196  
FXUS01 KWBC 170759  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
358 AM EDT THU SEP 17 2026  
 
VALID 12Z THU SEP 17 2026 - 12Z SAT SEP 19 2026  
 
...ADDITIONAL FLASH FLOODING EXPECTED OVER SECTIONS OF THE  
SOUTHWEST, NORTHERN PLAINS, AND UPPER MIDWEST OVER THE NEXT THREE  
DAYS...  
 
...RECORD-CHALLENGING HIGH TEMPERATURES CONTINUE ACROSS THE  
SOUTH-CENTRAL U.S....  
 
AFTER A VERY ACTIVE DAY OF FLASH FLOODING ACROSS THE SOUTHWEST AND  
GREAT BASIN, THE FOCUS FOR HEAVY RAINFALL IS EXPECTED TO SHIFT  
TOWARDS THE SOUTHERN ROCKIES AHEAD OF A MOISTURE-LADEN DISTURBANCE  
ACTING TO ENHANCE SHOWERS AND THUNDERSTORMS. WHILE THE OVERALL  
COVERAGE OF STORMS WILL BE LOWER THAN YESTERDAY, ANY FLASH  
FLOODING COULD BE SIMILARLY IMPACTFUL AS HIGH RAINFALL RATES  
CONTINUE AMID THE ANOMALOUS MOISTURE IN PLACE. THE SAME SOUTHERN  
ROCKIES DISTURBANCE WILL EVENTUALLY TRIGGER THE FORMATION OF A NEW  
LOW-PRESSURE SYSTEM OVER THE CENTRAL HIGH PLAINS TONIGHT. AS THIS  
SYSTEM CONSOLIDATES IN THE OVERNIGHT HOURS, A DEVELOPING AXIS OF  
HEAVY RAINFALL ALONG THE FRONT WILL SUPPORT THE THREAT OF WIDELY  
SCATTERED FLASH FLOODING FROM THE NORTHERN PLAINS TO THE UPPER  
MIDWEST TOMORROW AND SATURDAY.  
 
AS WE GET INTO MID-SEPTEMBER, COOLER AIR FROM CANADA IS BEGINNING  
TO DIP INTO THE NORTHERN TIER STATES, BRINGING COOLER THAN NORMAL  
TEMPERATURES BEHIND THE AFOREMENTIONED LOW-PRESSURE AREA.  
MEANWHILE, AN UPPER-LEVEL HIGH ASSOCIATED WITH THE PERSISTENT HEAT  
DOME REMAINS STRONG ACROSS THE SOUTH, RESULTING IN A PRONOUNCED  
NORTH-SOUTH TEMPERATURE CONTRAST. HIGH TEMPERATURES IN THE LOW 70S  
AND UPPER 60S CAN BE EXPECTED NORTH OF THE MEANDERING FRONT IN THE  
CENTRAL PLAINS AND MIDWEST, COMPARED TO UPPER 90S AND TRIPLE-DIGIT  
HIGHS SOUTH OF THE FRONT ACROSS THE SOUTHERN PLAINS AND MID/LOWER  
MISSISSIPPI VALLEY. UNFORTUNATELY, THE WESTERN END OF THE FRONT  
LIFTING NORTHWARD MEANS THAT THE HAZARDOUS HEAT IS HERE TO STAY  
THIS WEEK ACROSS THE SOUTH. IN FACT, HIGH TEMPERATURES REACHING  
INTO THE UPPER 90S TO LOWER 100S WILL CHALLENGE DAILY RECORDS FROM  
THE SOUTHERN PLAINS TO THE LOWER MISSISSIPPI VALLEY WHERE HEAT  
ADVISORIES REMAIN IN EFFECT. MEANWHILE, INSTABILITY ASSOCIATED  
WITH A STATIONARY FRONT ON THE SOUTHERN EDGE OF THE HEAT DOME WILL  
CONTINUE TO BRING SCATTERED THUNDERSTORMS WITH HEAVY DOWNPOURS  
ACROSS MUCH OF THE SUNSHINE STATE, ALTHOUGH EXCESSIVE RAINFALL IS  
NOT EXPECTED FROM THIS ACTIVITY.  
 
ASHERMAN/KONG  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 
 
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