595  
FXUS63 KIND 230541  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
141 AM EDT WED SEP 23 2026  
   
KEY MESSAGES  
 
- COOLER WEATHER WILL CONTINUE THROUGH THE UPCOMING WEEK, WITH  
AFTERNOON TEMPERATURES STAYING BELOW SEASONAL AVERAGES  
 
- A FEW LIGHT SHOWERS TONIGHT INTO TOMORROW, MAINLY ACROSS EASTERN  
INDIANA  
 
- PERSISTENT MOSTLY CLOUDY SKIES WILL BEGIN TO BREAK TOWARDS FRIDAY  
 
 
   
FORECAST UPDATE  
 
ISSUED AT 958 PM EDT TUE SEP 22 2026  
 
ONLY MINOR ADJUSTMENTS TO HOURLY TEMPERATURES WERE NEEDED, OTHERWISE  
FORECAST IS IN GOOD SHAPE.  
 
LOW CLOUDS AND SOMEWHAT BREEZY CONDITIONS PERSIST ACROSS CENTRAL  
INDIANA AND IS EXPECTED TO CONTINUE INTO TOMORROW. LIGHT DRIZZLE  
WILL BE POSSIBLE THROUGH THE NIGHT, GIVEN HOW LOW CLOUDS ARE, BUT  
THUS FAR ANY DRIZZLE THAT HAS BEEN REPORTED BY PEOPLE HAS BEEN LIGHT  
ENOUGH TO NOT BE PICKED UP BY OBSERVATION INSTRUMENTS OTHER THAN  
VISIBILITY REDUCTIONS.  
 
 
   
DISCUSSION (THIS EVENING THROUGH TUESDAY)  
 
ISSUED AT 202 PM EDT TUE SEP 22 2026  
 
OVERVIEW.  
 
CENTRAL INDIANA IS SET FOR A PROLONGED STRETCH OF COOL,  
DRY AUTUMN WEATHER. HIGH PRESSURE ANCHORED TO THE NORTH AND  
NORTHEAST WILL KEEP A CONTINUOUS SUPPLY OF COOL AIR MOVING INTO THE  
REGION ON NORTHEASTERLY WINDS. PERSISTENT LOW LEVEL MOISTURE  
COMBINED WITH COOLER AIR WILL KEEP SKIES MOSTLY CLOUDY TO CLOUDY  
THROUGH THURSDAY. SKIES WILL THEN CLEAR FRIDAY INTO THE WEEKEND WITH  
A SLIGHT WARMING TREND GOING INTO NEXT WEEK.  
 
TONIGHT THROUGH THURSDAY.  
 
BROAD HIGH PRESSURE CONTINUES TO REMAIN LOCKED IN PLACE ACROSS THE  
GREAT LAKES REGION ALONG WITH LOW PRESSURE TO THE SOUTHEAST ALLOWING  
FOR PERSISTENT NORTHEASTERLY FLOW BOTH AT THE SURFACE AND NEAR  
SURFACE. THIS IS HELPING TO KEEP WIDESPREAD CLOUD COVER IN PLACE  
ACROSS MUCH OF CENTRAL INDIANA ALONG WITH KEEPING TEMPERATURES  
SLIGHTLY BELOW NORMAL. A WEAK SHORTWAVE WILL PUSH SOUTHEAST ACROSS  
IOWA TONIGHT INTO TOMORROW WHICH WILL INTERACT WITH A REMNANT VORT  
MAX ACROSS OHIO DURING THE DAYTIME HOURS TO BRING FEW LIGHT RAIN  
SHOWERS TO CENTRAL INDIANA, MAINLY ACROSS THE EASTERN COUNTIES.  
BEYOND THOSE LOW CHANCES, DRY WEATHER IS EXPECTED THROUGH THE  
REMAINDER OF THE 7 DAY FORECAST WITH A FAIRLY STEADY-STATE WEATHER  
PATTERN CONTINUING INTO THURSDAY.  
 
FRIDAY THROUGH TUESDAY.  
 
INCREASING SUBSIDENCE ALOFT ALONG WITH WEAK UPPER LEVEL FLOW WILL  
BEGIN TO BREAK DOWN THE CLOUD COVER FRIDAY INTO THE WEEKEND WILL  
HELP TO BRING TEMPERATURES CLOSER TO NORMAL FOR THIS TIME OF THE  
YEAR. MIN RH VALUES WILL DROP BELOW 40 PERCENT ACROSS SOUTH CENTRAL  
INDIANA WHICH COMBINED WITH THE DRIER CONDITIONS OF LATE, MAY NEED  
TO BE MONITORED FOR A LOW-END FIRE DANGER. NEAR CALM WINDS WILL HELP  
TO LIMIT THAT THREAT.  
 
LOOKING FURTHER INTO EARLY NEXT WEEK, TEMPERATURES IN THE LOWER 80S  
LOOK TO RETURN AS THE SURFACE FLOW GRADUALLY GAINS A MORE SOUTHERLY  
COMPONENT ALONG WITH GRADUALLY INCREASING RAIN CHANCES TOWARDS LATE  
TUESDAY AHEAD OF THE NEXT SYSTEM.  
 
 
   
AVIATION (06Z TAF ISSUANCE)  
 
ISSUED AT 141 AM EDT WED SEP 23 2026  
 
IMPACTS:  
 
- MVFR/IFR CEILINGS THROUGH THE FORECAST PERIOD.  
- PATCHY DRIZZLE THIS MORNING, LIGHT RAIN SHOWERS AND DRIZZLE INTO  
WEDNESDAY NIGHT.  
 
DISCUSSION:  
 
STRONG SURFACE HIGH PRESSURE REMAINS IN PLACE OVER SOUTHEASTERN  
CANADA, PROVIDING NORTHEASTERLY WINDS BETWEEN 8-12KT ACROSS CENTRAL  
INDIANA. MOISTURE ADVECTION FROM THE EAST HAS ALLOWED EXTENSIVE  
CLOUD COVER TO DEVELOP AND PERSIST SINCE TUESDAY.  
 
AN UPPER-LEVEL LOW IS ARRIVING FROM THE WEST AND THIS HAS ALLOWED  
THE SURFACE WIND FIELD TO GAIN CYCLONIC CURVATURE. THE PRIMARY  
EFFECT THIS WILL HAVE IS TO CAUSE THE STRATUS LAYER TO THICKEN AND  
FOR PATCHY DRIZZLE TO DEVELOP. WE HAVE ALREADY SEEN DRIZZLE OVER  
MOST OF THE REGION SINCE MIDNIGHT. PATCHY DRIZZLE SHOULD CONTINUE  
INTO THE MORNING HOURS WEDNESDAY.  
 
DRIZZLE DIMINISHES LATER THIS MORNING AS DIURNAL MIXING INTENSIFIES.  
HOWEVER, THIS MAY ALLOW FOR LIGHT RAIN SHOWERS TO DEVELOP DURING THE  
AFTERNOON. SHOWERS AND RENEWED DRIZZLE THEN CONTINUE INTO TONIGHT,  
POTENTIALLY THROUGH 12Z THURSDAY.  
 
WINDS REMAIN OUT OF THE NORTHEAST THROUGH THE TAF PERIOD AROUND  
10KT, DECREASING A BIT AFTER 00Z.  
 
 
   
IND WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
UPDATE...KF  
AVIATION...ECKHOFF  
DISCUSSION...WHITE  
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