105
FXUS63 KOAX 140417
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1117 PM CDT SUN SEP 13 2026
KEY MESSAGES
- TWO ROUNDS OF STORMS CAN BE EXPECTED MONDAY. THE FIRST DURING
THE EARLY MORNING HOURS WITH A STRONG STORM OR TWO POSSIBLE.
THE SECOND ROUND, IN THE LATE AFTERNOON AND EVENING, BRINGS A
CONDITIONAL RISK FOR SEVERE STORMS CAPABLE OF PRODUCING LARGE
HAIL, DAMAGING WINDS, HEAVY RAIN, AND TORNADOES.
- COOLER WEATHER AND DAILY CHANCES FOR SHOWERS AND STORMS CAN BE
EXPECTED THROUGH THE MAJORITY OF THE WEEK.
DISCUSSION
ISSUED AT 1112 PM CDT SUN SEP 13 2026
TONIGHT THROUGH MONDAY...
A FEW SPOTTY SHOWERS AND SPRINKLES LINGERED OVER THE FORECAST AREA
THIS EVENING, WITH TEMPERATURES FINALLY FEELING CRISP AND FALL-LIKE,
IN THE UPPER 50S.
QUIET NIGHTTIME SKIES WILL BE INTERRUPTED BY A LINE OF CONVECTION
DEVELOPING ALONG AN ELEVATED BOUNDARY EARLY MONDAY MORNING, FROM
SOUTHEAST THROUGH NORTHEAST NEBRASKA. WHILE A STRONG STORM OR TWO
CAN'T BE TOTALLY RULED OUT, WEAK INSTABILITY AND THE ELEVATED NATURE
OF THE STORMS WILL LIKELY LIMIT LARGE HAIL AND STRONG WIND
PRODUCTION.
A STOUT LOW LEVEL JET WILL HELP ADVECT WARMER AIR INTO THE REGION
TOMORROW AFTERNOON, AS MORNING CONVECTION SHIFTS OFF TO THE EAST.
EXPECT SCATTERED SHOWERS WITH A FEW EMBEDDED RUMBLES OF THUNDER TO
DEVELOP ACROSS THE FORECAST AREA TOMORROW AFTERNOON, AS A MOIST
UNSTABLE AIRMASS BUILDS INTO THE CENTRAL PLAINS. HIGHS TOMORROW
AFTERNOON WILL TOP OUT IN THE 80S, WITH A FEW LOCATIONS REACHING THE
LOW 90S IN FAR SOUTHEAST NEBRASKA. HOWEVER, THIS WARM-UP WILL BE
BRIEF, AS A COLD FRONT APPROACHES FROM THE WEST MONDAY AFTERNOON AND
EVENING. OUT NEXT CONDITIONAL THREAT FOR SEVERE WEATHER WILL DEVELOP
AHEAD OF THIS FRONT, IN A FAIRLY IMPRESSIVE ENVIRONMENT. FORECAST
SOUNDINGS INDICATE 2000-3000+ J/KG OF CAPE, STEEP LAPSE RATES, 30-
40KTS OF LOW AND DEEP LAYER SHEAR, AS WELL AS NOTABLE LOW LEVEL
TURNING IN HODOGRAPHS. THESE WOULD SUGGEST THAT ALL SEVERE MODES,
INCLUDING TORNADOES, WOULD BE ON THE TABLE. THAT BEING SAID, IT
DOESN'T LOOK LIKE A SLAM DUNK WIDESPREAD SEVERE EVENT. DAYTIME CLOUD
COVER COULD LOWER TEMPERATURES A BIT AND STRENGTHEN THE CAP.
ADDITIONALLY, IF MULTIPLE STORMS DO BREAK THROUGH THE CAP AND
DEVELOP ALONG THE FRONT AT ONCE, THEY COULD QUICKLY GROW UPSCALE AND
CONGEAL INTO MORE OF A BLOB, AS OPPOSED TO STRONG DISCRETE CELLS.
ADDITIONALLY, STRONG DOWNBURSTS COULD COLLAPSE UPDRAFTS BEFORE THE
STORMS CAN ESTABLISH A STRONG MESOCYCLONE, CAPABLE OF PRODUCING
LARGE HAIL, DAMAGING WINDS, OR A TORNADO. OVERALL, IT APPEARS THE
MAIN THREAT FOR SEVERE POTENTIAL WOULD BE DURING THE FIRST 1-3 HOURS
AFTER CONVECTIVE INITIATION, WHEN MORE DISCRETE STORMS, WITH ROBUST
ROTATING UPDRAFTS WOULD BE POSSIBLE.
INITIAL POTENTIALLY DESTRUCTIVE STORMS WILL QUICKLY PUSH EAST OF THE
FORECAST AREA MONDAY EVENING, WITH MORE WIDESPREAD, BUT LESS SEVERE
CONVECTION FILLING IN BEHIND THEM. HEAVY RAINFALL WILL BE SOMETHING
TO KEEP AN EYE ON THROUGHOUT THE EVENING AND OVERNIGHT HOURS. WHILE
DEEP WARM CLOUD LAYERS AND HIGH PWATS INDICATE STORMS WILL BE
EFFICIENT RAIN PRODUCERS, THE OVERALL PROGRESSIVE MOVEMENT OF THE
STORMS SHOULD HELP LOWER FLOODING RISKS. THAT BEING SAID, THERE
REMAINS A 25% RISK OF FLASH FLOODING WITHIN A SLIGHT EXCESSIVE
RAINFALL OUTLOOK AREA, HIGHLIGHTING AREAS ALONG AND EAST OF THE
MISSOURI RIVER.
TUESDAY AND BEYOND...
SHOWER AND STORM CHANCES WILL CONTINUE BEHIND THE FRONT OVERNIGHT
AND INTO TUESDAY, AS THE LLJ NOSES BACK INTO THE REGION. THE BEST
CHANCE REMAINING ACROSS SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA.
TEMPERATURES WILL BE NOTICEABLY COOLER TUESDAY, AS WE SLIP BACK INTO
THE 70S.
SIMILARLY WET AND COOL CONDITIONS WILL REMAIN IN PLACE AS THE
BOUNDARY LINGERS IN THE REGION THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK, ENHANCED BY A FEW SHORTWAVE DISTURBANCES RIPPLING THROUGH THE
SOUTH WESTERLY FLOW. ABUNDANT MOISTURE TRAINING OVER THE SAME
LOCATIONS THIS WEEK COULD POTENTIALLY RAISE FLOODING CONCERNS ONCE
AGAIN, HOWEVER, THE GRADUAL, DRAWN OUT NATURE OF THE RAINFALL SHOULD
HELP.
TEMPS WILL REMAIN IN THE 70S THROUGH AT LEAST THURSDAY, WITH
SLIGHTLY WARMER CONDITIONS EXPECTED FRIDAY, AS A SUBTLE RIDGE
DEVELOPS AHEAD OF THE NEXT TROUGH AND COLD FRONT. LONG RANGE MODELS
CONTINUE TO HINT AT DAILY RAIN CHANCES THROUGH NEXT WEEKEND, WITH
TEMPERATURES DIPPING BACK BELOW SEASONAL LEVELS.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 630 PM CDT SUN SEP 13 2026
MVFR TO IFR CLOUD COVER WILL LINGER OVER THE REGION, BEFORE
RETREATING TO THE WEST. LATEST MODELS INDICATE THE DEVELOPMENT
OF A LINE OF STORMS FROM SOUTHEAST NEBRASKA THROUGH NORTHEAST
NEBRASKA AROUND 09Z TONIGHT, PUSHING NORTHEAST OF THE TAF SITES
BY AROUND 14Z. ANOTHER ROUND OF WIDESPREAD SHOWERS WITH A FEW
EMBEDDED THUNDERSTORMS WILL DEVELOP MONDAY AFTERNOON, AND
CONTINUE INTO THE EVENING HOURS, WHEN A LINE OF STRONG TO SEVERE
STORMS MAY POP UP WITH THE PASSAGE OF A COLD FRONT, AT THE TAIL
END OF THE PERIOD. AHEAD OF THE FRONT, WINDS WILL INCREASE OUT
OF THE SOUTH/SOUTHEAST AT 12-20 KTS WITH OCCASIONAL GUSTS UP TO
30 KTS. STRONGER WIND SPEEDS COULD BE POSSIBLE WITHIN ANY
STRONGER STORMS THAT DEVELOP.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...KG
AVIATION...KG
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