138
FXUS63 KTOP 032240
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
540 PM CDT FRI JUL 3 2026
KEY MESSAGES
- THE EXTREME HEAT WARNING HAS BEEN DOWNGRADED TO AN ADVISORY THROUGH
SATURDAY WITH HEAT INDICES EXPECTED TO STAY AROUND 100 DEGREES.
- THERE IS A CHANCE FOR THUNDERSTORMS AFTER MIDNIGHT. IF STORMS
DEVELOP THERE IS A RISK FOR DAMAGING WINDS.
- THUNDERSTORMS COULD REDEVELOP DURING THE LATE AFTERNOON AND EARLY
EVENING OF THE FOURTH OF JULY. HAVE A PLAN TO MOVE OUTDOOR
ACTIVITIES INSIDE SHOULD THUNDERSTORMS MOVE INTO YOUR AREA.
DISCUSSION
ISSUED AT 228 PM CDT FRI JUL 3 2026
19Z WATER VAPOR IMAGERY SHOWED THE MEAN WESTERLIES ACROSS THE
NORTHERN TIER OF THE COUNTRY WITH A RELATIVELY WEAK SOUTHWEST TO
WESTERLY UPPER LEVEL FLOW OVER THE CENTRAL PLAINS. SURFACE OBS PLACED
A LOW OVER SOUTHEAST CO WITH HIGH PRESSURE ACROSS THE SOUTHERN MS
RIVER VALLEY. OVERALL THIS WOULD SUPPORT SOUTHERLY FLOW WITH HOT AND
HUMID AIR ACROSS THE AREA. BUT THUNDERSTORMS THAT STARTED OUT ACROSS
NORTHWEST KS THIS MORNING MANAGED TO MOVE ALL THE WAY ACROSS THE
STATE AND ARE NOW MOVING INTO MO.
FOR TONIGHT THROUGH SATURDAY NIGHT, THERE IS NOT MUCH CONFIDENCE IN
THE CAMS RADAR SIMULATIONS AS THEY HAVE SHOWN A POOR HANDLE ON
CURRENT CONVECTION AND INCONSISTENT FORECASTS RECENTLY. HOWEVER
THINK THERE IS SOME POTENTIAL FOR AN MCS TO DEVELOP OVERNIGHT
TONIGHT. THINK EASTERN NEB IS THE FAVORED AREA FOR STORMS OVERNIGHT.
THIS IS WHERE A WEAK INVERTED TROUGH AXIS IS SET UP WITH MODELS
SHOWING THE LOW LEVEL JET CONVERGING INTO THIS FEATURE. THE QUESTION
IS WILL THE MCS MOVE INTO PARTS OF NORTHEAST KS. IT IS POSSIBLE, BUT
THERE ARE A COUPLE SIGNS FROM THE MODELS THAT POINT TOWARDS THIS
BEING LESS LIKELY. FIRST THE CORFIDI VECTORS FROM THE NAM/RAP FOR A
FORWARD PROPAGATING MCS ARE NEARLY DEW EAST ALONG THE STATE LINE.
SECOND IS THE ISENTROPIC SURFACES TEND TO KEEP THE BETTER
SATURATION/LIFT COMBO JUST NORTH OF THE STATE LINE THROUGH THE
NIGHT. THERE IS STILL THE CHANCE FOR SOME PROPAGATION SOUTH INTO THE
LOW LEVEL JET AND HAVE SOME 20 TO 50 PERCENT CHANCE POPS TO ACCOUNT
FOR THIS WITH THE HIGHER CHANCES ALONG THE STATE LINE. IF STORMS DO
MOVE INTO THE AREA, STEEP MID LEVEL LAPSE RATES AND A MODERATELY
UNSTABLE AIRMASS COULD SUPPORT THE MCS IN PRODUCING SEVERE WIND
GUSTS. INTERESTINGLY THE LAST COUPLE OF HRRR RUNS HIGHLIGHT THIS
POTENTIAL. AGAIN THE PROBABILITY FOR THIS LOOKS TO BE LESS THAN 50
PERCENT, BUT IT IS SOMETHING TO KEEP AN EYE ON IN ANY CASE.
FOR THE FOURTH OF JULY, THE FORECAST HAS CHANCE POPS IN THE
AFTERNOON WITH INCREASING CHANCES DURING THE EVENING. THE
EXPECTATION IS FOR A CONDITIONALLY UNSTABLE AIRMASS TO REMAIN IN
PLACE WAITING FOR SOMETHING TO TRIGGER THUNDERSTORM DEVELOPMENT.
THIS COULD BE CONVERGENCE ALONG AN OLD OUTFLOW BOUNDARY OR A
SHORTWAVE PROPAGATING ACROSS THE FORECAST AREA. THINK THE LOCATION
OF ANY BOUNDARY WILL HAVE A BIG EFFECT ON WHERE STORMS FORM, AND
THIS IS THE MAIN UNCERTAINTY IN THE FORECAST. OTHERWISE EVERYTHING
IS POINTING TO SHOWERS AND STORMS DEVELOPING LATE IN THE AFTERNOON
AND EARLY EVENING. FOR NOW THE FORECAST FAVORS LIKELY POPS ACROSS
THE SOUTHERN HALF OF THE FORECAST AREA EXPECTING THE OVERNIGHT
OUTFLOW TO PUSH INTO CENTRAL KS. A VERY UNSTABLE AIRMASS IS PROGGED
BY THE MODELS WITH SOME MODEST BULK SHEAR. SO INITIAL STORMS MAY
SHOW SOME SUPERCELL CHARACTERISTICS. BUT OVERALL MEAN FLOW BEING
AROUND 10KT OR LESS SUGGESTS STORM MERGERS AND EVOLUTION INTO
CLUSTERS ARE LIKELY TO OCCUR. THERE COULD BE DAMAGING WINDS AND
LARGE HAIL INITIALLY AS STORMS DEVELOP THAT IS EXPECTED TO
TRANSITION TO MORE OF A WIND AND HEAVY RAIN RISK AS WE GET INTO THE
OVERNIGHT HOURS.
WITH THIS MORNING'S STORMS KNOCKING TEMPS AND DEWPOINTS DOWN, IT IS
A LITTLE MORE MARGINAL THAT WE WILL SEE HEAT INDICES OF 105 OR
BETTER. AND THE CHANCE FOR SHOWERS AND CLOUDS SATURDAY MAKE IT A
LITTLE MARGINAL AGAIN THAT WE WOULD REACH ADVISORY LEVELS. SO A HEAT
WARNING SEEMS LIKE THE WRONG MESSAGE AT THIS POINT. WE SHOULD STILL
SEE HIGHS IN THE 90S WITH HEAT INDICES AROUND 100, BUT AT THIS POINT
THAT SEEMS NOT SO EXTREME. WITH THIS IN MIND, HAVE GONE AHEAD AND
DOWNGRADED THE HEAT WARNING TO AN ADVISORY THROUGH 8PM SATURDAY.
FOR SUNDAY THE NOCTURNAL CONVECTION IS PROGGED TO BE MOVING
SOUTHEAST OF THE AREA EARLY IN THE DAY. THE BLEND HELD ONTO SOME
CHANCE POPS THROUGH THE AFTERNOON WHICH LOOKS TO BE A RESULT OF THE
00Z ECMWF. FOR COLLABORATION I LEFT THE LOW END POPS IN, BUT WITH
MUCH OF THE 12Z OPERATIONAL SOLUTIONS SHOWING THINGS PUSHING OUT OF
THE AREA THROUGH THE MORNING THE POP FORECAST MAY BE A LITTLE
OVERDONE. CLUSTER ANALYSIS OF THE 00Z ENSEMBLES SHOW LITTLE
DIFFERENCE IN THE SYNOPTIC PATTERN ACROSS THE CENTRAL PLAINS LEADING
TO SOME CONFIDENCE IN THE NBM INITIALIZATION. THE MID RANGE
SOLUTIONS TEND TO KEEP MID LEVEL HIGH PRESSURE OVER THE FORECAST
AREA EARLY NEXT WEEK. THIS SHOULD FAVOR DRY WEATHER AND SEASONAL
TEMPS. BY THE BACK HALF OF NEXT WEEK MODELS SHOW THE PATTERN
BECOMING A LITTLE MORE ZONAL WITH PERTURBATIONS IMPACTING THE AREA.
SO PRECIP CHANCES RETURN TO THE FORECAST AS TEMPS GRADUALLY TREND
WARMER.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 538 PM CDT FRI JUL 3 2026
VFR AT ALL TAF SITES THROUGH THE TAF PERIOD. THERE IS A CHANCE STORMS
MAY MOVE IN TONIGHT AROUND 05Z, BUT CONFIDENCE ISN'T HIGH ENOUGH FOR
MORE THAN A PROB30 MENTION AT THIS TIME, BUT SHOULD TRENDS CHANGE AND
CONFIDENCE INCREASE, THUNDERSTORMS MAY BE ADDED.
TOP WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY UNTIL 8 PM CDT SATURDAY FOR KSZ012-KSZ024-KSZ026-
KSZ038-KSZ039-KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.
DISCUSSION...WOLTERS
AVIATION...JONES
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page