266
FXUS63 KOAX 172029
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
329 PM CDT FRI JUL 17 2026
KEY MESSAGES
- ISOLATED SHOWERS AND WEAK THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AND SATURDAY AFTERNOON.
- HEAT BUILDS THIS WEEKEND, WITH HEAT INDEX VALUES REACHING 100
TO 108 DEGREES SUNDAY AND MONDAY. A HEAT ADVISORY IS IN EFFECT
ON SUNDAY ACROSS NORTHEAST NEBRASKA AND THIS WILL LIKELY NEED
TO BE EXPANDED TO THE REST OF THE AREA ON MONDAY.
- COOLER WEATHER RETURNS BY MIDWEEK, ALONG WITH INCREASING
CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY NIGHT INTO
THURSDAY.
DISCUSSION
ISSUED AT 232 PM CDT FRI JUL 17 2026
TONIGHT THROUGH SATURDAY...
MUCH OF EASTERN NE AND WESTERN IA IS NEAR OR EXCEEDING THE
CONVECTIVE TEMPERATURE THIS AFTERNOON. IN FACT AROUND 2PM, A
LONE CELL HAD FORMED ALONG I-80 NEAR NEOLA, IA BUT HAS SINCE
DIMINISHED. A SCATTERED CUMULUS FIELD HAS ALSO DEVELOPED ACROSS
THE ENTIRE AREA, BUT SO FAR THERE ARE ONLY A COUPLE LOCATIONS
WITH ANY MEANINGFUL VERTICAL CLOUD DEPTH. DEVELOPMENT REMAINS
POSSIBLE THIS AFTERNOON DUE TO STRONG HEATING AND INSTABILITY.
EFFECTIVE DEEP SHEAR IS VERY MINIMAL, BUT MUCH LIKE YESTERDAY,
HIGH PRECIPITABLE WATER VALUES AND SLOW CELL MOTION WOULD
SUGGEST HIGH RAINFALL RATES FOR 15-20 MINUTES WITH ANY SHOWER OR
STORMS THIS AFTERNOON. OVERALL, IT DOES APPEAR LIKE SHOWER
ACTIVITY IS MORE FAVORABLE IN KANSAS AND MISSOURI TODAY.
IT'S A LITTLE MORE OF RINSE AND REPEAT ON SATURDAY ON THE BACK OF
STRONG DIURNAL HEATING. THE DIFFERENCE TOMORROW WILL BE A WEST-EAST
ORIENTATED BOUNDARY THAT DROPS SOUTH ACROSS THE AREA THROUGHOUT THE
DAY. THIS WILL LIKELY BE A FOCUS FOR CONVECTIVE INITIATION DURING
THE AFTERNOON. EVEN THOUGH MOST OF THE CONVECTIVE ALLOWING
MODELS SHOW ISOLATED TO SCATTERED COVERAGE, YOU COULD MAKE THE
ARGUMENT THAT 15-30% OF PRECIP MIGHT NOT CUT IT ACROSS FAR
EASTERN NE AND WESTERN IA IF THE PAST COUPLE DAYS ARE ANY
INDICATION. AFTERNOON CLOUDS COULD KEEP THE TEMPERATURES JUST A
BIT COOLER AS WELL.
SUNDAY AND MONDAY...
RIDGING OVER THE INTERMOUNTAIN WEST SLIDES A BIT FARTHER EAST
FOR THE SECOND HALF OF THE WEEKEND AND EARLY NEXT WEEK. THIS
WILL SET THE STAGE FOR EVEN WARMER TEMPERATURES DURING THIS TIME
FRAME. BUT BEFORE GETTING INTO TEMPERATURES, NOW THAT WE ARE
WITHIN 48 HOURS OF SUNDAY, HRRR/NSSL- WRF/RAP ALL TRY TO BRING
IN CONVECTION EARLY IN THE MORNING ACROSS NORTH CENTRAL AND
NORTHEAST PORTIONS OF NEBRASKA. PRECIP DURING THE EARLY MORNING
HOURS ON SUNDAY SEEM TO TIED TO PRONOUNCED WAA AT 925-850MB
ACROSS SOUTH DAKOTA. ACTIVITY WILL TRY TO MOVE EAST-SOUTHEAST
WITH TIME, BUT THE MODEL TREND IS TO DIMINISH ACTIVITY BEFORE
ARRIVING IN EASTERN PORTIONS OF THE STATE. WE WILL NEED TO
MONITOR HOW ANY RESIDUAL CLOUD COVER AFFECTS TEMPERATURES ON
SUNDAY.
AS PREVIOUS DISCUSSIONS HAVE MENTIONED, A SHORTWAVE TROUGH
PUSHING INTO THE NORTHERN PLAINS IS EXPECTED TO INITIATE
OVERNIGHT CONVECTION LATE IN THE DAY ON SUNDAY, POTENTIALLY
ORGANIZING INTO AN MCS OVERNIGHT. ENSEMBLE GUIDANCE HAS
CONSISTENTLY KEPT MOST OF THE ACTIVITY NORTH AND EAST OF THE
FORECAST AREA ACROSS SD/IA. 850MB TEMPERATURES CLIMB INTO THE
MID TO UPPER 20S ON MONDAY, WHICH COMBINED WITH BREEZY SOUTH/SOUTHWEST
WINDS, WILL SET THE STAGE FOR A RUN AT 100 F FOR MANY LOCATIONS
ACROSS THE AREA. UNLESS SOMETHING DRAMATIC CHANGES WITH THE
FORECAST, THIS WILL LIKELY BE OUR HOTTEST DAY OF THE SUMMER SO
FAR. MOST LOCATIONS HAVE TOPPED OUT IN THE MID 90S SO FAR THIS
YEAR.
TUESDAY THROUGH FRIDAY...
A BREAK FROM THE MORE EXTREME HEAT ARRIVES ON THE HEELS OF A
COLD FRONT AND WILL REMAIN IN PLACE THROUGH NEXT WEEK. BY
WEDNESDAY NIGHT INTO THURSDAY, WE'LL FIND OURSELVES ON THE
BACKSIDE OF THE SURFACE RIDGE JUST TO THE EAST OF THE FRONT.
THIS STILL LOOKS LIKE OUR BEST OPPORTUNITY FOR PRECIPITATION IN
THE NEXT 7 DAYS. WE HAVE INCLUDED RAIN CHANCES ON FRIDAY AS
WELL.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1242 PM CDT FRI JUL 17 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. BY THIS TIME
YESTERDAY AFTERNOON THE CUMULUS CLOUD FIELD WAS MUCH MORE
EXPANSIVE WITH SIGNS OF VERTICAL GROWTH, WHICH EVENTUALLY LEAD
TO THE AFTERNOON SHOWERS AND THUNDERSTORMS. IT'S LOOKING A BIT
DRIER THIS AFTERNOON, BUT WE CAN'T RULE OUT A POP UP SHOWER
BETWEEN 21-00Z AT KOMA OR KLNK. THE CHANCE FOR THAT IS ABOUT
10%.
OAX WATCHES/WARNINGS/ADVISORIES
NE...HEAT ADVISORY FROM 1 PM TO 9 PM CDT SUNDAY FOR NEZ011-012-016-
017.
IA...NONE.
DISCUSSION...FRANKS
AVIATION...FRANKS
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