Flooding in New York, April 2 to 6, 2005

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BUFFALO NY
550 PM EST SAT APR 2 2005

.UPDATE...

HAVE ISSUED A GENERAL FLOOD WARNING FOR THE EASTERN PORTION OF OUR
CWA UNTIL 11 PM TONIGHT. THIS INCLUDES WAYNE...NORTHERN CAYUGA...
ONTARIO...OSWEGO...JEFFERSON AND LEWIS.

AS MENTIONED IN PRIOR UPDATE...RAINFALL OF ONE TO ONE AND A HALF
/1.0-1.5/ INCHES OF RAIN IN THIS PARTICULAR AREA WILL BE AGGREVATED
BY ANOTHER HALF TO ONE /0.50-1.00/ INCH OF RAIN THROUGH 03Z.
REGIONAL DOPPLERS AND IR IMAGERY SHOW THAT MORE MODERATE TO HEAVY
RAIN (AND RICH 700MB MOISTURE) WILL MOVE NORTH TO NORTHWEST OUT OF
EASTERN PENNSYLVANIA DURING THE NEXT FEW HOURS ACROSS THE WARNED
AREA.

MEANWHILE...

TO THE WEST...REPORTS OF 5-7 INCHES OF HEAVY WET SNOW HAS BEEN
REPORTED OVER THE IAG FRONTIER FOR SITES LIKE GRIMSBY AND THOROLD.
HIGHEST SNOWFALL REPORTED ON THIS SIDE OF THE INTERNATIONAL BORDER
ARE AROUND 2 INCHES IN IAG COUNTY AND GRAND ISLAND...WITH LESSER
AMOUNTS FURTHER EAST.

RSH
&&

.SHORT TERM (TONIGHT THROUGH MONDAY)...

DEEPENING SFC LOW OVER VIRGINIA CONTINUES TO BRING A WIDE VARIETY OF
WEATHER TO THE CWA. ACROSS THE FAR WEST PRECIPITATION CONTINUES TO
FALL AS A MIX OF RAIN AND WET SNOW WHILE JUST ON THE OTHER SIDE OF
THE GENESEE VALLEY RAIN...OCCASIONALLY HEAVY...IS MOVING NORTH
ACROSS THE FINGER LAKES/ERN LAKE ONTARIO REGION. EXPECT THESE
CONDITIONS TO CONTINUE THROUGH THE EARLY OVERNIGHT. AS THE LOW
BEGINS TO FILL AND MOVE UP ACROSS PA AFT 06Z COLDER AIR WILL BEGIN
WRAPPING IN BEHIND THE LOW. HPC GRAPHIC FOR DAY 1 SHOWING 8-10
ACROSS CHAUT/CATT COUNTIES WITH 4-6 OVER THE REST OF THE NIAGARA
FRONTIER. GIVEN THE WET/RELATIVELY MILD GROUND BELIEVE THESE AMOUNTS
MAY BE A BIT OVERDONE. HAVE DECIDED TO TRIM THE AMOUNTS BACK ABOUT
25-30%. CHAUT/CATT COUNTIES A TOUGH CALL ON WINTER STORM WARNINGS,
BUT FOR NOW WILL BE ISSUING A WINTER WX ADV FOR THE 8 WRN COUNTIES.
LATER SHIFTS WILL HAVE TO MONITOR THE SITUATION CLOSELY FOR POSSIBLE
UPGRADE.

ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE CWA, PRECIPATION WILL
REMAIN RAIN THROUGH TONIGHT...SLOWLY CHANGING OVER TO A MIX SUNDAY
AFTERNOON AND NIGHT. FLOOD WATCH WILL BE CONTINUED ACROSS THE
REGION...SEE HYDRO DISCUSSION BELOW.

THE LOW GRADUALLY LIFTS NORTHEAST DOWN THE ST.LAWRENCE VALLEY WITH
WRAP AROUND PRECIP WINDING DOWN SUNDAY NIGHT AND EARLY MONDAY AS
SURFACE RIDGE BUILDS IN.

&&

.LONG TERM (TUESDAY THROUGH SATURDAY)...

CLOSED LOW OVER THE LOWER SAINT LAWRENCE RIVER WILL SLOWLY FILL AND
FINALLY GET PUSHED OUT TO SEA AS A SURFACE HIGH AND UPPER RIDGE
BUILD OVER THE GREAT LAKES AND MID ATLANTIC STATES ON TUESDAY AND
EARLY WEDNESDAY. UPPER RIDGE ACROSS THE REGION ON WEDNESDAY WILL
WARM TEMPS INTO THE 60S FOR MUCH OF THE FORECAST AREA. SOUTHERLY
WINDS WILL ENHANCE TEMPS AS WELL WITH DOWNSLOPING OVER THE WEST. THE
RIDGE SHIFTS TO THE EAST OF THE AREA WED NIGHT AS PACIFIC CUTOFF
TRACKS ACROSS THE SOUTHERN PLAINS AND A SPEED MAX DIVES SOUTHWARD
OVER THE PRAIRIE PROVINCES. THE NORTHERN LOW DEEPENS SHARPLY AND
PHASES WITH THE SOUTHERN LOW...ABSORBING IT INTO THE DEEPENING
TROUGH IN THE PROCESS. A SLOW MOVING COLD FRONT...WITH A SERIES OF
SURFACE WAVES ATTACHED...MOVES ACROSS THE STATE ON THURSDAY AND
EARLY FRIDAY...STALLING ACROSS THE STATE ON FRIDAY. THE UPPER CUTOFF
LOW SAGS SOUTH ACROSS THE CENTRAL GREAT LAKES AS THE TROUGH BECOMES
NEGATIVELY TILTED. THIS HOLDS A STEADY STREAM OF PRECIP ACROSS NEW
YORK STATE FROM MID THURSDAY THROUGH SATURDAY. HYDRO ISSUES WILL
AGAIN BECOME A CONCERN.

.AVIATION...

IFR TO LIFR WILL PERSIST ACROSS THE ENTIRE AREA IN RAIN AND SNOW
TONIGHT THROUGH SUNDAY.

&&

.HYDRO...

SEE ABOVE IN UPDATE.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FLOOD WARNING THROUGH 11 PM EST NYZ004>008-014.
     FLOOD WATCH THROUGH SUNDAY NYZ001>008-010>014-019>021-085.
     WINTER STORM WEATHER ADVISORY LATE TONIGHT AND SUNDAY
        NYZ001-002-010>012-019>021-085
.MARINE...NONE.

&&

SHORT TERM...JML
LONG TERM/AVIATION/MARINE...WCH
HYDRO...SFM

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE BUFFALO NY
443 AM EST SAT APR 2 2005

NYZ001>008-010>014-019>021-085-030900-
ALLEGANY-CATTARAUGUS-CHAUTAUQUA-GENESEE-JEFFERSON-LEWIS-LIVINGSTON-
MONROE-NIAGARA-NORTHERN CAYUGA-NORTHERN ERIE-ONTARIO-ORLEANS-OSWEGO-
SOUTHERN ERIE-WAYNE-WYOMING-
443 AM EST SAT APR 2 2005

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

.DAY ONE...

LOW PRESSURE DEEPENING OVER WEST VIRGINIA THIS MORNING WILL MOVE
NORTHEAST TO EASTERN PENNSYLVANIA BY THIS EVENING. THIS SYSTEM WILL
PRODUCE A WIDESPREAD HEAVY RAINFALL ACROSS THE AREA TODAY...WITH AS
MUCH AS 1 TO 2 INCHES OF RAINFALL POSSIBLE BY THIS EVENING. SUCH
RAINFALL AMOUNTS COULD BE ENOUGH TO CAUSE SMALL STREAM AND POOR
DRAINAGE FLOODING. SIGNIFICANT RISES ARE ALSO EXPECTED ON
LARGER GAGED CREEKS AND RIVERS...THOUGH MOST SHOULD REMAIN WITHIN
THEIR BANKS TODAY.

.DAYS TWO THROUGH SEVEN...

THE LOW IS EXPECTED TO MOVE FURTHER NORTHEAST INTO EASTERN NEW YORK
TONIGHT AND SUNDAY...THEN ON TO THE NEW ENGLAND STATES SUNDAY NIGHT.
ADDITIONAL RAINFALL AMOUNTS OF ANOTHER HALF INCH OR MORE ARE EXPECTED
TONIGHT AND MONDAY FOR AREAS EAST OF THE GENESEE VALLEY...AND THIS
COULD BE ENOUGH TO EVENTUALLY RESULT IN MINOR FLOODING ON THE LARGER
CREEKS AND RIVERS. FURTHER TO THE WEST...COLDER AIR WRAPPING AROUND
THE BACKSIDE OF THE LOW LATER TONIGHT AND SUNDAY WILL CAUSE THE RAIN
TO GRADUALLY CHANGE OVER TO ALL SNOW. SIGNIFICANT ACCUMULATIONS ARE
POSSIBLE ACROSS CHAUTAUQUA COUNTY BY LATE SUNDAY...WITH LIGHTER
SLUSHY ACCUMULATIONS OF 1 TO 3 INCHES LIKELY ELSEWHERE ACROSS THE
NIAGARA FRONTIER AND WESTERN SOUTHERN TIER.

LIGHT MIXED RAIN AND SNOW IS THEN EXPECTED TO SLOWLY DIMINISH ACROSS
THE AREA FROM SOUTHWEST TO NORTHEAST SUNDAY NIGHT AND MONDAY
MORNING...BEFORE THE STORM SYSTEM FINALLY PULLS TO THE NORTHEAST OF
THE AREA MONDAY AFTERNOON.

STAY TUNED TO LATER STATEMENTS ON THIS DEVELOPING SITUATION.

.SPOTTER INFORMATION STATEMENT...

SNOW SPOTTER REPORTS WILL BE HELPFUL AND ARE ENCOURAGED.

THIS PRODUCT...ALONG WITH OTHER WATCHES...WARNINGS...ADVISORIES...AND
STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN BUFFALO
CAN BE FOUND ON THE INTERNET AT THE FOLLOWING (LOWER CASE):
HTTP://WWW.ERH.NOAA.GOV/BUF/

JJR