Flash Flood in West Virginia, May 23, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
242 AM EDT FRI MAY 23 2003

FORECAST CONCERNS THIS MORNING CENTER ON THE EAST COAST LOW TRACKING
THROUGH THE CAROLINAS AND THE UPPER LEVEL LOW NOW OVER SOUTH CENTRAL
WISCONSIN.  AS THESE SYSTEMS SANDWICH THE REGION TODAY, THE MENTION
OF TRW HAS BEEN ADDED FOR THIS AFTERNOON...SPC SLIGHT RISK IN THE
LATEST ISSUANCE.  WITH 500 MB TEMPS APPROACHING -20C MOVING OVER THE
THERMAL RIDGE AND WET BULB ZERO AROUND 7,500, SOME SMALL HAIL NOT
OUT OF THE QUESTION FOR THOSE AREAS THAT RECEIVE TRW.  THINK
SUNSHINE WILL BE LIMITED AS CEILINGS RAPIDLY FALLING AS WE SPEAK AND
A FEW SHOWERS FORMING OVER SOUTHEAST OH. SUPPORT FROM UPPER LOW MAY
BE ENOUGH TO COUNTERACT FOR AFTERNOON ACTIVITY.

LOOKS LIKE TONIGHT INTO SATURDAY MORNING WILL BRING THE BEST CHANCE
OF STEADY RAIN AS THE EAST COAST LOW AND UPPER LOW BOTH INFLUENCE.
THE HIGHEST POPS HAVE BEEN PLACED OVERNIGHT.  SATURDAY MAY GIVE US A
BREAK AS DRY SLOT SHOULD ALLOW SOME SUN.  THE EXTENDED WILL BE
DRIVEN BY IMPULSES ROTATING AROUND THE PESKY UPPER LOW THAT HANGS
AROUND LIKE A BAD COLD. MAYBE A BREAK BY LATE WEEK.

PIT   66  55  64  48 /  40  80  50  30
HLG   65  50  64  48 /  40  80  50  30
MGW   64  49  66  48 /  40  80  40  20
ZZV   68  50  66  48 /  40  80  50  30
PHD   67  50  66  48 /  40  80  50  30
FKL   64  50  62  45 /  40  90  60  30
DUJ   63  51  62  45 /  40  90  60  30
LBE   65  51  64  48 /  40  80  50  30
BTP   65  50  62  45 /  40  90  60  30
IDI   62  51  62  45 /  40  90  60  30
ODM   59  48  62  47 /  50  80  40  10

.PBZ...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

TYBURSKI

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029>032-WVZ001>004-012-021>023-041-230915-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
510 AM EDT FRI MAY 23 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN PENNSYLVANIA
EAST CENTRAL OHIO...NORTHERN WEST VIRGINIA AND
GARRETT COUNTY MARYLAND.

.DAY ONE...TODAY

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXISTS THIS AFTERNOON AND
EVENING OVER WESTERN PENNSYLVANIA...EAST CENTRAL OHIO...NORTHERN
WEST VIRGINIA AND GARRETT COUNTY MARYLAND. CITIES THAT MAY BE
AFFECTED INCLUDE CLARION...NEW CASTLE...LATROBE...WHEELING AND
PITTSBURGH. AN INTENSIFYING UPPER LEVEL LOW PRESSURE SYSTEM WILL
LEAD TO THE FORMATION OF THUNDERSTORMS THAT MAY CONTAIN HAIL AND
GUSTY WINDS. HEAVY RAIN IS ALSO POSSIBLE FROM ANY THUNDERSTORMS THAT
DEVELOP.

A THREAT OF LOCALLY HEAVY RAIN EXISTS OVER MUCH OF THE AREA FROM
LATE THIS AFTERNOON INTO SATURDAY MORNING. LOCALIZED PROBLEMS IN
TYPICAL LOW SPOTS MAY IS POSSIBLE...BUT WIDESPREAD FLOODING IS NOT A
SIGNIFICANT CONCERN. THE RIVERS AND STREAMS ARE RUNNING AT NORMAL TO
BELOW NORMAL FLOWS FOR THIS TIME YEAR...AND THE GROWING VEGETATION
SHOULD HELP TO MINIMIZE THE RUNOFF FROM SHOWERS AND ANY
THUNDERSTORMS. HOWEVER...URBAN AREAS AND THE TYPICAL POOR DRAINAGE
AREAS MAY SEE SOME WATER BUILD UP IN SPOTS IF HEAVY RAIN PERSISTS OR
FALLS IN A SHORT AMOUNT OF TIME.

.DAYS TWO THROUGH SEVEN...

A WIDESPREAD RAINFALL WITH THE THREAT FOR SOME LOCALIZED HEAVY RAINS
WILL CONTINUE THROUGH THE MORNING HOURS ON SATURDAY...WHEN THE RAINS
SHOULD TAPER OFF. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

TYBURSKI

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029>032-WVZ001>004-012-021>023-041-231115-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
420 AM EDT FRI MAY 23 2003

...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND THIS EVENING AND
HEAVY RAIN POSSIBLE TONIGHT...

SHOWERS WILL DEVELOP THIS MORNING ALONG WITH A FEW THUNDERSTORMS
THIS AFTERNOON OVER WESTERN PENNSYLVANIA.  SOME OF THESE
THUNDERSTORMS MAY PRODUCE GUSTY WINDS...HAIL AND HEAVY DOWNPOURS.

THE THREAT FOR SEVERE THUNDERSTORMS WILL BE WEST OF THE RIDGES...IN
PLACES LIKE PITTSBURGH...WHEELING AND BEAVER FALLS. A STRONG UPPER
LEVEL LOW PRESSURE SYSTEM WILL PROVIDE THE INSTABILITY NECESSARY FOR
THE POSSIBILITY OF SEVERE THUNDERSTORMS THIS AFTERNOON.

HEAVY RAIN IS ALSO A POSSIBILITY.  THE HEAVY RAIN THREAT WILL BE
OVER WESTERN PENNSYLVANIA TONIGHT AS AN UPPER LEVEL LOW PRESSURE
SYSTEM DRAWS IN MOISTURE FROM A STORM SYSTEM MOVING UP THE ATLANTIC
COAST.

HEAVY RAIN THAT FALLS TONIGHT WILL AVERAGE AROUND ONE INCH BY
SATURDAY MORNING.  WHILE THIS AMOUNT OVER A 6 TO 12 HOUR PERIOD WILL
NOT CAUSE ANY SIGNIFICANT FLOODING...IF THE RAIN WERE TO FALL IN A
SHORTER TIME FRAME...IT MAY CAUSE MINOR FLOODING OF TYPICAL LOW
SPOTS.

SKYWARN ACTIVATION MAY BE NEEDED LATER TODAY. STAY TUNED TO NOAA
WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER DETAILS OR UPDATES.

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029>032-WVZ001>004-012-021>023-041-231445-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
449 AM EDT FRI MAY 23 2003

...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND THIS EVENING AND
HEAVY RAIN POSSIBLE TONIGHT...

SHOWERS WILL DEVELOP THIS MORNING ALONG WITH A FEW THUNDERSTORMS
THIS AFTERNOON OVER WESTERN PENNSYLVANIA.  SOME OF THESE
THUNDERSTORMS MAY PRODUCE GUSTY WINDS...HAIL AND HEAVY DOWNPOURS.

THE THREAT FOR SEVERE THUNDERSTORMS WILL BE WEST OF THE RIDGES...IN
PLACES LIKE PITTSBURGH...WHEELING AND BEAVER FALLS. A STRONG UPPER
LEVEL LOW PRESSURE SYSTEM WILL PROVIDE THE INSTABILITY NECESSARY FOR
THE POSSIBILITY OF SEVERE THUNDERSTORMS THIS AFTERNOON.

HEAVY RAIN IS ALSO A POSSIBILITY.  THE HEAVY RAIN THREAT WILL BE
OVER WESTERN PENNSYLVANIA TONIGHT AS AN UPPER LEVEL LOW PRESSURE
SYSTEM DRAWS IN MOISTURE FROM A STORM SYSTEM MOVING UP THE ATLANTIC
COAST.

HEAVY RAIN THAT FALLS TONIGHT WILL AVERAGE AROUND ONE INCH BY
SATURDAY MORNING.  WHILE THIS AMOUNT OVER A 6 TO 12 HOUR PERIOD WILL
NOT CAUSE ANY SIGNIFICANT FLOODING...IF THE RAIN WERE TO FALL IN A
SHORTER TIME FRAME...IT MAY CAUSE MINOR FLOODING OF TYPICAL LOW
SPOTS.

SKYWARN ACTIVATION MAY BE NEEDED LATER TODAY. STAY TUNED TO NOAA
WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER DETAILS OR UPDATES.