784
FXUS63 KTOP 301746
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1246 PM CDT WED SEP 30 2026
KEY MESSAGES
- ROUNDS OF HEAVY RAIN CONTINUE INTO THURSDAY EVENING. STILL
EXPECTING WIDESPREAD RAINFALL TOTALS OF 2-4", WITH LOCALLY HIGHER
AMOUNTS UP TO AROUND 6". FLOOD WATCH EXTENDED SLIGHTLY FARTHER SOUTH
AND EAST.
- A FEW STRONG OR SEVERE STORMS POSSIBLE THIS AFTERNOON AND EVENING,
MAINLY WEST OF HIGHWAY 75. DAMAGING WINDS AND A TORNADO OR TWO COULD
OCCUR.
- DRYING OUT FOR THE WEEKEND WITH TEMPERATURES SLIGHTLY COOLER THAN
AVERAGE.
DISCUSSION
ISSUED AT 240 AM CDT WED SEP 30 2026
CURRENT WATER VAPOR IMAGERY DEPICTS A TEXTBOOK UPPER LOW SPINNING
OVER ARIZONA. VERY DIFFLUENT UPPER FLOW IS PRESENT TO THE EAST OF
THE LOW, SUPPORTING THE WIDESPREAD PRECIPITATION OVER THE
CENTRAL/SOUTHERN PLAINS AND EVEN INTO THE SOUTHERN ROCKIES. GIVEN
THE DEEP SOUTHERLY FLOW AHEAD OF THE LOW AND THE ABSORPTION OF
HURRICANE POLO, NEAR RECORD MOISTURE FOR THE TIME OF YEAR IS IN
PLACE ACROSS MUCH OF THE AREA. TOP'S 0Z SOUNDING SHOWED 2.05" OF
PWAT, TIED FOR SECOND HIGHEST ON RECORD FOR ANY SOUNDING AFTER
SEPTEMBER 25.
HERE IN NORTHEAST KS, OUR INITIAL ROUND OF LIGHT TO MODERATE RAIN
CONTINUES THIS MORNING. HAVE SEEN A BIT OF A RECENT UPTICK IN RAIN
RATES WITHIN AN AREA OF 850 MB FRONTOGENESIS NORTH OF I-70. WOULD
NOT BE SURPRISED TO SEE SOME LOCAL 1-2" AMOUNTS ACROSS THIS AREA BY
MID-MORNING. WHILE THERE MAY BE A BIT OF A LULL BEHIND THE FIRST
ROUND OF ACTIVITY, EXPECTING THE WIDESPREAD RAIN OVER SOUTHWEST KS
AND THE OK/TX PANHANDLES TO LIFT NORTHEAST OVER THE AFTERNOON AND
EVENING. COVERAGE SHOULD BE GREATEST FARTHER WEST TOWARDS CENTRAL
KS, CLOSER TO A SURFACE LOW PARTIALLY TIED TO THE REMNANTS OF POLO.
GIVEN THE VERY HIGH MOISTURE AND STRONGER SYNOPTIC FORCING, WOULD
NOT BE SURPRISED TO SEE SOME ISOLATED SPOTS OF 3-6" RAIN IN A SHORT
PERIOD OF TIME ACROSS NORTH-CENTRAL KS. DAY 1 ERO FROM WPC SHOWS A
MODERATE RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF NORTH-CENTRAL
KS, WHICH MATCHES THINKING HERE VERY WELL.
AND WHILE THIS FLOOD RISK IS STILL THE MAIN HAZARD, ALSO BECOMING
INCREASINGLY CONCERNED ABOUT A SHORT-LIVED TORNADO SETUP LATE
AFTERNOON INTO THE EVENING. AHEAD OF THE SURFACE LOW OVER WESTERN
KS, THE LLJ IS FORECAST TO INCREASE TO AROUND 40-45 KTS BY 0-3 UTC
TONIGHT. COUPLED WITH VEERING LOW- LEVEL WINDS, EFFECTIVE SRH MAY
INCREASE TO AROUND 300 M2S2 WITH 35-40 KTS OF EFFECTIVE SHEAR.
INSTABILITY REMAINS THE MAIN QUESTION GIVEN PERSISTENT EARLY DAY
CLOUDS, BUT EVEN MODEST HEATING WOULD SUPPORT AN UNCAPPED 500-1000
J/KG OF ML CAPE. WITH THE HIGH PWAT AND VERY LOW LCLS, THIS MAY FAVOR
THE DEVELOPMENT OF SEVERAL MINI-SUPERCELLS CAPABLE OF PRODUCING
GUSTY WINDS AND A FEW TORNADOES. THE ENVIRONMENT LOOKS MOST FAVORABLE
TOWARDS CENTRAL KS, THOUGH SOME POTENTIAL COULD EXTEND AS FAR EAST
AS THE HIGHWAY 75 AREA. WHILE EVERY DAY IS DIFFERENT, AND
THERMODYNAMICS MAY HAVE BEEN SLIGHTLY MORE FAVORABLE YESTERDAY
EVENING, THE PRESENCE OF MULTIPLE SUPERCELLS AND TORNADOES IN A
SIMILAR SETUP NEAR AMARILLO YESTERDAY GIVES CREDENCE TO THE
POTENTIAL.
SHIFTING BACK TO THE HEAVY RAIN, WE MAY SEE ANOTHER BRIEF LULL
OVERNIGHT BEFORE RAIN FILLS BACK IN THURSDAY MORNING. THIS WILL
OCCUR AS THE WEAKENING UPPER LOW MOVES EAST ACROSS THE STATE AND
ASCENT INCREASES ALONG A SOUTHEASTWARD MOVING COLD FRONT. SO
COMPARED TO EARLIER ROUNDS, THIS ROUND SHOULD SEE MORE RAIN ACROSS
EASTERN PORTIONS OF THE STATE, ESPECIALLY BY THE AFTERNOON AND
EVENING. HAVE SEEN A BIT MORE OF A SOUTHEAST TREND IN RECENT
GUIDANCE, SO HAVE EXPANDED THE FLOOD WATCH SLIGHTLY SOUTHEASTWARD.
STILL EXPECTING A GENERAL 2-4" WITHIN THE WATCH AREA, WITH ISOLATED
HIGHER AMOUNTS OF AROUND 6". AMOUNTS OUTSIDE OF THE WATCH LOOK
SLIGHTLY LESS, GENERALLY 1-3", BUT SOME HIGHER AMOUNTS CAN'T BE RULED
OUT HERE AS WELL.
MUCH LESS TO WRITE ABOUT AFTER THURSDAY NIGHT, AS DRIER AIR BEHIND
THE FRONT AND BROAD NORTHWESTERLY FLOW WILL KEEP THINGS QUIETER.
TEMPERATURES REMAIN NEAR TO SLIGHTLY BELOW AVERAGE INTO EARLY NEXT
WEEK. HIGHS STAY MAINLY IN THE UPPER 60S TO LOW 70S, WITH LOWS IN
THE 50S TO EVEN UPPER 40S. NO NOTABLE PRECIPITATION CHANCES,
ALLOWING US TO DRY OUT AFTER THESE VERY WET NEXT FEW DAYS.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1232 PM CDT WED SEP 30 2026
RAIN HAS BEEN MORE PERSISTENT AT MHK AND EXPECT THAT TO CONTINUE TO
BE THE CASE THROUGH THE AFTERNOON, WHEREAS FURTHER EAST AT TOP/FOE,
LIGHT RAIN IS ONLY JUST STARTING TO GET NEAR TERMINALS. CONFIDENCE IN
TS STILL ISN'T HIGH ENOUGH TO DO ANY MORE THAN PROB30 GROUPS AT ALL
SITES, ALTHOUGH EVEN WITHOUT CONVECTION THERE COULD STILL BE PERIODS
OF MODERATE TO HEAVY RAIN THAT RESULT IN IFR VSBY, AS WE'VE ALREADY
SEEN AT TIMES. THERE SHOULD BE SOMEWHAT OF A BREAK LATER TONIGHT AND
OVERNIGHT BEFORE RAIN FILLS BACK IN MID TO LATE MORNING. CIGS LOOK TO
BECOME LOWER IN THE BACK HALF OF THE PERIOD. WAS HESITANT TO GO TO
IFR AS EARLY AS GUIDANCE SHOWS, AS IT APPEARS TO BE OVERDONE WITH
LOWER CIGS WITH CURRENT CONDITIONS, BUT THERE'S ENOUGH AGREEMENT THAT
IT SEEMS TO BE WORTH A MENTION FOR AT LEAST PART OF THE MORNING.
TOP WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR KSZ008-KSZ009-KSZ010-
KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026-KSZ034-
KSZ035-KSZ036-KSZ037-KSZ038-KSZ039.
DISCUSSION...REESE
AVIATION...PICHA
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