####018009975#### FGUS73 KAPX 141429 ESFAPX MIC001-007-009-011-019-029-031-033-039-047-051-055-069-079-089-097- 101-113-119-129-135-137-141-143-165-131428- Probabilistic Hydrologic Outlook National Weather Service Gaylord MI 1029 AM EDT Thu Mar 14 2024 ...SPRING FLOOD OUTLOOK FOR NORTHERN MICHIGAN... THE SPRING 2024 FLOOD OUTLOOK FOR NORTHERN MICHIGAN INDICATES A BELOW AVERAGE PROBABILITY OF FLOODING DUE TO SNOW MELT WITHIN MAJOR EASTERN UPPER AND NORTHERN LOWER MICHIGAN RIVER BASINS. THIS OUTLOOK COVERS CHIPPEWA AND MACKINAC COUNTIES IN EASTERN UPPER MICHIGAN WHICH INCLUDES THE PINE RIVER BASIN...AND THE NORTHERN HALF OF LOWER MICHIGAN ENCOMPASSING THE AU SABLE... BOARDMAN...MANISTEE...RIFLE...AND TOBACCO RIVER BASINS. THE FIRST TABLE BELOW LISTS THE PROBABILITIES OF REACHING FLOOD STAGE (MINOR FLOODING)...AS WELL AS MODERATE AND MAJOR FLOOD LEVELS FOR THE SIX FORECAST POINTS WITHIN THE GAYLORD NATIONAL WEATHER SERVICE OFFICE HYDROLOGIC SERVICE AREA. THE CURRENT (CS) AND HISTORICAL 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 MORE 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/MAJOR FLOODING Valid Period: 03/18/2024 - 06/16/2024 : 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 -------- ----- ----- ----- : --- --- --- --- --- --- :Manistee River Sherman 15.0 16.0 17.0 : 7 12 <5 <5 <5 <5 :Boardman River Mayfield--Brown B 7.0 8.0 9.0 : <5 <5 <5 <5 <5 <5 :Au Sable River Red Oak 7.0 8.0 9.0 : <5 12 <5 <5 <5 <5 :Rifle River Sterling 6.0 11.0 13.0 : 30 62 <5 <5 <5 <5 :Pine River Rudyard 17.0 19.0 20.0 : <5 <5 <5 <5 <5 <5 :Tobacco River Beaverton 12.0 14.0 17.0 : <5 <5 <5 <5 <5 <5 Legend CS = Conditional Simulation (Current Outlook) HS = Historical Simulation FT = Feet DEPARTURE FROM NORMAL OF REACHING FLOOD STAGE IS THE DIFFERENCE BETWEEN THE CURRENT PROJECTED CHANCE FOR REACHING FLOOD STAGE (CS) AND THE CLIMATIC NORMAL (HS). FOR EXAMPLE...THE RIFLE RIVER NEAR STERLING...WITH A FLOOD STAGE OF 6 FEET...HAS A 30 PERCENT CHANCE OF REACHING OR EXCEEDING FLOOD STAGE...WHICH IS 32 PERCENTAGE POINTS BELOW NORMAL. DURING THE 90 DAY PERIOD LISTED...THE TYPICAL PROBABILITY OF THE RIFLE RIVER NEAR STERLING REACHING FLOOD STAGE IS 62 PERCENT. THE NEXT TABLE SHOWS THE CHANCE THAT A PARTICULAR RIVER LOCATION COULD RISE ABOVE THE LISTED STAGES IN THE SPECIFIED 90 DAY PERIOD (HIGH FLOW FORECAST): ...TABLE 2--EXCEEDANCE PROBABILITIES Chance of Exceeding Stages at Specific Locations Valid Period: 03/18/2024 - 06/16/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Manistee River Sherman 13.3 13.3 13.5 13.7 14.2 14.7 15.2 :Boardman River Mayfield--Brown B 3.9 4.0 4.2 4.4 4.7 5.1 5.2 :Au Sable River Red Oak 4.3 4.3 4.4 4.8 5.1 5.9 6.1 :Rifle River Sterling 3.3 3.8 4.4 5.1 6.2 7.5 8.3 :Pine River Rudyard 3.3 3.8 4.8 6.4 8.2 9.3 10.3 :Tobacco River Beaverton 4.1 4.9 5.7 6.3 7.0 7.9 8.8 CURRENT FORECASTS SUGGEST PROBABILITIES OF EXCEEDING FLOOD STAGE ARE LESS THAN 5 PERCENT EXCEPT FOR THE RIFLE RIVER NEAR STERLING...WHERE THEE PROBABILITY OF EXCEEDING THE FLOOD STAGE OF 6 FEET IS AROUND 30 PERCENT. THE LAST TABLE INDICATES THE CHANCE THAT A PARTICULAR RIVER LOCATION COULD FALL BELOW THE LISTED STAGES IN THE SPECIFIED 90 DAY PERIOD (LOW FLOW FORECAST): ...TABLE 3--NON-EXCEEDANCE PROBABILITIES... Chance of Falling Below Stages at Specific Locations Valid Period: 03/18/2024 - 06/16/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Manistee River Sherman 12.2 12.1 11.9 11.7 11.4 11.4 11.2 :Boardman River Mayfield--Brown B 3.6 3.6 3.5 3.4 3.4 3.3 3.3 :Au Sable River Red Oak 3.5 3.4 3.3 3.1 3.0 2.9 2.8 :Rifle River Sterling 2.0 1.9 1.8 1.7 1.5 1.4 1.4 :Pine River Rudyard 1.3 1.2 1.2 1.1 1.1 1.0 1.0 :Tobacco River Beaverton 2.5 2.4 2.4 2.4 2.3 2.3 2.2 SPRING FLOOD OUTLOOKS ARE ROUTINELY ISSUED IN FEBRUARY AND MARCH IN ORDER TO GIVE ADVANCE NOTICE OF POSSIBLE FLOODING. THE LONG RANGE PROBABILISTIC OUTLOOKS GIVEN IN THE ABOVE TABLES CONTAIN FORECAST VALUES THAT ARE CALCULATED USING MULTIPLE SEASON SCENARIOS FROM 30 OR MORE YEARS OF CLIMATOLOGICAL DATA...AND INCORPORATE CURRENT RIVER LEVELS...SOIL MOISTURE CONDITIONS...SNOW DEPTH AND SNOW WATER EQUIVALENT VALUES...AND BOTH 30 AND 90 DAY OUTLOOKS FOR TEMPERATURE AND PRECIPITATION PROVIDED BY THE NOAA/NWS CLIMATE PREDICTION CENTER. ACTUAL RIVER CRESTS WILL DIFFER FROM THIS OUTLOOK IF FUTURE CONDITIONS DIFFER SIGNIFICANTLY FROM FORECAST CONDITIONS... OR IF ICE JAMS DEVELOP. ...CURRENT CONDITIONS... AN HISTORICALLY WARM WINTER IS THE DOMINANT FACTOR IN THE BELOW NORMAL SNOWMELT FLOOD PROBABILITIES ACROSS NORTHERN MICHIGAN THIS SPRING...CONTRIBUTING TO A MINIMAL SNOWPACK. AVERAGE TEMPERATURES FOR THE WINTER SEASON (DECEMBER THROUGH FEBRUARY) WERE 6 TO 8 DEGREES ABOVE NORMAL...WHICH WAS A RECORD WARMEST WINTER FOR ALL OF THE MAJOR CLIMATOLOGICAL STATIONS ACROSS NORTHERN MICHIGAN (BY 1 TO 3 DEGREES ABOVE THE PREVIOUS RECORD). THE WARM WEATHER HAS CONTINUED THROUGH THE FIRST TWO WEEKS OF MARCH...WITH DEPARTURES FROM NORMAL AVERAGE TEMPERATURES OF +13 TO +15 DEGREES. AS A RESULT OF ALL OF THIS ANOMALOUS WARMTH...SNOWFALL THUS FAR SINCE JULY 1 IS RUNNING ABOUT 50 TO 75 PERCENT OF NORMAL. A MAJORITY OF THAT SNOWFALL OCCURRED DURING THE PERIOD OF JANUARY 9-23 WHERE SOME LOCATIONS RECEIVED MORE THAN 50 PERCENT OF THEIR SEASONAL TOTAL THUS FAR IN JUST THAT TWO WEEK PERIOD. AS OF MARCH 14...THE ONLY SNOW COVER WAS A MINIMAL AMOUNT REMAINING AROUND THE WEST SIDE OF WHITEFISH BAY. PRECIPITATION DURING THE FALL MONTHS OF 2023 (SEPTEMBER THROUGH NOVEMBER) WAS NEAR NORMAL ACROSS EASTERN UPPER AND NORTHWEST LOWER MICHIGAN...TRENDING BELOW NORMAL (50 TO 75 PERCENT OF NORMAL) CLOSER TO SAGINAW BAY. FOR THE WINTER PERIOD (DECEMBER THROUGH FEBRUARY)... PRECIPITATION WAS 50 TO 75 PERCENT OF NORMAL ACROSS MOST OF NORTHWEST LOWER MICHIGAN AND AREAS ADJACENT TO THE ST. MARY'S RIVER IN EASTERN UPPER MICHIGAN...AND 75 TO 100 PERCENT OF NORMAL ELSEWHERE. MARCH HAS GOTTEN OFF TO A MUCH WETTER START...WITH A LARGE SWATH OF PRECIPITATION AMOUNTS 200 TO 300 PERCENT OF NORMAL ENCOMPASSING MOST OF NORTHERN LOWER MICHIGAN. SOIL MOISTURE IS RUNNING BELOW NORMAL ACROSS EASTERN UPPER AND FAR NORTHWEST LOWER MICHIGAN...ABOUT 20 TO 30 PERCENT OF NORMAL. SOIL MOISTURE IS NEAR NORMAL FOR MUCH OF NORTHEAST LOWER MICHIGAN. CURRENT DROUGHT CONDITIONS BASED ON THE U.S. DROUGHT MONITOR FOR MARCH 14 INDICATES MODERATE DROUGHT CONDITIONS ACROSS EASTERN UPPER MICHIGAN AS WELL AS ACROSS MANISTEE COUNTY IN NORTHWEST LOWER MICHIGAN...AND ABNORMALLY DRY CONDITIONS FOR PARTS OF THE REMAINDER OF NORTHERN LOWER MICHIGAN. HOWEVER RAINFALL OVER THE PAST 10 DAYS HAS ALLEVIATED ANY DROUGHT CONDITIONS ALONG A AXIS FROM CADILLAC TO GAYLORD TO ROGERS CITY. MOST GAUGING STATIONS ON AREA RIVERS ARE RUNNING AT MOSTLY NORMAL STREAMFLOWS. ...WEATHER OUTLOOK... THE CURRENT CLIMATOLOGICAL OUTLOOK FOR THE REMAINDER OF MARCH HAS NO DISCERNIBLE TREND WITH REGARD TO TEMPERATURE (EQUAL PROBABILITIES FOR ABOVE...NORMAL...AND BELOW NORMAL TEMPERATURES)...AND A HIGHER PROBABILITY FOR ABOVE NORMAL PRECIPITATION. THE OUTLOOK FOR THE SPRING (MARCH THROUGH MAY) INDICATES A 50 TO 60 PERCENT PROBABILITY FOR ABOVE NORMAL TEMPERATURES...AND NO DISCERNIBLE TREND WITH REGARD TO PRECIPITATION (EQUAL PROBABILITIES FOR ABOVE...NORMAL...AND BELOW NORMAL PRECIPITATION). ...ADDITIONAL INFORMATION... THIS IS THE FINAL SPRING FLOOD OUTLOOK ISSUANCE FOR THIS YEAR. LONG RANGE PROBABILISTIC OUTLOOKS SUCH AS THOSE GIVEN IN THE ABOVE TABLES ARE ISSUED DURING THE LAST WEEK OF EACH MONTH THROUGHOUT THE YEAR. VISIT WATER.WEATHER.GOV/AHPS2/INDEX.PHP?WFO=APX (ALL LOWER CASE) FOR MORE RIVER INFORMATION...INCLUDING GRAPHS OF THE PROBABILISTIC INFORMATION GIVEN IN THE ABOVE TABLES...AS WELL AS THE LATEST OBSERVED CONDITIONS ON NORTHERN MICHIGAN STREAMS. $$ JPB