Updated Spring Snowmelt Flood Potential Outlook

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
905 AM CST FRI MAR 29 2013

      ...UPDATED SPRING HYDROLOGIC SUMMARY AND OUTLOOK...

THE FOLLOWING INFORMATION IS THE FINAL SPRING FLOOD POTENTIAL
OUTLOOK FOR THIS YEAR. 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/...CLIMATE PREDICTION CENTER
/CPC/...US DROUGHT MONITOR...AND THE NATIONAL OPERATIONAL REMOTE
SENSING CENTER /NOHRSC/.

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


*** FLOOD POTENTIAL HIGHLIGHTS ***

IN SUMMARY...THE FLOODING POTENTIAL FOR THIS SPRING REMAINS ABOUT
NORMAL WHEN COMPARED TO A TYPICAL YEAR.

THERE IS A RISK FOR MINOR FLOODING FOR SOME OF THE TRIBUTARY RIVERS
FEEDING INTO THE MISSISSIPPI. THE RISK IS HIGHEST FOR THE BLACK AND
TREMPEALEAU RIVERS IN WISCONSIN. THE OVERALL FLOOD RISK FOR THE
MISSISSIPPI RIVER ITSELF IS STILL RATHER SMALL.

HOWEVER...THERE ARE SOME FACTORS THAT COULD STILL CONTRIBUTE TO AN
INCREASE IN THE FLOODING POTENTIAL THIS SPRING.

THE FROST CONDITION REMAINS A CONCERN. THE FROST DEPTH IS STILL
RATHER DEEP FOR LATE MARCH...RANGING FROM 1.5 TO 2.5 FEET DEEP
ACROSS THE REGION. IN ADDITION...THE TOP SEVERAL INCHES OF SOIL
REMAINS FROZEN IN MANY PLACES...LEADING TO WHAT IS CALLED CONCRETE
FROST.  THIS FROZEN SOIL WILL RESULT IN INCREASED RUNOFF INTO CREEKS
AND RIVERS AS THE SNOW MELTS...AS ANY MELT WATER WILL BE UNABLE TO
PENETRATE THE FROZEN GROUND...AND WILL DIRECTLY RUN OFF INTO RIVERS
AND CREEKS.

THE WARM PERIOD THIS WEEK IS HELPING TO MELT OFF SOME OF THE SNOW
COVER. BUT ANOTHER SYSTEM THIS WEEKEND WILL BRING A RETURN TO COOLER
WEATHER AGAIN TO START NEXT WEEK. THIS WILL ENSURE THAT AT LEAST
SOME SNOW COVER WILL LINGER INTO THE FIRST AND SECOND WEEKS OF
APRIL. ANOTHER CONCERN IS...THE LONGER THE FROZEN GROUND AND SNOW
COVER LASTS INTO APRIL...THE GREATER THE RISK THAT TEMPERATURES WILL
RAPIDLY WARM UP AND ALLOW THE SNOW TO QUICKLY MELT. A FAST MELT...OR
A MELT COMBINED WITH SIGNIFICANT RAINFALL...WILL BE A RECIPE FOR
MORE SEVERE FLOODING.  THIS SITUATION WILL BE MONITORED.


*** FLOOD POTENTIAL ***

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: 4/1/2013 - 6/30/2013

                                       :    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 :  57   55   27   26   <5    5
GALESVILLE          12.0   13.0   15.0 :  59   53   41   37   <5   <5
:CEDAR RIVER
LANSING             18.0   20.0   22.0 :  <5   <5   <5   <5   <5   <5
AUSTIN              15.0   18.0   20.0 :  <5   <5   <5   <5   <5   <5
CHARLES CTY         12.0   15.0   18.0 :   9   16   <5    8   <5   <5
:TURTLE CREEK
AUSTIN              10.5   12.0   14.0 :  16   16   14   14   11   13
:KICKAPOO RIVER
LA FARGE            12.0   13.0   14.0 :  <5    7   <5   <5   <5   <5
VIOLA               14.0   17.0   20.0 :  29   28   <5   <5   <5   <5
READSTOWN           11.0   14.0   17.0 :  34   33   <5   <5   <5   <5
SLDRS GROVE         13.0   16.0   19.0 :  24   21   <5   <5   <5   <5
GAYS MILLS          13.0   15.0   17.0 :  39   41    6    8   <5   <5
STEUBEN             12.0   13.0   15.0 :  32   33   13   12   <5   <5
:MISSISSIPPI RIVER
LAKE CITY           16.0   18.0   20.0 :  <5   26   <5    8   <5    6
WABASHA             12.0   14.0   16.0 :  39   55   <5   18   <5    6
ALMA                16.0   17.0   18.0 :  <5    6   <5    6   <5   <5
DAM 5              660.0  662.0  665.0 :   6   29   <5   14   <5    6
DAM 5A             656.0  659.0  661.0 :   6   27   <5    6   <5    6
WINONA              13.0   15.0   18.0 :  18   41   <5   21   <5    6
TREMPEALEAU        647.0  649.0  651.0 :  13   34   <5   16   <5    6
LA CRESCENT        641.0  643.0  645.0 :   8   34   <5   13   <5    6
LA CROSSE           12.0   13.0   15.5 :  16   36   <5   21   <5    6
GENOA              631.0  634.0  636.0 :  24   47   <5   11   <5    6
LANSING             17.0   19.0   20.0 :  <5    8   <5    6   <5   <5
LYNXVILLE          625.0  628.0  631.0 :   6   27   <5    6   <5   <5
MCGREGOR            16.0   20.0   23.0 :  29   52   <5   18   <5    6
GUTTENBERG          15.0   18.0   21.0 :  21   49   <5    9   <5   <5
:ROOT RIVER
HOUSTON             15.0   17.0   18.0 :   8    9   <5   <5   <5   <5
:SOUTH BRANCH BARABOO RIVER
HILLSBORO           13.0   14.0   16.0 :  27   19   11    8   <5   <5
:SOUTH BRANCH ROOT RIVER
LANESBORO           12.0   16.0   18.0 :   8    9   <5   <5   <5   <5
:TREMPEALEAU RIVER
DODGE                9.0   11.0   12.0 :  75   51    8   <5   <5   <5
:TURKEY RIVER
ELKADER             12.0   16.0   20.0 :  41   36    9   14   <5    6
GARBER              17.0   20.0   23.0 :  18   21    9   14    6    6
:UPPER IOWA RIVER
DECORAH             12.0   13.0   14.0 :  <5   <5   <5   <5   <5   <5
DORCHESTER          14.0   17.0   19.0 :  26   26    8   11    6   <5
:WISCONSIN RIVER
MUSCODA              9.0   10.0   11.0 :  32   26    9   11   <5   <5
:ZUMBRO RIVER
ZUMBRO FLS          18.0   24.0   26.0 :   9   11   <5   <5   <5   <5
:SOUTH FORK ZUMBRO RIVER
ROCHESTER           14.0   18.0   20.0 :   6   <5   <5   <5   <5   <5

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


*** CLIMATE OVERVIEW  ***

THE REGION CONTINUES TO EXPERIENCE ABNORMALLY DRY /D0/ CONDITIONS TO
A SEVERE DROUGHT /D2/.  DURING MARCH OF 2013...NEAR-NORMAL
PRECIPITATION OF 1 TO 3 INCHES FELL ACROSS THE AREA. MUCH OF THIS
PRECIPITATION FELL IN THE FORM OF SNOW...THUS...IT ADDED TO THE
AMOUNT OF MOISTURE IN THE SNOW PACK.

DURING THE PAST WEEK...THE COMBINATION OF DRY WEATHER AND SUNSHINE
HAS ALLOWED MUCH OF THE SNOW TO MELT ACROSS SOUTHWEST WISCONSIN AND
PARTS OF NORTHEAST IOWA. MUCH OF THIS MOISTURE IS RUNNING OFF INTO
AREA RIVERS DUE TO THE DEEP FROST /UP TO 3 FEET/.  MANY OF THE
RIVERS IN THESE AREAS SAW WITHIN-BANK RISES OF 2 TO 5 FEET.

ELSEWHERE...THE SNOW DEPTH RANGES FROM 3 TO 12 INCHES. THE WATER
EQUIVALENT OF THIS SNOW PACK RANGES FROM 1 TO 3 INCHES. THE HIGHEST
AMOUNTS ARE IN THE BLACK AND TREMPEALEAU RIVER BASINS...WHERE SNOW
WATER AMOUNTS OF UP TO 3 INCHES ARE FOUND. WITH FROST DEPTHS RANGING
FROM 1 TO 3 FEET...THIS CONCRETE FROST WILL GREATLY IMPEDE THE
AMOUNT OF SNOW MELT THAT CAN MAKE IT INTO THE SOILS.  THUS...MUCH OF
THIS WATER IS EXPECTED TO END UP IN AREA RIVERS AND STREAMS...AND
MAY NOT HELP IMPROVE THE DROUGHT CONDITIONS MUCH.

DUE TO THE LONG-TERM DROUGHT IN PLACE...RIVER CONDITIONS ARE
EXPECTED TO QUICKLY REVERT BACK TO THE LOW CONDITIONS AFTER THE
SNOWMELT RUNOFF SEASON.


*** LONG RANGE FLOOD POTENTIAL OUTLOOK ***

THE OUTLOOK IN TABLE 2 BELOW WILL SHOW THE PROBABILITY FOR FLOODING
AT SEVERAL SPECIFIC LOCATIONS AROUND THE REGION.

THIS OUTLOOK PROVIDES LONG-RANGE PROBABILISTIC RIVER OUTLOOKS FOR
RIVER BASINS IN PARTS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND
SOUTHWEST WISCONSIN.

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.

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

                              CHANCE OF EXCEEDING STAGES
                                AT SPECIFIC  LOCATIONS
                          VALID  PERIOD: 4/1/2013 - 6/30/2013
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:BLACK RIVER
NEILLSVILLE           9.1    9.5   10.1   11.7   13.7   16.0   17.7
BLK RVR FLS          43.7   44.3   45.4   48.2   51.2   53.0   54.3
GALESVILLE            9.8   10.4   11.1   12.4   13.4   13.9   14.5
:CEDAR RIVER
LANSING              13.7   13.7   13.9   14.5   15.6   16.7   18.2
AUSTIN                6.9    7.0    7.1    7.9    9.9   12.0   14.1
CHARLES CTY           5.1    5.2    5.7    6.8   10.0   13.6   15.3
:TURTLE CREEK
AUSTIN                6.3    6.4    6.7    7.9    9.3   14.4   15.1
:KICKAPOO RIVER
LA FARGE              5.3    5.4    6.2    7.2    9.4   10.2   11.3
VIOLA                11.2   11.3   11.8   12.6   14.5   15.4   15.6
READSTOWN             7.3    7.3    7.9   10.1   11.6   12.6   13.1
SLDRS GROVE           9.6    9.7   10.2   11.8   13.0   14.1   15.3
GAYS MILLS           10.1   10.2   10.8   12.4   13.7   14.5   16.0
STEUBEN               9.7    9.8   10.4   11.4   12.5   13.2   14.0
:MISSISSIPPI RIVER
LAKE CITY            10.1   10.6   11.9   13.3   14.5   15.8   16.3
WABASHA               9.3    9.6   10.6   11.7   12.5   13.3   13.8
ALMA                  7.3    7.7    8.7   10.2   11.4   12.6   13.2
DAM 5               653.7  654.1  655.3  657.1  658.5  659.8  660.6
DAM 5A              649.3  649.7  650.8  652.7  654.1  655.7  656.5
WINONA                7.8    8.2    9.4   11.2   12.6   14.1   15.0
TREMPEALEAU         642.4  642.7  643.6  645.1  646.3  647.4  648.1
LA CRESCENT         635.5  636.2  637.1  638.8  640.0  640.9  641.8
LA CROSSE             7.0    7.6    8.8   10.4   11.5   12.3   13.0
GENOA               626.1  626.9  628.2  629.8  631.0  631.8  632.6
LANSING               8.9    9.4   10.2   11.5   12.8   14.1   15.1
LYNXVILLE           618.2  618.8  620.0  621.6  623.0  624.4  625.4
MCGREGOR             11.0   11.7   13.0   15.0   16.6   19.0   20.2
GUTTENBERG           10.1   10.6   11.9   13.6   14.8   16.5   17.7
:ROOT RIVER
HOUSTON               7.8    7.8    8.3    9.1   12.7   14.7   16.2
:SOUTH BRANCH BARABOO RIVER
HILLSBORO             7.0    7.1    9.2   12.1   13.1   14.2   14.7
:SOUTH BRANCH ROOT RIVER
LANESBORO             3.1    3.1    3.5    4.1    5.8   11.0   15.2
:TREMPEALEAU RIVER
DODGE                 8.4    8.5    9.1    9.5   10.2   10.9   11.1
:TURKEY RIVER
ELKADER               7.6    7.8    8.9   10.9   13.3   16.7   21.0
GARBER                9.1    9.7   10.9   13.0   16.3   20.0   27.4
:UPPER IOWA RIVER
DECORAH               3.9    3.9    4.3    5.2    6.8    8.6   10.1
DORCHESTER           10.0   10.0   10.3   11.8   14.1   16.8   20.5
:WISCONSIN RIVER
MUSCODA               5.6    5.8    6.3    7.7    9.4   10.1   11.1
:ZUMBRO RIVER
ZUMBRO FLS            8.4    8.8    9.7   11.1   13.2   18.9   20.9
:SOUTH FORK ZUMBRO RIVER
ROCHESTER             4.9    5.0    5.3    6.4    7.9   11.6   17.2


THIS LONG-RANGE PROBABILISTIC OUTLOOK CONTAINS 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.

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

THIS IS THE LAST SPRING SNOWMELT FLOOD POTENTIAL OUTLOOK FOR THE
SEASON. REFER TO OUR WEB SITE FOR MORE INFORMATION AT...

HTTP://WWW.WEATHER.GOV/LACROSSE

$$


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