196
FXUS63 KLSX 271956
AFDLSX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAINT LOUIS MO
256 PM CDT THU MAR 27 2025
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DECREASE IN COVERAGE THROUGH
THIS EVENING. THERE IS STILL SOME POTENTIAL FOR AN ISOLATED
SEVERE THUNDERSTORM THIS EVENING THAT COULD PRODUCE UP TO
QUARTER SIZED HAIL NORTH OF I-70.
- THERE WILL BE SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS
FRIDAY NIGHT INTO SUNDAY. A FEW STRONG TO SEVERE THUNDERSTORMS
ARE POSSIBLE ON SUNDAY.
SHORT TERM
(THROUGH LATE FRIDAY NIGHT)
ISSUED AT 255 PM CDT THU MAR 27 2025
SHOWERS AND THUNDERSTORMS CONTINUED ALONG AND NORTH OF I-70 IN A
BAND OF STRONG MOISTURE CONVERGENCE ON THE NOSE OF A LOW LEVEL JET.
THE RAP IS SHOWING THIS CONVERGENCE GRADUALLY DECREASING AND MOVING
OFF TO THE NORTHEAST OVER THE NEXT FEW HOURS WHICH SHOULD CAUSE THE
SHOWERS AND THUNDERSTORMS TO BECOME LESS CONCETRATED. THERE IS A
WARM FRONT WHICH HAS NOW MOVED TO JUST SOUTH OF THE AREA OF THE AREA
OF CONVECTION, ROUGHLY OVER CENTRAL AND SOUTHEAST MISSOURI. THERE
WILL STILL BE A CHANCE (20-40%) FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS) OUTSIDE OF THIS BAND OF SHOWERS AND THUNDERSTORMS
ALONG AND NORTH OF THE WARM FRONT. AS THE WARM FRONT LIFTS
NORTHWARD THIS EVENING, AND THE LLJ INCREASES IN STRENGTH ONCE
AGAIN, WE SHOULD SEE ADDITIONAL THUNDERSTORMS DEVELOP LATE THIS
EVENING AND OVERNIGHT ACROSS NORTHEAST MISSOURI INTO WEST CENTRAL
AND SOUTH CENTRAL ILLINOIS. THERE STILL REMAINS SOME POTENTIAL FOR
AN ISOLATED STRONG TO SEVERE THUNDERSTORM WITH THIS ACTIVITY, WITH
THE MAIN THREAT BEING LARGE HAIL UP TO SIZE OF QUARTERS.
THERE IS A CURRENTLY MARKED DIFFERENCE IN TEMPERATURES ACROSS THE
WARM FRONT WITH UPPER 40S AND LOWER 50S WHERE IT IS RAINING TO THE
MIDDLE 70S JUST SOUTHWEST OF THE CWA. I STILL BELIEVE THESE WARMER
TEMPERATURES WILL MAKE IT INTO CENTRAL AND SOUTHEAST MISSOURI THIS
AFTERNOON. HIGHS ON FRIDAY STILL LOOK TO BE AROUND 80 DEGREES
BEHIND THE WARM FRONT.
STILL EXPECT FRIDAY TO BE A DRY DAY AS SHORTWAVE RIDGING MOVES
ACROSS THE AREA. WE WILL BEGIN TO SEE A CHANCE (20-30%) OF SHOWERS
MOVE INTO THE SOUTHEAST HALF OF THE CWA BY LATE FRIDAY NIGHT AHEAD
OF A SOUTHERN STREAM SYSTEM.
BRITT
LONG TERM
(SATURDAY THROUGH NEXT THURSDAY)
ISSUED AT 255 PM CDT THU MAR 27 2025
WE ARE STILL ON TRACK TO HAVE AN ACTIVE PATTERN OVER THE WEEKEND
WITH TWO SYSTEMS OF NOTE. THE FIRST WILL BE THE AFOREMENTIONED
SOUTHERN WAVE WHICH WILL BRING LIKELY POPS (50-70%) OVER SOUTHEAST
MISSOURI AND SOUTHWEST ILLINOIS ON SATURDAY. THE SECOND WILL BE A
MORE PRONOUNCED TROUGH THAT WILL MOVE INTO FROM THE WEST. WE WILL
BE MAINTAINING HIGH POPS ON SUNDAY WITH THE PASSAGE OF THIS TROUGH
AND THE ATTEDANT COLD FRONT (70-90%). IT STILL APPEARS THAT THE
BEST CHANCE FOR STRONG TO SEVERE THUNDERSTORMS WILL BE ON SUNDAY
WHEN THE LREF IS SHOWING JOINT PROBABILITIES OF MUCAPE>500 AND 0-
500MB SHEAR >30 KNOTS REACHING 70-90%. IT SHOULD STILL BE STATED
THAT THIS SYSTEM IS NOT EXPECTED TO BE AS SEVERE AS WHAT WE SAW TWO
WEEKS AGO AS THE OPERATIONAL ECMWF/GFS MASS FIELDS ARE NOT NEARLY AS
STRONG.
THERE WILL BE ANOTHER TROUGH THE MIDDLE OF NEXT WEEK WHICH WILL
BRING A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS TO THE AREA BY
THE MIDDLE OF NEXT WEEK. THE CLUSTER ANALYSIS ARE ALL SHOWING THIS
TROUGH, BUT THERE IS A SPREAD IN HOW QUICKLY IT WILL MOVE THROUGH
THE AREA.
TEMPERATURES WILL FALL BEHIND THE FRONT OVER THE WEEKEND WITH
NBM/LREF BOTH SHOWING HIGHS ONLY IN THE 50S AND 60S BUT REBOUNDING
INTO THE 70S BY THE MIDDLE OF NEXT WEEK. THE IQR SPREAD IS FAIRLY
SMALL WITH THE COOL DOWN, BUT INCREASES AS WE GO THROUGH NEXT WEEK
GIVEN UNCERTAINTY WITH HOW QUICKLY THE NEXT TROUGH MOVES THROUGH.
BRITT
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1213 PM CDT THU MAR 27 2025
SHOWERS AND ISOLATED THUNDERSTORMS WILL AFFECT UIN/STL/SUS/CPS
THROUGH 20-21Z. THERE WILL ALSO BE A CHANCE OF SHOWERS AND
THUNDERSTORMS AT COU AND JEF BETWEEN 22-02Z AND AT UIN BETWEEN
03-07Z. THERE WILL ALSO BE A LOWER CHANCE FOR SHOWERS AND
THUNDERSTORMS OUTSIDE OF THESE TIMES THROUGH LATE TONIGHT, BUT
THE CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS. ANY OF
THE HEAVIER SHOWERS AND THUNDERSTORMS WILL HAVE THE POTENTIAL TO
REDUCE CEILINGS AND VISIBILITIES TO MVFR OR POSSIBLY IFR
CONDITIONS WITH SOME HAIL ALSO POSSIBLE. WINDS WILL ALSO GUST OUT
OF THE SOUTH AT 20 TO 25 KNOTS AT TIMES THIS AFTERNOON, AND OUT
OF THE SOUTHWEST AT AROUND 25 KNOTS ON FRIDAY MORNING.
BRITT
LSX WATCHES/WARNINGS/ADVISORIES
MO...NONE.
IL...NONE.
WFO LSX
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