766
FXUS63 KTOP 202236
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
536 PM CDT MON APR 20 2026
KEY MESSAGES
- RED FLAG WARNING REMAINS IN EFFECT UNTIL 8PM THIS EVENING FOR
COUNTIES ALONG THE HWY 81 CORRIDOR.
- DRY AND WARM UNTIL THURSDAY, WHEN THE NEXT CHANCE FOR
THUNDERSTORMS ARRIVES, INCLUDING THE POTENTIAL FOR SEVERE WEATHER.
- COOLER LATE THIS WEEK INTO NEXT WEEK WITH OFF AND ON RAIN
CHANCES.
DISCUSSION
ISSUED AT 239 PM CDT MON APR 20 2026
NORTHWEST FLOW ALOFT HOLDS THIS AFTERNOON WHILE THE NEXT LARGE UPPER
LOW CAN BE SEEN CIRCULATING OFF THE PACIFIC COAST VIA WATER VAPOR
IMAGERY. AT THE SURFACE, HIGH PRESSURE DOMINATES MUCH OF THE EASTERN
CONUS WHILE LEE TROUGHING HAS DEVELOPED, LEAVING A TIGHTENING
PRESSURE GRADIENT OVER OUR AREA. SOUTHERLY WINDS HAVE TURNED GUSTY
IN RESPONSE AND WILL LIKELY REMAIN BREEZY INTO TUESDAY, WITH THE
PRESSURE GRADIENT RELAXING SLIGHTLY THAT NIGHT. IN THE MEANTIME, THE
BL LOOKS TO STAY FAIRLY WELL-MIXED TONIGHT, WHICH COULD KEEP
TEMPERATURES WARMER THAN FORECAST OVERNIGHT INTO TUESDAY MORNING.
UPPER-LEVEL RIDGING CONTINUES TO FAVOR WARM AND DRY WEATHER INTO
WEDNESDAY, ALL WHILE THE LOW MOVES ACROSS THE WESTERN US. THE MAIN
PART OF THIS LOW LOOKS TO EJECT ACROSS THE NORTHERN PLAINS INTO
THURSDAY, BRINGING THE BEST LIFT ASSOCIATED WITH THAT FEATURE TO THE
NORTH OF THIS AREA. STILL, IT'S A LARGE ENOUGH SYSTEM THAT THE BASE
OF THE TROUGH AS WELL AS AN ASSOCIATED SPEED MAX SHOULD HELP TO
GENERATE SOME LIFT ALONG WITH A DRYLINE AND COLD FRONT MOVING ACROSS
THE REGION. AN EARLY LOOK AT INSTABILITY, SHEAR, AND SOUNDING DATA
IN THE ENVIRONMENT JUST AHEAD OF THESE BOUNDARIES INDICATES THE
POTENTIAL FOR ALL SEVERE HAZARDS TO BE IN PLAY IF ALL THE
INGREDIENTS COME TOGETHER JUST RIGHT. IT'S STILL SEVERAL DAYS OUT,
AND CLUSTER ANALYSIS SHOWS SOME DIFFERENCES IN THE STRENGTH OF THE
MAIN UPPER LOW, WHICH COULD IMPACT THE TIMING AND PLACEMENT OF THE
AFOREMENTIONED SURFACE FEATURES. ADDITIONALLY, GUIDANCE IS SHOWING
CLOUD COVER IN THE MORNING AND AFTERNOON, SO IF THIS PREVENTS THE
ATMOSPHERE FROM DESTABILIZING AS MUCH AS CURRENTLY INDICATED, THIS
COULD TEMPER THE SEVERE THREAT AS WELL. ALL THIS TO SAY, PLENTY OF
UNCERTAINTY EXISTS AS IS TYPICAL IN THIS TIME FRAME.
A COOLER AIR MASS ARRIVES BEHIND THE FRONT FOR FRIDAY, AND STICKS
AROUND INTO EARLY NEXT WEEK. THE LARGE UPPER LOW STALLS OUT AND MAY
EVEN RETROGRADE IN THE NORTHERN US AND SOUTHERN CANADA DURING THE
WEEKEND. EMBEDDED PERTURBATIONS WITHIN THE FLOW ALOFT OVER US KEEP
PRECIPITATION CHANCES AROUND THROUGH MUCH OF THIS TIME PERIOD, BUT
SHOULDN'T BE A WASHOUT AS RAIN DOES NOT LOOK CONTINUOUS.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 536 PM CDT MON APR 20 2026
MODELS CONTINUE TO SHOW A STRONG PRESSURE GRADIENT ACROSS THE
TERMINALS TONIGHT WITH FORECAST SOUNDINGS KEEPING SOME MIXING IN
THE BOUNDARY LAYER. THIS IS FORECAST TO MITIGATE WIND SHEAR
POTENTIAL WITH SFC GUSTS THROUGH THE OVERNIGHT HOURS. SO WILL
KEEP WIND SHEAR OUT OF THE FORECAST AND MONITOR FOR THE BOUNDARY
LAYER DECOUPLING. OTHERWISE VFR CONDITIONS SHOULD PREVAIL. THE
LOW LEVEL MIXING SHOULD ALSO LIMIT POTENTIAL FOR LOW CLOUDS WITH
THE EXPECTED INCREASE IN DEWPOINTS TONIGHT.
FIRE WEATHER
ISSUED AT 150 AM CDT MON APR 20 2026
WINDS INCREASE FROM THE SOUTH THROUGH THE DAY TODAY; EXPECT
SUSTAINED WINDS OF 10-20 MPH WITH GUSTS OF 25-30 MPH THIS
AFTERNOON. GIVEN HOW LOW RELATIVE HUMIDITY VALUES WERE
YESTERDAY, HAVE TRENDED DEWPOINTS TOWARDS DRIER GUIDANCE WHICH
CREATES RELATIVE HUMIDITY VALUES OF 15- 20 PERCENT ACROSS NORTH-
CENTRAL KANSAS THIS AFTERNOON. A LACK OF GREEN-UP FOR AREAS
ALONG THE HIGHWAY 81 CORRIDOR KEEPS FUELS RECEPTIVE TO RAPID
FIRE SPREAD AND ERRATIC FIRE BEHAVIOR, SO HAVE ISSUED A RED FLAG
WARNING FOR THIS AREA FROM 1-8 PM TODAY.
INCREASING MOISTURE TUESDAY AND WEDNESDAY SHOULD KEEP RELATIVE
HUMIDITY VALUES ABOVE 30 PERCENT AND LIMIT FIRE WEATHER CONCERNS,
EVEN WITH GUSTY SOUTH WINDS.
TOP WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR KSZ008-KSZ020-
KSZ034.
DISCUSSION...PICHA
AVIATION...WOLTERS
FIRE WEATHER...FLANAGAN
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