727  
FXUS63 KIND 151500  
AFDIND  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE INDIANAPOLIS IN  
1100 AM EDT SUN SEP 15 2024  
   
KEY MESSAGES  
 
- ABOVE NORMAL TEMPERATURES AND QUIET WEATHER EXPECTED THROUGH THIS  
WEEK  
 
- AFTERNOON RH VALUES WILL BE NEAR OR BELOW 30% OVER THE NEXT FEW  
DAYS  
 
 
   
FORECAST UPDATE  
 
ISSUED AT 1002 AM EDT SUN SEP 15 2024  
 
GOES-16 VISIBLE SATELLITE LOOP AND OBS WERE INDICATING THERE WAS  
SOME HIGH BASED CU ACROSS THE WABASH VALLEY DUE TO THE REX  
BLOCK INDUCED MOISTURE RETURN. OTHERWISE, SUBSIDENCE ASSOCIATED  
WITH THE NORTHEASTERN HIGH PORTION OF THE REX BLOCK WAS DOMINATING  
THE WEATHER ACROSS CENTRAL INDIANA WITH SUNNY SKIES AND LIGHT  
SOUTHEAST WINDS. TEMPERATURES HAVE REBOUNDED FROM OVERNIGHT LOWS IN  
THE UPPER 50S AND LOWER 60S TO 10 AM READINGS IN THE UPPER 60S AND  
LOWER 70S. THE SOUTHEAST WINDS AND DEEP MIXING TO AROUND 7K FEET  
WILL ALLOW TEMPERATURES TO ONCE AGAIN SORE WELL ABOVE NORMAL INTO  
THE UPPER 80S THIS AFTERNOON PER THE DESI GRAND ENSEMBLE 2M METER  
TEMPERATURE THE TO THE PERCENTILES.  
 
 
   
SHORT TERM (TODAY AND TONIGHT)  
 
ISSUED AT 231 AM EDT SUN SEP 15 2024  
 
STRONG SURFACE HIGH PRESSURE CENTERED OVER THE NORTHEAST WILL  
CONTINUE TO REMAIN THE DOMINANT WEATHER FEATURE AS RIDGING EXTENDS  
WEST ACROSS THE OHIO VALLEY. EXPECT QUIET WEATHER CONDITIONS THROUGH  
THE SHORT TERM PERIOD FOR THIS REASON. ANOTHER WARM DAY IS IN STORE  
WITH TEMPERATURES WELL IN THE 80S. SUBSIDENCE COMBINED WITH DIURNAL  
MIXING WILL RESULT IN LOW RH VALUES AT LEAST BRIEFLY AROUND 25-30%  
THIS AFTERNOON. WHILE BRIEF CRITICAL RH VALUES ARE EXPECTED, LIGHT  
WINDS SHOULD GREATLY LIMIT ANY FIRE WEATHER CONCERNS.  
 
GOOD RADIATIONAL COOLING AND A DRY AIRMASS WILL ALLOW FOR  
TEMPERATURES TO QUICKLY COOL AFTER SUNSET. EXPECT A LARGE DIURNAL  
SWING IN TEMPERATURES WITH NEAR SEASONAL LOWS IN THE MID-UPPER 50S  
TONIGHT.  
 
 
   
LONG TERM (MONDAY THROUGH SATURDAY)  
 
ISSUED AT 231 AM EDT SUN SEP 15 2024  
 
MONDAY THROUGH WEDNESDAY...  
 
THE UPPER PATTERN WILL CONTINUE TO SHOW DEEP TROUGHING ALOFT OVER  
THE WESTERN CONUS EARLY IN THE WEEK, WITH RIDGING ALOFT OVER THE  
EAST COAST. THE RIDGING ALOFT WILL STEER ANY UPPER FORCING WELL  
NORTH OF INDIANA, ACROSS ONTARIO AND QUEBEC. AN UPPER LEVEL HIGH  
PRESSURE SYSTEM OVER THE NORTHEASTERN STATES IS ALSO NOTED, AS ALL  
THESE FEATURES ARE PROTECTING INDIANA FROM ANY POTENTIAL  
PRECIPITATION. THIS STACKED HIGH HAD INFLUENCE TO THE LOWER LEVELS,  
RESULTING IN DRY LOWER LEVELS THROUGH MONDAY AND INTO TUESDAY. WITH  
LITTLE OVERALL CHANGE IN THE AIR MASS, A PERSISTENCE TYPE FORECAST,  
WITH CONTINUED MOSTLY SUNNY DAYS AND MOSTLY CLEAR NIGHTS.  
 
A CAVEAT IN PLAY INCLUDES A QUASI-TROPICAL SYSTEM AS NOTED BY THE  
NHC. THIS SYSTEM APPEARS TO COME ONSHORE IN THE SOUTHEASTERN STATES  
ON MONDAY, BEFORE CONTINUING ON A SLOW NORTHWEST TRACK THROUGH MID  
WEEK. UNCERTAINTY EXISTS ON HOW FAR WEST AS WELL AS HOW ORGANIZED  
THIS FEATURE MAY BE UPON ARRIVAL WITHIN OUR VICINITY. FORECAST  
SOUNDINGS DO SUGGEST A BIT MORE SATURATION WITHIN THE COLUMN ON  
TUESDAY NIGHT AND INTO WEDNESDAY, HOWEVER CONFIDENCE IS TOO LOW ON  
THE PROGRESSION OF THIS POORLY ORGANIZED SYSTEM TO INCLUDE ANYTHING  
OTHER THAN A FEW MORE CLOUDS ON WEDNESDAY.  
 
THURSDAY THROUGH SATURDAY...  
 
AS WE PROGRESS TO THE END OF THE WEEK, THE REMAINS OF THE QUASI-  
TROPICAL SYSTEM ARE SUGGESTED TO DISSIPATE AND WEAKEN. THERE IS MORE  
CONFIDENCE IN THE OVERALL UPPER PATTERN OF AN OMEGA BLOCK DEVELOPING  
ACROSS THE CONUS. THIS PATTERN WILL RESULT IN INDIANA BEING LOCATED  
ON THE LEE SIDE OF THE UPPER RIDGE, RESIDING IN AN AREA OF  
SUBSIDENCE, JUST EAST OF THE UPPER RIDGE AXIS. MEANWHILE WITHIN THE  
LOWER LEVELS, DRY, EASTERLY FLOW LOOKS PREDOMINANT, CONTROLLED BY  
STRONG SURFACE HIGH PRESSURE STILL ANCHORED OVER THE NE UNITED  
STATES AND QUEBEC. AGAIN, WITH LITTLE CHANGE IN THE AIR MASS, ABOVE  
NORMAL TEMPERATURES WITH HIGHS IN THE 80S WILL BE EXPECTED.  
 
ALTHOUGH OUTSIDE OF OUR TYPICAL FORECAST PERIOD, THE NEXT BEST  
CHANCE FOR RAIN MAY NOT BE UNTIL SOMETIME IN LATE SEPTEMBER, WHEN A  
STRONG COLD FRONT MAY FINALLY ALLOW AN INTRUSION OF CANADA AIR.  
 
 
   
AVIATION (18Z TAF ISSUANCE)  
 
ISSUED AT 1100 AM EDT SUN SEP 15 2024  
 
IMPACTS:  
 
- A FEW GUSTS TO NEAR KNOTS TO NEAR 18 KNOTS THROUGH 00Z  
WITH DIRECTION 090-120 DEGREES  
 
DISCUSSION:  
 
HIGH PRESSURE AND A VERY DRY COLUMN PER HI-RES SOUNDINGS WILL LEAD  
TO VFR FLYING CONDITIONS WITH LITTLE TO NO CLOUD COVER EXCEPT FOR  
PERHAPS PASSING CIRRUS OR HIGH BASED CU.  
 
WINDS WILL BE LIGHT ESE TO CALM EXCEPT UP TO 10 KNOTS WITH GUSTS  
TO NEAR 18 KNOTS THIS AFTERNOON.  
 
 
   
FIRE WEATHER  
 
ISSUED AT 1002 AM EDT SUN SEP 15 2024  
 
THE RH MAY APPROACH 25% THIS AFTERNOON OVER NORTHEASTERN SECTIONS.  
HOWEVER, THE HIGHER DEW POINTS ACROSS SOUTHWESTERN SECTIONS LOOK  
LIKE THE RH WILL NOT FALL BELOW 30%. THE LAST FEW DAYS, RAW SITES  
HAVE SEEN THE FUEL MOISTURE DROP BELOW 8%. THE BIGGEST LIMITING  
FACTOR LOOKS LIKE IT WILL BE THE 20 FOOT WINDS AS THEY SHOULD STAY  
BELOW 15 KNOTS, WHICH IS RED FLAG CRITERIA. WE WILL HAVE TO KEEP AN  
EYE ON THINGS THIS AFTERNOON AND THE NEXT COUPLE OF DAYS, HOWEVER,  
REGARDING THE POTENTIAL FOR HEADLINES.  
 
 
   
IND WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
UPDATE...MK  
SHORT TERM...MELO  
LONG TERM...PUMA  
AVIATION...MK  
FIRE WEATHER...MK  
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