000
FGUS71 KBUF 261716
ESFBUF
NYZ001>008-010>014-019>021-085-031200-

WINTER / SPRING FLOOD OUTLOOK...UPDATE/FINAL
NATIONAL WEATHER SERVICE BUFFALO NY
130 PM EST THU MAR 26 2009

...WINTER/SPRING FLOOD OUTLOOK NOW IS SLIGHTLY BELOW NORMAL ACROSS 
ALL OF WESTERN NEW YORK AND THE BLACK AND OSWEGO RIVER BASIN EAST OF 
LAKE ONTARIO...

...THIS IS THE EIGHTH AND FINAL WINTER /SPRING FLOOD POTENTIAL 
OUTLOOK OF THE 2008-09 SEASON. IT HAS BEEN ISSUED EVERY TWO WEEKS TO 
SUMMARIZE BASIN HYDROMETEOROLOGICAL CONDITIONS AND TO ASSESS THE 
POTENTIAL FOR WINTER/SPRING FLOODING. THE OUTLOOKS ARE BASED ON 
CURRENT AND FORECAST HYDROMETEOROLOGICAL CONDITIONS INCLUDING SNOW 
COVER AND SNOW WATER EQUIVALENT...SOIL MOISTURE CONDITIONS...CREEK 
AND RIVER LEVELS AND THE AMOUNT OF ICE COVER ON THEM...ALONG WITH 
EXPECTED PRECIPITATION OVER THE NEXT 1 TO 2 WEEKS.

THE SPRING FLOOD POTENTIAL CONTINUES TO BE SLIGHTLY BELOW NORMAL 
OVER ALL OF WESTERN NEW YORK WHICH INCLUDES THE ALLEGHENY AND 
GENESEE RIVER BASINS AS WELL AS THE BUFFALO AREA CREEK BASINS...AND 
WAS NOW ALSO SLIGHTLY BELOW NORMAL ACROSS THE EASTERN LAKE ONTARIO 
REGION WHICH INCLUDES THE BLACK AND SALMON RIVER BASINS IN NORTH 
CENTRAL NEW YORK. 

THE HYDROLOGICAL WINTER OF 2008-09 HAS BEEN EXTRAORDINARILY ACTIVE. 
NEAR CONSTANT COLD AND ALMOST DAILY SNOWS FROM LATE NOVEMBER THROUGH 
EARLY FEBRUARY WERE INTERRUPTED BY TWO EXTREME THAWS WHICH CONTAINED 
PLENTY OF RAIN AND NEAR RECORD WARM TEMPERATURES. THESE THAWS 
RESULTED IN SIGNIFICANT FLOODING TO RIVERS AND CREEKS IN WESTERN NEW 
YORK DURING THE PERIODS DECEMBER 27-29 AND FEBRUARY 12-14. 

THERE WERE SILVER LININGS TO THESE THAWS HOWEVER. NEARLY ALL OF THE 
SNOW WAS CLEARED FROM THE GROUND ACROSS LOWER ELEVATIONS OF WESTERN 
NEW YORK IN BOTH CASES...AND THERE WAS A SUBSTANTIAL REDUCTION OF 
THE SNOWPACK AND WATER EQUIVALENTS EVEN AT HIGHER ELEVATIONS. THIS 
NEVER ALLOWED THE WINTERLONG SNOWPACK TO BUILD UP TO ANY 
APPRECIABLE EXTENT. IN FACT...THE GROUND HAS BEEN LARGELY BARE 
ACROSS THE WESTERN AREAS SINCE MID FEBRUARY THAW. 

AN EXCEPTION TO THE FLOODING HAS BEEN OUR EASTERN LAKE ONTARIO 
REGION. SNOWPACK AND ASSOCIATED WATER EQUIVALENTS BUILT UP TO NORMAL 
LEVELS BY EARLY FEBRUARY...BUT LITTLE HAS FALLEN SINCE. THE TWO MOST 
RECENT THAWS (MID FEBRUARY AND THIS PAST WEEK) WERE ACCOMPANIED BY 
APPRECIABLE RAINS AND DID RESULT IN MUCH SETTLING AND SOME MELTING 
OF THE SNOWPACK...BUT THE THAW WAS NOT AS EXTENDED OR INTENSE AS 
FURTHER WEST...SO COLDER WEATHER RETURNED BEFORE ANY FLOODING COULD 
OCCUR. RIVERS DID RISE TO BANKFUL THOUGH...AND ICE WAS PRETTY MUCH 
BEEN FLUSHED OUT OF THE WATERWAYS.

MORE RECENTLY...FOR THE THIRD TIME THIS WINTER SEASON... 
UNPRECEDENTED FOR MANY YEARS...WESTERN NEW YORK EXPERIENCED 
WIDESPREAD RIVER AND CREEK FLOODING DURING THE SECOND WEEK OF MARCH. 
THIS RESULTED FROM THREE SEPARATE STORMS SYSTEMS WHICH DROPPED A 
TOTAL OF TWO TO FOUR INCHES OF RAIN IN A 4 DAY PERIOD FROM MARCH 
7-11 THROUGHOUT THE AREA. THERE WAS LITTLE OR SNOW LEFT TO MELT AND 
ADD TO THE RUNOFF...BUT THESE RAINS FELL ON FROZEN AND/OR SATURATED 
GROUND AND WERE NEARLY TOTAL RUNOFF. THE RAINS WERE NOT AS HEAVY 
OVER OUR EASTERN LAKE ONTARIO REGION...AND EXISTING SNOWPACK 
ABSORBED SOME OF IT...SO NO FLOODING WAS REPORTED IN THAT AREA.

WITH THE END OF THE MOST RECENT FLOODING...THE AREA HAS ENTERED INTO 
A RATHER MILD AND DRY PATTERN...INTERRUPTED BY SOME LOCAL RAINS ON 
MARCH 18...AND THIS HAS AIDED IN DRYING OUT THE TOPSOILS OVER THE 
WEST...AND CONTINUING AN ORDERLY SETTLING AND RUNOFF OF THE SNOWPACK 
EAST OF LAKE ONTARIO. IN FACT...AS OF THE MORNING OF THE 26TH...THE 
ONLY AREA WITH SNOW ON THE GROUND WAS AT HIGHER ELEVATIONS OF THE 
TUG HILL WHERE AS MUCH AS 1 TO 2 FEET REMAINED...WITH A WATER 
EQUIVALENT OF UP TO 4 TO 8 INCHES. ELSEWHERE THE GROUND WAS BARE. 
WESTERN AREAS ALSO HAD NO FROST LEFT IN THE GROUND OR ICE IN THE 
CREEKS. THESE CONDITIONS ARE SOMEWHAT MORE FAVORABLE (FOR A REDUCED 
FLOOD THREAT) THAN USUAL AS WE BEGIN THE SPRING SEASON.

AS FOR THE FUTURE...AFTER A VERY DRY WEEK...IT APPEARS THE REGION IS 
IN FOR MORE ACTIVE WEATHER PATTERN AS LOW PRESSURE AREAS LIFT UP TO 
OUR NORTH AND WEST AT ROUGHLY THREE DAY INTERVALS FOR THE NEXT WEEK 
TO TEN DAYS. THIS WOULD ALLOW FOR A FEW RAINY PERIODS...BUT THE 
EVENTS SHOULD BE RELATIVELY BRIEF AND EXCESSIVE AMOUNTS ARE NOT 
EXPECTED. THIS SHOULD ALLOW FOR A CONTINUED ORDERLY SNOWMELT OFF THE 
TUG HILL WITH ONLY MINOR IMPLICATIONS FOR THE BLACK RIVER...WITH NO 
MORE THAN THE USUAL SPRING PROBLEMS AT PLACES SUCH AS EAST 
MARTINSBURG ROAD. FURTHER WEST...THE RAINS WILL ACTUALLY BE 
BENEFICIAL AS SURFACE SOILS HAVE REALLY DRIED OUT. 

SINCE OUR MAIN THREATS FOR SPRING FLOODING ARE ICE JAMS AND 
SNOWMELT...AND SINCE WE WILL HAVE NONE LEFT IN THE WEST...WE WOULD 
HAVE TO CONSIDER OUR CHANCES FOR SPRING FLOODING NOW SOMEWHAT BELOW 
NORMAL OVER ALL OF OUR REGION. OF COURSE...HEAVY RAINFALL CAN ALWAYS 
CAUSE FLOODING ANYTIME IN EARLY SPRING...SO WE WILL BE ON THE ALERT 
FOR SUCH AN EVENT.

SUMMARIZING...THE SPRING FLOOD OUTLOOK CAN BE CONSIDERED SLIGHTLY 
BELOW NORMAL ACROSS ALL OF WESTERN AND NORTH CENTRAL NEW YORK AT 
THIS TIME. 


THE FOLLOWING IS A SUMMARY OF CONDITIONS AND OUTLOOK BY BASIN AS OF 
FRIDAY MORNING MARCH 26:

...BUFFALO AREA CREEKS / LAKE ERIE BASIN...
.SNOW COVER.........NONE.
.WATER EQUIVALENT...NONE.
.CREEK FLOWS...NEAR NORMAL.
.CREEK ICE.....NONE. 
.GROUND FROST..NONE.
.GROUND STATE..NEAR NORMAL...DRY TOPSOIL.
.LONG TERM OUTLOOK...SLIGHTLY BELOW NORMAL.

...GENESEE RIVER BASIN / FINGER LAKES / ROCHESTER AREA...
.SNOW COVER..........NONE.
.WATER EQUIVALENT... NONE.
.RIVER/CREEK FLOWS...NEAR NORMAL.
.RIVER/CREEK ICE.....NONE.
.GROUND FROST........NONE.
.GROUND STATE........NEAR NORMAL...DRY TOPSOIL.
.LONG TERM OUTLOOK...SLIGHTLY BELOW NORMAL.

...ALLEGHENY RIVER BASIN...
.SNOW COVER......... NONE.
.WATER EQUIVALENT... NONE.
.RIVER/CREEK FLOWS...NEAR NORMAL.
.RIVER CREEK ICE.....NONE.
.GROUND FROST........NONE.
.GROUND STATE........NEAR NORMAL. DRY TOPSOIL.
.LONG TERM OUTLOOK...SLIGHTLY BELOW NORMAL.

...BLACK AND SALMON RIVER BASINS / TUG HILL...
.SNOW COVER..........NONE VALLEY, 4 TO 18 INCHES TUG HILL.
.WATER EQUIVALENT... NONE VALLEY, 1 TO 6 INCHES TUG.
.RIVER/CREEK FLOWS...NEAR NORMAL.
.RIVER/CREEK ICE.....NONE.
.GROUND FROST........NONE.
.GROUND STATE........NEAR NORMAL.
.LONG TERM OUTLOOK...SLIGHTLY BELOW NORMAL.


YOU MAY ACCESS THIS AND OTHER HYDROLOGICALLY RELATED INFORMATION ON 
OUR WEBSITE AT WWW.WEATHER.GOV/BUFFALO UNDER THE "TOP NEWS OF THE 
DAY" SCROLL ON THE TITLE PAGE OR UNDER "HYDROLOGY". ALSO UNDER 
"RIVER AND LAKES AHPS". YOU MAY ALSO LINK TO THE RIVER FORECAST 
CENTERS' WEBSITES FROM THERE FOR ADDITIONAL REGIONAL INFORMATION.

FINALLY...WE WOULD LIKE TO THANK MANY OF OUR 300 PLUS SNOWSPOTTERS 
AND COOPERATIVE OBSERVERS AS WELL AS VARIOUS PUBLIC AGENCIES FOR 
PROVIDING TIMELY SNOW DEPTH AND WATER EQUIVALENT INFORMATION ON A 
WEEKLY BASIS. THIS INFORMATION IS COMBINED WITH THE COMPREHENSIVE 
GUIDANCE RECEIVED FROM THE NORTHEAST AND OHIO RIVER FORECAST CENTERS 
AS WELL AS THE NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER 
(NOHRSC) IN DEVELOPING THESE STATEMENTS. 

PLEASE REFER TO THE LATEST FLOOD WARNINGS...WATCHES...AND STATEMENTS 
FOR ADDITIONAL INFORMATION.

DUE TO THE FAVORABLE CONDITIONS...THIS WILL BE THE FINAL 
WINTER/SPRING FLOOD OUTLOOK ISSUED BY NWS BUFFALO FOR THE 2008-09 
SEASON. THESE PRODUCTS WILL RESUME IN JANUARY 2010. 


STEVE MCLAUGHLIN
WFO BUFFALO


$$