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FGUS71 KBUF 051131
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NYZ001>008-010>014-019>021-085-191200-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK 
NATIONAL WEATHER SERVICE BUFFALO NY
633 AM EST FRI FEB 5 2010

...WINTER/SPRING FLOOD OUTLOOK NEAR TO SLIGHTLY BELOW NORMAL ACROSS 
THE GENESEE AND BUFFALO AREA BASINS AS WELL AS THE ALLEGHENY AND 
BLACK RIVER BASINS...

...THIS IS THE THIRD WINTER / SPRING FLOOD POTENTIAL OUTLOOK OF THE 
2009-2010 SEASON. IT WILL BE ISSUED EVERY TWO WEEKS INTO THE EARLY 
SPRING 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 LONG TERM WINTER/SPRING FLOOD POTENTIAL CAN BE CONSIDERED NEAR 
NORMAL OVER ALL OF WESTERN AND NORTH CENTRAL NEW YORK AT THIS TIME. 
THIS INCLUDES THE ALLEGHENY AND GENESEE BASINS IN WESTERN NEW 
YORK...THE BUFFALO AREA BASINS...AND THE BLACK AND SALMON RIVER 
BASINS IN NORTH CENTRAL NEW YORK.

HOWEVER...THE SHORT TERM FLOOD OUTLOOK (2 WEEKS) CAN BE CONSIDERED 
BELOW NORMAL WITH LITTLE OR NO THREAT OF THAWING OR APPRECIABLE 
RAIN IN STORE.

OUR REGION EXPERIENCED A RELATIVELY MOIST WARM WEATHER SEASON DURING 
THE SUMMER OF 2009. RAINFALL...ALTHOUGH NOT EXCESSIVE...WAS FREQUENT 
ENOUGH TO PRECLUDE ANY EXTENDED WATER SHORTAGES OR DROUGHT 
CONDITIONS. THE AUTUMN FEATURED A COOL WET OCTOBER BUT AN UNUSUALLY 
MILD DRY AND SNOWLESS NOVEMBER. DECEMBER BROUGHT SOME CHANGEABLE 
CONDITIONS WITH SEVERAL LAKE EFFECT EVENTS BUT SYNOPTIC SNOWS STAYED 
TO OUR EAST. A WARMUP OVER CHRISTMAS BROUGHT RAIN WHICH CLEARED MOST 
OF THE SNOW FROM THE GROUND BUT A VERY WINTRY PATTERN SET UP DURING 
THE FIRST TEN DAYS OF JANUARY WITH NEAR CONSTANT SMALL DAILY 
SNOWFALLS AND SUBFREEZING TEMPERATURES. THIS ALLOWED PLENTY OF ICE 
TO FORM ON AREA CREEKS AND PONDS AND ESTABLISHED A DECENT...BUT NOT 
EXCESSIVE SNOWPACK. 

A PATTERN CHANGE THEN TOOK PLACE FOR THE NEXT TWO WEEKS AS BULK AS 
THE UPPER LEVEL FLOW TURNED "ZONAL" WITH OUR REGION REMAINING IN A 
LULL BETWEEN ACTIVE JET STREAMS. THIS ALLOWED GENERALLY MILD AND 
QUIET WEATHER TO PREVAIL ACROSS THE AREA FOR THE MIDDLE AND LATTER 
PART OF THE MONTH. IT WAS DRY AND RELATIVELY MILD WITH TEMPERATURES 
AVERAGING 5 TO 10 DEGREES ABOVE MIDWINTER NORMALS...WITH A SLOW 
GRADUAL THAW. SNOW COVER DIMINISHED AT A SLOW PACE...OPTIMUM 
HYDROLOGICALLY...AND RIVER AND CREEK ICE LOOSENED AS WELL. 

CONDITIONS HAVE AGAIN CHANGED...RATHER DRAMATICALLY...SINCE THE LAST 
SPRING FLOOD OUTLOOK WAS ISSUED ON JANUARY 22. A MAJOR RAINSTORM ON 
24-25TH BROUGHT ONE TO TWO INCHES OF RAIN AND COMBINED WITH 50 
DEGREE TEMPERATURES TO MELT NEARLY ALL OF THE REMAINING SNOWPACK 
ACROSS ALL AREAS EXCEPT THE TUG HILL. THIS RESULTED IN SOME MINOR 
FLOODING WITH SEVERAL OF OUR RIVERS AND CREEKS RISING TO FLOOD 
STAGE. THE SILVER LINING TO THIS EVENT WAS THE FACT THAT MOST AREAS 
FINISHED JANUARY WITH NEARLY BARE GROUND AND ICE FREE WATERWAYS. 
ANOTHER PATTERN CHANGE HAS BROUGHT COLDER WEATHER AND SUBFREEZING 
TEMPERATURES ONCE AGAIN WITH ONLY SOME MINOR DAILY LAKE EFFECT SNOWS 
REESTABLISHING A MODEST SNOWCOVER...BUT IT WAS MUCH THINNER THAN 
USUAL FOR EARLY FEBRUARY. ICE WAS BEGINNING TO BUILD AGAIN ON AREA 
WATERWAYS.  

AS OF FRIDAY FEBRUARY 5...SNOW COVER...SNOW WATER EQUIVALENTS...AND 
RIVER AND CREEK ICE WERE LESS THAN EARLY FEBRUARY NORMS. DEPTHS 
AVERAGED 3 TO 6 INCHES IN THE BUFFALO CREEK HEADWATERS...AS WELL AS 
ACROSS THE ALLEGHENY AND UPPER GENESEE BASINS...AND ONE TO TWO 
FEET IN THE UPPER BLACK RIVER BASIN EAST OF LAKE ONTARIO. WATER 
EQUIVALENTS AVERAGED 1 TO 2 INCHES OVER HIGHER ELEVATIONS OF THE 
WEST...AND UP TO FIVE INCHES ON THE TUG HILL. THESE VALUES WERE ALL 
BELOW NORMAL.

RIVER AND CREEK FLOWS WERE AVERAGE AND THERE WAS SOME ICE BEGINNING 
TO FORM AGAIN ON THE BUFFALO AREA CREEKS...ESPECIALLY CAZENOVIA AND 
BUFFALO...BUT THICKNESS WAS ALSO LESS THAN USUAL. 

AS FOR THE NEAR FUTURE...ALL SIGNS POINT TO A CONTINUATION OF BELOW 
NORMAL TEMPERATURES AND PRECIPITATION...AT LEAST THROUGH ABOUT THE 
13TH...THEN SOME MODERATION LOOKS LIKELY AS THE UPPER FLOW TURNS 
MORE ZONAL. ANY PRECIPITATION DURING THIS PERIOD WOULD BE IN THE 
FORM OF SNOW BUT NO MAJOR STORMS ARE INDICATED. RIVER/CREEK ICE 
SHOULD CONTINUE TO BUILD AND THICKEN DURING THIS PERIOD...BUT 
SNOWPACK WILL ONLY INCREASE SLIGHTLY. WITH NO MAJOR THAW OR HEAVY 
RAIN EXPECTED...THE SHORT TERM (2 WEEK) FLOOD THREAT WOULD HAVE TO 
BE CONSIDERED "BELOW NORMAL" ACROSS OUR ENTIRE REGION. 

LONGER TERM...THE POTENTIAL IS HIGHLY DEPENDENT ON WEATHER PATTERNS 
LATER IN THE WINTER...WHICH ARE UNFORESEEN. SINCE OUR MAIN THREATS 
FOR SPRING FLOODING ARE ICE JAMS AND SNOWMELT...AND SINCE WE SHOULD 
HAVE LESSER AMOUNTS OF SNOW ON THE GROUND THAN USUAL BUT PERHAPS 
EVENTUALLY A GOOD DEAL OF ICE IN THE CREEKS FROM THE CONTINUED COLD 
WEATHER...WE WOULD HAVE TO CONSIDER OUR CHANCES FOR LONG TERM SPRING 
FLOODING "NEAR NORMAL" AT WORST AT THIS STAGE. OF COURSE... HEAVY 
RAINFALL CAN ALWAYS CAUSE FLOODING IN LATE WINTER OR EARLY 
SPRING...SO WE WILL BE ON THE ALERT FOR SUCH AN EVENT.

SUMMARIZING...THE LONG TERM WINTER/SPRING FLOOD OUTLOOK CAN BE 
CONSIDERED NEAR NORMAL FOR ALL OF WESTERN AND NORTH CENTRAL NEW YORK 
AT THIS TIME...WHILE THE SHORT TERM FLOOD OUTLOOK IS BELOW NORMAL.


THE FOLLOWING IS A SUMMARY OF CONDITIONS AND OUTLOOK BY BASIN AS OF 
THE MORNING OF FRIDAY FEBRUARY 5TH:

...BUFFALO AREA CREEKS / LAKE ERIE BASIN...
.SNOW COVER...2 TO 4 INCHES (METRO/NORTH)...3 TO 6 INCHES 
(HEADWATERS).
.WATER EQUIVALENT...1 TO 2 INCHES IN HEADWATERS. LESS THAN INCH      
 METRO/NORTH.
.CREEK FLOWS...NORMAL.
.CREEK ICE.....SOME...MAINLY CAZENOVIA AND BUFFALO CREEKS. 
.GROUND FROST..6 TO 12 INCHES.
.GROUND STATE..SATURATED.
.SHORT TERM OUTLOOK (1-2 WEEKS)...BELOW NORMAL.
.LONG TERM OUTLOOK (2-8 WEEKS)...NEAR NORMAL.

...GENESEE RIVER BASIN / FINGER LAKES / ROCHESTER AREA...
.SNOW COVER...2 TO 6 INCHES. 
.WATER EQUIVALENT... 1 INCH MAX.
.RIVER/CREEK FLOWS...NORMAL.
.RIVER/CREEK ICE.....LIMITED.
.GROUND FROST........6 TO 12 INCHES.
.GROUND STATE........SATURATED.
.SHORT TERM OUTLOOK  (1-2 WEEKS)...BELOW NORMAL.
.LONG TERM OUTLOOK (2-8 WEEKS)...NEAR NORMAL.

...ALLEGHENY RIVER BASIN...
.SNOW COVER......... 2 TO 8 INCHES (GREATEST NORTHWEST).
.WATER EQUIVALENT... 1 TO 2 INCHES.
.RIVER/CREEK FLOWS...NORMAL.
.RIVER CREEK ICE.....LIMITED.
.GROUND FROST........12 INCHES.
.GROUND STATE........SATURATED.
.SHORT TERM OUTLOOK (1-2 WEEKS)...BELOW NORMAL.
.LONG TERM OUTLOOK  (2-8 WEEKS)..NEAR NORMAL.

...BLACK AND SALMON RIVER BASINS / TUG HILL...
.SNOW COVER..........6 TO 12 INCHES VALLEY, 12 TO 24 INCHES TUG HILL.
.WATER EQUIVALENT... 2-4 INCHES VALLEY TO 4-6 INCHES TUG.
.RIVER/CREEK FLOWS...NORMAL.
.RIVER/CREEK ICE.....SOME.
.GROUND FROST........1-2 FEET.
.GROUND STATE........SATURATED.
.SHORT TERM OUTLOOK (1-2 WEEKS)...BELOW NORMAL.
.LONG TERM OUTLOOK  (2-10 WEEKS)...NEAR 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, 
COCORAHS 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 AND NOHRSC IN DEVELOPING THESE STATEMENTS. 

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

THE NEXT REGULARLY SCHEDULED OUTLOOK WILL BE ISSUED ON FRIDAY 
FEBRUARY 19 2010.


STEVE MCLAUGHLIN
WFO BUFFALO


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