972  
FXUS01 KWBC 151943  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
343 PM EDT SAT JUN 15 2024  
 
VALID 00Z SUN JUN 16 2024 - 00Z TUE JUN 18 2024  
 
...MULTIPLE ROUNDS OF LOCALLY HEAVY RAIN WITH THE RISK FOR FLASH  
FLOODING, AS WELL AS SEVERE THUNDERSTORMS, EXPECTED IN THE  
NORTH-CENTRAL U.S....  
 
...LATE-SEASON WET SNOW IS FORECAST FOR THE NORTHERN ROCKIES  
BEGINNING ON MONDAY...  
 
...A HEAT WAVE WILL QUICKLY SPREAD FROM THE PLAINS SUNDAY INTO THE  
GREAT LAKES/UPPER OHIO VALLEY ON MONDAY...  
 
...A PLUME OF TROPICAL MOISTURE WILL BRING THE THREAT FOR HEAVY  
DOWNPOURS AND FLASH FLOODING TO THE CENTRAL GULF COAST...  
 
CLUSTERS OF SHOWERS AND THUNDERSTORMS ARE FORECAST TO DEVELOP  
AHEAD OF A SHORTWAVE AND IN VICINITY OF A WARM FRONT LIFTING  
NORTHWARD OVER THE UPPER MISSISSIPPI VALLEY SATURDAY EVENING. A  
SLIGHT RISK OF EXCESSIVE RAINFALL (LEVEL 2/4) HAS BEEN ISSUED FOR  
THE REGION AS RICH MOISTURE MOVING NORTHWARD WITH THE FRONT AND  
OVERNIGHT LOW LEVEL JET MAY LEAD TO SOME HEAVIER DOWNPOURS AND  
LOCALIZED FLASH FLOODING. JUST TO THE WEST, A DEEPER UPPER-LEVEL  
LOW AND THE MAIN ACCOMPANYING SURFACE LOW PRESSURE/FRONTAL SYSTEM  
WILL BEGIN TO PROGRESS SLOWLY EASTWARD THROUGH THE NORTHERN PLAINS  
AND INTO THE UPPER MIDWEST OVER THE NEXT COUPLE OF DAYS, BRINGING  
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WITH BOTH THE RISK  
FOR HEAVY RAINFALL/FLASH FLOODING AS WELL AS SEVERE WEATHER. SOME  
SEVERE STORMS WILL BE POSSIBLE SATURDAY EVENING AHEAD OF THE COLD  
FRONT OVER THE NORTHERN HIGH PLAINS WHERE THE STORM PREDICTION  
CENTER HAS OUTLINED A SLIGHT RISK (LEVEL 2/5) FOR THE THREAT OF  
VERY LARGE HAIL, SIGNIFICANT DAMAGING WINDS, AND A FEW TORNADOES.  
THE FRONT WILL PROGRESS SOUTHEASTWARD THROUGH THE DAY SUNDAY  
BEFORE STALLING OUT SUNDAY EVENING, WITH THE NEXT ROUND OF STORMS  
EXPECTED ALONG AN AXIS FROM THE UPPER MISSISSIPPI VALLEY  
SOUTHWESTWARD INTO THE UPPER MISSOURI VALLEY. A SLIGHT RISK OF  
EXCESSIVE RAINFALL IS IN EFFECT AS CLUSTERING OF STORMS WITH  
REPETITIVE MOTIONS ALONG THE STALLING FRONT WITH ABUNDANT MOISTURE  
AVAILABLE WILL LEAD TO HEAVY RAINFALL RATES/TOTALS AND THE RISK  
FOR FLASH FLOODING. A SLIGHT RISK OF SEVERE WEATHER IS ALSO IN  
PLACE FOR THE THREAT OF SOME LARGE HAIL. LEE CYCLOGENESIS OVER THE  
CENTRAL HIGH PLAINS AHEAD OF ANOTHER UPPER-LEVEL WAVE OVER THE  
WEST WILL BRING STRENGTHENING SOUTHERLY FLOW, WITH THE STALLED  
FRONT EXPECTED TO BEGIN SLOWLY LIFTING BACK TO THE NORTH AS A WARM  
FRONT THROUGH THE UPPER MISSISSIPPI VALLEY ON MONDAY. A MODERATE  
RISK OF EXCESSIVE RAINFALL (LEVEL 3/4) HAS BEEN INTRODUCED AS  
CLUSTERING/SLOW-MOVING STORMS ALONG THE BOUNDARY AS WELL AS STILL  
ABUNDANT MOISTURE AND IMPRESSIVE UPPER-LEVEL DYNAMICS WILL PROMOTE  
MORE WIDESPREAD, INTENSE DOWNPOURS AND POTENTIALLY NUMEROUS,  
SIGNIFICANT INCIDENTS OF FLASH FLOODING. THIS RISK WILL CONTINUE  
INTO MONDAY EVENING/NIGHT, JUST BEYOND THE CURRENT FORECAST  
PERIOD. A SLIGHT RISK FOR THE THREAT OF SOME LARGE HAIL AND  
DAMAGING WINDS IS ALSO IN PLACE.  
 
ANOTHER IMPACT FROM THIS UNSEASONABLY STRONG SERIES OF UPPER-LEVEL  
SYSTEMS FOR MID-JUNE WILL BE MUCH COLDER AIR SWEEPING SOUTHWARD TO  
THE WEST OF THE COLD FRONT, PARTICULARLY INTO THE NORTHERN  
ROCKIES. HIGH TEMPERATURES WILL BE MOSTLY IN THE 60S SUNDAY FROM  
THE PACIFIC NORTHWEST EAST THROUGH THE NORTHERN GREAT BASIN AND  
INTO THE NORTHERN ROCKIES. THESE COOLER TEMPERATURES WILL SPREAD  
FURTHER SOUTHWARD IN THE GREAT BASIN AND INTO THE NORTHERN PLAINS  
BY MONDAY. HIGHS FOR THE MOUNTAIN VALLEYS OF THE NORTHERN ROCKIES  
WILL ONLY BE IN THE 40S AND 50S. PRECIPITATION CHANCES WILL ALSO  
PICK UP HERE MONDAY, WITH A WINTER STORM WATCH IN EFFECT FOR THE  
POTENTIAL OF SEVERAL INCHES OF SNOW AT HIGHER MOUNTAIN ELEVATIONS.  
WHILE A MOSTLY COLD RAIN IS EXPECTED AT LOWER ELEVATIONS, A FEW OF  
THE HIGHER MOUNTAIN VALLEYS MAY SEE SOME SNOW MIX IN.  
 
WHILE CONDITIONS WILL BE WELL BELOW AVERAGE FOR MUCH OF THE WEST,  
MUCH ABOVE AVERAGE, HOT SUMMER TEMPERATURES OVER THE PLAINS WILL  
BEGIN TO SPREAD EASTWARD INTO THE GREAT LAKES/UPPER OHIO VALLEY AS  
AN INTENSE HEAT WAVE BEGINS TO SETTLE IN FOR THE REGION. FORECAST  
HIGHS SUNDAY WILL BE IN THE MID- TO UPPER 90S FROM THE CENTRAL  
PLAINS INTO THE UPPER MIDWEST, WITH UPPER 80S AND LOW 90S MORE  
BROADLY THROUGH THE GREAT LAKES. HIGHS MONDAY THEN SOAR INTO THE  
MID- AND EVEN UPPER 90S FOR THE GREAT LAKES/UPPER OHIO VALLEY  
MONDAY AS WELL, WITH NUMEROUS RECORD-TYING/BREAKING HIGHS  
POSSIBLE. MORNING LOWS WILL BE JUST AS IMPRESSIVE, AS TEMPERATURES  
REMAIN IN THE MID- TO EVEN UPPER 70S. THE COMBINATION OF HEAT,  
HUMIDITY, AND LITTLE OVERNIGHT RELIEF WILL BRING POTENTIALLY  
WIDESPREAD, SIGNIFICANT HEAT-RELATED IMPACTS TO ANYONE WITHOUT  
ADEQUATE HYDRATION OR RELIABLE COOLING. UNFORTUNATELY, MONDAY WILL  
BE JUST THE START AS THIS HEATWAVE IS EXPECTED TO CONTINUE THROUGH  
THIS WEEK AND INTO NEXT WEEKEND AS A STRONG UPPER-LEVEL HIGH  
REMAINS STAGNANT OVER THE EASTERN U.S.  
 
TO THE SOUTH, AN IMPRESSIVE FLOW OF MOISTURE FROM THE CARIBBEAN ON  
THE WESTERN SIDE OF THE RIDGE WILL STREAM INTO THE CENTRAL GULF  
COAST OVER THE NEXT COUPLE OF DAYS. WHILE THERE WILL BE A LACK OF  
UPPER-LEVEL FORCING, THE CONTINUAL INFLUX OF MOISTURE WILL BE  
ENOUGH TO BRING MULTIPLE ROUNDS OF CONVECTION WITH THE POTENTIAL  
TO PRODUCE VERY HEAVY DOWNPOURS. THE RATHER STAGNANT FLOW WILL  
ALSO LEAD TO SLOW-MOVING, CLUSTERING STORMS, INCREASING THE  
LIKELIHOOD OF HEAVIER RAINFALL TOTALS. SLIGHT RISKS OF EXCESSIVE  
RAINFALL ARE IN PLACE FOR BOTH SUNDAY AND MONDAY FOR THE THREAT OF  
SOME SCATTERED FLASH FLOODING, PARTICULARLY FOR URBAN AREAS. THE  
THREAT ON MONDAY MAY BECOME MORE SIGNIFICANT IF NEW STORMS OVERLAP  
AREAS THAT SEE HEAVY RAINFALL ON SUNDAY.  
 
PUTNAM  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 

 
 
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