495
FXUS63 KOAX 181902
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
202 PM CDT FRI SEP 18 2026
KEY MESSAGES
- A COUPLE ROUNDS OF SHOWERS AND STORMS POSSIBLE THIS EVENING
(30-40%) AND OVERNIGHT (40-50%). MAY SEE A FEW ISOLATED STRONG
WIND GUSTS WITH STRONGER STORMS THIS EVENING.
- COOLER AND CLOUDY ON SATURDAY WITH POTENTIAL FOR
SHOWERS/STORMS ACROSS SOUTHEAST NEBRASKA SOUTHWEST IOWA
(30-50%).
- MUCH COOLER STARTING ON SUNDAY INTO NEXT WEEK WITH HIGHS IN
THE 60S AND LOWS IN THE 50S. PERIODIC CHANCE FOR RAIN SUNDAY
AND MONDAY AND AGAIN THURSDAY AND FRIDAY.
DISCUSSION
ISSUED AT 202 PM CDT FRI SEP 18 2026
PARTLY CLOUDY SKIES THIS AFTERNOON WITH A WARM FRONT LIFTING
NORTHEAST ACROSS OUR AREA. BREEZY WINDS GUSTING TO 20-25 MPH
BEHIND THE FRONT OUT OF THE SOUTH-SOUTHWEST HELPING
TEMPERATURES TO WARM INTO THE UPPER 80S TO LOW 90S THIS
AFTERNOON. LOOKING AT THE UPPER-LEVEL PATTERN, WE HAVE BROAD
RIDGING OVER THE CENTRAL US WITH A TROUGH OVER THE INTER-
MOUNTAIN WEST. A SUBTLE SHORTWAVE HAS LED TO THE DEVELOPMENT OF
OUR SURFACE LOW CURRENTLY POSITIONED OVER NORTH-CENTRAL NEBRASKA
NEAR THE SD STATE LINE. AT THE SAME TIME, ANOTHER WEAK SURFACE
LOW IS DEVELOPING OVER SOUTHEASTERN COLORADO.
THIS EVENING WE'RE MONITORING THE LOW OVER NORTH-CENTRAL
NEBRASKA, EXPECTED TO PULL THE COLD FRONT SOUTH BUT HANGING UP
ON THE DEVELOPING SYSTEM TO OUR SOUTHWEST. THIS WILL POSITION A
STATIONARY FRONT SOMEWHERE SOUTHWEST TO NORTHEAST ALONG OR JUST
NORTH OF I-80 AS THE UPPER-LEVEL WAVE MOVES THROUGH. WE EXPECT
SCATTERED STORMS TO TRIGGER ALONG THIS BOUNDARY AROUND 7PM THIS
EVENING AND TRACK NORTHEAST ALONG THE FRONT EXITING AROUND
11PM-12AM. MODEL SOUNDINGS SHOW A FAIRLY STRONG SURFACE STABLE
LAYER WITH AN EXORBITANT AMOUNT OF MUCAPE ALOFT (3000-4500
J/KG). DRY AIR ENTRAINMENT WILL LIKELY LIMIT THE ABILITY TO
UTILIZE THAT AMOUNT OF ENERGY. WHILE SHEAR IS FAIRLY GOOD IN THE
LOW-LEVELS NEAR THE FRONTAL BOUNDARY, THIS IS MOSTLY GENERATED
BY THE ENHANCEMENT OF THE LLJ WITH BULK OF CONVECTION OCCURRING
ABOVE THIS LAYER. THIS MEANS STORMS MAY STRUGGLE TO ORGANIZE
INTO ANYTHING STRONG TO SEVERE. WHAT WE MAY SEE, THOUGH, IF WE
CAN GET A COUPLE OF STRONGER STORMS TO DEVELOP, IS POTENTIAL
FOR LOCALIZED STRONG TO SEVERE WINDS. AS STORMS COLLAPSE, WE
MAY SEE DOWNBURSTS ATTEMPT TO PUSH THROUGH THE SURFACE STABLE
LAYER. IF THEY CAN PUNCH THROUGH, THIS WOULD LEAD TO A COUPLE
OF ISOLATED BURSTS OF STRONG TO SEVERE WIND. THAT'S PROBABLY OUR
MAIN HAZARD POSSIBLE WITH ANY OF THESE STORMS THIS EVENING.
OVERNIGHT TONIGHT WE SEE THE SECOND WEAK LOW PRESSURE CENTER
RIDE UP THE STATIONARY FRONT INTO CENTRAL NEBRASKA BRINGING A
BROADER COMPLEX OF SHOWERS WITH A FEW RUMBLES OF THUNDER INTO
OUR AREA EARLY SATURDAY MORNING. BY THE TIME THIS SYSTEM
ARRIVES, ENVIRONMENTAL INSTABILITY WILL HAVE SIGNIFICANTLY WANED
REDUCING THE CHANCE OF THUNDERSTORMS WITH THIS SECOND ROUND.
MORE OF WHAT THIS WILL DO IS PICK UP THE STATIONARY FRONT AND
PUSH IT SOUTH ACROSS FAR SOUTHEAST NEBRASKA INTO SOUTH-CENTRAL
IOWA. MODELS HAVE BEEN SHIFTING THE POSITION OF WHERE THIS
FRONTAL BOUNDARY WILL STALL ON SATURDAY, SHIFTING THE AREA OF
POTENTIAL SEVERE WEATHER SATURDAY AFTERNOON AND EVENING AS
ANOTHER SHORTWAVE MOVES THROUGH. LATEST TRENDS HAVE BEEN TO
BRING IT FARTHER SOUTH, KEEPING THE STRONGER STORMS SOUTH ACROSS
EASTERN KANSAS INTO NORTHWEST MISSOURI. FOR THIS REASON, SPC HAS
SHIFTED OUR MARGINAL AND SLIGHT RISKS FOR SEVERE STORMS SOUTH,
OUT OF OUR AREA. WE'LL STILL WATCH FOR SOME POTENTIAL THIS
SHIFTS BACK NORTH, BUT AS OF NOW I'D EXPECT SATURDAY EVENING TO
STAY QUIET ACROSS OUR AREA.
GOING INTO THE LATTER HALF OF THE WEEKEND, WE SEE THE BROAD
RIDGE OVER THE CENTRAL US SHIFT EAST WITH THE UPPER-LEVEL TROUGH
MOVING IN FROM THE WEST. THIS WILL MEAN PERIODIC CHANCES FOR
SHOWERS AND WEAK STORMS SUNDAY THROUGH MONDAY WITH A COOLER AIR
MASS IN PLACE. HIGHS ON SUNDAY WILL ONLY WARM INTO THE LOW-TO-
MID 60S FOR MOST OF OUR AREA, AND MONDAY MANY MAY ONLY PEAK AT
60 DEGREES.
BEYOND MONDAY WE SEE RIDGING BUILD BACK UP BEHIND THE TRANSIENT
UPPER-LEVEL TROUGH WITH RETURN FLOW BRINGING BACK IN DRIER
CONDITIONS FOR TUESDAY AND WEDNESDAY. WE SEE THE BELT OF
MOISTURE ADVECTION FROM THE GULF SHIFT EAST BACK OVER OUR AREA
FOR THE LATTER HALF OF THE WEEK NEXT WEEK. THIS WILL MEAN MORE
CHANCES FOR SHOWERS AND STORMS THURSDAY AND FRIDAY THOUGH
TEMPERATURES LOOK TO REMAIN RELATIVELY COOL WITH HIGHS STILL
ONLY IN THE MID 60S TO LOW 70S.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1226 PM CDT FRI SEP 18 2026
VFR CONDITIONS THIS AFTERNOON UNDER MOSTLY CLEAR SKIES. LOW
CLOUDS HAVE RETREATED NORTH FOR THE DAY, BUT WE'LL SEE THEM
SPREAD BACK SOUTH THIS EVENING, WITH CIGS AROUND 700 FT MOVING
BACK INTO KOFK AROUND 05-07Z. MEANWHILE, WE'LL BE WATCHING
STORMS FORECAST TO DEVELOP LATE THIS AFTERNOON AND EVENING,
STARTING AROUND 23Z. CONFIDENCE IS LOW IN WHERE THESE STORMS
WILL INITIATE AND TRACK DUE TO UNCERTAINTY IN WHERE THE FRONTAL
BOUNDARY WILL STALL, BUT THERE IS A WINDOW FROM 00-04Z WHERE
STORMS COULD IMPACT KLNK OR KOMA. WE'LL SEE ANOTHER MORE
WIDESPREAD ROUND OF SHOWERS OVERNIGHT WITH A FEW EMBEDDED
THUNDERSTORMS, FORECAST TO REACH THE TERMINALS AROUND 09-12Z
WITH WINDS SHIFTING TO NORTHERLY AS THIS FINALLY PUSHES THE
FRONT THROUGH THE TERMINALS. THERE IS A 20% CHANCE WE SEE MVFR
CIGS MOVE INTO KOMA TOWARD THE END OF THE TAF PERIOD (17-18Z),
AS THE SOUTHERN EDGE OF THE LOW CLOUD SHIELD NORTH COULD TRY AND
PUSH FAR ENOUGH SOUTH.
LOW-LEVEL WIND SHEAR ALSO EXPECTED TO IMPACT KOMA AND KLNK
LATE THIS EVENING THROUGH AROUND 07Z AS SOUTHWESTERLY WINDS
INCREASE JUST OFF THE SURFACE ALONG THE FRONT. THIS GOES AWAY AS
STRONGER WINDS ALOFT SHIFT OFF TO THE EAST AROUND 06-07Z.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...MCCOY
AVIATION...MCCOY
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