421  
AWUS01 KWNH 210202  
FFGMPD  
MIZ000-WIZ000-MNZ000-NDZ000-210800-  
 
MESOSCALE PRECIPITATION DISCUSSION 0488  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1001 PM EDT FRI JUN 20 2025  
 
AREAS AFFECTED...EASTERN NORTH DAKOTA, NORTHERN MINNESOTA,  
NORTHWESTERN WISCONSIN  
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE  
 
VALID 210200Z - 210800Z  
 
SUMMARY...CONVECTION IS EXPECTED TO RAPIDLY DEEPEN AND EXPAND IN  
COVERAGE ACROSS THE DISCUSSION AREA IN THE 03-08Z (10P-3A CDT)  
TIMEFRAME. THESE STORMS WILL EXHIBIT MERGERS AND LOCALIZED  
TRAINING, WITH A RISK OF 2 INCH/HR RAIN RATES AND A FEW AREAS OF  
FLASH FLOODING.  
 
DISCUSSION...INTENSE, DEEP CONVECTION HAS BEGUN TO QUICKLY FORWARD  
PROPAGATE EASTWARD ACROSS SOUTHWESTERN SOUTH DAKOTA. MEANWHILE,  
ISOLATED CELLS HAVE FORMED ON THE NOSE OF STRENGTHENING LOW-LEVEL  
FLOW ACROSS EASTERN SOUTH DAKOTA, WITH SUPERCELLULAR STRUCTURES  
NOTED NEAR JAMESTOWN, ND. THESE STORMS ARE EXHIBITING A LIMITED  
FLASH FLOOD RISK AT THE MOMENT, WITH FAST STORM MOTIONS ACROSS  
WESTERN NORTH DAKOTA AND ISOLATED STORM COVERAGE IN EASTERN NORTH  
DAKOTA BOTH LIMITING THE SPATIAL EXTENT OF ANY HEAVY RAINFALL. A  
FEW SPOTS OF 2 INCH/HR RAIN RATES NEAR JAMESTOWN COULD PROMPT  
ISOLATED FLASH FLOOD ISSUES IN THE SHORT TERM.  
 
OVER TIME (MORE LIKELY AFTER 03Z/10P CDT), INCREASING LOW-LEVEL  
FLOW ACROSS THE EASTERN DAKOTAS AND STRONG SPEED CONVERGENCE ALONG  
THE NOSE OF THAT LOW-LEVEL FLOW ACROSS NORTHERN MINNESOTA WILL  
COMBINE WITH STRONG INSTABILITY (1500-4000 J/KG MLCAPE) TO PRODUCE  
WIDESPREAD THUNDERSTORM ACTIVITY. THESE STORMS SHOULD EVENTUALLY  
CONCENTRATE ALONG AN AXIS FROM NEAR/NORTH OF FARGO TO NER DULUTH.  
THEY'LL ALSO FORM IN CLOSE ENOUGH PROXIMITY TO PROMOTE OCCASIONAL  
MERGERS AND LOCALIZED TRAINING, WITH SPOTS OF 2 INCH/HR RAIN RATES  
EXPECTED AT TIMES. ADDITIONALLY, STORMS SHOULD EVENTUALLY MERGE  
WITH UPSTREAM CONVECTION ACROSS NORTH DAKOTA, PROVIDING FURTHER  
OPPORTUNITY FOR PROLONGING OF HEAVY RAIN RATES AT ANY ONE SPOT.  
WIDESPREAD 1-3 INCH RAINFALL TOTALS ARE EXPECTED BENEATH THE  
CONVECTION, WITH LOCAL AMOUNTS OF 5 INCHES POSSIBLE WHERE  
TRAINING/MERGERS ARE MOST PRONOUNCED. THESE RATES WILL FALL ON  
AREAS OF 1-2 INCH/HR FFG THRESHOLDS (LOWEST ALONG THE ND/MN BORDER  
AND ACROSS NORTHEASTERN MINNESOTA), WITH EXCEEDENCE EXPECTED AT  
TIMES. FLASH FLOODING IS POSSIBLE IN THIS SCENARIO.  
 
COOK  
   
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...BIS...DLH...FGF...GRB...MPX...MQT...  
 
ATTN...RFC...KRF...MSR...NWC...  
 
LAT...LON 48909458 48399232 47819106 47079065 45809004  
45429061 45729145 46589408 46639663 46399986  
46820093 47540036 47839969 48409860 48889700  
 
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