217
FXUS63 KOAX 080521
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1221 AM CDT TUE SEP 8 2026
KEY MESSAGES
- SCATTERED SHOWERS AND STORMS CONTINUE OVERNIGHT, MAINLY ACROSS
NORTHEAST NEBRASKA. A STRONG STORM CANNOT BE RULED OUT.
- HIGHS CLIMB INTO THE MID TO UPPER 90S TUESDAY BEFORE A COLD
FRONT BRINGS SHOWERS AND STORMS. A FEW STRONG STORMS ARE
POSSIBLE, WITH HAIL, DAMAGING WINDS, AND HEAVY RAINFALL THE
MAIN HAZARDS.
- COOLER WEATHER RETURNS WEDNESDAY AND THURSDAY, WITH HIGHS IN
THE UPPER 70S TO MID 80S. RAIN CHANCES RETURN THIS WEEKEND,
FOLLOWED BY ANOTHER COOL-DOWN EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 1018 PM CDT MON SEP 7 2026
TONIGHT AND TUESDAY...
WATER VAPOR IMAGERY AND OBJECTIVE ANALYSIS LATE THIS EVENING DEPICTS
A MID-LEVEL RIDGE CENTERED OVER THE SOUTHERN AND CENTRAL PLAINS
WHILE A DEEPENING CUT-OFF LOW TRACKS EASTWARD ACROSS
MONTANA/ALBERTA. A WEAK SURFACE FRONT DRAPED FROM CENTRAL NEBRASKA
INTO SOUTHEASTERN SOUTH DAKOTA HAS SERVED AS A FOCUS FOR
THUNDERSTORM DEVELOPMENT EARLIER THIS EVENING. A MODESTLY UNSTABLE
AIRMASS WITH STEEP MID-LEVEL LAPSE RATES IS IN PLACE OVER NORTHEAST
NEBRASKA, THOUGH DEEP-LAYER SHEAR REMAINS RATHER LIMITED (AROUND
25 KTS). HOWEVER, A 35-40 KT LLJ IN PLACE HAS ALLOWED FOR SOME
HODOGRAPH CURVATURE AND ENOUGH LOW-LEVEL SHEAR FOR INITIAL STORM
ORGANIZATION WITH A SUPERCELL THAT TRACKED OVER NORTHEAST
NEBRASKA INTO SOUTHEAST SOUTH DAKOTA BEFORE GROWING INTO MORE OF
A MESSY, UPSCALE CLUSTER. WITH THIS IN MIND, A STRONG STORM OR
TWO SWIPING ACROSS NORTHEAST NEBRASKA CAN'T BE RULED OUT, THOUGH
THAT CHANCE WILL DECREASE THROUGH THE OVERNIGHT PERIOD AS
STABILITY INCREASES. SCATTERED SHOWERS AND STORM WILL PERSIST
AND SLOWLY SAG SOUTHWARD INTO TUESDAY MORNING AS LOW-LEVEL
MOISTURE TRANSPORT AND WAA CONTINUES TO POINT INTO THE AREA.
TUESDAY, THE AFOREMENTIONED NORTHERN LOW WILL PUSH A NORTHEAST-TO-
SOUTHWEST ORIENTED TRAILING COLD FRONT INTO THE AREA. HIGH
TEMPERATURES WILL DEPEND ON HOW FAR SOUTH THE FRONT PROGRESSES
BEFORE PEAK DAYTIME HEATING. HIGH TEMPERATURES ARE EXPECTED TO REACH
THE MID TO UPPER 90S ACROSS SOUTHEAST NE AND SOUTHWEST IA.
CONTINUED LOW- LEVEL MOISTURE TRANSPORT AHEAD OF THE FRONT WILL
BRING DEWPOINTS INTO THE LOW TO MID 70S, PUSHING HEAT INDEX
VALUES INTO THE 104-108 DEGREE RANGE, GENERALLY ALONG AND SOUTH
OF INTERSTATE-80 WHERE A HEAT ADVISORY IS IN PLACE. FURTHER
NORTH, HIGHS ARE EXPECTED TO PEAK IN THE MID 80S THANKS TO THE
PASSING FRONT AND CONTINUED SHOWERS/CLOUD COVER.
STORM CHANCES INCREASE ALONG THE SLOWLY ADVANCING FRONT TUESDAY
AFTERNOON AND EVENING AS IT PASSES THROUGH AN INCREASING UNSTABLE
AIRMASS. WHILE LARGE SCALE FORCING FOR ASCENT REMAINS RATHER WEAK,
THERE SHOULD BE ENOUGH CONVERGENCE ALONG THE FRONT FOR CONVECTIVE
INITIATION. SHEAR WILL BE THE LIMITING FACTOR, WITH AROUND 20-25 KTS
OF BULK SHEAR, LIMITING OVERALL STORM ORGANIZATION. MODEL SOUNDINGS
INDICATE FAIRLY DRY LOW-LEVELS AND DCAPE VALUES APPROACHING 1000
J/KG, WHICH COULD HELP TO PROMOTE SEVERE WEATHER GUSTS (60-70 MPH)
WITH ANY STORMS THAT QUICKLY PULSE UP AND COLLAPSE. POCKET OF HAIL
(UP TO 1.50") ALSO CAN'T BE RULED OUT GIVEN THE MODESTLY STEEP
LOW-LEVEL LAPSE RATES IN PLACE. INTO THE EVENING AND OVERNIGHT
PERIOD, ATTENTION WILL SHIFT TO HEAVY RAINFALL AS TRAINING
STORMS PERSIST BEHIND THE FRONT, GENERALLY ALONG AND SOUTH OF
I-80, BRINING REPEATED ROUNDS OF RAINFALL. STORMS WILL BE
EFFICIENT RAIN PRODUCERS, WITH PWAT VALUES APPROACHING 2 INCHES
(NEAR THE DAILY MAXIMUM OF SOUNDING CLIMATOLOGY) AND WARM CLOUD
DEPTHS OF 4-4.5 KM. CAM GUIDANCE SUGGESTS POCKETS OF 2-3+"
BEFORE SHOWERS GRADUALLY TAPER OFF FROM NORTH TO SOUTH THROUGH
WEDNESDAY MORNING.
WEDNESDAY AND BEYOND...
THE PASSING DISTURBANCE TO THE NORTH WILL HELP TO DAMPEN THE RIDGE
THAT HAS DOMINATED THE REGION WITH ABOVE-AVERAGE TEMPERATURES
THROUGH THE BEGINNING OF SEPTEMBER. AS A RESULT, ZONAL FLOW WILL
RETURN TO THE AREA AND DROP HIGHS ON WEDNESDAY AND THURSDAY INTO THE
UPPER 70S TO LOW 80S. ON FRIDAY, A BRIEF MID-LEVEL RIDGE WILL PULL A
WARM FRONT NORTHWARD ACROSS THE AREA AND ALLOW HIGHS TO CLIMB BACK
INTO THE MID TO UPPER 80S. THE WARMER TEMPERATURES WON'T LAST LONG,
AS A PASSING DISTURBANCE WILL PUSH A COLD FRONT BACK ACROSS THE AREA
INTO SATURDAY, DROPPING HIGHS INTO THE UPPER 70S TO MID 80S, WHILE
ALSO BRINGING POPS OF 40-60%.
LOOKING FURTHER AHEAD, LONG-RANGE GUIDANCE IS COMING INTO CONSENSUS
ON BRINGING A MID-LEVEL LOW ACROSS THE NORTHERN PLAINS LATE NEXT
WEEKEND INTO THE EARLY WORK WEEK. THIS SYSTEM IS EXPECTED TO BRING
ANOTHER ROUND OF 30-50% POPS AS WELL AS A PUSH OF CAA INTO THE
REGION, DROPPING HIGH TEMPERATURES INTO THE 70S FOR MOST
LOCATIONS, WITH A FEW SPOTS POTENTIALLY PEAKING IN THE UPPER 60S
MONDAY AND TUESDAY. FOR REFERENCE, THE LAST TIME OMAHA'S HIGH
TEMPERATURE PEAKED BELOW 70 DEGREES WAS MAY 21ST.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1217 AM CDT TUE SEP 8 2026
PLENTY GOING ON. CURRENT STORMS/SHOWERS SHOULD AVOID TAF SITES
UNTIL ABOUT 5AM WHEN THEY MAY MEANDER INTO THE KOFK AREA. EXPECT
THEM TO BE WEAKER BY THEN, SO HAVE KEPT THEM MENTIONED AS -SHRA.
ALSO HAVE CONTINUING LLWS AT ALL SITES THROUGH THE OVERNIGHT
HOURS WITH 45 KNOT WINDS AT FL017.
THUNDERSTORM CHANCES REDEVELOP ON TUESDAY AFTERNOON. TIMING IS
STILL UNCERTAIN, BUT I'VE PUSHED BACK THE TIMING BY ABOUT 4
HOURS AT KOFK AND ADDED THREE HOURS OF -TSRA AT KOMA AND KLNK
IN THE EVENING, TOO.
OAX WATCHES/WARNINGS/ADVISORIES
NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR NEZ066>068-078-088>093.
IA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR IAZ079-080-090-091.
DISCUSSION...WOOD
AVIATION...NICOLAISEN
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