770
FXUS63 KTOP 260802
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
302 AM CDT TUE AUG 26 2025
KEY MESSAGES
- FALL-LIKE TEMPERATURES PERSIST THROUGH THE WEEKEND.
- WIDESPREAD RAIN EXPECTED WEDNESDAY INTO THURSDAY. RAINFALL TOTALS
OVER 1" LIKELY (>60% CHANCE) FROM MINNEAPOLIS TO OTTAWA AND
SOUTHWARDS, BUT AMOUNTS DROP OFF QUICKLY WITH NORTHERN EXTENT.
DISCUSSION
ISSUED AT 301 AM CDT TUE AUG 26 2025
THE DEEP UPPER TROUGH OVER THE EASTERN CONUS CONTINUES TO SUPPLY
COOL AND DRY AIRMASS ACROSS MUCH OF THE REGION. WITH SURFACE HIGH
PRESSURE NEARBY AND MOSTLY CLEAR SKIES, TEMPERATURES EARLY THIS
MORNING HAVE QUICKLY DROPPED INTO THE 50S. A FEW OF THE TYPICAL
COOLER SPOTS (KLWC) HAVE EVEN DIPPED INTO THE UPPER 40S! WITH PLENTY
OF SUNSHINE, EXPECTING A BIT WARMER TEMPERATURES THIS AFTERNOON
COMPARED TO YESTERDAY, BUT STILL STAYING MOSTLY IN THE UPPER 70S.
ATTENTION THEN TURNS TO A WEAK MID-LEVEL PERTURBATION CURRENTLY OVER
ARIZONA. THIS SYSTEM WILL ROUND THE UPPER RIDGE OVER THE DESERT
SOUTHWEST AND MOVE ACROSS KANSAS WEDNESDAY INTO WEDNESDAY NIGHT. IN
ADVANCE OF THIS, ISENTROPIC ASCENT COUPLED WITH AROUND 1000 J/KG OF
ELEVATED INSTABILITY WILL SUPPORT A BAND OF MODERATE RAIN, LOCALLY
HEAVY AT TIMES WHERE CONVECTIVE ELEMENTS ARE PRESENT. WHILE GUIDANCE
IS GRADUALLY TRENDING TOWARDS A CONSENSUS ON WHERE THIS BAND WILL
SET UP, THERE IS STILL SOME MODERATE UNCERTAINTY IN ITS EXACT
NORTH/SOUTH POSITION. THIS IS AMPLIFIED BY THE FACT THAT THERE
SHOULD BE A TIGHT GRADIENT IN RAINFALL ON THE NORTH SIDE OF THE
SYSTEM, WITH POTENTIALLY 50 MILES SEPARATING SEVERAL INCHES OF RAIN
FROM ALMOST NO RAINFALL. SO RIGHT NOW, CONFIDENCE IS HIGHEST IN A
WIDESPREAD 1-3" OF RAIN SOUTH OF A MINNEAPOLIS TO OTTAWA LINE, AND
HIGHEST IN VERY LITTLE RAINFALL (POTENTIALLY NOTHING) NEAR THE
NEBRASKA BORDER. IN BETWEEN, NEAR THE I-70 CORRIDOR FROM MANHATTAN
TO TOPEKA AND LAWRENCE IS THE GREATEST UNCERTAINTY. AT ANY
RATE, RAIN SHOULD TAPER OFF THURSDAY MORNING AS A NORTHERN
STREAM SHORTWAVE DROPPING SOUTHEAST OVER THE UPPER MIDWEST
BRINGS DRIER MID- LEVEL AIR SOUTHWARD.
COOLER THAN AVERAGE CONDITIONS WILL CONTINUE FRIDAY AND OVER THE
WEEKEND AS EASTERN TROUGHING PERSISTS. CLOUD COVER WILL REMAIN THE
MAIN VARIABLE WITH REGARD TO TEMPERATURES, WITH CLOUD-FREE AREAS
LIKELY ABLE TO HEAT INTO THE UPPER 70S DURING THE AFTERNOONS.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1207 AM CDT TUE AUG 26 2025
EXPECTING VFR CONDITIONS AND LIGHT/VARIABLE WINDS TO
CONTINUE THROUGH THE PERIOD, WITH JUST SOME SCATTERED HIGH CLOUDS.
TOP WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...REESE
AVIATION...REESE
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