790
FXUS63 KTOP 261052
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
552 AM CDT SUN APR 26 2026
KEY MESSAGES
- COMPLICATED SEVERE WEATHER SETUP TONIGHT. LIKELY TWO ROUNDS OF
SEVERE, ONE AFTERNOON INTO EARLY EVENING AND ANOTHER LATE EVENING
INTO THE OVERNIGHT HOURS. THE SECOND ROUND WILL CARRY THE LARGEST
SEVERE THREAT, BUT LARGE HAIL, DAMAGING WINDS, AND A FEW TORNADOES
WILL BE POSSIBLE WITH BOTH ROUNDS.
- A FEW STORMS MAY LINGER INTO MONDAY, BUT SEVERE WEATHER THREAT
MOSTLY SHIFTS TO OUR EAST.
- COOLER PATTERN ARRIVES FOR THE REST OF THE WEEK BEHIND
MONDAY'S COLD FRONT. A FEW CHANCES FOR LIGHT RAIN.
DISCUSSION
ISSUED AT 339 AM CDT SUN APR 26 2026
CURRENT WATER VAPOR IMAGERY SHOWS THE MAIN FOCUS FOR TODAY - A
STRONG SHORTWAVE TROUGH MOVING ONSHORE TO CALIFORNIA AND PHASING
WITH THE MAIN WESTERN US LONGWAVE TROUGH. BROAD SOUTHWEST FLOW IS IN
PLACE AHEAD OF THIS SYSTEM, WITH THE EMBEDDED WEAKER PERTURBATION
RESPONSIBLE FOR YESTERDAY'S SEVERE WEATHER WEAKENING OVER THE
PLAINS. AS THE MAIN SHORTWAVE APPROACHES THE PLAINS THIS MORNING,
PRESSURE WILL BEGIN TO QUICKLY DROP IN THE LEE OF THE ROCKIES.
SOUTHERLY WINDS WILL ALLOW MOISTURE TO STREAM BACK NORTHWARDS, THOUGH
THE EXACT DEGREE OF MOISTURE RETURN MAY BE IMPACTED SOMEWHAT BY THE
AMOUNT OF MORNING CONVECTION OVER THE ARKLATEX AREA.
STILL EXPECTING TWO ROUNDS OF CONVECTION IN GENERAL, WITH PERHAPS A
BRIEF LULL IN BETWEEN. THE FIRST APPEARS LIKELY AS EARLY AS MID-DAY,
WITH THE INITIAL SURGE OF 850 MB WAA. ISENTROPIC ASCENT ALONG THE
FRONTAL BOUNDARY CURRENTLY BISECTING THE FORECAST AREA SHOULD
SUPPORT A CLUSTER OF THUNDERSTORMS DEVELOPING TOWARDS CENTRAL AND
NORTH-CENTRAL KS. THE BROAD FORCING FOR ASCENT MAY SUPPORT A MESSY
STORM MODE, BUT WITH INCREASING SHEAR AND INSTABILITY A MORE
ORGANIZED LINE OR EMBEDDED SUPERCELL COULD EMERGE, MOVING EAST
THROUGH THE EARLY EVENING HOURS. IF THIS WERE THE CASE, LARGE HAIL
AND DAMAGING WINDS WOULD BE POSSIBLE, ALONG WITH A LOW THREAT FOR A
BRIEF TORNADO. SOME LOCALLY HEAVY RAIN COULD ALSO OCCUR,
PARTICULARLY IF STORMS CAN TRAIN FROM WEST TO EAST.
BEHIND THIS INITIAL ACTIVITY, ANOTHER ROUND OF WIDESPREAD CONVECTION
IS EXPECTED TO DEVELOP AFTER SUNSET ACROSS PORTIONS OF CENTRAL
KANSAS. THIS WOULD OCCUR AS THE SURFACE LOW BEGINS TO LIFT NORTHEAST
AND A VERY STRONG LLJ DEVELOPS. LOTS OF UNCERTAINTY AS TO THE
LOCATION AND EXTENT OF THIS CONVECTION, WITH SHORT-TERM MODELS STILL
STRUGGLING TO DEAL WITH THE EVOLUTION OF VARIOUS SURFACE FEATURES.
NEVERTHELESS, GIVEN THE STRENGTH OF THE LLJ AND THE APPROACHING
SHORTWAVE, THE ENVIRONMENT WILL BE CHARACTERIZED BY EXTREME SHEAR.
SO LARGE TO VERY LARGE HAIL WILL BE POSSIBLE WITH ANY MORE DISCRETE
SUPERCELL, AND WIDESPREAD DAMAGING WINDS WITH ANY MORE LINEAR
SEGMENT. THE OVERNIGHT TORNADO THREAT IS SLIGHTLY MORE UNCERTAIN,
AND TIED TO THE DEGREE OF NOCTURNAL STABILIZATION. HOWEVER MOST
GUIDANCE TENDS TO KEEP THE CAP WEAK ENOUGH THAT SURFACE BASED STORMS
WILL REMAIN POSSIBLE, PARTICULARLY ALONG AND SOUTH OF INTERSTATE 70.
THIS WOULD SUPPORT THE RISK OF TORNADOES, PERHAPS STRONG, WELL INTO
THE NIGHT, WITH ANY SEMI-DISCRETE SUPERCELL. ANY LINEAR SEGMENT
WOULD CARRY A QLCS TORNADO RISK, GIVEN STRONG 0-3 KM SHEAR LARGELY
PERPENDICULAR TO THE FRONT. THE SEVERE THREAT (AND POTENTIAL FOR
MORE LOCALLY HEAVY RAIN) WILL LINGER INTO THE EARLY MORNING HOURS
TOMORROW, AS PRESSURES CONTINUE TO FALL JUST AHEAD OF THE SURFACE
LOW TRACK. DESPITE THE EXTREMELY FAVORABLE INGREDIENTS, IT'S
IMPORTANT AS ALWAYS TO KEEP IN MIND ANY POTENTIAL FAILURE MODES. ONE
PLAUSIBLE FAILURE MODE COULD BE IF MORE WIDESPREAD CONVECTION
DEVELOPS EARLIER IN THE DAY ACROSS PARTS OF NORTHERN OKLAHOMA. THIS
COULD HELP LIMIT MOISTURE RETURN OVERNIGHT, KEEPING OUR STORMS MORE
ELEVATED AND THE STRONGEST SURFACE BASED STORMS TO OUR SOUTH. BUT
GIVEN THE POTENTIAL CEILING OF THE EVENT AND THE VERY LATE TIMING,
CERTAINLY IMPORTANT TO HAVE A WAY TO MONITOR THE STORM THREAT AND
RECEIVE WARNINGS OVERNIGHT TONIGHT.
STILL WATCHING EARLY AFTERNOON MONDAY FOR A LOW PROBABILITY SEVERE
THREAT (MAINLY IN THE FORM OF HAIL) ACROSS FAR EASTERN KS BEFORE THE
FRONT FULLY CLEARS THE AREA. HOWEVER THE MAJORITY OF GUIDANCE
CONTINUES TO KEEP ANY DEVELOPING CONVECTION TO OUR EAST ACROSS
MISSOURI, LEAVING BEHIND A DRY AFTERNOON AS WINDS TURN TO THE WEST
AND THEN NORTHWEST BEHIND THE FRONT. FOLLOWING THE FRONT, WE STAY IN
A NOTICEABLY COOLER PATTERN FOR THE REST OF THE WEEK AS UPPER
TROUGHING DEEPENS TO OUR EAST. HIGHS STAY MOSTLY IN THE 60S, WITH
LOWS IN THE 40S. A FEW LOW CHANCES FOR LIGHT RAIN TUESDAY AND AGAIN
THU/FRI AS EMBEDDED SHORTWAVES PASS NEARBY TO OUR SOUTH.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 552 AM CDT SUN APR 26 2026
IFR TO MVFR STRATUS REMAINS WEST OF THE MAIN TAF SITES,
AND CONFIDENCE IS STILL LOW THAT IT WILL REACH KMHK AT ANY POINT
THIS MORNING. CONFIDENCE IS INCREASING THAT THUNDERSTORMS WILL
IMPACT THE TERMINALS AT SOME POINT THIS AFTERNOON, THOUGH EXACT
TIMING AND PLACEMENT IS STILL SOMEWHAT UNCERTAIN. MORE
THUNDERSTORMS, LIKELY ACCOMPANIED BY MORE WIDESPREAD MVFR CEILINGS,
LOOK TO ARRIVE LATE EVENING AND OVERNIGHT, BUT TIMING AND COVERAGE
IS UNCERTAIN FOR THIS ROUND AS WELL. WINDS SHOULD BE MORE
SOUTHEASTERLY AFTER SUNRISE AND STAY SO THROUGH THE PERIOD,
GENERALLY AROUND 8-14 KTS.
TOP WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...REESE
AVIATION...REESE
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