199
FXUS63 KOAX 211737
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1237 PM CDT SUN JUN 21 2026
KEY MESSAGES
- HEAVY RAIN AND FLASH FLOODING WILL CONTINUE TO BE THE MAIN
CONCERN OVERNIGHT. ONE TO TWO INCH RAINFALL TOTALS EXPECTED
WITH ISOLATED TOTALS THREE TO FIVE INCHES MAINLY SOUTH.
- ANOTHER LOW CHANCE (30%) OF SHOWERS/STORMS FOR NORTHEAST
NEBRASKA SUNDAY AFTERNOON. NOT ANTICIPATING MUCH OF A RISK FOR
SEVERE WEATHER WITH THESE STORMS.
- PLEASANTLY MILD TEMPERATURES FOR THE FIRST FULL WEEK OF
SUMMER. HIGH TEMPERATURES IN THE 70S AND LOW TEMPERATURES IN
THE 50S ARE EXPECTED. PERIODIC CHANCES FOR SHOWERS AND STORMS.
DISCUSSION
ISSUED AT 1124 PM CDT SAT JUN 20 2026
SHOWERS HAVE OVERSPREAD OUR AREA ACROSS EASTERN NEBRASKA AND
MOST OF SOUTHWEST IOWA THIS EVENING. THE INSTABILITY AXIS HAS
SET UP FARTHER SOUTHWEST THAN ANTICIPATED, DRIVING STRONGER
STORMS GENERALLY SOUTH OF OUR AREA OUT OF CENTRAL NEBRASKA AT
LEAST SO FAR THIS EVENING. WE STILL HAVE THE NOSE OF THE LOW-
LEVEL JET FORECAST TO SHIFT EASTWARD INTO OUR AREA CLOSER TO
MIDNIGHT TONIGHT. IF THIS OCCURS, THIS SHOULD LEAD TO
ADDITIONAL DESTABILIZATION IN THE ELEVATED MIXED LAYER,
POTENTIALLY RAMPING UP MORE THUNDERSTORM ACTIVITY ACROSS OUR
SOUTHERN COUNTIES. THE ONE ELEMENT THAT COULD HAMPER THIS IS
THAT STORMS OVER NORTHWESTERN KANSAS RIGHT NOW ARE DISRUPTING
THE 850-MB JET. IF THIS CONTINUES, WE WOULD SEE LESS OF AN
IMPACT FROM THE LLJ, WHICH WOULD LIMIT ANY ADDITIONAL
CONVECTIVE GROWTH.
A SECOND WAVE OF SHOWERS AND STORMS MOVE IN FROM THE WEST
OVERNIGHT, CURRENTLY ACTIVE OVER THE NEBRASKA PANHANDLE. THIS
WILL BE WEAKENING AS IT MOVES INTO A MORE STABLE AIR MASS, BUT
COULD BRING ADDITIONAL RAINFALL TO AREAS THAT WILL HAVE SEEN A
DECENT AMOUNT OF RAIN ALREADY. SO FAR OUR HEAVIEST RAINFALL
AMOUNTS HAVE OCCURRED ALONG THE CONVECTIVE LINE THROUGH SALINE,
JEFFERSON, GAGE, AND PAWNEE COUNTIES. A SWATH OF JEFFERSON
COUNTY SAW 3.5 TO 3.85 INCHES OF RAIN WITH THE STORM THAT MOVED
THROUGH EARLIER, SO WE'LL BE WATCHING THIS AREA FOR ANY
ADDITIONAL HEAVY RAINFALL OVERNIGHT. WITH THIS SECOND ROUND,
HEAVIEST RAINFALL AMOUNTS WILL OCCUR ALONG THE SOUTHERN PART OF
THAT LINE CLOSER TO THE NOSE OF THE LLJ. THIS AGAIN WILL GREATLY
DEPEND ON THE AMOUNT OF INFLUENCE WE CAN GET FROM THE LLJ COMING
UP OUT OF KANSAS. THE POTENTIAL DEVELOPMENT TOWARD MIDNIGHT
TONIGHT AND THE SECOND WAVE CLOSER TO 3-5 AM BOTH STILL BRING
CHANCES FOR HEAVY RAIN AND FLASH FLOODING ACROSS SOUTHEASTERN
PORTIONS OF OUR AREA, SO LEAVING THE FLOOD WATCH IN PLACE FOR
NOW.
RAIN CLEARS OUT OF OUR AREA AROUND 7-8 AM ON SUNDAY WITH CLOUDS
LINGERING THROUGH THE DAY ON SUNDAY. THIS SHOULD KEEP
TEMPERATURES COOL WITH HIGHS IN NORTHEAST NEBRASKA ONLY IN THE
UPPER 60S, AND LOW-TO-MID 70S ACROSS SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. SUNDAY AFTERNOON AND EVENING WE SEE A VORTICITY
LOBE MOVE THROUGH BRINGING ANOTHER CHANCE FOR SHOWERS AND
STORMS, MAINLY TO NORTHEAST NEBRASKA. WHILE MOST HI-RES GUIDANCE
TRACK THESE STORMS SOUTH INTO KANSAS, THE HRRR AND FV3 BRING
STORMS INTO NORTHEAST NEBRASKA. IF THEY TRACK INTO OUR AREA,
THEY SHOULD BE TRENDING WEAKER WITH NOT MUCH OF A RISK FOR ANY
SEVERE WEATHER. THESE SHOULD BE DONE BY MIDNIGHT.
LOOKING BACK AT THE BROADER PICTURE, WE HAVE FAIRLY ZONAL FLOW
ACROSS THE CENTRAL PLAINS SUNDAY INTO MONDAY WITH RIDGING
BUILDING OUT WEST TOWARD MIDWEEK. THIS WILL LEAD TO A TRANSITION
TO NORTHWESTERLY FLOW STARTING TUESDAY WITH THE ARRIVAL OF A
WEAK TROUGH. THIS COULD BRING SOME SHOWERS AND STORMS TUESDAY
MORNING INTO THE AFTERNOON BUT WEAK FORCING AND DYNAMIC FORCING
SHOULD KEEP ANY OF THIS FROM BEING TOO MUCH OF A CONCERN.
WEAK SHORTWAVES IN THE NORTHWESTERLY FLOW WILL BRING ADDITIONAL
PERIODIC CHANCES FOR RAIN THROUGH THE END OF THE WEEK. HIGHS
MOSTLY STAY IN THE 70S WITH OVERNIGHT LOWS IN THE 50S. COULD SEE
A WARMING TREND GOING INTO NEXT WEEKEND AS DETERMINISTIC
GUIDANCE START TO PUSH THE RIDGE EASTWARD INTO OUR AREA AS A
TROUGH MOVES OUT OF THE GULF OF ALASKA INTO THE PACNW. THIS
WOULD LEAD TO ENHANCED SOUTHERLY FLOW ADVECTING HOTTER, MORE
HUMID AIR BACK INTO THE REGION OVER NEXT WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1235 PM CDT SUN JUN 21 2026
A LARGE AREA OF IFR/MVFR STRATUS CONTINUES TO ENVELOP THE
FORECAST AREA EARLY THIS AFTERNOON. THE LATEST SATELLITE IMAGERY
SHOWS SOME THINNING OF THE CLOUDS AS SUCCESSIVE GRAVITY WAVES
RIPPLE SOUTHWEST ACROSS THE REGION. NBM AND HREF INDICATE
IMPROVING CONDITIONS FOR KOMA BY 21-22Z WITH DRIER AIR
ENTRAINMENT H8-H5. A MORE PERSISTENT FETCH OF NEAR SATURATED
FLOW PERSISTS ACROSS SOUTHERN IOWA INTO SOUTHERN AND NORTHEAST
THUS MVFR CIGS MAY REMAIN AT KLNK AND KOFK THROUGH MONDAY
MORNING. NBM OUTPUT IS THE MOST PESSIMISSTIC WITH IFR CONDITIONS
RETURNING TO BOTH KLNK AND KOFK BETWEEN 10Z-12Z. SIMILARLY, NBM
SHOWING MVFR CIGS REDEVELOPING AT KOMA BETWEEN 08-11Z.
AN ADDITIONAL AVIATION IMPACT OF ISOLATED TO SCATTERED
THUNDERSTORMS (15-30%) AT KOFK EXISTS FROM 03Z-07Z, WITH
ISOLATED SHOWERS LINGERING THROUGH 10Z.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...FORTIN
AVIATION...CA
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