Flood Potential Outlook
Issued by NWS La Crosse, WI

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000
FGUS73 KARX 192212
ESFARX
IAC005-037-043-065-067-089-131-191-MNC039-045-055-099-109-157-169-
WIC001-011-019-023-043-053-057-063-081-103-119-121-123-051800-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
410 PM CST THU FEB 19 2015

     ...FIRST SPRING HYDROLOGIC SUMMARY AND OUTLOOK...

THE FOLLOWING INFORMATION IS THE FIRST OF TWO PLANNED HYDROLOGIC
OUTLOOKS PROVIDING SPRING SNOWMELT AND FLOOD POTENTIAL INFORMATION
AS WELL AS CLIMATOLOGICAL INFORMATION FOR THIS COMING SPRING. THIS
OUTLOOK CONTAINS INFORMATION WHICH WAS COLLECTED FROM A NUMBER OF
SOURCES...INCLUDING THE UNITED STATES GEOLOGICAL SURVEY /USGS/...
US ARMY CORPS OF ENGINEERS /USACE/...MIDWEST REGIONAL CLIMATE
CENTER /MRCC/...AND THE NATIONAL OPERATIONAL REMOTE SENSING CENTER
/NOHRSC/.

THE OUTLOOK THAT FOLLOWS BELOW IS A SUMMARY OF THE PAST AND PRESENT
BASIN CONDITIONS FOR PORTIONS OF SOUTHEAST MINNESOTA...NORTHEAST
IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST INTO CENTRAL WISCONSIN.

*** FLOOD POTENTIAL HIGHLIGHTS ***

THE FLOOD POTENTIAL FOR THIS SPRING LOOKS TO BE BELOW NORMAL. FOR
SOME AREAS...THE CHANCE EVEN APPEARS TO BE MUCH BELOW NORMAL.

THE WIDESPREAD LACK OF WINTER PRECIPITATION AND RESULTANT CURRENT
SNOWPACK CONDITIONS THAT ARE BELOW NORMAL OVER MUCH OF THE REGION IS
INDICATING A LOW LIKELIHOOD OF ANY SIGNIFICANT OR WIDESPREAD SPRING
FLOODING FROM SNOWMELT RUNOFF AT THIS TIME.

HOWEVER...ONE ITEM OF CONCERN IS THE AMOUNT AND THICKNESS OF ICE IN
AREA CREEKS AND RIVERS. THE PROLONGED AND DEEP COLD OF THE LAST
SEVERAL WEEKS HAS ALLOWED FOR WIDESPREAD FORMATION OF ICE. AS THIS
ICE BREAKS UP...ICE JAMS ARE A DEFINITE POSSIBILITY...ESPECIALLY IN
TYPICAL AREAS SUCH AS NEAR BRIDGES AND OTHER CONSTRICTIONS IN THE
RIVER...OR WHERE THE RIVER MAKES SHARP TURNS OR MEANDERS. LARGE
CHUNKS OF ICE MOVING DOWNSTREAM COULD GET HUNG UP IN THESE
AREAS...LEADING TO JAMS AND POTENTIAL FLOODING.

IT IS ALSO IMPORTANT TO REMEMBER THAT THERE ARE SEVERAL MORE WEEKS
OF WINTER REMAINING. IF THE TEMPERATURE AND PRECIPITATION PATTERNS
SHIFT OVER THE REMAINING WEEKS OF WINTER...CONDITIONS COULD CHANGE
AND ICE AND SNOWMELT MAY BECOME MORE IMPORTANT CONTRIBUTORS DURING
THE SPRING SEASON.


IN TABLE 1 BELOW...THE CURRENT /CS/ AND HISTORICAL /HS/ /OR NORMAL/
PROBABILITIES OF EXCEEDING MINOR...MODERATE...AND MAJOR FLOOD STAGES
ARE LISTED FOR THE VALID TIME PERIOD.

CS VALUES INDICATE THE PROBABILITY OF REACHING A FLOOD CATEGORY
BASED ON CURRENT CONDITIONS.

HS VALUES INDICATE THE PROBABILITY OF REACHING A FLOOD CATEGORY
BASED ON HISTORICAL OR NORMAL CONDITIONS.

WHEN THE VALUE OF CS IS GREATER THAN HS...THE PROBABILITY OF
EXCEEDING THAT LEVEL IS HIGHER THAN NORMAL. WHEN THE VALUE OF CS IS
LESS THAN HS...THE PROBABILITY OF EXCEEDING THAT LEVEL IS LOWER THAN
NORMAL.

...TABLE 1--PROBABILITIES FOR MINOR...MODERATE AND MAJOR FLOODING...
                    VALID  PERIOD: 2/23/2015 - 5/24/2015

                                       :    CURRENT AND HISTORICAL
                                       :     CHANCES OF EXCEEDING
                                       :       FLOOD CATEGORIES
                                       :      AS A PERCENTAGE (%)
                      CATEGORICAL      :
                   FLOOD STAGES (FT)   :   MINOR    MODERATE   MAJOR
LOCATION           MINOR   MOD   MAJOR :  CS   HS   CS   HS   CS   HS
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:BLACK RIVER
NEILLSVILLE         18.0   20.0   22.0 :  <5   <5   <5   <5   <5   <5
BLK RVR FLS         47.0   51.0   55.0 :  44   55   13   18   <5   <5
GALESVILLE          12.0   13.0   15.0 :  44   53   23   35   <5   <5
:CEDAR RIVER
LANSING             18.0   20.0   22.0 :  <5    6   <5   <5   <5   <5
AUSTIN              15.0   18.0   20.0 :  <5   10   <5    6   <5   <5
CHARLES CTY         12.0   15.0   18.0 :  10   21    6   10   <5    7
:TURTLE CREEK
AUSTIN              10.5   12.0   14.0 :  10   15   <5   <5   <5   <5
:KICKAPOO RIVER
LA FARGE            12.0   13.0   14.0 :  <5   <5   <5   <5   <5   <5
VIOLA               14.0   17.0   20.0 :  15   32   <5   <5   <5   <5
READSTOWN           11.0   14.0   17.0 :  16   36   <5   <5   <5   <5
SLDRS GROVE         13.0   16.0   19.0 :  12   21   <5   <5   <5   <5
GAYS MILLS          13.0   15.0   17.0 :  27   47   <5    6   <5   <5
STEUBEN             12.0   13.0   15.0 :  20   36   <5   10   <5   <5
:MISSISSIPPI RIVER
LAKE CITY           16.0   18.0   20.0 :   9   26    6    7   <5   <5
WABASHA             12.0   14.0   16.0 :  23   53    9   18   <5    7
ALMA                16.0   17.0   18.0 :  <5    7   <5   <5   <5   <5
DAM 5              660.0  662.0  665.0 :   9   26    7   10   <5    6
DAM 5A             656.0  659.0  661.0 :   9   26    6    7   <5   <5
WINONA              13.0   15.0   18.0 :  15   43    9   18    6    7
TREMPEALEAU        647.0  649.0  651.0 :  13   33    7   13   <5    6
LA CRESCENT        641.0  643.0  645.0 :  12   29    7   10   <5    6
LA CROSSE           12.0   13.0   15.5 :  13   36    9   18   <5    6
GENOA              631.0  634.0  636.0 :  15   46    7   10   <5    6
LANSING             17.0   19.0   20.0 :   7    9   <5    7   <5   <5
LYNXVILLE          625.0  628.0  631.0 :   9   21   <5    7   <5   <5
MCGREGOR            16.0   19.0   22.0 :  23   50   12   23   <5    7
GUTTENBERG          15.0   18.0   21.0 :  20   41    7   12   <5   <5
:ROOT RIVER
HOUSTON             15.0   17.0   18.0 :   9    9   <5   <5   <5   <5
:SOUTH BRANCH ROOT RIVER
LANESBORO           12.0   16.0   18.0 :   9   12   <5   <5   <5   <5
:TREMPEALEAU RIVER
DODGE                9.0   11.0   12.0 :  63   52    6   <5   <5   <5
:TURKEY RIVER
ELKADER             12.0   16.0   20.0 :  38   47   20   16    6   <5
GARBER              17.0   20.0   23.0 :  27   38   18   20   10    9
:UPPER IOWA RIVER
DECORAH             12.0   13.0   14.0 :  <5   <5   <5   <5   <5   <5
DORCHESTER          14.0   17.0   19.0 :  32   35    9    6   <5   <5
:WISCONSIN RIVER
MUSCODA              9.0   10.0   11.0 :  10    8    6   <5   <5   <5
:ZUMBRO RIVER
ZUMBRO FLS          18.0   24.0   26.0 :  <5    6   <5   <5   <5   <5
:SOUTH FORK ZUMBRO RIVER
ROCHESTER           14.0   18.0   20.0 :  <5   <5   <5   <5   <5   <5

LEGEND
CS = CONDITIONAL SIMULATION (CURRENT OUTLOOK)
HS = HISTORICAL SIMULATION


*** CLIMATE INFORMATION ***

AUTUMN OF 2014 WAS SLIGHTLY WETTER...UP TO 2 INCHES ABOVE
NORMAL...TO THE NORTH OF INTERSTATE 94. BUT IT WAS DRIER ACROSS THE
REMAINDER OF THE HYDROLOGIC SERVICE AREA...UP TO 3 INCHES BELOW
NORMAL. THIS DRYNESS CONTINUED INTO THE 2014-15 METEOROLOGICAL
WINTER. AT THIS TIME...THE GREATEST PRECIPITATION DEFICITS OF 2 TO 4
INCHES BELOW NORMAL ARE FOUND IN SOUTHWEST AND WEST CENTRAL
WISCONSIN...INTO SOUTHEAST MINNESOTA. THESE AREAS ARE CURRENTLY
CLASSIFIED AS ABNORMALLY DRY /D0/ BY THE U.S. DROUGHT MONITOR.

AS WE HEAD INTO THE SPRING OF 2015...THE PREDOMINANT NORTHWEST FLOW
ALOFT IS EXPECTED TO CONTINUE.  THIS WILL RESULT IN ENHANCED
PROBABILITIES FOR BELOW-NORMAL MARCH TEMPERATURES AND EQUAL CHANCES
FOR THE REMAINDER OF THE SPRING.  THIS WILL SLOW THE SNOW MELT.
HOWEVER THE WATER EQUIVALENT IN THE SNOW PACK IS ONLY UP TO 1.5
INCHES AND THE SOILS ARE DRY AND CAN EASILY ACCOMMODATE THIS
MOISTURE.  THE NORTHWEST FLOW ALOFT IS ALSO A DRY ONE. WHILE THERE
IS NO SHIFT IN THE CLIMATE PREDICTION CENTER/S PRECIPITATION
PROBABILITIES...THE SEASONAL DROUGHT OUTLOOK IS FORECASTING THAT A
DROUGHT IS EXPECTED TO DEVELOP FROM SOUTHEAST MINNESOTA SOUTHEAST
INTO THE SOUTHERN THIRD OF WISCONSIN.


*** FLOOD POTENTIAL SUMMARY ***

THE FLOOD POTENTIAL ANALYSIS IS BASED ON CURRENT SOIL AND SNOW
CONDITIONS COMBINED WITH A BROAD SPECTRUM OF POTENTIAL SPRING
WEATHER CONDITIONS REFLECTED IN THE CLIMATE RECORD FROM 1949 TO
2013. THE ANALYSIS BELOW IS VERY GENERAL. A MORE QUANTIFIED RISK
OF FLOODING WITH RESPECT TO CLIMATOLOGY IS AVAILABLE THROUGH WEB
GRAPHICS AND TABLES AT
HTTP://WATER.WEATHER.GOV/AHPS/LONG_RANGE.PHP?PERCENT=50

STREAMFLOW CONDITIONS AS REPORTED BY THE USGS WERE NEAR NORMAL FOR
MINNESOTA...IOWA...AND SOUTHWEST WISCONSIN...BUT WERE SLIGHTLY ABOVE
NORMAL IN THE BLACK...TREMPEALEAU...AND WISCONSIN RIVER BASINS OF
NORTHERN AND CENTRAL WISCONSIN.

OVERALL THE WINTER PRECIPITATION HAS BEEN BELOW NORMAL. SNOW WATER
CONTENT IS QUITE LOW FOR THIS TIME OF YEAR...WITH MOST AREAS RANGING
BETWEEN 0.50 AND 1.50 INCHES. THE GREATEST WATER EQUIVALENT WAS SEEN
IN THE HEADWATERS OF THE BLACK RIVER WHERE AROUND 2.00 TO 2.25
INCHES IS SEEN. WATER CONTENT OF 3 TO 4 INCHES EXISTS IN THE
HEADWATER AREAS OF THE WISCONSIN RIVER.

WINTER TEMPERATURES HAVE BEEN BOTH ABOVE AND BELOW NORMAL FOR LONG
PERIODS SINCE NOVEMBER. FEBRUARY IS RUNNING BELOW NORMAL FOLLOWING A
RELATIVELY WARM JANUARY. AS A RESULT...SOIL FROST IS AGAIN BUILDING
ACROSS THE BASIN WITH 2 TO 3 FEET REPORTED OVER MUCH OF MINNESOTA
AND WISCONSIN...AND 1 TO 2 FEET IN NORTHEAST IOWA. THIS IS ABOUT
NORMAL FOR THIS TIME OF YEAR.

WHEN LOOKING AT ALL THESE FACTORS...THE OVERALL CHANCES FOR
WIDESPREAD FLOODING DUE TO SNOWMELT THIS SPRING ARE RATHER LOW.


IN TABLE 2 BELOW...THE 95 THROUGH 5 PERCENT COLUMNS INDICATE THE
PROBABILITY OF EXCEEDING THE LISTED STAGE LEVELS (FT) FOR THE VALID
TIME PERIOD. FOR EXAMPLE...FOR THE CEDAR RIVER AT LANSING...THERE IS
A 50% CHANCE THAT THE RIVER WILL RISE ABOVE 14.0 FEET...AND A 25%
CHANCE TO RISE ABOVE 15.2 FEET.

...TABLE 2--EXCEEDANCE PROBABILITIES...

                              CHANCE OF EXCEEDING STAGES
                                 AT SPECIFIC LOCATIONS
                          VALID  PERIOD: 2/23/2015 - 5/24/2015
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:BLACK RIVER
NEILLSVILLE           8.3    8.9    9.3   11.8   12.8   14.1   15.0
BLK RVR FLS          42.3   42.7   43.6   46.5   49.3   52.1   52.7
GALESVILLE            8.4    8.8    9.8   11.7   13.0   13.8   13.9
:CEDAR RIVER
LANSING              12.1   12.4   13.3   14.0   15.2   16.0   16.3
AUSTIN                5.7    6.2    7.0    8.1   10.1   11.5   13.1
CHARLES CTY           5.0    5.2    6.0    7.7    9.5   13.0   15.9
:TURTLE CREEK
AUSTIN                3.5    4.4    5.2    6.7    7.6   10.6   11.2
:KICKAPOO RIVER
LA FARGE              4.8    5.0    5.9    6.7    8.9   10.3   10.9
VIOLA                10.4   10.6   11.5   12.2   13.7   14.6   14.7
READSTOWN             6.1    6.5    7.4    9.1   10.9   11.8   12.0
SLDRS GROVE           8.4    8.7    9.6   11.2   12.3   13.2   13.4
GAYS MILLS            9.0    9.3   10.2   12.0   13.2   13.8   14.0
STEUBEN               8.4    8.9    9.9   11.2   11.8   12.6   12.7
:MISSISSIPPI RIVER
LAKE CITY             8.2    9.0   10.5   11.7   13.5   16.2   18.4
WABASHA               8.2    8.8    9.6   10.4   11.9   13.7   15.7
ALMA                  5.9    6.6    7.6    8.5   10.4   13.1   15.4
DAM 5               652.3  653.0  654.2  655.2  657.4  660.6  663.5
DAM 5A              647.1  648.1  649.7  650.6  653.0  656.4  659.4
WINONA                6.3    6.9    8.2    9.2   11.4   14.9   18.0
TREMPEALEAU         641.0  641.7  642.7  643.5  645.3  648.0  650.2
LA CRESCENT         633.7  634.7  636.0  637.2  638.9  641.9  644.1
LA CROSSE             6.2    6.6    7.5    8.9   10.5   13.0   14.7
GENOA               624.5  625.4  626.9  628.3  629.9  632.8  634.9
LANSING               8.5    8.7    9.3   10.3   11.5   15.1   17.6
LYNXVILLE           616.7  617.5  618.8  620.0  621.6  625.4  628.0
MCGREGOR             10.1   10.7   11.9   13.6   15.8   19.8   22.2
GUTTENBERG            9.3    9.9   11.1   12.4   14.2   17.7   19.1
:ROOT RIVER
HOUSTON               5.9    7.3    8.3   10.0   13.3   15.0   16.2
:SOUTH BRANCH ROOT RIVER
LANESBORO             3.8    4.4    5.5    7.3    9.2   11.9   14.6
:TREMPEALEAU RIVER
DODGE                 7.7    8.0    8.8    9.3    9.7   10.6   11.2
:TURKEY RIVER
ELKADER               7.0    7.8    9.2   11.6   14.6   18.0   22.8
GARBER                8.6    9.6   11.4   14.4   18.5   24.6   27.2
:UPPER IOWA RIVER
DECORAH               3.6    3.9    4.7    5.6    7.7    9.1    9.8
DORCHESTER            9.2    9.8   10.6   12.1   14.7   18.5   19.4
:WISCONSIN RIVER
MUSCODA               3.9    4.4    5.3    6.8    7.9    9.0   10.2
:ZUMBRO RIVER
ZUMBRO FLS            7.2    7.7    8.5   10.4   11.8   13.5   17.4
:SOUTH FORK ZUMBRO RIVER
ROCHESTER


THESE LONG-RANGE PROBABILISTIC OUTLOOKS CONTAIN FORECAST VALUES THAT
ARE CALCULATED USING MULTIPLE SEASON SCENARIOS FROM 30 OR MORE YEARS
OF CLIMATOLOGICAL DATA...INCLUDING CURRENT CONDITIONS OF THE
RIVER...SOIL MOISTURE...SNOW COVER...AND 30 TO 90 DAY LONG-RANGE
OUTLOOKS OF TEMPERATURE AND PRECIPITATION. BY PROVIDING A RANGE OF
PROBABILITIES...THE LEVEL OF RISK ASSOCIATED WITH LONG-RANGE
PLANNING DECISIONS CAN BE DETERMINED. THESE PROBABILISTIC FORECASTS
ARE PART OF THE NATIONAL WEATHER SERVICE/S ADVANCED HYDROLOGIC
PREDICTION SERVICE /AHPS/.

ALL OF THIS INFORMATION IS ALSO AVAILABLE IN GRAPHICAL FORMAT ON THE
INTERNET AT:  HTTP://WWW.WEATHER.GOV/LACROSSE

ADDITIONAL INFORMATION IS ALSO AVAILABLE ON THE NORTH CENTRAL RIVER
FORECAST CENTER WEBSITE AT:  HTTP://WWW.CRH.NOAA.GOV/NCRFC

THE NEXT OUTLOOK WILL BE ISSUED ON MARCH 5TH.

$$

WELVAERT/BOYNE



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