026
FXUS63 KOAX 121127
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
627 AM CDT WED AUG 12 2026
KEY MESSAGES
- THERE IS A 50 TO 80% CHANCE OF STORMS IN NORTHEAST NEBRASKA
AND WEST-CENTRAL IOWA THROUGH 8 AM THURSDAY, WITH LOWER
CHANCES FARTHER SOUTH. SOME OF THESE STORMS COULD BE STRONG TO
SEVERE, WITH DAMAGING WINDS OVER 70 MPH BEING THE PRIMARY
THREAT.
- WIDESPREAD SHOWERS AND STORMS ARRIVE LATE WEDNESDAY (60-80%
CHANCE) INTO THURSDAY. SOME STORMS COULD BE SEVERE WITH STRONG
WINDS, HAIL, AND HEAVY RAIN.
- PERIODIC SHOWER AND STORM CHANCES CONTINUE THROUGH THE WEEKEND
INTO EARLY NEXT WEEK. COOLER TEMPERATURES ARRIVE BY SUNDAY AND
MONDAY.
DISCUSSION
ISSUED AT 1142 PM CDT TUE AUG 11 2026
MAIN STORY IN THE SHORT TERM IS SEVERE STORM POTENTIAL
OVERNIGHT INTO EARLY WEDNESDAY MORNING. AS OF 11 PM, ONGOING
STORMS OVER SOUTHWEST SD WERE PUSHING SOUTHEAST AND PRODUCING
70+ MPH WIND GUSTS IN SOME LOCATIONS. LOOKING AT THE ENVIRONMENT
AHEAD OF SAID STORMS, THERE IS PLENTY OF INSTABILITY IN PLACE
(4000+ J/KG OF MUCAPE PER SPS OBJECTIVE MESOANALYSIS) ALONG WITH
PLENTY OF EFFECTIVE AND DEEP LAYER SHEAR TO REMAIN ORGANIZED.
0-3 KM SHEAR DOES TAPER OFF FARTHER SOUTHEAST, SO ASSUMING
STORMS GET HERE, THEY COULD BECOME A LITTLE MORE OUTFLOW
DOMINANT. THAT SAID, GUIDANCE DOES SUGGEST 0-3 KM SHEAR
STRENGTHENS, OR AT LEAST MAINTAINS AS WE GO THROUGH THE
OVERNIGHT HOURS. THINGS WORKING AGAINST THE STORMS MAINTAINING
ARE A LITTLE BIT OF DRY AIR ALOFT AND THE PRIMARY FORCING
SLIDING BY JUST TO OUR NORTH. HOWEVER, WITH LOW LEVEL MOISTURE
TRANSPORT POINTING INTO OUR AREA, AN ALREADY UNSTABLE AIRMASS IN
PLACE, AND LATEST SHORT-TERM GUIDANCE BEING IN FAIRLY GOOD
AGREEMENT THAT THEY MAKE IT TO AND THROUGH THE AREA, THINK WE
WILL HAVE A SEVERE WEATHER THREAT STARTING AROUND 3-4 AM. THE
PRIMARY THREAT WILL BE POCKETS OF 50 TO ISOLATED 70+ MPH GUSTS
AND PERHAPS SOME HAIL. IN ADDITION, PRECIPITABLE WATER VALUES
AROUND 1.75" AND WARM CLOUD DEPTHS OVER 4 KM SUGGEST THEY'LL BE
EFFICIENT RAIN PRODUCERS AND COULD LEAD TO SOME LOCALIZED
FLOODING, BUT GUIDANCE DOES SUGGEST THEY SHOULD BE SOMEWHAT
PROGRESSIVE. THE BIG QUESTIONS WILL BE HOW FAR SOUTH THE WIND
THREAT EXTENDS AND JUST HOW STRONG THE WINDS WILL BE. SOME
GUIDANCE SUGGESTS AREAS AS FAR SOUTH AS I-80 COULD SEE DAMAGING
WINDS, WHILE OTHER SOLUTIONS FAVOR THE THREAT REMAINING MAINLY
IN NORTHEAST NE AND WEST-CENTRAL IA. FINALLY, ONE THING TO WATCH
IS HOW ONGOING WEAKER STORMS IN NORTH-CENTRAL NE EVOLVE. FOR
NOW, THEY SEEM WEAK ENOUGH THAT THEY WON'T PUT MUCH OF A DENT IN
THE INSTABILITY IN PLACE. HOWEVER, IF THEY STRENGTHEN, THEY
COULD WORK THE ENVIRONMENT OVER JUST ENOUGH THAT THE INCOMING
STORMS FROM SD END UP SUB-SEVERE.
WHATEVER STORMS DO MOVE THROUGH SHOULD EXIT TO THE SOUTHEAST BY
8-9 AM WITH PERHAPS A FEW LINGERING SHOWERS IN SOUTHEAST NE AND
FAR SOUTHWEST IA ALONG THE THE SURFACE BOUNDARY AND ANY REMNANT
OUTFLOW. WITH THE BOUNDARY TO THE SOUTH, WE'LL BE A BIT
"COOLER," BUT STILL WARM AND MUGGY, WITH HIGHS IN THE UPPER 80S
TO LOWER 90S AND DEWPOINTS IN THE 70S. BY LATE
AFTERNOON/EVENING, WE SHOULD START TO SEE STORMS DEVELOP ACROSS
WESTERN NE AS SHORTWAVE ENERGY CURRENTLY OVER THE DESERT
SOUTHWEST ROUNDS THE RIDGE AND PUSHES INTO THE AREA. IN THE LOW
LEVELS, A LOW WILL PUSH EAST OUT OF CO AND INTO KS, HELPING TO
INDUCE A STRENGTHENING LOW LEVEL JET/MOISTURE TRANSPORT THAT
RUNS OVER THE SURFACE BOUNDARY NEAR THE NE/KS BORDER AND POINTS
INTO THE AREA. EXPECT STORM DEVELOPMENT ON THE NOSE OF THIS
MOISTURE TRANSPORT, WITH LATEST CAMS SUGGESTING THEY'LL BE
MOSTLY NORTH OF I- 80. THAT SAID, IT MAY BE WORTH WATCHING FOR
DEVELOPMENT A LITTLE FARTHER SOUTH/CLOSER TO THE SURFACE
BOUNDARY WHERE 900 MB MOISTURE TRANSPORT POINTS INTO VERY STRONG
FRONTOGENESIS. MODEL SOUNDINGS SUGGEST THERE WILL BE A LITTLE
CIN TO OVERCOME FOR PARCELS ORIGINATING AT THAT LEVEL, BUT GIVEN
THE FORCING, THINK IT'S POSSIBLE FOR THAT CIN TO BE OVERCOME.
REGARDLESS OF WHERE STORMS DEVELOP, DEEP LAYER SHEAR LOOKS
FAVORABLE FOR STORM ORGANIZATION WITH PLENTY OF INSTABILITY TO
WORK WITH FOR A DAMAGING WIND AND HAIL THREAT. IN ADDITION,
GUIDANCE HINTS AT PRECIPITABLE WATER VALUES OF 1.75 TO 2+ INCHES
WITH WARM CLOUD DEPTHS OF 4+ KM, SUGGESTING POTENTIAL FOR HEAVY
RAIN. WITH CAMS INDICATING POTENTIAL FOR STORMS TRAINING FROM
WEST TO EAST, A FLOODING THREAT COULD DEVELOP INTO EARLY
THURSDAY MORNING.
PRECIP SHOULD TAPER OFF THROUGH THE MORNING HOURS WITH
LINGERING CLOUD COVER ACROSS MUCH OF THE AREA LIMITING
TEMPERATURES TO THE MID 70S TO MID 80S, EXCEPT FOR NEAR THE
NE/KS/IA/MO BORDER AREA, WHERE A FEW LOWER 90S WILL BE POSSIBLE.
RINSE, REPEAT WITH EVENING SHOWER AND STORM CHANCES ONCE AGAIN
AS SHORTWAVE ENERGY SLIDES THROUGH AND WE SEE MORE WARM AIR
ADVECTION, WHILE THE SURFACE BOUNDARY REMAINS IN/NEAR THE AREA.
WHILE THERE WILL BE SLIGHTLY LESS INSTABILITY AND SHEAR, THERE
COULD BE JUST ENOUGH OF BOTH TO YIELD AT LEAST SOME STRONGER
STORMS. THIS PATTERN WITH NIGHTLY (STRONG/SEVERE?) STORM CHANCES
CONTINUES INTO THE WEEKEND BEFORE ENSEMBLE CONSENSUS SHOWS
SURFACE HIGH PRESSURE BUILDING IN ON SUNDAY WITH THE SURFACE
BOUNDARY FINALLY PUSHING WELL SOUTH OF OUR AREA. HOWEVER, ANY
BREAK WE GET LOOKS SHORT-LIVED AS GUIDANCE HINTS THAT THE TRAIN
OF SHORTWAVES RETURNS INTO NEXT WEEK WITH MORE ON AND OFF PRECIP
CHANCES. OTHERWISE, TEMPERATURES REMAIN STEADY THROUGH
SATURDAY, BEFORE COOLER HIGH PRESSURE PUSHES IN AND LEADS TO
HIGHS IN THE MID 70S TO LOWER/MID 80S SUNDAY AND MONDAY.
TEMPERATURES SHOULD WARM SLIGHTLY THROUGH THE REST OF THE WEEK,
THOUGH WILL DEPEND ON TIMING OF THOSE PRECIP CHANCES.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 627 AM CDT WED AUG 12 2026
A LINE OF SHOWERS AND THUNDERSTORMS IS EXITING FAR EASTERN
NEBRASKA EARLY THIS MORNING. WHILE THE LINE IS LARGELY
SUB-SEVERE AT THIS TIME, EXPECT TO SEE SOME WEST NORTHWESTERLY
GUSTS OF 30 TO 40 KTS AT KOMA AND KLNK FOR THE NEXT HOUR OR SO.
THEREAFTER, SHOULD SEE WINDS LOWER TO LESS THAN 12 KTS FROM THE
EAST NORTHEAST FOR THE REST OF THE TAF CYCLE WITH VFR
CONDITIONS.
ANOTHER ROUND OF SHOWERS AND STORMS WILL DEVELOP AFTER 06Z AND
TRACK TO THE EAST IMPACTING TAF SITES. HAVE INTRODUCED -TSRA
AND -SHRA MENTIONS WITH THIS ISSUANCE, BUT WILL LIKELY NEED TO
REFINE TIMING IN FORTHCOMING ISSUANCES. THESE STORMS COULD BE
SEVERE WITH DAMAGING WIND GUSTS OF 50 KTS, LARGE HAIL, AND HEAVY
RAIN REDUCING VISIBILITIES TO MVFR/IFR. CEILINGS LOWER TO MVFR
LATE IN THE PERIOD AFTER 12Z.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...CA
AVIATION...CASTILLO
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