Flash Flooding and Damaging Winds in New York, May 23 to 24, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
935 PM EDT SUN MAY 23 2004

TWO BATCHES OF RAIN WILL BE AFFECTING THE AREA OVERNIGHT.
FIRST...A SOLID LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED
ALONG THE WARM FRONT WHICH LIES SOUTH OF BUFFALO AND ROCHESTER AND
EXTENDS WEST TO THE SURFACE LOW OVER SOUTHERN WISCONSIN. ONE HOUR
RADAR PRECIPITATION ESTIMATES SHOW RAINFALL RATES UP TO 1.5 INCHES
PER HOUR OVER PARTS OF ORLEANS AND MONROE COUNTIES. AN URBAN AND
SMALL STREAM FLOOD ADVISORY HAS BEEN ISSUED FOR THIS AREA UNTIL 11
PM AS THUNDERSTORMS CONTINUE TO TRAIN EAST ALONG THE FRONT. THE
STEADY PCPN WILL CONTINUE TO DRIFT SLOWLY TO THE NORTH AS THE FRONT
LIFTS TO THE NORTH OVERNIGHT. RIGHT NOW IT LOOKS LIKE THE BULK OF
THE WARM FRONTAL PCPN WILL CLEAR MOST OF THE FA (EXCEPT FOR THE
NORTH COUNTRY) BY MIDNIGHT.

THE SECOND AREA OF SHOWERS AND THUNDERSTORMS OVER OHIO WESTERN OHIO
AND INDIANA IS DEVELOPING AHEAD OF THE MIDWEST COLD FRONT. THIS PCPN
WILL SPREAD EAST ACROSS THE FA BETWEEN 06Z AND 12Z.  BECAUSE OF THE
HIGH PROBABILITY OF MORE HEAVY RAIN...A FLOOD WATCH REMAINS IN
EFFECT TONIGHT.

THE COLD FRONT IS FORECAST TO PUSH EAST ACROSS THE AREA MONDAY
MORNING...BUT COLDER AIR ALOFT (ASSOCIATED WITH THE 500 MB TROUGH)
AND DRIER AIR IN THE MID LEVELS WILL LIKELY PRODUCE MORE
THUNDERSTORMS DURING THE AFTERNOON. SOME OF THE THUNDERSTORMS COULD
SEVERE LIMITS.

MONDAY NIGHT AND EARLY TUESDAY WILL LIKELY BE THE QUIETEST PERIOD AS
THE SHORT WAVE MOVES EAST. ANOTHER SHORT WAVE APPROACHES FROM THE
WEST TUESDAY AFTERNOON.  WILL HAVE TO KEEP WITH CHANCE POPS THROUGH
WEDNESDAY NIGHT.

EXTENDED LOOKS A LITTLE MORE PROMISING.  WONT MENTION ANY
PRECIPITATION FOR THURSDAY OR FRIDAY AT THIS TIME ALTHOUGH EVEN THEN
IT CANT BE RULED OUT.

AVIATION DISCUSSION...

CIGS EXPECTED TO BE QUITE VARIABLE ACROSS THE REGION AS SURFACE
FRONT WILL LINGER AND OSCILLATE NORTH AND SOUTH ACROSS THE AREA
DURING THE NEXT 24 TO 36 HOURS. CONDS GENERALLY EXPECTED TO REMAIN
MVFR THROUGHOUT THE PERIOD...BUT MAY BE LIFR UNDER LOW CLOUDS JUST
NORTH OF THE FRONT.  LIFR CONDITIONS ALSO POSSIBLE IN THUNDERSTORMS
AS A SERIES OF CONVECTIVE CLUSTERS MOVE FROM WEST TO EAST TODAY AND
TONIGHT. AREA REMAINS IN SLIGHT RISK AREA FOR SEVERE TSTMS AND
ISOLATED WIND GUSTS OF 30-40KTS ARE POSSIBLE WITH THE TSTMS LATE
THIS AFTERNOON/EARLY TONIGHT.

.BUF...FLOOD WATCH TONIGHT NYZ001>004-010>014-019>021-085.

PUBLIC...TJP/SAGE
AVIATION...WCH

HAZARDOUS WEATHER OUTLOOK CORRECTION
NATIONAL WEATHER SERVICE BUFFALO NY
450 AM EDT SUN MAY 23 2004

NYZ001>008-010-011-231041-
GENESEE-JEFFERSON-LEWIS-MONROE-NIAGARA-NORTHERN CAYUGA-NORTHERN ERIE-
ORLEANS-OSWEGO-WAYNE-
450 AM EDT SUN MAY 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND NORTH CENTRAL NEW
YORK.

.DAY ONE...

THERE IS A SLIGHT RISK OF SEVERE WEATHER TODAY AND TONIGHT.
THE GREATEST THREAT IS DAMAGING WINDS BUT LARGE HAIL IS ALSO
POSSIBLE. HEAVY RAIN IN THE THUNDERSTORMS COULD CAUSE ROAD AND POOR
DRAINAGE FLOODING.

.DAYS TWO THROUGH SEVEN...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

.SPOTTER ACTIVATION MAY BE REQUIRED.

NYZ012>014-019>021-085-231046-
ALLEGANY-CATTARAUGUS-CHAUTAUQUA-LIVINGSTON-ONTARIO-SOUTHERN ERIE-
WYOMING-
450 AM EDT SUN MAY 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND NORTH CENTRAL NEW
YORK.

.DAY ONE...

THERE IS A SLIGHT RISK OF SEVERE WEATHER TODAY AND TONIGHT. THE
GREATEST THREAT IS STRONG DAMAGING WINDS BUT LARGE HAIL IS ALSO
POSSIBLE.

A FLOOD WATCH IS IN EFFECT FOR TODAY AND TONIGHT. HEAVY RAINS THE
PAST COUPLE OF DAYS ALONG WITH THE THREAT OF MORE HEAVY RAIN THROUGH
TONIGHT COULD CAUSE ROAD AND POOR DRAINAGE FLOODING.

.DAYS TWO THROUGH SEVEN...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

.SPOTTER ACTIVATION MAY BE REQUIRED.

JJP