110
FXUS63 KOAX 182217
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
517 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 /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 512 PM CDT FRI SEP 18 2026
VFR CONDITIONS PREVAIL THIS EVENING BEFORE A LINE OF
THUNDERSTORMS DEVELOPS ACROSS EAST-CENTRAL NEBRASKA AND SLOWLY
PUSHES SOUTH. INITIAL THUNDERSTORMS SHOULD REMAIN SOUTH OF KOFK,
WITH A 60% CHANCE OF IMPACTS AT KOMA AND KLNK. BRIEF GUSTY
WINDS (UP TO 40 KTS) AND PATCHY MVFR CONDITIONS ARE POSSIBLE
UNDER AND STRONGER STORMS. A BRIEF PERIOD OF LLWS WILL ALSO WORK
INTO KOMA AND KLNK THIS EVENING AS A 40-45 KT LLJ MOVES IN AT
FL017.
INTO THE OVERNIGHT PERIOD, A FRONT PUSHING SOUTH ACROSS THE AREA WILL
SHIFT WINDS FROM SOUTHERLY TO NORTHERLY. ADDITIONAL SCATTERED
SHOWERS, AND PERHAPS A THUNDERSTORM OR TWO, ARE POSSIBLE INTO
THE OVERNIGHT PERIOD. THE HIGHEST CHANCES OF IMPACTS ARE AT KOMA
AND KLNK (50% CHANCE), THOUGH EXACT TIME FRAME MAY NEED
REFINING. ADDITIONALLY, A DECK OF MVFR TO IFR CEILINGS, ALONG
WITH PATCHY VISIBILITY RESTRICTIONS, WILL SINK SOUTH INTO THE
AREA OVERNIGHT. CONFIDENCE IS HIGH THAT KOFK WILL SEE A
PROLONGED STRETCH OF MVFR TO IFR CONDITIONS, WITH LOWER CHANCES
(30-40%) FURTHER SOUTH TOWARDS KOMA AND KLNK.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...MCCOY
AVIATION...WOOD
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