309
FXUS63 KLSX 311128
AFDLSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE SAINT LOUIS MO
628 AM CDT SUN MAY 31 2026
KEY MESSAGES
- THERE WILL BE SEVERAL CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
TOMORROW WITH A LOW CHANCE OF SEVERE THUNDERSTORMS CAPABLE OF
PRODUCING LARGE HAIL AND DAMAGING WINDS.
- DRY WEATHER IS FORECAST TUESDAY THROUGH THURSDAY ALONG WITH NEAR
NORMAL TEMPERATURES.
SHORT TERM
(THROUGH LATE MONDAY AFTERNOON)
ISSUED AT 418 AM CDT SUN MAY 31 2026
PATCHY FOG HAS DEVELOPED OVER PARTS OF THE AREA LIKE YESTERDAY
MORNING WITH VARYING VISIBILITIES. WITH LIGHT WINDS AND YESTERDAY'S
RAINFALL, VISIBILITIES HAVE FALLEN AS LOW AS 1/4 MILE SO FAR AT SUS
AND CPS, BUT HAVE SINCE CLIMBED BACK UP TO 10 MILES. WITH THE
CLOUDS OVERHEAD AND THE RELATIVELY SHORT NIGHT, I SUSPECT ANY DENSE
FOG WILL STAY PATCHY THE REST OF THE NIGHT.
THERE WILL THE POTENTIAL FOR SEVERAL ROUNDS OF SHOWERS AND
THUNDERSTORMS TO MOVE ACROSS PARTS OF THE CWA THROUGH MONDAY. THERE
REMAINS A STRONG CAPE GRADIENT THAT IS EXPECTED TO REMAIN IN PLACE
FROM WEST TO EAST IN ADDITION TO THE PERSISTENT LOW LEVEL
CONVERGENCE AXIS. SHOWERS AND THUNDERSTORMS CURRENTLY OVER WESTERN
MISSOURI ARE SLOWLY MOVING EAST, AND MAY MOVE INTO CENTRAL MISSOURI
EARLY THIS MORNING. AN UPPER TROUGH OVER THE CENTRAL PLAINS WILL
LIFT NORTHEAST THIS MORNING AND SUPPLY DECENT ASCENT OVER THE AREA
THIS AFTERNOON. THE CAMS ARE SHOWING AN INCREASE IN CONVECTION OVER
THE AREA BY MID AFTERNOON INTO THIS EVENING, THOUGH THEY ARE
INCONSISTENT WITH THEIR TIMING AND LOCATION. THIS IS LIKELY BECAUSE
THERE WILL BE AN UPPER RIDGE BUILDING OVER MISSOURI AND ILLINOIS
TODAY CAUSING WEAK STEERING CURRENTS. THE CAMS ARE ALSO SHOWING
SOME REDEVELOPMENT OF THE THUNDERSTORMS OVER NORTHERN MISSOURI
THIS EVENING THAT WILL MOVE INTO THE CWA OVERNIGHT. BOTH OF THESE
ROUNDS WILL HAVE SOME POTENTIAL OF ISOLATED SEVERE THUNDERSTORMS
IN THE SPC MARGINAL RISK WITH UP TO 1" HAIL AND 60 MPH WINDS,
THOUGH THE COVERAGES AN SEVERITY OF STORMS WILL BE DEPENDENT ON
THE PREVIOUS ROUNDS OF STORMS. THERE WILL ALSO BE THE POTENTIAL
FOR HEAVY RAINFALL TO PRODUCE LOCALIZED FLOODING, PARTICULARLY
OVER CENTRAL AND SOUTHEAST MISSOURI WHERE PWATS WILL BE AROUND
1.8" WITH WARM CLOUD DEPTHS OVER 10K FEET.
THE CAMS ARE SHOWING THE SECOND ROUND OF CONVECTION EXITING THE
CWA BY 12Z ON MONDAY. BOTH THE RAP/GFS IS SHOWING A FRONT
LINGERING BACK ACROSS CENTRAL AND SOUTHEAST MISSOURI DURING THE
DAY WITH SUFFICIENT CAP/SHEAR TO BRING THE RISK OF AN ISOLATED
STRONG TO SEVERE THUNDERSTORM.
BRITT
LONG TERM
(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 418 AM CDT SUN MAY 31 2026
MODEL GUIDANCE IS CONSISTENT SHOWING AN UPPER HIGH MOVING SOUTH
ACROSS MIDWEST TUESDAY INTO THURSDAY RESULTING IN DRY WEATHER ACROSS
THE CWA DURING THIS PERIOD. THE CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL RETURN BEGINNING ON THURSDAY NIGHT AND CONTINUES
INTO SATURDAY WHEN MOISTURE RETURN WILL INCREASE AHEAD OF UPPER LOW
OVER THE PLAINS. THE LREF IS SHOWING 40-60% OF ITS MEMBERS
PRODUCING RAIN OVER THE CWA BY SATURDAY.
WHILE TEMPERATURES MAY COOL DOWN TO AROUND 80 ON TUESDAY AND
WEDNESDAY, HIGHS ARE FORECAST TO BE MAINLY IN 80S THIS WEEK AS THEY
CLIMB BACK INTO THE UPPER 80S BY FRIDAY AND SATURDAY.
BRITT
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 616 AM CDT SUN MAY 31 2026
A SMALL COMPLEX OF THUNDERSTORMS WILL AFFECT COU/JEF BETWEEN
12-14Z. WHILE THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGHOUT THE PERIOD, THE MOST LIKELY TIMES WILL BE BETWEEN
15-19Z AND 07-10Z AT UIN, BETWEEN 12-15Z, 21-01Z, AND AGAIN 06-10Z
AT COU/JEF, AND BETWEEN 23-03Z AND 08-12Z AT THE ST. LOUIS AREA
TERMINALS. ANY OF THE HEAVIER SHOWERS OR THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING MVFR (POSSIBLE IFR) CEILINGS AND VISIBILITIES
IN HEAVY DOWNPOURS AS WELL AS POSSIBLE HAIL AND WIND GUSTS OVER 35
KNOTS. OTHERWISE WINDS WILL REMAIN OUT OF THE EAST SOUTHEAST AT
LESS THAN 10 KNOTS.
BRITT
LSX WATCHES/WARNINGS/ADVISORIES
MO...NONE.
IL...NONE.
WFO LSX
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