295  
FXUS63 KIND 220118  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
918 PM EDT SAT JUN 21 2025  
   
KEY MESSAGES
 
 
- HEAT ADVISORY IN EFFECT THROUGH TUESDAY  
 
- HOTTEST CONDITIONS OF THE SEASON THUS FAR INTO MUCH OF NEXT WEEK,  
WITH HEAT INDEX VALUES 100-105 DEGREES EACH AFTERNOON  
 
- SCATTERED THUNDERSTORMS POSSIBLE MID-WEEK INTO NEXT WEEKEND  
 

 
   
FORECAST UPDATE
 
 
ISSUED AT 917 PM EDT SAT JUN 21 2025  
 
NO CHANGES NEEDED TO THE FORECAST WITH CONDITIONS EVOLVING AS  
EXPECTED. WITH TEMPERATURE BEGINNING TO FALL, THE GUSTS OF 20-25 MPH  
ARE COMING TO AN END WITH THE LOSS OF DEEPER MIXING. SOUTHERLY WINDS  
OF 5-10 MPH WILL CONTINUE THROUGH HE NIGHT WITH MOSTLY CLEAR SKIES.  
OVERNIGHT LOWS IN THE MID 70S LOOK REASONABLE WITH CURRENT DEW  
POINTS STILL IN THE LOW 70S ACROSS CENTRAL INDIANA.  
 
HREF FOG PROBABILITIES ARE NEAR 0 EXCEPT FOR PORTIONS OF THE  
HEADWATERS OF THE EAST FORK WHITE RIVER WHERE WINDS ARE EXPECTED TO  
BE CLOSER TO CALM COMBINED WITH THE NEAR 0 DEW POINT DEPRESSION  
TOWARDS DAYBREAK TOMORROW. CHANCES ARE STILL MINIMAL, BUT WORTH  
MENTIONING.  
 

 
   
SHORT TERM (THIS EVENING THROUGH SUNDAY)
 
 
ISSUED AT 303 PM EDT SAT JUN 21 2025  
 
THE WELL ADVERTISED FIRST HEAT WAVE OF THE SUMMER IS UNDERWAY ACROSS  
THE ENTIRE REGION. TEMPERATURES HAVE REACHED THE 90 DEGREE MARK FOR  
MANY LOCATIONS WITHIN CENTRAL INDIANA, INCLUDING THE INDIANAPOLIS  
FOR THE FIRST TIME THIS SEASON. HOT AND HUMID CONDITIONS PERSIST FOR  
THE REST OF THE DAY, WITH THE ONLY "RELIEF" BEING GUSTY WINDS OF 20-  
25 MPH THROUGH AROUND SUNSET. DO NOT EXPECT MUCH RELIEF AT NIGHT  
OVER THE NEXT WEEK AS OVERNIGHT LOWS MAY NOT FALL BELOW THE MID 70S!  
 
UPPER RIDGING WILL CONTINUE TO BUILD OVER THE OHIO VALLEY AND GREAT  
LAKES REGION THE NEXT SEVERAL DAYS, KEEPING THE HOT AND HUMID  
AIRMASS IN PLACE. LOW LEVEL RIDGING SHIFTS SLIGHTLY WESTWARD  
TOMORROW, PUSHING THE CORE OF THE LOW LEVEL JET FURTHER TO THE WEST  
AS WELL. EXPECT DEEP LOW LEVEL MIXING TOMORROW AFTERNOON, HOWEVER  
NOT EXPECT AS STRONG OF GUSTS TOMORROW DUE TO THE WEAKER LOW LEVEL  
JET ALOFT. EACH DAY DURING THIS HEAT WAVE MAY BE A FEW DEGREES  
WARMER THAN THE PREVIOUS AS THE GROUND RAPIDLY DRIES OUT. WENT A  
LITTLE ABOVE GUIDANCE FOR HIGHS TOMORROW WITH FORECAST HIGHS  
REACHING THE MID 90S FOR ALL LOCATIONS. THE HEAT ADVISORY REMAINS IN  
EFFECT AS HIGH HUMIDITY VALUES COMBINED WITH THE HOT TEMPERATURES  
WILL RESULT IN HEAT INDEX VALUES OF 100-105 DEGREES DURING PEAK  
HEATING OF THE DAY.  
 
COPY/PASTE THIS FORECAST FOR THE NEXT SEVERAL DAYS INTO AT LEAST  
EARLY NEXT WEEK AS THERE IS HIGH CONFIDENCE IN THIS HEAT WAVE  
PERSISTING.  
 

 
   
LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)
 
 
ISSUED AT 303 PM EDT SAT JUN 21 2025  
   
..PROLONGED HEAT AND HUMIDITY EXPECTED INTO LATE NEXT WEEK
 
 
SUNDAY NIGHT THROUGH TUESDAY...  
 
STRONG, HOT AND HUMID, SUBTROPICAL RIDGE WILL BE WELL ESTABLISHED  
OVER MOST OF THE EASTERN CONUS BY THE TIME THE LONG TERM PERIOD  
BEGINS, WITH ITS CUT-OFF 594 DM H500 HEIGHT EXPANDING FROM THE  
OZARKS TO THE NEW ENGLAND COAST. INDIANA'S PROXIMITY SLIGHTLY WEST  
OF THE STACKED RIDGE'S CENTER WILL PROMOTE GENERALLY LIGHT,  
SOUTHWESTERLY SURFACE FLOW THROUGH THE EARLY WEEK...THAT WILL  
MAINTAIN OPPRESSIVE DEWPOINTS AND CORRESPONDING UNSEASONABLY HIGH  
DAILY MINIMUM TEMPS...IN THE LOW TO MID-70S.  
 
WIDESPREAD LOW 90S CAN BE EXPECTED BOTH AFTERNOONS...COURTESY OF THE  
HIGHER STARTING POINT, H850 READINGS AROUND 20 CELSIUS, AND  
GENERALLY AMPLE AMOUNTS OF SUMMER SOLSTICE SUNSHINE. MAXIMUMS MAY  
NEAR 95F ALONG THE WABASH VALLEY AS WELL AS TYPICALLY HOTTER ARES  
ACROSS SOUTHERN ZONES. HEAT INDEX VALUES TO PEAK NEAR OR SLIGHTLY  
ABOVE 100 DEGREES BOTH DAYS FOR MOST LOCATIONS...ALTHOUGH GREATER  
CONCERN WILL BE OVERNIGHT HEAT INDICES NOT FALLING BELOW THE MID-  
70S, AS THIS STREAK WILL NEAR 4 DAYS STRAIGHT BY LATE TUESDAY NIGHT.  
 
BIGGEST CHANGE IN MOST RECENT GUIDANCE IS THE UPPER RIDGE'S LESS-  
AMPLIFIED GEOMETRY, WITH A POTENTIAL WEAK SURFACE BOUNDARY SLIDING  
FROM THE SOUTHERN GREAT LAKES TO THE NORTHERN MIDWEST AROUND THE  
TUESDAY-TUESDAY NIGHT TIMEFRAME. DOUBT THIS COOL FRONT MAKES ANY  
HEADWAY INTO THE LOCAL CWA, YET PARTLY CLOUDY SKIES AND PERHAPS  
BRIEFLY SCATTERED SHOWERS/T-STORMS FROM ASSOCIATED MODEST LIFT...MAY  
BE IN ORDER LATE TUESDAY NEAR NORTHWEST/FAR NORTHERN COUNTIES...  
WHICH COULD LOWER HEAT INDEX VALUES 5-10 DEGREES FROM CURRENT  
EXPECTATIONS FOR A FEW SPOTS.  
 
WEDNESDAY THROUGH SATURDAY...  
 
ABOVE NORMAL HEAT AND HUMIDITY IS EXPECTED TO CONTINUE THROUGH THE  
SECOND HALF OF THE WEEK, ALTHOUGH LIKELY WIDELY SCATTERED DIURNAL  
CONVECTION SHOULD PROVIDE SUB-90F AFTERNOON HIGHS FOR A FEW  
LOCATIONS, ESPECIALLY BY THE END OF THE WEEK. NO NOTICEABLE RELIEF  
IS EXPECTED FROM THE HIGH HUMIDITY, HOWEVER, AMID WEST-SOUTHWESTERLY  
FLOW UNDER PRECIPITABLE WATER VALUES AROUND 1.80 INCHES...ALTHOUGH  
THE TROPICAL FLOW SHOULD HAVE MORE OF A DAYTIME BREEZE AROUND THE  
THURSDAY-FRIDAY TIMEFRAME...WITH LOW PRESSURE NEAR THE UPPER MIDWEST  
PROVIDING A MODEST GRADIENT. CORRESPONDING WEAK FORCING AND AMPLE  
AFTERNOON CAPE MAY SET OFF PULSE CELLS, THAT SHOULD HAVE NEXT TO NO  
SHEAR TO UTILIZE.  
 
THE RANGE OF HEAT INDEX VALUES SHOULD BE SIMILAR TO EARLY WEEK  
LEVELS, WITH MORNING MINIMUMS STILL IN THE MID-70S, ALTHOUGH  
AFTERNOON MAXIMUMS MAY A TOUCH LOWER WITH ONLY UPPER 90S IN THE  
REGION'S COOLER LOCALES. THE HEAT ADVISORY MAY BE EXTENDED THROUGH  
AT LEAST THE MID-WEEK IF AND WHEN CONFIDENCE INCREASES IN CRITERIA  
THRESHOLDS BEING REACHED.  
 

 
   
AVIATION (00Z TAF ISSUANCE)
 
 
ISSUED AT 713 PM EDT SAT JUN 21 2025  
 
IMPACTS:  
 
- SOUTHERLY WIND GUSTS UP TO 22KTS THROUGH 02Z  
 
DISCUSSION:  
 
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH CLEAR SKIES  
OTHER THAN FEW TO POTENTIALLY SCT DIURNALLY DRIVEN CU AT AROUND 040.  
ANY ONGOING WIND GUSTS WILL COME TO AN END BY 02Z WITH LIGHT  
SOUTHERLY WINDS TONIGHT. THERE MAY BE A FEW WIND GUSTS TOMORROW AT  
LAF OR HUF, BUT CONFIDENCE IS TOO LOW FOR A MENTION IN THE TAF AT  
THIS TIME.  
 

 
   
IND WATCHES/WARNINGS/ADVISORIES
 
 
HEAT ADVISORY UNTIL 8 PM EDT TUESDAY FOR INZ021-028>031-035>049-  
051>057-060>065-067>072.  
 

 
 

 
 
UPDATE...WHITE  
SHORT TERM...CM  
LONG TERM...AGM  
AVIATION...WHITE  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab IN Page Main Text Page