000
FGUS73 KIWX 251728
ESFIWX

PROBABILISTIC HYDROLOGIC OUTLOOK 
NATIONAL WEATHER SERVICE NORTHERN INDIANA 
1227 PM EDT THU FEB 25 2021

...SPRING FLOOD AND WATER RESOURCES OUTLOOK NUMBER 2 FOR THE SAINT 
JOSEPH RIVER IN MICHIGAN AND KANKAKEE RIVER BASINS...

... ADVANCED HYDROLOGIC PREDICTION SERVICE 90 DAY PROBABILISTIC
FORECAST...

THIS IS THE 90 DAY PROBABILISTIC FORECAST FOR LOCATIONS ALONG THE
KANKAKEE RIVER BASIN IN NORTHERN INDIANA AND FOR THE SAINT
JOSEPH RIVER BASIN IN NORTHERN INDIANA AND SOUTHERN MICHIGAN.

IN THE TABLE BELOW THE 95 THROUGH 5 PERCENT COLUMNS INDICATE THE
CHANCE THE RIVER COULD RISE TO OR ABOVE THE LISTED STAGE LEVELS IN
THE NEXT 90 DAYS.

FOR EXAMPLE, THE KANKAKEE RIVER AT DAVIS, INDIANA HAS A FLOOD STAGE 
OF 10 FEET. IN THE NEXT 90 DAYS THERE IS A 10 PERCENT CHANCE THE 
RIVER WILL RISE TO OR ABOVE 10.3 FEET.

THE ST. JOSEPH RIVER AT SOUTH BEND, INDIANA HAS A FLOOD STAGE OF 
5.5 FEET. IN THE NEXT 90 DAYS THERE IS A 25 PERCENT CHANCE THE 
RIVER WILL RISE TO OR ABOVE  4.9 FEET. 


 CHANCE OF EXCEEDING STAGES AT SPECIFIC LOCATIONS
 ...VALID MARCH 1 2021 - MAY 30 2021... 

KANKAKEE RIVER BASIN...
LOCATION         FS(FT)   95%  90%  75%  50%  25%  10%   5% 

KANKAKEE RIVER
DAVIS IN            10    8.4  8.5  8.7  9.2  9.6 10.3 10.7  


YELLOW RIVER
PLYMOUTH IN         13    7.3  8.2  8.9 10.1 11.4 12.8 12.9  
KNOX IN             10    6.5  6.8  7.1  7.5  8.2  9.1  9.4  


SAINT JOSEPH RIVER MICHIGAN BASIN...
LOCATION         FS(FT)   95%  90%  75%  50%  25%  10%   5% 

SAINT JOSEPH RIVER MICHIGAN
THREE RIVERS MI      7    4.9  5.3  5.7  6.2  6.8  7.4  7.8  
MOTTVILLE MI         8    4.2  4.5  5.0  5.5  6.1  6.7  7.1  
ELKHART IN          24   20.0 20.6 21.2 21.8 22.7 23.4 24.4  
SOUTH BEND IN      5.5    1.4  2.1  2.9  3.8  4.9  5.7  6.6  
NILES MI            11    6.0  6.7  7.5  8.2  9.4 10.3 11.5   


ELKHART RIVER
GOSHEN IN            7    3.5  3.8  4.2  4.8  5.6  7.1  7.5  
COSPERVILLE IN       6    5.5  5.7  6.0  6.2  6.3  6.5  7.0  


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 MELT AND 30 TO 90 DAY LONG-RANGE
OUTLOOKS OF TEMPERATURE AND PRECIPITATION. BY PROVIDING THE COMPLETE
RANGE OF PROBABILITIES, THE LEVEL OF RISK ASSOCIATED WITH
LONG-RANGE PLANNING DECISIONS CAN BE DETERMINED. THESE
PROBABILISTIC FORECASTS ARE A PART OF NOAA NATIONAL WEATHER
SERVICES ADVANCED HYDROLOGIC PREDICTION SERVICE.

ADDITIONAL SUPPORTIVE DATA AND EXPLANATIONS ARE AVAILABLE ON
AHPS AT WWW.WEATHER.GOV/IWX, UNDER RIVERS AND LAKES.

...SNOW COVER/SOIL CONDITIONS...

THE REGION SAW SIGNIFICANT CHANGES IN SNOWPACK OVER THE PAST 
TWO WEEKS. INITIAL SNOWPACK RANGED WIDELY FROM 2 INCHES TO A 
FOOT BEFORE INCREASING TO WIDESPREAD 10 TO 18 INCHES WITH ISOLATED
AMOUNTS OF GREATER THAN 20 INCHES AFTER A POTENT SYSTEM BROUGHT 
SUB-FREEZING TEMPERATURES FOR MUCH OF THE COUNTRY. AS TEMPERATURES
WARMED, THE SNOWPACK HAS BEGUN TO MELT AND WAS SHOWN TO RANGE FROM
A TRACE TO 6 INCHES WITH ISOLATED AMOUNTS NEAR 10 INCHES ALONG 
LAKE MICHIGAN THIS MORNING. AT ITS PEAK THE SNOWPACK HELD 1 TO 3 
INCHES OF WATER EQUIVALENT WITH ISOLATED AMOUNTS NEAR 4 INCHES 
NEAR LAKE MICHIGAN. THIS MORNING'S SNOWPACK STILL HOLDS FROM A 
TRACE TO 2 INCHES WITH ISOLATED SWATHS OF 2 TO 3 INCHES OF WATER 
EQUIVALENT ACROSS THE ST. JOSEPH BASIN NEAR LAKE MICHIGAN. 

WHILE FROST DEPTH REACHED A PEAK OF 3 TO 6 INCHES, IT HAS SINCE 
REDUCED TO GENERALLY LESS THAN 1 INCH.  

NEAR SURFACE SOIL MOISTURE (TOP 10 CENTIMETERS) HAS IMPROVED 
SLIGHTLY IN THE PAST COUPLE OF DAYS AS THE SNOW HAS MELTED 
HOWEVER,DEEPER MOISTURE (TOP 100 CENTIMETERS) IS MUCH BELOW NORMAL, 
GENERALLY 10TH PERCENTILE OR LESS. 

...WEATHER OUTLOOK...

THE NEAR TERM FORECAST IS FROM NEAR OR ABOVE NORMAL TEMPERATURES TO 
CONTINUE WELL INTO THE FIRST COUPLE DAYS OF MARCH WHILE REMAINING 
MOSTLY DRY. THE EXCEPTION IF FOR LIGHT RAIN THIS FRIDAY NIGHT INTO 
SATURDAY. 

THE CLIMATE PREDICTION CENTER (CPC) 8 TO 14 DAY OUTLOOK INDICATES 
A STRONG SIGNAL FOR CONTINUED ABOVE NORMAL TEMPERATURES WITH CHANCES 
FOR ABOVE NORMAL PRECIPITATION. 

CPC'S OUTLOOK FOR THE MONTH OF MARCH INDICATES A SLIGHT SIGNAL FOR 
CONTINUED ABOVE NORMAL TEMPERATURES AND ABOVE NORMAL PRECIPITATION 
ACROSS THE AREA. THIS MIRRORS THE THREE MONTH OUTLOOK FOR MARCH 
THROUGH MAY WITH BOTH ABOVE NORMAL TEMPERATURES AND PRECIPITATION 
BEING FAVORED. 

...DROUGHT CONDITIONS... 

LONG TERM ABNORMALLY DRY TO MODERATE DROUGHT CONDITIONS EXIST ALONG
A SWATH FROM WEST CENTRAL INDIANA AND PORTIONS OF SOUTHERN LOWER 
MICHIGAN. IN THE SHORTER TERM, PRECIPITATION TOTALS RANGED FROM 
AROUND 100 TO 150 PERCENT OF NORMAL THROUGHOUT MUCH OF THE REGION.  

...RIVER CONDITIONS...

WE ARE SEEING STREAMFLOWS RESPOND TO THE RECENT SNOW MELT. A WIDE 
RANGE OF STREAMFLOWS EXIST ACROSS THE BASINS FROM MUCH BELOW NORMAL
TO NORMAL FLOW FOR THIS TIME OF YEAR. GIVEN THE CONTINUED ABOVE 
AVERAGE TEMPERATURES, WE SHOULD SEE AN INCREASE IN STREAMFLOWS AS 
THE SNOWPACK CONTINUES TO MELT. 

...OVERALL FLOOD RISK...

THE FLOOD RISK IS CONSIDERED BELOW AVERAGE FOR THE KANKAKEE BASIN, 
AND NEAR NORMAL FOR THE ST. JOSEPH RIVER IN MICHIGAN. THERE WILL 
BE CHANCES FOR MINOR RIVER FLOODING ON THE ST. JOSEPH RIVER DUE TO
THE COMBINATION OF INCREASED RUNOFF SNOWMELT, FUTURE RAINFALL 
EVENTS, AND SPRINGTIME THUNDERSTORMS. IN ADDITION, EXTENSIVE ICE 
FORMATION ON AREA RIVERS HAS INCREASED THE POTENTIAL FOR ICE JAM 
FLOODING IN THE NEAR TERM AS ICE THAWS. 

...FLOOD TERMINOLOGY...
THE TERM MINOR FLOODING IS USED TO INDICATE MINIMAL OR NO PROPERTY
DAMAGE. HOWEVER, SOME PUBLIC INCONVENIENCE IS POSSIBLE.

THE TERM MODERATE FLOODING IS USED TO INDICATE THE INUNDATION OF 
SECONDARY ROADS. TRANSFER TO A HIGHER ELEVATION MAY BE NECESSARY TO
SAVE PROPERTY.

THE TERM MAJOR FLOODING IS USED TO INDICATE EXTENSIVE INUNDATION
AND PROPERTY DAMAGE, USUALLY CHARACTERIZED BY THE EVACUATION OF 
PEOPLE AND LIVESTOCK AND THE CLOSURE OF BOTH PRIMARY AND SECONDARY 
ROADS.

THE NEXT LONG-RANGE PROBABILISTIC OUTLOOK WILL BE ISSUED IN
THURSDAY, MARCH 11, 2021 FOR THE KANKAKEE AND SAINT JOSEPH RIVER
BASINS.


$$

MURPHY/MORRIS