HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE MARQUETTE MI
930 AM EST FRI MAR 31 2006
...SPRING FLOOD AND WATER RESOURCES OUTLOOK...
THIS OUTLOOK PERTAINS TO RIVERS LOCATED IN UPPER MICHIGAN...EXCEPT
THOSE IN CHIPPEWA AND MACKINAC COUNTIES...AND THOSE BORDERING
WISCONSIN.
AT THIS TIME...THERE IS LITTLE POTENTIAL FOR SNOWMELT FLOODING
ACROSS THE AREA...THOUGH MANY RIVERS ARE EXPECTED TO RISE OUT OF
THEIR BANKS. THE RECENT WARM TEMPERATURES HAVE CAUSED THE SNOWPACK
TO BEGIN MELTING AND MANY RIVERS HAVE BEGUN RESPONDING TO THE
RUNOFF. ALSO...RECENT RAINFALL HAS HELPED TO FACILITATE THE
SNOWMELT...ESPECIALLY OVER THE WEST HALF OF UPPER MICHIGAN. COOLER
TEMPERATURES THIS WEEKEND WILL SLOW DOWN THE MELTING PROCESS AND
ALLOW RIVER LEVELS TO DIMINISH SLIGHTLY. THE SNOWPACK WILL GRADUALLY
CONTINUE MELTING OVER THE NEXT COUPLE OF WEEKS AS PRECIPITATION IS
EXPECTED TO BE ABOVE NORMAL WITH NEAR NORMAL TEMPERATURES.
IN THE TABLE BELOW...THE 90 THROUGH 10 PERCENT COLUMNS INDICATE THE
CHANCE THE RIVER COULD RISE ABOVE THE LISTED STAGE OR FLOW IN THE
NEXT 90 DAYS. FOR EXAMPLE...THE STURGEON RIVER NEAR ALSTON HAS A
FLOOD STAGE OF 8.0 FEET. IN THE NEXT 90 DAYS...THERE IS A 10 PERCENT
CHANCE THE RIVER WILL RISE ABOVE 8.2 FEET.
CHANCE OF EXCEEDING STAGES AT SPECIFIC LOCATIONS
VALID APR 3 2006 THROUGH JUL 2 2006
LOCATION FS(FT) 90% 80% 70% 60% 50% 40% 30% 20% 10%
-------- ------ --- --- --- --- --- --- --- --- ---
PAINT RIVER
CRYSTAL FALLS 7.0 4.5 4.6 4.7 4.9 5.0 5.2 5.6 5.8 6.0
ONTONAGON RIVER
ROCKLAND 25.0 12.3 12.7 13.3 13.7 14.0 14.4 15.1 15.7 17.2
CHOCOLAY RIVER
HARVEY 9.0 4.9 5.4 5.7 5.9 6.2 6.3 6.4 6.9 7.3
ESCANABA RIVER
GWINN 7.0 4.1 4.7 5.6 5.8 5.9 6.2 6.7 7.0 7.6
STURGEON RIVER
ALSTON 8.0 6.1 6.3 6.4 6.6 6.8 7.1 7.4 7.7 8.2
CHANCE OF EXCEEDING FLOWS (CFS) AT SPECIFIC LOCATIONS
VALID APR 3 2006 THROUGH JUL 2 2006
LOCATION 90% 80% 70% 60% 50% 40% 30% 20% 10%
-------- --- --- --- --- --- --- --- --- ---
MICHIGAMME RIVER
WAY DAM 1.4 1.7 2.0 2.2 2.5 2.8 3.2 4.0 4.8
THE NATIONAL WEATHER SERVICE OFFICE IN MARQUETTE HAS IMPLEMENTED
ADVANCED HYDROLOGIC PREDICTION SERVICES (AHPS) FOR SELECT RIVERS IN
UPPER MICHIGAN AND THE UPPER PORTIONS OF THE MENOMINEE RIVER BASIN.
AHPS ENABLES THE NATIONAL WEATHER SERVICE TO PROVIDE LONG-RANGE
PROBABILISTIC NUMBERS WHICH CAN BE USED TO DETERMINE THE LEVEL OF
RISK FOR LONG-RANGE PLANNING DECISIONS.
THIS LONG-RANGE PROBABILISTIC OUTLOOK CONTAINS NUMBERS CALCULATED
USING MULTIPLE SCENARIOS FROM 30 OR MORE YEARS OF CLIMATOLOGICAL
DATA. THESE NUMBERS ALSO TAKE INTO ACCOUNT CURRENT CONDITIONS OF THE
RIVER...SNOW COVER...SOIL MOISTURE...AND THE 30 TO 90 DAY LONG-RANGE
OUTLOOKS OF TEMPERATURE AND PRECIPITATION.
...SNOW COVER AND SNOW WATER EQUIVALENT...
MOST LOCATIONS ACROSS UPPER MICHIGAN HAVE RECEIVED NEAR NORMAL
SNOWFALL FOR THE SEASON. SNOW DEPTHS HAVE DIMINISHED TO 0 TO 12
INCHES ACROSS THE SOUTH HALF OF UPPER MICHIGAN...AND 12 TO 24 INCHES
ACROSS THE NORTH HALF. LOCALLY HIGHER SNOW DEPTHS UP TO 36 INCHES
REMAINED OVER THE HIGHER TERRAIN OF THE KEWEENAW PENINSULA.
SNOW WATER EQUIVALENT VALUES RANGE FROM 0 TO 3 INCHES ACROSS THE
SOUTH HALF OF UPPER MICHIGAN...AND 3 TO 6 INCHES ACROSS THE NORTH
HALF. LOCALLY HIGHER AMOUNTS OF 6 TO 10 INCHES REMAINED OVER THE
HIGHER TERRAIN OF THE KEWEENAW PENINSULA AND THE HURON MOUNTAINS.
...SOIL CONDITIONS AND FROST DEPTHS...
SOIL MOISTURE ACROSS THE AREA WAS ABOVE NORMAL DUE TO SIGNIFICANT
PRECIPITATION LAST FALL AND RECENT SNOWMELT...AND FROST DEPTHS ARE
SOMEWHAT SHALLOW RANGING FROM 0 TO 12 INCHES. THE ACCUMULATED
FREEZING DEGREE DAYS ARE BELOW NORMAL AS OF THIS DATE. FREEZING
DEGREE DAYS ARE USEFUL FOR DETERMINING THE EXTENT OF ICE COVER IN
THE AREA...AND ASSESSING THE POTENTIAL FOR ICE JAM FORMATION DURING
THE SPRING SNOWMELT. THE TABLE BELOW COMPARES THE ACCUMULATED
FREEZING DEGREE DAYS ON MARCH 30 AT THE NATIONAL WEATHER SERVICE
MARQUETTE OFFICE OVER THE PAST FIVE YEARS.
NORMAL 2002 2003 2004 2005 2006
-------- ------ ------ ------ ------ ------
1820 1106 2108 1542 1723 1418
...RIVER CONDITIONS...
RIVER LEVELS ARE BEGINNING TO RISE FROM THE SNOWMELT...AND ARE
EXPECTED TO CONTINUE RISING THROUGH THE WEEKEND. WITH THE CONTINUED
SNOWMELT OVER THE NEXT COUPLE OF WEEKS...RIVER LEVELS ARE EXPECTED
TO REMAIN ABOVE NORMAL THROUGH MID-APRIL.
...WEATHER OUTLOOKS...
THE 8 TO 14 DAY OUTLOOK FOR UPPER MICHIGAN INDICATES ABOVE NORMAL
PRECIPITATION AND NEAR NORMAL TEMPERATURES. THE 30 DAY OUTLOOK FOR
THE UPPER GREAT LAKES INDICATES AN ABOVE NORMAL CHANCE FOR
PRECIPITATION...AND EQUAL CHANCES FOR ABOVE...BELOW...OR NORMAL
TEMPERATURES.
...FLOOD OUTLOOK SUMMARY...
AT THIS TIME...THERE IS LITTLE POTENTIAL FOR SNOWMELT FLOODING
ACROSS THE AREA...THOUGH MANY RIVERS ARE EXPECTED TO RISE OUT OF
THEIR BANKS. COOLER TEMPERATURES THIS WEEKEND WILL SLOW DOWN THE
SNOWMELT ALLOWING FOR RIVER LEVELS TO DIMINISH SLIGHTLY...HOWEVER
THE SNOWPACK IS EXPECTED TO GRADUALLY CONTINUE MELTING OVER THE NEXT
COUPLE OF WEEKS DUE TO ABOVE NORMAL PRECIPITATION AND NEAR NORMAL
TEMPERATURES.
ADDITIONAL HYDROLOGIC DATA AND WEATHER INFORMATION CAN BE FOUND ON
THE INTERNET AT:
http://www.weather.gov/mqt/
THIS IS THE LAST SPRING SNOWMELT OUTLOOK AS FLOODING CONCERNS HAVE
GREATLY DIMINISHED. ANY ADDITIONAL HYDROLOGIC PRODUCTS WILL BE
ISSUED ON AN EVENT DRIVEN BASIS.
LAROSA