY. SPC HAS
THE SUSQ VALLEY AND POINTS EAST UNDER A SLIGHT RISK FOR SVR
THURSDAY.

MAX TEMPS THURSDAY WILL RANGE FROM THE MID AND UPPER 70S IN THE
SUSQ VALLEY...TO THE COOLER MID 60S IN THE FAR NW.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AN UPPER-LEVEL TROUGH CROSSING THE INTERIOR NORTHEAST AND NORTHERN
MID-ATLANTIC STATES EARLY FRIDAY WILL LINGER ALONG/OFFSHORE THE
EASTERN SEABOARD THRU SATURDAY. THE UPPER LEVEL TROUGHING AND
RELATIVELY COOL CYCLONIC FLOW ALOFT WILL BE REPLACED BY RISING
HEIGHTS EXPANDING NNEWD IN ADVANCE OF A HIGH-LEVEL RIDGE MIGRATING
EWD ACROSS THE SOUTH-CENTRAL U.S. THE UPPER RIDGE IS FORECAST TO
FLATTEN INTO THE MIDDLE OF NEXT WEEK IN ASSOCIATION WITH SHORTWAVE
ENERGY MOVING THROUGH SOUTHEASTERN CANADA. THE MODELS GENERALLY
AGREE ON THE ABOVE MENTIONED LARGE SCALE PATTERN EVOLUTION...WITH
NOTEWORTHY DIFFERENCES CREEPING INTO DETERMINISTIC SOLUTIONS IN THE
OUTER PERIODS. SPECIFICALLY...THE 21/12Z OPRNL GFS IS MUCH MORE
AGGRESSIVE IN LOWERING HEIGHTS OVER THE NORTHEAST/NEW ENGLAND
STATES BY NEXT WED/THU...WHICH RESULTS IN A SIGNIFICANT SPREAD IN
MEDIUM RANGE X/N GFS AND ECMWF BASED MOS TEMPERATURE GUIDANCE.

SENSIBLE WEATHER HIGHLIGHTS...THE DY2 FRONTAL PASSAGE WILL BRIEFLY
RETURN THE COOL/DRY CYC FLOW PATTERN ALOFT WITH DIURNAL/INSTABILITY
SHOWERS EXPECTED MAINLY OVER NERN/ERN PA ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL FAVOR A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TEMPERATURE AND HUMIDITY TREND FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK. THE POTENTIAL FLY IN
THE OINTMENT MIGHT BE ANY RING OF FIRE CONVECTION THAT COULD
THWART THE PROJECTED WARMING TREND. IN GENERAL EXPECT A BETTER
CHANCE FOR SHOWERS AND AFTN TSTMS INTO THE MIDDLE OF NEXT WEEK.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
CONVECTION HAS SHIFTED TO MORE CELLULAR...WITH SCATTERED
THUNDERSTORMS MOVING THROUGH CENTRAL PA THIS EVENING.

BRIEF/LOCALIZED IFR IN HEAVIER SHOWERS WILL BE POSSIBLE FROM KIPT
TO KSEG...KMDT AND KLNS THROUGH 01Z.

ADDITIONAL SCTD SHOWERS/ISOLATED TSRA WITH PERIODS OF MVFR
ARE EXPECTED TONIGHT.

MOIST...WEST TO SWRLY UPSLOPE FLOW ACROSS THE ALLEGHENIES WILL
LEAD TO AREAS OF LIFR CIGS /AND MVFR TO IFR VSBYS/ IN STRATUS
CLOUDS AND FOG INVOF KJST AND KBFD.

COLD FRONT PUSHES EAST ACROSS THE STATE THURSDAY...TRIGGERING ANOTHER
FEW SHOWERS/TSRA. HIGHLY LOCALIZED IFR CIGS/VSBYS IN BRIEF HEAVY
RAIN WILL BE POSSIBLE...ESPECIALLY ACROSS THE EASTERN HALF OF
PENN.

SOME SHOWERS COULD PERSIST INTO THE WEEKEND...AS ADDITIONAL
ENERGY ROTATES SE AROUND A DEEP UPPER LEVEL LOW.

BEST DAY FOR DRY WEATHER AND VFR CONDITIONS WILL BE SUNDAY.

.OUTLOOK...
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.

SUN AND MON...NO RESTRICTIONS EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...STEINBUGL
AVIATION...LAMBERT/CERU
HYDROLOGY...

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1025 PM EDT WED MAY 21 2014

PAZ012-018-019-024>028-033>037-041-042-045-046-049>053-056>059-
063>066-230230-
NORTHERN CLINTON-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-
1025 PM EDT WED MAY 21 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT. SOME
OF THESE STORMS MAY PRODUCE LOCALIZED HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

PAZ004>006-010-011-017-230230-
WARREN-MCKEAN-POTTER-ELK-CAMERON-CLEARFIELD-
1025 PM EDT WED MAY 21 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT. SOME
OF THESE STORMS MAY PRODUCE LOCALIZED HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1111 PM EDT WED MAY 21 2014

PAZ004-220345-
WARREN PA-
1111 PM EDT WED MAY 21 2014

...SPECIAL WEATHER STATEMENT...

AT 1110 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR
SPRING CREEK...MOVING EAST AT 60 MPH.

DIME SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

THIS STRONG THUNDERSTORM WILL BE NEAR...
  YOUNGSVILLE AROUND 1120 PM EDT.
  CHAPMAN STATE PARK AROUND 1130 PM EDT.
  SHEFFIELD AROUND 1140 PM EDT.

OTHER LOCATIONS IMPACTED BY THIS STORM INCLUDE CLARENDON...TIDIOUTE
AND STARBRICK.

THIS INCLUDES THE FOLLOWING HIGHWAYS...
 ROUTE 6 BETWEEN NEAR PITTSFIELD AND NEAR LUDLOW.
 ROUTE 62 BETWEEN SOUTH OF TIDIOUTE AND WEST OF WARREN.
 STATE ROAD 59 NEAR WARREN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

VERY HEAVY RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 4192 7961 4181 7896 4181 7895 4163 7898
      4162 7961
TIME...MOT...LOC 0310Z 292DEG 51KT 4182 7957

DANGELO

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1118 PM EDT WED MAY 21 2014

PAZ006-220345-
POTTER PA-
1118 PM EDT WED MAY 21 2014

...SPECIAL WEATHER STATEMENT...

AT 1117 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
COUDERSPORT...MOVING SOUTHEAST AT 30 MPH.

PEA SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS
STORM.

THIS STRONG THUNDERSTORM WILL BE NEAR...
  DENTON HILL STATE PARK AROUND 1130 PM EDT.
  CHERRY SPRINGS STATE PARK AND LYMAN RUN STATE PARK AROUND 1140 PM
EDT.

OTHER LOCATIONS IMPACTED BY THIS STORM INCLUDE SKI DENTON SKI AREA
AND SWEDEN VALLEY.

LAT...LON 4167 7760 4162 7760 4147 7779 4147 7783
      4176 7816 4189 7799
TIME...MOT...LOC 0317Z 313DEG 28KT 4178 7801

DANGELO

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1143 PM EDT WED MAY 21 2014

PAZ006-012-037-041-220430-
NORTHERN LYCOMING PA-POTTER PA-NORTHERN CLINTON PA-TIOGA PA-
1143 PM EDT WED MAY 21 2014

...SPECIAL WEATHER STATEMENT...

AT 1143 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR
OLE BULL STATE PARK...MOVING SOUTHEAST AT 40 MPH.

PEA SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS
STORM.

THIS STRONG THUNDERSTORM WILL BE NEAR...
  LEETONIA AROUND 1200 AM EDT.
  CEDAR RUN...SLATE RUN AND CAMMAL AROUND 1210 AM EDT.
  ENGLISH CENTER...LITTLE PINE STATE PARK AND WATERVILLE AROUND 1220
AM EDT.

OTHER LOCATIONS IMPACTED BY THIS STORM INCLUDE SKI SAWMILL SKI AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 4169 7795 4181 7767 4143 7707 4120 7739
TIME...MOT...LOC 0343Z 309DEG 34KT 4164 7768

CERU