726
FXUS63 KOAX 292313
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
613 PM CDT TUE SEP 29 2026
KEY MESSAGES
- WIDESPREAD RAINFALL OF 2 TO 4 INCHES EXPECTED THROUGH
THURSDAY, WITH LOCALLY HIGHER AMOUNTS. A FLOOD WATCH HAS BEEN
ISSUED FOR TUESDAY EVENING THROUGH THURSDAY.
- IF WE GET ANY CLEARING ON WEDNESDAY, A FEW STRONG TO SEVERE
THUNDERSTORMS WILL BE POSSIBLE DURING THE AFTERNOON AND
EVENING, MAINLY IN SOUTHEAST NEBRASKA.
- RAIN WILL END THURSDAY NIGHT, WITH COOLER, DRY CONDITIONS
EXPECTED THROUGH THE WEEKEND.
DISCUSSION
ISSUED AT 226 PM CDT TUE SEP 29 2026
TODAY THROUGH THURSDAY:
WATER VAPOR IMAGERY THIS AFTERNOON FEATURES LARGELY ZONAL FLOW
ACROSS THE NORTHERN HALF OF THE CONUS WITH A POSITIVELY-TILTED
SHORTWAVE TROUGH EXTENDING FROM THE DAKOTAS/NORTHWEST MN SOUTHWEST
TO A CUTOFF LOW OVER THE SOUTHERN GREAT BASIN. THIS CUTOFF
LOW/SHORTWAVE AND THE REMNANTS OF THE FORMER HURRICANE POLO REMAIN
THE FOCUS FOR THE FORECAST PERIOD, WITH STRONG MOISTURE
ADVECTION EXPECTED TO CONTRIBUTE TO EFFICIENT RAINFALL PROCESSES
THAT WILL BE PRESENT THROUGH THE FIRST HALF OF THURSDAY. HIDDEN
IN HIGHER RIVER/FLASH FLOODING THREAT, SEVERE WEATHER WILL ALSO
BE POSSIBLE WEDNESDAY WITH A 5% CHANCE OF DAMAGING HAIL/WIND OR
AN ISOLATED TORNADO NEAR THAT REACHES FROM KANSAS INTO FAR
SOUTH-CENTRAL NEBRASKA.
TAKING A LOOK AT THE SYNOPTIC SETUP FOR THIS PERIOD, THE REMNANT MCV
FROM POLO WILL JOIN THE GREAT BASIN LOW AS THEY EJECT TO THE
NORTHEAST. THIS WILL HELP INITIALLY DEEPEN THE MID/UPPER LOWS, AND
PROMOTE A STRONGER MASS RESPONSE ACROSS THE SOUTHERN AND CENTRAL
PLAINS THAT WILL AMP UP WARM AIR ADVECTION AND MOISTURE
TRANSPORT FROM THE GULF IN ADDITION TO THE REMNANTS FROM POLO.
ALREADY, A COLD FRONT STRETCHES FROM EASTERN ND TO SOUTHEAST CO,
WHILE A WARM FRONT EXTENDS FROM THERE TOWARDS LA. THAT
AFOREMENTIONED COLD FRONT WILL SHIFT INTO THE FORECAST AREA
LATER THIS EVENING, STALLING OUT/BECOMING INCREASINGLY
POSITIVELY-TILTED, AND REMAINING IN THE AREA THROUGH THE FIRST
HALF OF THURSDAY. CONVERGENCE ALONG THE FRONT AS MOISTURE
TRANSPORT RUNS INTO THE FRONTAL INTERFACE ALONG WITH DEEPER LIFT
ASSOCIATED WITH THE LARGE-SCALE HEIGHT FALLS WILL HELP "SKINNY"
CAPE PROFILES TO BE REALIZED AND LEAD TO EFFICIENT RAINFALL
PROCESSES.
LOOKING AT THE PERIODS OF PEAK RAINFALL, THE FIRST WAVE OF HEALTHY
RAINFALL IS SET TO OCCUR THIS OVERNIGHT TONIGHT INTO THE MORNING
HOURS (4 AM TO 10 AM). AFTER A LULL IN ACTIVITY, STRONG CONVERGENCE
IN THE LOWEST LEVELS WILL HELP TO SPREAD STRONGER STORM ACTIVITY
NORTHWARD FROM KANSAS INTO SOUTHERN NEBRASKA AFTER 3 PM TOMORROW.
WE'LL SEE OUR BEST INSTABILITY OF THE FORECAST TO GO ALONG WITH
MODEST SHEAR THAT COULD ORGANIZE SOME OF THE STRONGER STORMS TO
MAKE SEVERE ACTIVITY A POSSIBILITY. THAT MODEST SHEAR AND
CURVATURE IN THE LOW-LEVEL HODOGRAPH WILL KEEP ALL HAZARDS ON
THE TABLE. THOSE SHOWERS AND STORMS PRESENT THE HIGHEST RAINFALL
POTENTIAL AS THE MOVE ACROSS SOUTHEAST NEBRASKA INTO IOWA FROM
3 PM TO 3 AM, AND AMOUNTS DURING THIS TIME COULD EXCEED 2"
ALONE. ONCE THAT PERIOD ENDS, WE'LL BE DEALING WITH EXITING
RAINFALL ACROSS FAR SOUTHEASTERN NEBRASKA INTO SOUTHWEST IOWA
THAT WILL LEAVE US HIGH AND DRY BY THURSDAY NIGHT.
MOST OF SOUTHEAST NEBRASKA ARE SET TO RECEIVE 2-4" OF RAINFALL,
WITH AN NARROW BAND OF 5-6" OR MORE POSSIBLE WHERE THE STRONG
STORMS TRACK WEDNESDAY EVENING. THIS SHOULD TRANSLATE TO AREAS
OF FLASH FLOODING, SEVERAL AREA STREAMS AND RIVERS HITTING
ACTION STAGE, AND A HANDFUL OF LOCATIONS HITTING MINOR FLOOD
STAGES SOUTH OF THE PLATTE RIVER. RIVER LEVELS SHOULD PEAK
FRIDAY AND SATURDAY ACCORDING TO ENSEMBLE RIVER GUIDANCE, AND
COULD COMPLICATE RURAL TRAVEL IF CONDITIONS DO REACH MINOR FLOOD
STAGE.
FRIDAY AND BEYOND:
FRIDAY ONWARD IN THE FORECAST WILL SEE THE AREA DRY OUT
CONSIDERABLY, MUCH TO THE JOY OF THOSE HOPING TO HARVEST. WEST-
NORTHWESTERLY FLOW WILL MOVE INTO THE AREA AND WE'LL SEE
TEMPERATURES HANG IN THE 60S THROUGH THE REMAINING FORECAST THAT
WARMS A TAD BIT TOWARDS THE END OF NEXT WEEK. VERY FEW ENSEMBLE
MODELS OUTPUT ANY QPF FOR EASTERN NEBRASKA AND SOUTHWEST IOWA,
MAKING FOR A WELL-TIMED DRY PERIOD THAT WILL CARRY US INTO
METEOROLOGICAL FALL WITH EXCELLENT WEATHER.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 613 PM CDT TUE SEP 29 2026
DETERIORATING CONDITIONS EXPECTED TONIGHT WITH RAIN BECOMING
HEAVY AT TIMES ACROSS SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
WHILE AREAS NORTH SEE SIGNIFICANT AREAS TO WIDESPREAD FOG
DEVELOPMENT. CIGS WILL BE LOWERING TO IFR, POTENTIALLY LIFR AT
TIMES THROUGH WEDNESDAY MORNING WITH VISIBILITY DROPPING AS
WELL. WE'LL SEE THE BAND OF HEAVY RAIN LIFT NORTH INTO KLNK AND
KOMA WEDNESDAY AFTERNOON POTENTIALLY LEADING TO SLIGHTLY
IMPROVED CIGS BUT REDUCED VISIBILITY. COULD SEE SOME EMBEDDED
THUNDERSTORMS THROUGH THE 20Z-00Z TIMEFRAME WEDNESDAY, BUT HIGH
UNCERTAINTY KEEPS IT OUT OF THIS TAF PACKAGE.
WINDS FOR THE MOST PART STAY OUT OF THE SOUTH THROUGH THE TAF
PERIOD FOR KOMA AND KLNK, WHILE AREAS NORTH SEE WINDS BECOME
LIGHT AND VARIABLE OR EVEN NORTHERLY. WE COULD SEE A FEW HOURS
THROUGH WEDNESDAY MORNING WHERE LIGHT WINDS BECOME VARIABLE OR
EVEN EASTERLY AT KOMA AND KLNK DEPENDING ON WHERE EXACTLY THE
WARM FRONT SETS UP THROUGH THE MORNING, BUT SHOULD TURN BACK TO
SOUTHERLY BY THE AFTERNOON.
OAX WATCHES/WARNINGS/ADVISORIES
NE...FLOOD WATCH THROUGH THURSDAY EVENING FOR NEZ015-018-030>034-
042>045-050>053-065>068-078-088>093.
IA...FLOOD WATCH THROUGH THURSDAY EVENING FOR IAZ043-055-056-069-
079-080-090-091.
DISCUSSION...PETERSEN
AVIATION...MCCOY
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