407  
FGUS75 KTFX 292028  
ESFTFX  
MTC013-015-035-041-045-049-051-059-073-099-101-300600-  
 
HYDROLOGIC OUTLOOK  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
228 PM MDT FRI MAY 29 2026  
 
WHAT: HEAVY HEAVY RAINFALL SATURDAY INTO MONDAY.  
 
WHERE: GREATEST IMPACTS WILL BE ALONG AND WEST OF THE I-15 CORRIDOR  
OF NORTH-CENTRAL MT.  
 
TIMING: THE WINDOW FOR THE HEAVIEST RAINFALL WILL BE BETWEEN  
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. HERE, RAINFALL RATES OF  
0.5" TO 0.75" EVERY 6 HOURS ARE POSSIBLE. LIGHT TO MODERATE RAINFALL  
LINGERS THROUGH AT LEAST MONDAY.  
 
DETAILS:  
 
RAINFALL AMOUNTS RANGE FROM 1 TO 3 INCHES FOR THE AREA, WITH A 10%  
CHANCE FOR 4 INCHES ALONG AND WEST OF THE I-15 CORRIDOR. ADDITIONAL  
SNOWMELT RUNOFF FROM THE ROCKY MOUNTAIN FRONT CAN ENHANCE CREEK AND  
RIVER RISES INCLUDING BUT NOT LIMITED TO THE SUN RIVER, MARIAS  
RIVER, AND SAINT MARY RIVER. LOW LYING-AREAS AND POOR DRAINAGE AREAS  
ARE ALSO AT RISK FOR FLOODING. RURAL DIRT ROADS WILL BE SUSCEPTIBLE  
TO BECOME WASHED OUT OR IMPASSABLE.  
 
DUE TO INCREASING CONFIDENCE IN FLOOD IMPACTS, A FLOOD WATCH WAS  
ISSUED FOR AREAS ALONG AND WEST OF THE I-15 CORRIDOR FOR  
NORTH-CENTRAL MT SATURDAY THROUGH MONDAY. RIVERS AND CREEKS ARE  
EXPECTED TO CREST MONDAY, WHICH CAN LINGER IMPACTS FOR AREAS PRONE  
TO RIVER/CREEK FLOODING. AREAS FARTHER EAST OF THE I-15 CORRIDOR ARE  
EXPECTED TO SEE LESSER FLOOD IMPACTS.  
 
EVERYONE IS REMINDED THAT SHOULD FLOODING DEVELOP, REGARDLESS IF THE  
ROADWAY IS PAVED OR NOT, DO NOT DRIVE THROUGH ANY FLOOD WATERS, AS  
YOU DO NOT KNOW IF THE ROAD HAS BEEN WASHED OUT UNDER THE FLOOD  
WATERS.  
 
PLEASE MONITOR THE NATIONAL WEATHER SERVICE OR THE LOCAL MEDIA THIS  
WEEKEND FOR FURTHER UPDATES ON THIS SPRING STORM.  
 
 
WILSON  
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