580  
FXUS63 KOAX 231042  
AFDOAX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE  
542 AM CDT WED SEP 23 2026  
   
KEY MESSAGES  
 
- THERE IS A 20-40% CHANCE OF SHOWERS IN PORTIONS OF EASTERN  
NEBRASKA WEDNESDAY, BUT EXPECT MORE DRY TIME THAN WET.  
 
- WIDESPREAD SHOWER AND STORM CHANCES RETURN WEDNESDAY NIGHT  
AND LAST THROUGH SATURDAY, WITH CHANCES PEAKING AT 80-90%  
DURING THE OVERNIGHT AND MORNING HOURS EACH DAY.  
 
- COOL WEATHER WILL STICK AROUND WITH THE RAIN CHANCES, FOLLOWED  
BY A BRIEF WARMUP AND DRY PERIOD ON SUNDAY.  
 
- STORM CHANCES RETURN EARLY NEXT WEEK. SATURATED SOIL COMBINED  
WITH POTENTIAL FOR HEAVY RAIN MAY YIELD A FLOODING THREAT.  
 
 
   
DISCUSSION  
 
ISSUED AT 1118 PM CDT TUE SEP 22 2026  
 
WATER VAPOR IMAGERY THIS EVENING SHOWED A SHORTWAVE TROUGH  
SLIDING ACROSS NORTHEAST NE INTO WESTERN IA WITH AN UPPER LEVEL  
RIDGE AXIS JUST TO OUR WEST. SAID SHORTWAVE ALONG WITH WARM AIR  
ADVECTION AND SOME WEAK FRONTOGENESIS ALOFT WAS LEADING TO  
SHOWERS AND A FEW STORMS ACROSS THE EASTERN SANDHILLS. THESE  
WILL SLOWLY CONTINUE EASTWARD, THOUGH HAVE SHOWN A DIMINISHING  
TREND AS THEY HAVE DONE SO OWING TO LESS INSTABILITY THIS WAY,  
SO NOT EXPECTING THEM TO AMOUNT TO MUCH IN OUR AREA. HOWEVER,  
ADDITIONAL DEVELOPMENT IS EXPECTED OVERNIGHT AS MOISTURE  
TRANSPORT RAMPS UP WITH LATEST SHORT TERM GUIDANCE IN DECENT  
AGREEMENT OF AT LEAST SOME SPOTTY SHOWERS LINGERING ACROSS  
NORTHEAST NE INTO THE AFTERNOON. A FEW SOLUTIONS EVEN SHOW THOSE  
SHOWERS EXTENDING AS FAR SOUTH AS THE KS BORDER. AS IT STANDS,  
HAVE 30-40% CHANCES IN FAR NORTHEAST NE AND 20% CHANCES  
EXTENDING SOUTH FROM THERE, BUT DIMINISHING AS THEY PUSH EAST  
TOWARD LINCOLN AND OMAHA. IN GENERAL, STILL EXPECT MUCH MORE DRY  
TIME THAN WET DURING THE DAY WEDNESDAY AS THAT AFOREMENTIONED  
RIDGE AXIS PUSHES EAST THROUGH THE AREA.  
 
ON ITS HEELS, THOUGH, WILL BE A STEADY STREAM OF SHORTWAVE  
ENERGY OUT OF THE DESERT SOUTHWEST, WARM AIR ADVECTION, AND  
MOISTURE TRANSPORT THAT WILL LEAD TO PERSISTENT RAIN CHANCES  
LASTING INTO SATURDAY. CHANCES ACROSS MOST OF THE AREA NEVER DIP  
BELOW 40% IN THAT PERIOD AND GENERALLY PEAK AROUND 80-90% IN  
THE OVERNIGHT/MORNING HOURS. WITH LIMITED INSTABILITY, NOT  
EXPECTING MUCH IN THE WAY OF THUNDERSTORMS, THOUGH WITH  
PRECIPITABLE WATER VALUES IN THE 1.50-1.75+ INCH RANGE  
(APPROACHING THE 99TH PERCENTILE OF CLIMATOLOGY FOR THIS TIME OF  
YEAR) THERE COULD BE SOME PERIODS OF VERY EFFICIENT RAIN  
PRODUCTION. TOTALS THROUGH THAT PERIOD LOOK TO BE IN THE 1-2"  
RANGE FOR MOST OF THE AREA. TEMPERATURES ALSO LOOK TO REMAIN ON  
THE COOLER SIDE, WITH HIGHS IN THE 60S TO AROUND 70 THROUGH  
FRIDAY. ASSUMING PRECIP TAPERS OFF BY SATURDAY AFTERNOON, WE  
SHOULD SEE SOME MID TO UPPER 70S RETURN TO THE AREA. UPPER LEVEL  
RIDGING WILL BUILD IN ON SUNDAY AND LEAD TO A DRY AND WARMER  
DAY WITH A FEW SPOTS IN SOUTHEAST NE AND SOUTHWEST IA MAKING A  
RUN AT 80 DEGREES.  
 
HEADING INTO EARLY NEXT WEEK, THERE IS GOOD AGREEMENT THAT  
SHOWER AND STORM CHANCES WILL RETURN, BUT THERE REMAINS QUITE A  
BIT OF SPREAD IN TIMING OF THOSE CHANCES. THE GENERAL IDEA IS  
THAT THE UPPER LEVEL RIDGE PUSHES OFF TO THE EAST WITH SOUTHERLY  
FLOW ALLOWING A GOOD PLUME OF GULF MOISTURE TO PUSH INTO THE  
AREA. IN ADDITION, SOME GUIDANCE HINTS THAT SOME TROPICAL  
MOISTURE OUT OF THE PACIFIC ON THE EDGES OF HURRICANE POLO COULD  
WORK ITS WAY TOWARD THE AREA. EVENTUALLY, A POTENT SHORTWAVE  
TROUGH PUSHES STRAIGHT EAST OUT OF CA, SPINNING UP A SURFACE LOW  
EAST OF THE ROCKIES, WITH THE SYSTEM EVENTUALLY MOVING THROUGH  
THE FORECAST AREA AND GIVING US WIDESPREAD SHOWER AND STORM  
CHANCES. AGAIN, TIMING OF THIS WAVE IS STILL UP IN THE AIR, BUT  
IT LOOKS TO BE SOMETIME MONDAY OR TUESDAY, WITH MAYBE A SLIGHT  
TREND TOWARD BEING LATER. GIVEN THE POTENTIAL TROPICAL MOISTURE  
PLUME IN PLACE WITH A LITTLE INSTABILITY AND THE EXPECTED  
RAINFALL A FEW DAYS PRIOR FURTHER SATURATING THE GROUND, A  
FLOODING THREAT COULD DEVELOP. IN ADDITION, GIVEN THE STRENGTH  
OF THE SYSTEM, THERE WILL LIKELY BE SOME DECENT SHEAR IN PLACE,  
WHICH COULD YIELD A SEVERE THUNDERSTORM THREAT. FOR WHAT IT'S  
WORTH, MACHINE LEARNING SEVERE WEATHER GUIDANCE IS STARTING TO  
SUGGEST AT LEAST A 5% CHANCE OF SEVERE STORMS BY MONDAY. WOULD  
EXPECT THAT TO INCREASE A BIT SOMEWHERE IN THE REGION AS  
ENSEMBLE GUIDANCE COMES INTO BETTER AGREEMENT ON SYSTEM TIMING.  
OVERALL, STILL A LOT OF DETAILS TO WORK OUT, BUT EARLY NEXT WEEK  
WILL BE A TIME PERIOD TO KEEP AN EYE ON.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/  
 
ISSUED AT 539 AM CDT WED SEP 23 2026  
 
THE WORST CONDITIONS OF THE TAF PERIOD ARE SET TO OCCUR FOR THE  
NEXT 2-3 HOURS, WITH MVFR TO IFR CEILINGS IN PLACE AT ALL THREE  
TERMINALS. SCATTERED SHOWERS AND STORMS REMAIN WEST OF KOFK AS  
OF THE START OF THE PERIOD, WITH THE EXPECTATION BEING THAT  
THEY'LL DRIFT EAST AND DROP ANY LIGHTNING THEY HAD AS THEY PASS.  
CONFIDENCE IS MUCH LOWER IN THOSE SHOWERS AFFECTING KOMA/KLNK,  
SO THEY DID NOT MAKE THE CUT FOR THIS TAF ISSUANCE. OTHERWISE,  
SOUTHEASTERLY WINDS WILL CONTINUE WITH SOME GUSTS THIS AFTERNOON  
OF OVER 20 KTS AT KOFK, WITH VFR CONDITIONS RETURNING THIS  
AFTERNOON. TOWARDS THE END/JUST BEYOND THE TAF PERIOD,  
ADDITIONAL SHOWERS AND STORMS MOVE IN FROM THE SOUTHWEST  
THURSDAY MORNING.  
 
 
   
OAX WATCHES/WARNINGS/ADVISORIES  
 
NE...NONE.  
IA...NONE.  
 
 
 
 
 
DISCUSSION...CA  
AVIATION...PETERSEN  
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