724
FXUS63 KTOP 262347
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
647 PM CDT SAT SEP 26 2026
KEY MESSAGES
- SCATTERED SHOWER AND PERHAPS A THUNDERSTORM COULD REDEVELOP
OVERNIGHT TONIGHT ACROSS NORTHEAST AND EAST CENTRAL KANSAS.
- MAINLY DRY WEATHER IS EXPECTED SUNDAY AND MONDAY. THOUGH AN
ISOLATED SHOWER CANNOT BE RULED OUT.
- THERE IS GOOD CONFIDENCE IN WET WEATHER FOR TUE THROUGH FRI.
PERIODS OF HEAVY RAIN COULD LEAD TO SEVERAL INCHES OF ACCUMULATION
WITH A FLOODING RISK.
DISCUSSION
ISSUED AT 202 PM CDT SAT SEP 26 2026
19Z WATER VAPOR IMAGERY SHOWED A SHORTWAVE LIFTING ACROSS THE
FORECAST AREA WITHIN A BROADER UPPER TROUGH OVER MUCH OF THE WESTERN
U.S. SURFACE OBS SHOWED LOW PRESSURE ALONG THE HIGH PLAINS WITH HIGH
PRESSURE TO THE EAST OF THE GREAT PLAINS ALLOWING SOUTHERLY LOW LEVEL
FLOW TO CONTINUE TO BRING MOISTURE NORTH.
FOR THE REST OF THIS AFTERNOON, THE LIGHT RAIN ASSOCIATED WITH THE
SHORTWAVE SHOULD EXIT THE FORECAST AREA AS THE WAVE MOVES NORTHEAST
OF THE AREA. GENERAL SUBSIDENCE BEHIND THIS WAVE IS FORECAST TO
PRECLUDE ANY REDEVELOPMENT ACROSS NORTH CENTRAL KANSAS. HOWEVER THE
SOUTHERLY LOW LEVEL FLOW IS EXPECTED TO MAINTAIN SOME ISENTROPIC
LIFT TONIGHT AND THE CAMS CONTINUE TO SHOW SCATTERED SHOWERS
DEVELOPING TOWARDS MIDNIGHT. FORECAST SOUNDINGS SUGGEST THERE WILL
BE SOME MODEST ELEVATED INSTABILITY AROUND 500 J/KG. BUT BULK SHEAR
SHOULD BE WEAK (AROUND 20KT) AND EFFECTIVE SHEAR FOR AN ELEVATED
PARCEL EVEN WEAKER. THE FORECAST HAS SOME CHANCE POPS ACROSS
NORTHEAST AND EAST CENTRAL KANSAS EXPECTING COVERAGE FOR THE MOST
PART TO BE SCATTERED.
SHORTWAVE RIDGING IS PROGGED TO DEVELOP OVERHEAD FOR SUNDAY AND
MONDAY. SOME OF THE DETERMINISTIC SOLUTIONS HAVE ISOLATED QPF PROGS
SUNDAY AFTERNOON AND OVERNIGHT INTO MONDAY MORNING. AM NOT SURE WHAT
IS CAUSING THIS SINCE THERE ISN'T MUCH SYNOPTIC SUPPORT NOR LIFT ON
THE ISENTROPIC CHARTS. WITH THIS IN MIND HAVE KEPT POPS LESS THAN 20
PERCENT. THERE SHOULD BE SCATTERED CLOUD COVER WITH NO STRONG TEMP
ADVECTION FOR SUNDAY AND MONDAY. THIS SHOULD ALLOW TEMPS TO PERSIST
IN THE UPPER 70S FOR HIGHS AND LOWER 60S FOR LOWS.
THE MAIN FOCUS OF THE FORECAST REMAINS ON THE EXTENDED PERIOD OF WET
WEATHER FOR TUESDAY THROUGH FRIDAY. DETERMINISTIC SOLUTIONS ARE
CONVERGING ON A CLOSED UPPER LOW SLOWLY TREKKING FROM THE
SOUTHWESTERN U.S. ACROSS THE PLAINS. AND THERE IS A TREND IN THE
ENSEMBLE SOLUTIONS TO THIS IDEA AS WELL. SO FORECAST CONFIDENCE IS
IMPROVING. INITIALLY THE REMNANTS OF POLO ARE PROGGED TO BE ABSORBED
INTO THE UPPER TROUGH WITH A GOOD FETCH OF TROPICAL MOISTURE
ADVECTING INTO THE CENTRAL PLAINS FOR TUESDAY AND TUESDAY NIGHT.
ENSEMBLES CONTINUE TO SHOW MOISTURE FORECAST TO BE IN THE ATMOSPHERE
AS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL. AND OPERATIONAL
SOLUTIONS SHOW PWS AROUND 2 INCHES. AS THIS MOISTURE ADVECTS INTO
THE CENTRAL PLAINS TUESDAY AND TUESDAY NIGHT, THIS REPRESENTS FIRST
OPPORTUNITY FOR HEAVY RAINFALL TO IMPACT THE AREA. THE SECOND
OPPORTUNITY IS WITH CYCLOGENESIS PROGGED TO OCCUR WEDNESDAY NIGHT
AND THURSDAY. THE 12Z GFS AND ECMWF TEND TO KEEP THE SURFACE LOW TO
THE SOUTHWEST AND SOUTH OF THE FORECAST AREA THROUGH THURSDAY NIGHT
PLACING THE FORECAST AREA WITHIN A FAVORABLE SYNOPTIC LOCATION FOR
GOOD MOISTURE ADVECTION AND UPPER LEVEL DIVERGENCE TO ALLOW THE
REGENERATION OF PRECIPITATION. BY THIS TIME THE AVAILABLE MOISTURE
SHOULD HAVE SHIFTED TO THE EAST, BUT SOILS COULD BE SATURATED FROM
EARLIER PRECIPITATION. AS FOR RAIN TOTALS, THE NBM HAS THE
PROBABILITY FOR 1 TO 3 INCHES OR RAIN IN THE 60 TO 75 PERCENT
RANGE. CHANCES FOR GREATER THAN 3 INCHES SIT AROUND 50 PERCENT.
WORSE CASE SCENARIOS ARE POINTING TO RAIN TOTALS OF 3 TO 5 INCHES
WHICH COULD LEAD TO FLOODING. EVENTUALLY THE UPPER LOW SHOULD GET
KICKED EAST WITH DRY FORECAST FOR SATURDAY.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 627 PM CDT SAT SEP 26 2026
THERE IS SOME INDICATION THAT LOW LEVEL SATURATION MAY BE SLIGHTLY
DEEPER FOR A FEW HOURS DURING THE EARLY MORNING HOURS WHICH COULD
BRING MARGINAL VFR CIGS SLIGHTLY FURTHER SOUTH INTO THE TERMINALS.
TRENDS STILL SUGGEST THAT THE DEEPER SATURATION AND THICKER CLOUD
COVERAGE REMAINS OVER NORTHCENTRAL INTO FAR NORTHEASTERN KS AREAS
MORE TOWARD THE KS/NE BORDER. IF IFR CIGS DO OCCUR WOULD ANTICIPATE
ON BRIEF RESTRICTION MAINLY IMPACTING THE KMHK TERMINAL. THE
POTENTIAL FOR -SHRA AFTER MIDNIGHT TO AROUND SUNRISE STILL LOOKS
BEST FOCUSED OVER EASTERN TERMINALS. HOWEVER, COVERAGE LOOKS MINIMAL
SO VCSH STILL APPEARS REASONABLE. WINDS REMAIN ESE THROUGH MUCH OF
THE PERIOD WITH A SLIGHT INCREASE IN SPEED AFTER SUNRISE.
TOP WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...WOLTERS
AVIATION...DRAKE/WOLTERS
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