Flash Flood Warning 18, NWS State College, PA

665 
WGUS71 KCTP 122045
FFSCTP

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
445 PM EDT THU AUG 12 2010

PAC001-041-043-071-133-122345-
/O.CON.KCTP.FF.W.0018.000000T0000Z-100812T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
YORK PA-LANCASTER PA-CUMBERLAND PA-DAUPHIN PA-ADAMS PA-
445 PM EDT THU AUG 12 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM EDT FOR
ADAMS...SOUTHERN DAUPHIN...CUMBERLAND...SOUTHWESTERN LANCASTER AND
YORK COUNTIES...

LOCAL LAW ENFORCEMENT OFFICIALS AND TRAINED WEATHER SPOTTERS REPORT 
FLOODING HAS BEGUN AND IS CONTINUING. THE THUNDERSTORMS THAT CAUSED 
THE TORRENTIAL RAINFALL ARE MOVING TO THE SOUTH...AND THE RAIN HAS 
TAPERED OFF OVER CARLISLE...HARRISBURG AND GETTYSBURG. CAPITAL CITY 
AIRPORT HAD OVER 3 INCHES OF RAIN FALL IN ONE HOUR...AND MANY 
LOCATIONS HAVE HAD BETWEEN ONE AND TWO INCHES OF RAIN IN A SHORT 
PERIOD OF TIME. 

MANY ROADS AND UNDERPASSES HAVE BEEN CLOSED DUE TO HIGH WATER AND A 
FEW CARS HAVE BEEN REPORTED STALLED OUT IN THE FLOODED AREAS. 

HOWEVER...THE FLOODING THAT IS OCCURRING WILL CONTINUE FOR THE NEXT 
COUPLE OF HOURS AS THE FLOOD WATERS RUN OFF INTO THE LARGER 
WATERWAYS. SOME NEW AREAS MAY BEGIN TO EXPERIENCE FLOODING AS THE 
RAIN SWELLS THE LARGER STREAMS. 

ADDITIONAL RAINFALL AMOUNTS OF AN INCH OR MORE ARE POSSIBLE OVER 
SOUTHERN YORK COUNTY THROUGH 530 PM. THE REST OF THE WARNED AREA 
WILL SEE ONLY VERY LIGHT RAINFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 3971 7747 4017 7744 4039 7672 3972 7619

$$

FORECASTER: DANGELO

213 
WGUS71 KCTP 122158
FFSCTP

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
558 PM EDT THU AUG 12 2010

PAC071-122156-
/O.CAN.KCTP.FF.W.0018.000000T0000Z-100812T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LANCASTER PA-
558 PM EDT THU AUG 12 2010

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR WESTERN
LANCASTER COUNTY...

THE WATERS FROM THE EARLIER HEAVY RAINS ARE RECEDING AND FLOOD WATERS
NO LONGER POSE A THREAT TO LIFE OR PROPERTY IN WESTERN LANCASTER 
COUNTY. THEREFORE...THE FLASH FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 4017 7744 4037 7678 4019 7662 4014 7674
      4004 7662 3972 7652 3972 7747

$$

PAC001-041-043-133-122345-
/O.CON.KCTP.FF.W.0018.000000T0000Z-100812T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
YORK PA-CUMBERLAND PA-DAUPHIN PA-ADAMS PA-
558 PM EDT THU AUG 12 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM EDT FOR
ADAMS...SOUTH CENTRAL DAUPHIN...CUMBERLAND AND YORK COUNTIES...

AT 545 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS CONTINUE TO REPORT 
MANY AREAS OF FLOODING OVER ADAMS...CUMBERLAND...DAUPHIN AND YORK 
COUNTIES. THE WORST OF THE FLOODING SEEMS TO BE IN HARRISBURG...AND 
IN SPOTS ALL ACROSS YORK COUNTY.

A FEW WATER RESCUES ARE OCCURRING OR HAVE OCCURRED ACROSS THE WARNED 
AREA...AND A FEW HOMES HAVE RECENTLY BEEN EVACUATED IN HARRISBURG. 

THE RAINFALL HAS TAPERED OFF TO ALMOST NOTHING. LIGHT TO MODERATE 
RAIN MAY MOVE BACK IN LATER THIS EVENING...BUT THE RAINFALL RATES 
ARE NOT AT THIS TIME EXPECTED TO BE ENOUGH TO CAUSE NEW AREAS OF 
FLOODING. IT MAY...HOWEVER...DELAY THE END OF THE FLOODING 
SLIGHTLY.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL
LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE
TOLL FREE AT...1 8 7 7 6 3 3 6 7 7 2.

&&

LAT...LON 4017 7744 4037 7678 4019 7662 4014 7674
      4004 7662 3972 7652 3972 7747

$$

FORECASTER: DANGELO

122 
WGUS71 KCTP 122338
FFSCTP

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
738 PM EDT THU AUG 12 2010

PAC001-041-043-133-122346-
/O.EXP.KCTP.FF.W.0018.000000T0000Z-100812T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
YORK PA-CUMBERLAND PA-DAUPHIN PA-ADAMS PA-
738 PM EDT THU AUG 12 2010

...THE FLASH FLOOD WARNING WILL EXPIRE AT 745 PM EDT FOR 
ADAMS...DAUPHIN...CUMBERLAND AND YORK COUNTIES...

THE WATERS FROM THE EARLIER HEAVY RAINS ARE RECEDING AND NO 
ADDITIONAL FLOODING PROBLEMS HAVE OCCURRED IN THE LAST HOUR OR SO. 
THEREFORE...THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE.

ADDITIONAL LIGHT RAIN IS EXPECTED FOR MUCH OF THE NIGHT...BUT THE 
RAIN SHOULD NOT BE HEAVY ENOUGH TO RENEW FLOODING ACROSS THE REGION. 

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL 
LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE 
TOLL FREE AT...1 8 7 7 6 3 3 6 7 7 2.

LAT...LON 4017 7744 4037 7678 4019 7662 4014 7674
      4004 7662 3972 7652 3972 7747

$$

FORECASTER: DANGELO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
326 PM EDT THU AUG 12 2010

.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL BRING UNSETTLED WEATHER TO
THE COMMONWEALTH THROUGH THE END OF THE WORK WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MCV TRACKING FROM THE CENTRAL MOUNTAINS TOWARDS THE RIDGE AND
VALLEY REGION THIS AFTERNOON AND ON ITS WAY TO THE LOWER SUSQ.
THIS EVENING HAS LEFT A SWATH OF BENEFICIAL 1 TO 2 INCH RAINFALLS
FROM EASTERN CENTRE COUNTY SEWD. BOUNDARY LAYER WINDS ARE
EXCEEDINGLY WEAK...BUT WITH ABUNDANT MOISTURE (PW APPROACHING 2
INCHES) AND MODERATE MOISTURE CONVERGENCE...WILL KEEP PLAYING UP
THE HIGH POPS FOR THIS AFTERNOON AND EVENING FROM THE LAURELS
THROUGHOUT CENTRAL AND EASTERN PORTIONS OF THE CWA. NORTHWEST
AREAS HAVE ENTRAINED ENOUGH DRY AIR TO KEEP SCATTERED SHOWER
COVERAGE AND THERE MAY BE SUFFICIENT LAPSE RATES TO PRODUCE A FEW
GUSTY STORMS THIS EVENING.

SEVERE THREAT REMAINS LOW...ALTHOUGH AREAS NEAR THE MARYLAND
BORDER MIGHT BE ABLE TO WARM SUFFICIENTLY TO BREAK THE 750 MB CAP
WHICH IS KEEPING THE LOW TOPPED CONVECTION IN CHECK THIS
AFTERNOON. UNLESS THIS HAPPENS...MAIN CONCERNS WILL REMAIN SLOW
MOVING OR TRAINING SHOWERS...ALTHOUGH EVEN THIS THREAT IS BELOW
NORMAL GIVEN THE RECENT DRYNESS AND ASSOCIATED HIGH FFG VALUES.

POPS GENERALLY DECREASE OVERNIGHT BUT ADDITIONAL SHORTWAVE(S)
ARRIVING FROM THE CENTRAL AND EASTERN LAKE INTO NORTHEAST OHIO AND
WESTERN PA ALONG WITH ANOMALOUSLY HIGH PW STILL 1.5" OR GREATER
FOR MUCH OF EASTERN PA WILL KEEP CHC POPS GOING FOR MOST. AREAS OF
FOG AND DRIZZLE SHOULD ALSO DEVELOP GIVEN THE INCREASING ESELY
FLOW AROUND SFC HIGH PRESSURE CENTERED OVER THE GULF OF MAINE.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE ALONG THE NEW ENGLAND COAST WILL REMAIN
QUASI-STATIONARY THROUGH FRIDAY WITH SELY MARITIME FLOW PRODUCING
PLENTY OF CLOUD COVER AND NEAR TO SLIGHTLY BELOW NORMAL TEMPS FOR
THE COMMONWEALTH ON FRIDAY AFTERNOON. H5 FLOW AMPLIFIES BY LATE IN
THE DAY LEADING TO DECREASED SHOWER CHANCES BY FRIDAY NIGHT...BUT
PERSISTENT SOUTHEAST FLOW SHOULD KEEP LOW CLOUDS AND AREAS OF
DRIZZLE OR VERY LIGHT SHOWERS IN THE FORECAST FOR MOST CENTRAL AND
EASTERN SECTIONS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
ENSEMBLE DATA IS SHOWING A RELATIVE MIN IN PWATS ACROSS CENTRAL PA
FRI NIGHT INTO SATURDAY. THIS...COMBINED WITH SHORT-LIVED UPPER-
LVL RIDGING ACROSS THE AREA...SHOULD GIVE US A BREAK IN THE WET
WEATHER FOR THE FIRST HALF OF THE UPCOMING WEEKEND.

BY SUNDAY...THE UPPER-LVL RIDGE WILL BE PUSHED TO THE EAST IN
RESPONSE TO A DIGGING TROUGH OVER THE GLAKES. AT THE SFC...A COLD
FRONT WILL APPROACH THE AREA FROM THE GLAKES. PWATS RISE BACK UP
TO +2 SD FROM SUNDAY INTO MONDAY...SO EXPECT A GOOD CHC FOR
SHRA/TSRA.

THE FRONT WILL BE SLOW TO CROSS THE REGION. THERE IS SOME
DISCREPANCY BETWEEN THE OPERATIONAL MODELS AS TO HOW QUICKLY THE
FRONT WILL DEPART. THE 12Z GFS PUSHES THE FRONT TO OUR EAST BY
TUESDAY NIGHT...TAKING THE CLOUDS AND WET WEATHER WITH IT.
HOWEVER...THE ECMWF HANGS THE FRONT ACROSS SE PA UNTIL NEXT
THURSDAY NIGHT OR FRIDAY...WHEN IT IS FINALLY PUSHED OUT TO SEA
BY A SECONDARY COLD FRONT. HPC GUIDANCE KEEPS POPS ABOVE-NORMAL
FROM SUNDAY THROUGH THURSDAY OF NEXT WEEK.

BOTTOM-LINE...IT LOOKS LIKE THE SECOND HALF OF THIS WEEKEND INTO
EARLY...AND POSSIBLY THE MIDDLE OF...NEXT WEEK WILL BE UNSETTLED.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AN AREA OF MODERATE TO HEAVY RAIN SHOWERS AND EMBEDDED
THUNDERSTORMS WILL CONTINUE TO DRIFT SOUTHEASTWARD ACROSS THE
EASTERN PART OF THE REGION THIS AFTERNOON. IN ADDITION...A LINE
OF SCATTERED SHOWERS AND THUNDERSTORMS FORMING BEHIND THE SYSTEM
WILL AFFECT THE SOUTH AND WEST. LOW CLOUDS AND POOR VISIBILITIES
ASSOCIATED WITH THIS MOIST AIR MASS WILL KEEP MOST AIRFIELDS BELOW
VFR THROUGH THE REST OF THE AFTERNOON...WITH THE EXCEPTION OF THE
NORTHWEST WHERE SUN HAS BROKEN THROUGH THE CLOUDS.

CEILINGS ARE EXPECTED TO DROP EVEN FURTHER THIS EVENING AND LATER
TONIGHT AS AN EASTERLY FLOW STRENGTHENS. CEILINGS WILL TYPICALLY BE
MVFR AND IFR THROUGHOUT THE NIGHT...WITH SOME LOCALIZED PATCHES OF
LIFR CLOUD COVER. MVFR/IFR VISIBILITIES WILL ALSO MIX IN WITH THE
LOW CLOUDS AS FOG DEVELOPS BEFORE SUNRISE. CONDITIONS WILL IMPROVE
SLIGHTLY TOMORROW MORNING. HOWEVER MUCH OF THE REGION WILL REMAIN
UNDER MVFR CEILINGS INTO THE AFTERNOON HOURS AS THE EASTERLY FLOW
PERSISTS.

OUTLOOK...
FRI-SAT...LATE NIGHT AND AM IFR CIGS LIFTING BY AFTN.
SUN-TUE...MAINLY VFR WITH MVFR POSSIBLE IN SCT TSRA.

&&

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

&&

SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...EVANEGO
AVIATION...DEVOIR/KOZAR

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
549 AM EDT THU AUG 12 2010

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-131000-
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-
549 AM EDT THU AUG 12 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THE PROBABILITY FOR 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
320 PM EDT THU AUG 12 2010

PAZ057-063>066-122000-
ADAMS PA-CUMBERLAND PA-DAUPHIN PA-LANCASTER PA-YORK PA-
320 PM EDT THU AUG 12 2010

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHEASTERN ADAMS...
NORTHERN YORK...SOUTH CENTRAL DAUPHIN...SOUTHERN CUMBERLAND AND WEST
CENTRAL LANCASTER COUNTIES...

AT 312 PM EDT...A LINE OF STRONG THUNDERSTORMS WAS LOCATED FROM
MIDDLETOWN TO CARLISLE...MOVING SOUTHEAST AT 20 MPH.

VERY HEAVY RAIN WILL FALL FROM THESE STORMS...REDUCING VISIBILITIES
TO NEAR ZERO AND CAUSING WATER TO POND ON ROADS AND FILL POOR
DRAINAGE AREAS. THE RAIN WILL CAUSE RAPID RISES ON SMALL STREAMS AND
CREEKS. WIND GUSTS TO 45 MPH ARE ALSO POSSIBLE...WHICH COULD COMBINE
WITH THE HEAVY RAIN AND WET LEAVES TO DOWN TREE LIMBS.

THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 222 AND 251...I-81 BETWEEN
MILE MARKERS 37 AND 49...I-83 BETWEEN MILE MARKERS 19 AND 41...I-283.

THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...THE HARRISBURG
EXPRESSWAY...THE HARRISBURG AIRPORT CONNECTOR...STATE HIGHWAY 283...
ROUTE 11...ROUTE 15...ROUTE 30...STATE ROAD 94.

LAT...LON 4000 7644 3993 7715 4019 7743 4025 7677

FORECASTER: DANGELO