970
FXUS63 KOAX 181124
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
624 AM CDT MON MAY 18 2026
KEY MESSAGES
- POTENTIAL FOR MORE SEVERE WEATHER ON MONDAY, MAINLY ACROSS
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. LARGE HAIL, DAMAGING
WINDS, STRONG TORNADOES, AND FLASH FLOODING WILL ALL BE
POSSIBLE.
- COOLER WEATHER MOVES IN ON TUESDAY WITH POTENTIAL FOR MORNING
FROST FOR NORTHEAST NEBRASKA ON WEDNESDAY.
- ANOTHER ACTIVE PATTERN MAY SET UP GOING INTO NEXT WEEKEND WITH
CHANCES FOR MORE STORMS, AND POSSIBLY SEVERE WEATHER.
DISCUSSION
ISSUED AT 1155 PM CDT SUN MAY 17 2026
THE LINE OF STORMS HAS CLEARED EAST OF THE AREA BUT MUCH OF
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA REMAIN UNDER THE
STRATIFORM RAIN SHIELD WITH SOME EMBEDDED WEAK THUNDERSTORMS.
THIS LIKELY WON'T COMPLETELY CLEAR UNTIL CLOSER TO 7AM MONDAY
MORNING. GOING INTO MONDAY WE'RE GOING TO BE WATCHING TO SEE
WHERE THE COLD FRONT STALLS, WHICH WILL HELP DETERMINE OUR AREA
OF POTENTIAL SEVERE WEATHER MONDAY EVENING.
MONDAY WILL START OUT CLOUDY, WITH SCATTERED LIGHT RAIN SHOWERS
ACROSS MUCH OF THE AREA NORTH AND WEST OF THE COLD FRONT
STALLED ACROSS OUR AREA. THROUGH THE LATE MORNING INTO THE
AFTERNOON WE'LL SEE CLOUDS GRADUALLY CLEAR IN AREAS SOUTH AND
EAST OF THE COLD FRONT. AREAS NORTH OF THE COLD FRONT WILL STAY
CLOUDY. THE UPPER-LEVEL SHORTWAVE ARRIVES, KICKING OFF STORM
INITIATION AROUND 2-4PM. STORMS THAT DEVELOP IN THE WARM SECTOR
WILL HAVE AMPLE INSTABILITY AND SHEAR TO GROW INTO DISCRETE
SUPERCELLS WITH POTENTIAL FOR LARGE HAIL, DAMAGING WINDS, AND
STRONG TORNADOES. EXPECT SIMILAR STORM EVOLUTION, GROWING INTO A
QLCS WITH EMBEDDED SUPERCELLS, WHICH EXITS OUR AREA BY 10PM.
SEVERAL CAMS SHOW A SECOND LINE OF STORMS WHICH DEVELOPS AROUND
8-9PM OVER OUR WESTERN COUNTIES AND MOVES THROUGH POTENTIALLY
BRINGING ANOTHER CHANCE FOR SEVERE HAIL AND DAMAGING WINDS.
THESE STORMS WILL BE ELEVATED IN NATURE, BUT MAY STILL HAVE 1500
J/KG OF ELEVATED MUCAPE TO WORK WITH. THIS SECOND LINE CLEARS BY
MIDNIGHT, BRINGING AN END TO THE LONG, SEVERAL DAY STRETCH OF
SEVERE WEATHER.
WE'LL SEE THE COLD FRONT CLEAR WELL TO THE SOUTH AND EAST OF OUR
AREA BY TUESDAY, PUTTING A COOLER CANADIAN AIR MASS IN PLACE
ACROSS THE REGION. TUESDAY WILL START OUT CLOUDY ONCE AGAIN, BUT
REALLY CLEAR BY THE AFTERNOON AS HIGH PRESSURE BUILDS OVER OUR
AREA. HIGH TEMPERATURES ON TUESDAY WILL ONLY REACH INTO THE
UPPER 50S TO MID 60S. WITH CLEAR SKIES AND NEARLY CALM WINDS,
THIS LENDS TO POTENTIAL FOR FROST EARLY WEDNESDAY. OVERNIGHT
LOWS WILL DROP INTO THE MID 30S FOR NORTHEAST NEBRASKA TO LOW
40S ACROSS SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. COOLER WEATHER
HOLDS INTO WEDNESDAY THOUGH WE DO SEE A REVERSAL TO SOUTHERLY
WINDS AND START TO ADVECT MOISTURE BACK INTO THE REGION. AN
UPPER-LEVEL SHORTWAVE COULD POTENTIALLY BRING A FEW SHOWERS TO
THE AREA WEDNESDAY AFTERNOON AND EVENING, BUT THE ENSEMBLES
HAVEN'T PICKED UP ON THIS LATEST CHANGE IN THE DETERMINISTIC
GUIDANCE. IN ANY CASE, THIS WOULDN'T BE ANYTHING IMPACTFUL.
A BETTER CHANCE FOR SHOWERS AND STORMS MOVES IN THURSDAY AS THE
LONGWAVE TROUGH THAT'S BEEN NEARLY STATIONARY OVER THE WESTERN
US SHIFTS EASTWARD TOWARD OUR AREA. WITH TEMPERATURES STILL IN
THE SIXTIES FOR HIGHS, I WOULDN'T ANTICIPATE MUCH OF A SEVERE
WEATHER THREAT WITH THIS SYSTEM FOR OUR AREA.
TEMPERATURES START TO REBOUND ON FRIDAY THOUGH AS WE SEE
ENHANCED WARM AIR ADVECTION AHEAD OF A DEEPENING SURFACE LOW
WHICH DEVELOPS ON THE LEE SIDE OF THE ROCKIES OVER EASTERN
COLORADO AND WESTERN NEBRASKA. DEPENDING ON THE TRACK OF THIS
SYSTEM, WE COULD POTENTIALLY SEE MORE ACTIVE WEATHER NEXT
WEEKEND WITH SEVERAL CHANCES FOR STORMS.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 616 AM CDT MON MAY 18 2026
A COMPLEX AVIATION FORECAST IS SET OUT, WITH MVFR TO IFR
CONDITIONS EXPECTED TO QUICKLY TAKE HOLD FOR THE REMAINDER OF
THE AREA TERMINALS, WITH THE WORST OF THE RESTRICTIONS LASTING
THROUGH THE BETTER PART OF THE MORNING HOURS, DRIVEN BY LOWER
CEILINGS. WINDS WILL BE ON THE INCREASE LATER THIS AFTERNOON AND
EVENING, WITH A VERY SHORT DISTANCE BETWEEN NORTHERLY WINDS AND
SOUTH-SOUTHEASTERLY WINDS TO THE EAST OF KOMA.
STRONG STORMS ARE ANTICIPATED TO SPREAD NORTHWARD FROM SOUTHEAST
NEBRASKA LATE THIS AFTERNOON INTO THE EVENING HOURS. WE'VE
EXPANDED THE TIME THAT THUNDER COVERS IN THE TAFS, DUE TO
INCREASING CONFIDENCE THAT WIDESPREAD THUNDER ACTIVITY WILL
LINGER PAST 00Z. KOFK LOOKS TO DODGE THUNDER CHANCES WITH RAIN
EARLY THIS EVENING, WITH THE BACK EDGE OF THE ACTIVITY SWEEPING
THROUGH AND BRINGING IMPROVING CEILINGS THROUGH TOMORROW
MORNING.
OAX WATCHES/WARNINGS/ADVISORIES
NE...FLOOD WATCH THROUGH TUESDAY MORNING FOR NEZ065-066-068-078-
088>093.
IA...NONE.
DISCUSSION...MCCOY
AVIATION...PETERSEN
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