419  
FXUS63 KIND 181357  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
957 AM EDT WED MAY 18 2022  
   
FORECAST UPDATE
 
 
ISSUED AT 956 AM EDT WED MAY 18 2022  
 
LIGHT TO MODERATE RAIN IS MOVING INTO WESTERN COUNTIES AS A WEAK  
DISTURBANCE APPROACHES THE AREA. RAIN CHANCES WILL CONTINUE TO  
INCREASE FROM SW TO NE THROUGH THE MORNING. WITH WEAK INSTABILITY IN  
PLACE THERE IS A SLIGHT CHANCE FOR THUNDER TODAY, MAINLY FOR FAR  
SOUTHERN COUNTIES. THIS DISTURBANCE WILL EXIT THE REGION LATER THIS  
EVENING WITH DRY WEATHER EXPECTED OVERNIGHT. TEMPERATURES WILL ONLY  
REACH THE LOW TO MID 70S THIS AFTERNOON AS CLOUD COVER WILL LIMIT  
DAYTIME HEATING.  
 

 
   
SHORT TERM
 
(TODAY THROUGH THURSDAY)  
ISSUED AT 229 AM EDT WED MAY 18 2022  
 
EARLY THIS MORNING, WEAKENING CONVECTION WAS ACROSS CENTRAL ILLINOIS  
INTO FAR WESTERN INDIANA WITH A WEAK DISTURBANCE. THE CONVECTION WAS  
OUTRUNNING INSTABILITY AND MOISTURE. DEWPOINTS ACROSS CENTRAL  
INDIANA WERE IN THE 40S TO MIDDLE 50S. MEANWHILE, ADDITIONAL  
CONVECTION WAS BACK IN WESTERN MISSOURI AND IOWA, ASSOCIATED WITH  
ANOTHER UPPER DISTURBANCE.  
 
THE INITIAL ROUND OF WEAKENING CONVECTION WILL PASS THROUGH CENTRAL  
INDIANA MAINLY BEFORE 12Z, WITH THE STRONGEST CONVECTION REMAINING  
MOSTLY TO THE SOUTH WHERE BETTER MOISTURE IS. WILL HAVE SOME MAINLY  
CHANCE POPS TO ACCOUNT FOR THIS.  
 
THE MAIN FOCUS FOR CONVECTION AFTER 12Z WILL COME FROM YET ANOTHER  
UPPER DISTURBANCE MOVING EASTWARD IN THE QUASI-ZONAL FLOW ALOFT. THE  
EARLY MORNING RAIN ACROSS CENTRAL INDIANA SHOULD BEGIN TO MOISTEN UP  
THE ATMOSPHERE. AS THE NEXT DISTURBANCE APPROACHES, WINDS WILL TURN  
SOUTHERLY AND BRING SOME MOISTURE AND INSTABILITY BACK INTO THE AREA.  
 
HOWEVER, PLENTY OF CLOUDS WILL BE ACROSS THE AREA FROM THE OLD  
CONVECTION AND WILL SLOW DOWN HEATING, SO INSTABILITY WON'T BE  
GREAT. THE CONVECTION ASSOCIATED WITH THE WESTERN UPPER DISTURBANCE  
AT THE MOMENT SHOULD WEAKEN DIURNALLY THROUGH DAYBREAK. AS IT MOVES  
INTO CENTRAL INDIANA LATER THIS MORNING, IT WILL STRENGTHEN SOME  
WITH WHAT INSTABILITY CAN BUILD. HOWEVER, SINCE WHAT INSTABILITY  
BUILDS SHOULD BE LIMITED, FEEL THAT THE SEVERE THREAT SHOULD BE LOW  
OVER THE AREA. BETTER CHANCES FOR SEVERE STORMS WILL BE SOUTH OF  
CENTRAL INDIANA WHERE BETTER INSTABILITY WILL BE.  
 
ENOUGH MOISTURE, FORCING, AND INSTABILITY WILL BE AROUND FOR LIKELY  
OR HIGHER POPS MOST AREAS TODAY, ESPECIALLY FROM LATE MORNING  
THROUGH THE AFTERNOON. THE CLOUDS AND RAIN WILL KEEP HIGHS IN THE  
70S TODAY.  
 
IT SHOULD BE NOTED THAT AS USUAL, MESOSCALE FEATURES COULD CHANGE  
THE EXPECTED TIMING AND COVERAGE OF RAIN TODAY, SO CONFIDENCE IS  
LOWER THAN WOULD LIKE TO SEE TODAY.  
 
OUTFLOW FROM THE THE STORMS WILL PUSH MOST WHAT'S LEFT OF  
INSTABILITY SOUTH OF THE AREA THIS EVENING. FORCING WILL BE LIMITED  
WITH NO SIGNIFICANT UPPER WAVES MOVING THROUGH. THUS, WILL ONLY HAVE  
SOME CHANCE POPS THIS EVENING TO ACCOUNT FOR ANY LINGERING RAIN FROM  
THE DEPARTING UPPER DISTURBANCE. LOWS SHOULD GET INTO THE UPPER 50S  
TO LOWER 60S.  
 
THURSDAY, UPPER FLOW WILL REMAIN MAINLY QUASI-ZONAL FOR MUCH OF THE  
DAY, BUT NO SIGNIFICANT UPPER DISTURBANCES SHOULD BE MOVING THROUGH.  
THE OLD OUTFLOW BOUNDARY/SURFACE FRONT WILL BE SOUTH OF THE AREA.  
THUS, NOT EXPECTING MUCH IF ANY FORCING. WILL GO WITH A DRY FORECAST  
MOST AREAS, BUT WILL KEEP A SLIGHT CHANCE IN THE FAR SOUTH DURING  
THE AFTERNOON AS THE OLD FRONT MAY BEGIN TO MOVE NORTHEAST BY THEN.  
 
WITH MORE SUNSHINE EXPECTED, HIGHS ON THURSDAY WILL GET INTO THE  
LOWER TO MIDDLE 80S.  
 

 
   
LONG TERM
 
(THURSDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 229 AM EDT WED MAY 18 2022  
 
THURSDAY NIGHT THROUGH SATURDAY.  
 
DRY CONDITIONS ARE EXPECTED FOR THURSDAY NIGHT INTO FRIDAY AS MODELS  
CONTINUE TO SLOW THE PROGRESSION OF THE UPPER LEVEL TROUGH THAT  
ORIGINALLY LOOKED TO BRING STRONG TO SEVERE STORMS TO THE AREA ON  
FRIDAY. ZONAL FLOW LOOKS TO HOLD AT LEAST INTO THE LATE EVENING  
HOURS OF FRIDAY WITH ABUNDANT WAA AND STRONG PRESSURE GRADIENTS  
BRINGING OCCASIONAL WIND GUSTS OF 30-40 MPH DURING THE AFTERNOON AND  
EVENING HOURS. THE DEPTH OF THE MIXING LAYER WILL BE A LARGE FACTOR  
IN HOW WIDESPREAD THE STRONGER WIND GUSTS WILL BE AND CONFIDENCE IN  
THOSE DETAILS THIS FAR OUT REMAINS LOW. IN ADDITION TO THE WINDS,  
TEMPERATURES WILL BE NEAR RECORD FRIDAY AFTERNOON WITH HIGHS IN THE  
UPPER 80S TO NEAR 90 ACROSS CENTRAL INDIANA.  
 
THE AFOREMENTIONED TROUGH NOW LOOKS TO ARRIVE SATURDAY AS A SURFACE  
COLD FRONT ENTERS THE AREA. THERE COULD BE A FEW STRONG TO SEVERE  
STORMS DURING THE EVENING TO EARLY OVERNIGHT HOURS WITH ABUNDANT  
CAPE BUT MARGINAL SHEAR ACROSS CENTRAL INDIANA. ISOLATED FLOODING  
WILL ALSO BE A CONCERN WITH A WIDESPREAD 1-1.5 INCHES OF RAIN  
EXPECTED.  
 
SUNDAY THROUGH TUESDAY.  
 
THE FRONT IS EXPECTED TO CONTINUE TO EXIT CENTRAL INDIANA SUNDAY  
MORNING WITH A FEW LINGERING SHOWERS POSSIBLE. IN THE AFTERMATH OF  
THE FRONTAL PASSAGE STRONG CAA WILL PUSH TEMPERATURES BELOW AVERAGE  
WITH LOWS IN THE 40S SUNDAY NIGHT. COOL AND DRY CONDITIONS WILL  
THEN CONTINUE INTO MONDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA.  
THE NEXT SYSTEM WILL EJECT FROM THE ROCKIES ON TUESDAY BUT NO  
IMPACTS ARE EXPECTED IN INDIANA UNTIL LATER IN THE WEEK. WILL NEED  
TO WATCH THE PROGRESSION OF THIS SYSTEM AS THE STORM TRACK FAVORS  
SEVERE WEATHER ACROSS THE OHIO VALLEY.  
 

 
   
AVIATION
 
(12Z TAF ISSUANCE)  
ISSUED AT 630 AM EDT WED MAY 18 2022  
 
IMPACTS:  
 
* MVFR CONDITIONS IN SHOWERS DEVELOPING THIS MORNING. SCATTERED  
THUNDERSTORMS WILL BE AROUND AS WELL.  
 
* MVFR CONDITIONS WILL PERSIST THIS AFTERNOON AFTER MORE WIDESPREAD  
RAIN ENDS, WITH SOME IMPROVEMENT POSSIBLE THIS EVENING AND  
OVERNIGHT.  
 
* WINDS WILL BECOME SOUTH TO SOUTHWEST WITH GUSTS NEAR 20KT POSSIBLE  
THIS AFTERNOON. WEST WINDS EXPECTED TONIGHT WITH LOWER SPEEDS.  
 
DISCUSSION:  
 
AREA OF SHOWERS (WITH SOME EMBEDDED THUNDERSTORMS) NEAR ST LOUIS AT  
THE MOMENT WILL MOVE EAST INTO THE AREA LATER THIS MORNING AND WILL  
PERSIST INTO THE AFTERNOON. MVFR CONDITIONS ARE EXPECTED WITH THIS,  
WITH PERHAPS LOWER CONDITIONS IN ANY STRONGER CONVECTION.  
 
SCATTERED CONVECTION COULD REDEVELOP LATER THIS AFTERNOON, AND THIS  
WILL DIMINISH DURING THE EVENING.  
 
THERE IS THE POTENTIAL FOR MORE MVFR CEILINGS TO DEVELOP LATE  
TONIGHT, BUT DID NOT INCLUDE AT MOST SITES DUE TO LOW CONFIDENCE.  
 

 
   
IND WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
UPDATE...MELO  
SHORT TERM...50  
LONG TERM...WHITE  
AVIATION...50  
 
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