868  
FXUS63 KOAX 181106  
AFDOAX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE  
606 AM CDT TUE AUG 18 2026  
   
KEY MESSAGES
 
 
- STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TONIGHT INTO  
EARLY TUESDAY AFTERNOON. LARGE HAIL, DAMAGING WINDS, HEAVY  
RAIN, AND AN ISOLATED TORNADO ARE POTENTIAL HAZARDS.  
 
- COOLER TEMPERATURES ARRIVE BEHIND A COLD FRONT ON TUESDAY  
AND WEDNESDAY. LINGERING SHOWERS AND THUNDERSTORMS ARE  
ANTICIPATED WITH A LOW CHANCE OF A STRONG TO SEVERE  
THUNDERSTORMS.  
 
- A WARMING TREND BEGINS ON THURSDAY WITH TEMPERATURES GRADUALLY  
INCREASING INTO THE 80S. PERIODIC RAIN CHANCES REMAIN IN THE  
FORECAST.  
 

 
   
DISCUSSION
 
 
ISSUED AT 1250 AM CDT TUE AUG 18 2026  
 
WIDESPREAD STRONG TO SEVERE THUNDERSTORMS HAVE DEVELOPED ACROSS  
WESTERN SOUTH DAKOTA AND NEBRASKA. CLOSER TO OUR AREA, A FEW  
RELATIVELY ISOLATED SEVERE THUNDERSTORMS HAVE FORMED IN A WEAK  
CONFLUENCE ZONE OVER NORTHEAST NEBRASKA. ALL THIS ACTIVITY IS  
EXPECTED TO SPREAD EAST THROUGH THE REMAINDER OF THE EVENING INTO AT  
LEAST EARLY TUESDAY AFTERNOON AS MULTIPLE ROUNDS OF THUNDERSTORMS.  
THIS BROAD AREA OF STRONG TO SEVERE WEATHER IS ASSOCIATED WITH A  
WEAK UPPER-LEVEL TROUGH MOVING ACROSS THE NORTHERN PLAINS AND A WEAK  
COLD FRONT DRAPED OVER THE REGION. THESE FEATURES ARE HELPING TO  
INITIATE WIDESPREAD ACTIVITY OVER A SEASONABLY UNSTABLE AIRMASS. IN  
ADDITION, STRONGER WESTERLY AND NORTHWESTERLY UPPER-LEVEL WINDS HAVE  
BEGUN TO OVERSPREAD THE AREA HELPING TO INCREASE EFFECTIVE WIND  
SHEAR TO BETWEEN 40-50 KTS. THE COMBINATION OF ALL THESE FACTORS IS  
RESULTING IN A COMBINED THREAT OF LARGE HAIL, DAMAGING WINDS, HEAVY  
RAIN, AND PERHAPS A TORNADO OR TWO.  
 
HEADING INTO TUESDAY, A COMBINATION OF THE COLD FRONT AND OUTFLOW  
BEHIND LATE MORNING AND EARLY AFTERNOON THUNDERSTORMS SHOULD LIMIT  
THE AMOUNT OF ADDITIONAL THUNDERSTORMS LATER TUESDAY AFTERNOON. THAT  
SAID, AREAS OF FAR SOUTHEAST NEBRASKA NEAREST THE COLD FRONT MAY SEE  
ADDITIONAL AFTERNOON THUNDERSTORMS BY AFTERNOON. AT LEAST SOME RISK  
OF SEVERE WEATHER IS EXPECTED WITH THIS ACTIVITY. FURTHER TO THE  
NORTH, A COOLER AND MORE STABLE AIRMASS SHOULD LIMIT ADDITIONAL  
THUNDERSTORM DEVELOPMENT. A FEW SHOWERS AND THUNDERSTORMS MAY LINGER  
DESPITE THIS. THE SEVERE WEATHER THREAT WITH THIS ACTIVITY WILL BE  
COMPARATIVELY LOWER. OTHERWISE, COOLER TEMPERATURES BEGIN TO FILTER  
INTO THE REGION BEHIND THE FRONT, BRINGING AFTERNOON HIGHS IN THE  
70S FOR MANY.  
 
WEDNESDAY SEES TEMPERATURES IN THE 70S ONCE AGAIN. OUR NEXT WEATHER  
SYSTEM BEGINS TO PUSH INTO THE NORTHERN PLAINS BY WEDNESDAY  
AFTERNOON. INITIAL THUNDERSTORMS DEVELOPMENT IS EXPECTED TO THE WEST  
OF THE REGION, BUT THIS IS FORECAST TO SPREAD EAST INTO OUR AREA BY  
WEDNESDAY EVENING INTO THE OVERNIGHT HOURS. SEVERE WEATHER MAY AGAIN  
BE A POTENTIAL HAZARD WITH THIS ACTIVITY, BUT THIS THREAT IS LOW  
CURRENTLY.  
 
HEADING INTO THURSDAY AND BEYOND, A GRADUAL WARMING TREND BEGINS.  
AFTERNOON HIGH TEMPERATURES RETURN TO THE 80S. THE BROAD PATTERN  
ACROSS THE NORTHERN PLAINS DOES NOT CHANGE SUBSTANTIALLY DURING THIS  
TIME, THIS WILL RESULT IN CONTINUED PERIODIC RAIN CHANCES FOR THE  
REGION WITH STEADY TEMPERATURES.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
 
 
ISSUED AT 606 AM CDT TUE AUG 18 2026  
 
THUNDERSTORMS WILL CONTINUE TO PUSH THROUGH THE AREA THIS  
MORNING, WITH OCCASIONAL MVFR TO IFR CONDITIONS AND PERIODS OF  
GUSTY WINDS. SOME ADDITIONAL DEVELOPMENT IS POSSIBLE THIS  
AFTERNOON/EVENING, BUT LATEST GUIDANCE SUGGESTS HIGHEST CHANCES  
WILL BE SOUTHEAST OF THE TAF SITES. STILL SOME QUESTIONS ON  
CEILINGS FOLLOWING THE MAIN STORMS THIS MORNING, WITH SOME  
GUIDANCE HINTING AT LINGERING MVFR CEILINGS, BUT FOR NOW KEPT  
VFR. WINDS WILL ALSO BE SOMEWHAT VARIABLE AND TURNING THROUGH  
THE DAY, BUT SHOULD GENERALLY REMAIN LIGHT OUTSIDE OF STORMS.  
EVENTUALLY EXPECT NORTHERLY TO NORTHEASTERLY BY LATE  
AFTERNOON/EVENING.  
 

 
   
OAX WATCHES/WARNINGS/ADVISORIES
 
 
NE...NONE.  
IA...NONE.  
 

 
 

 
 
DISCUSSION...CHEHAK  
AVIATION...CA  
 
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