000
FGUS71 KBUF 181018
ESFBUF
NYC003-009-011-013-029-037-045-049-051-055-063-069-073-075-117-
121-021030-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE BUFFALO NY
618 AM EDT THU APR 18 2013

...BELOW NORMAL FLOOD RISK THROUGH THE END OF APRIL...

THIS IS THE EIGHTH WINTER / SPRING FLOOD POTENTIAL OUTLOOK OF THE
2013 SEASON. FLOOD OUTLOOKS WILL BE ISSUED EVERY TWO WEEKS INTO
EARLY SPRING TO SUMMARIZE BASIN HYDROMETEOROLOGICAL CONDITIONS AND
TO ASSESS THE POTENTIAL FOR FLOODING. THE OUTLOOKS ARE BASED ON
CURRENT AND FORECAST HYDROMETEOROLOGICAL CONDITIONS. THIS INCLUDES
SNOW COVER AND SNOW WATER EQUIVALENT...CREEK AND RIVER LEVELS AND
THE AMOUNT OF ICE COVER ON THEM...ALONG WITH THE EXPECTED
PRECIPITATION OVER THE NEXT TWO WEEKS.

...CURRENT CONDITIONS SUMMARY...

SIGNIFICANT RAINS LATE LAST WEEK BROUGHT FLOWS UP CONSIDERABLY...WITH
MOST RIVERS AND CREEKS NEAR OR ABOVE NORMAL. DESPITE THE RAIN AND
WARMER WEATHER...TEMPERATURES ONLY ROSE MARGINALLY ABOVE FREEZING IN THE
BLACK RIVER BASIN LAST WEEK...WHICH MUTED THE SNOW MELT. WARMER
AIR DID BUILD INTO THE ENTIRE REGION THE PAST COUPLE DAYS...WHICH
BROUGHT ADDITIONAL SNOW MELT.

LATEST MEASUREMENTS FROM THE TUG HILL WERE TAKEN A DAY OR TWO
AGO...WITH CURRENT SNOW PACKS LIKELY TO BE LESS THAN THESE
MEASUREMENTS. ACCOUNTING FOR THIS...EXPECT LINGERING SNOW PACK IS
PRETTY MUCH CONFINED TO THE TUG HILL AND HIGHER TERRAIN...WITH
WATER EQUIVALENT VALUES IN THE 2 TO 4 INCH RANGE. THIS IS ABOUT
NORMAL FOR THIS TIME OF YEAR.

THE FOLLOWING IS A SUMMARY OF CONDITIONS AND OUTLOOK BY BASIN AS
OF THURSDAY MORNING ON APRIL 18TH:

...BUFFALO AREA CREEKS / LAKE ERIE BASIN...
.SNOW COVER..........NONE.
.WATER EQUIVALENT....NONE.
.CREEK FLOWS.........ABOVE NORMAL.
.CREEK ICE...........NONE.
.GROUND FROST........NONE.
.GROUND STATE........SATURATED.

...GENESEE RIVER BASIN / FINGER LAKES / ROCHESTER AREA...
.SNOW COVER..........NONE.
.WATER EQUIVALENT....NONE.
.RIVER/CREEK FLOWS...ABOVE NORMAL.
.RIVER/CREEK ICE.....NONE.
.GROUND FROST........NONE.
.GROUND STATE........SATURATED.

...ALLEGHENY RIVER BASIN...
.SNOW COVER..........NONE.
.WATER EQUIVALENT....NONE.
.RIVER/CREEK FLOWS...NEAR NORMAL.
.RIVER CREEK ICE.....NONE.
.GROUND FROST........NONE.
.GROUND STATE........SATURATED.

...BLACK RIVER BASINS / TUG HILL...
.SNOW COVER..........NONE...EXCEPT UP TO A FOOT ON THE TUG HILL.
.WATER EQUIVALENT....NONE...EXCEPT 2 TO 4 INCHES ON THE TUG HILL.
.RIVER/CREEK FLOWS...ABOVE NORMAL.
.RIVER/CREEK ICE.....NONE.
.GROUND FROST........PATCHY.
.GROUND STATE........SATURATED.

...TEMPERATURE AND PRECIPITATION OUTLOOK...
UNSEASONABLY WARM TEMPERATURES TODAY WILL BE FOLLOWED BY THE
PASSAGE OF A SIGNIFICANT COLD FRONT ON FRIDAY. THIS WILL BRING
SHOWERS AND THUNDERSTORMS...WITH RAINFALL TOTALS LIKELY TO BE A
HALF INCH OR LESS. AFTER THIS COOL AND FAIR WEATHER WILL BUILD
INTO THE REGION...AND LAST INTO EARLY NEXT WEEK.

ANOTHER FRONTAL BOUNDARY IS FORECAST TO CROSS THE REGION AROUND
MID-WEEK. AT THIS TIME...THIS FRONT ALSO APPEARS TO BE FAIRLY
PROGRESSIVE. AS LONG AS THIS IS THE CASE...RAINFALL TOTALS WILL BE
ON THE LIGHT SIDE AS WELL.

AFTER THIS...A FAIRLY PERSISTENT UPPER LEVEL TROF IS LIKELY TO
BUILD ACROSS THE NORTHEAST. THIS PATTERN WOULD RESULT IN COOLER
THAN NORMAL TEMPERATURES IN THE REGION...AND FREQUENT BUT
GENERALLY LIGHT PRECIPITATION. THIS PATTERN IS UNLIKELY TO PRODUCE
HEAVY RAINFALL.

...FLOOD POTENTIAL OUTLOOK...

SNOWPACK BECOMES LESS OF AN ISSUE THIS TIME OF YEAR...ESPECIALLY
SINCE WHAT IS LEFT IS COVERING A SMALL PERCENTAGE OF THE BLACK
RIVER BASIN. OVERALL...THE FORECAST WEATHER PATTERN DOES NOT
APPEAR LIKELY TO RESULT IN FLOODING IN OUR REGION. THERE ARE TWO
FRONTS FORECAST TO MOVE ACROSS RATHER QUICKLY...WITH OTHERWISE NO
SIGNIFICANT SYSTEMS FOR THE NEXT WEEK. IN EACH CASE...RAINFALL
TOTALS ARE LIKELY TO ON THE LIGHT SIDE...WITH ENSEMBLE FORECASTS
SUGGESTING THERE IS A LOW PROBABLY FOR FLOODING.

AFTER THIS...THE WEATHER PATTERN IS UNLIKELY TO PRODUCE HEAVY
RAINFALL. MEANWHILE...WHAT IS LEFT OF THE SNOW PACK WILL LIKELY
CONTINUE TO MELT GRADUALLY. ALL THIS SUGGESTS THAT FLOOD POTENTIAL
FOR THIS PERIOD IS BELOW NORMAL. THIS OUTLOOK DEPENDS SIGNIFICANTLY
ON THE FORECAST...SO CHANGES IN THE FORECAST COULD INCREASE THE
FLOOD RISK.

...ADDITIONAL INFORMATION...

REAL TIME RIVER INFORMATION AND PROBABILISTIC FORECASTS FOR
SPECIFIC LOCATIONS ALONG RIVERS ACROSS WESTERN NEW YORK CAN BE
FOUND ON THE INTERNET AT WWW.WEATHER.GOV/BUF BY CLICKING ON THE
RIVERS AND LAKES AHPS LINK ON THE LEFT SIDE OF THE PAGE. SINCE
CONDITIONS CAN CHANGE PLEASE REFER TO THE LATEST FLOOD
WARNINGS...WATCHES...AND STATEMENTS FOR ADDITIONAL INFORMATION.

THE NEXT OUTLOOK MAY BE ISSUED BY ON THURSDAY MAY 2ND IF ANY SNOWPACK
REMAINS. BASED ON THE FORECAST...THIS PROBABLY WILL BE THE LAST
HYDROLOGIC OUTLOOK OF THE SEASON. THANKS TO ALL THE OBSERVERS AND
AGENCIES WHICH HAVE HELPED GATHER DATA IN SUPPORT OF THIS OUTLOOK.

$$

APFFEL