184
FXUS63 KIND 081327
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 AM EDT MON SEP 8 2025
KEY MESSAGES
- DRY AND COOLER THROUGH TUESDAY WITH LOWS IN THE 40S
- WARMING TREND BACK TO THE 80S BY MID TO LATE WEEK AND BEYOND
- ABNORMALLY DRY CONDITIONS CONTINUE INTO NEXT WEEKEND
FORECAST UPDATE
ISSUED AT 924 AM EDT MON SEP 8 2025
THE FORECAST REMAINS IN GREAT SHAPE WITH ONLY MINOR ADJUSTMENTS
NEEDED. CURRENT SATELLITE AND SURFACE OBSERVATIONS SHOW QUIET
WEATHER CONDITIONS ACROSS THE REGION AS SURFACE HIGH PRESSURE
REMAINS IN CONTROL. CLEAR SKIES ARE ALLOWING FOR TEMPERATURES TO
QUICKLY WARM THIS MORNING AFTER A CHILLY START TO THE DAY.
LOOK FOR HIGHS TO REACH THE MID 70S IN MOST LOCATIONS THANKS TO
PLENTIFUL SUNSHINE. FORECAST SOUNDINGS ALSO SHOW DEEP MIXING WHICH
SHOULD HELP TEMPERATURES WARM UP. DEEP MIXING WILL LEAD TO LOW RH
VALUES NEAR OR BELOW 30% DURING THE AFTERNOON. FIRE CONCERNS ARE
STILL LOW THOUGH DUE TO VERY LIGHT WINDS.
SHORT TERM (TODAY AND TONIGHT)
ISSUED AT 255 AM EDT MON SEP 8 2025
TODAY.
ANOTHER COOLER THAN NORMAL DAY IS EXPECTED FOR TODAY WITH A SURFACE
HIGH PRESSURE SLOWLY MOVING ACROSS THE SOUTHERN GREAT LAKES REGION.
AS OF EARLY THIS MORNING, WINDS HAVE BEEN NEAR CALM WITH MOSTLY
CLEAR SKIES ALLOWING FOR IDEAL RADIATIONAL COOLING. TEMPERATURES
HAVE ALREADY FALLEN INTO THE 40S TO LOW 50S WITH ANOTHER FEW DEGREE
DROP TOWARDS DAYBREAK EXPECTED. THE BOUNDARY LAYER WILL DEEPEN TO
AROUND 5000FT AGAIN THIS AFTERNOON BUT DRIER AIR BOTH AT THE SURFACE
AND ALOFT WILL PREVENT SATURATION AT THE TOP OF THE BOUNDARY LAYER
WHICH WILL GREATLY LIMIT AFTERNOON CU COVERAGE COMPARED TO RECENT
DAYS.
WINDS AT THE TOP OF THE BOUNDARY LAYER WILL BE 5 MPH OR LESS WHICH
WILL ALSO HELP TO LIMIT THE MIXING COMPARE TO RECENT DAYS AND LIMIT
THE DIURNAL FALL IN SURFACE DEW POINTS. THAT BEING SAID, THE AIR
MASS CONTINUES TO DRY WITH MANY LOCATIONS HAVING SEEN LESS THAN A
HALF INCH OF RAIN IN THE LAST 15-20 DAYS. EXPECT TO SEE MIN RH
VALUES AGAIN FALL DOWN INTO THE UPPER 20 TO LOW 30 PERCENT RANGE
AGAIN TODAY WHICH WILL CREATE A SLIGHTLY ELEVATED FIRE WEATHER RISK.
ADDITIONAL DETAILS ON THE FIRE CONCERNS BELOW.
TONIGHT.
ANY DIURNAL CU WILL DISSIPATE BY SUNSET WITH CLEAR SKIES EXPECTED
OUTSIDE OF SOME THIN PASSING CIRRUS. ANOTHER NIGHT OF EFFICIENT
RADIATIONAL COOLING IS EXPECTED WITH THE CLEAR SKIES AND LIGHT WINDS
WITH LOWS LIKELY TO FALL INTO THE 40S AGAIN.
LONG TERM (TUESDAY THROUGH SUNDAY)
ISSUED AT 255 AM EDT MON SEP 8 2025
AN EXTENDED STRETCH OF ABNORMALLY DRY CONDITIONS AND ABOVE AVERAGE
TEMPERATURES PERSISTS FOR THE NEXT 8-14 DAYS ACROSS INDIANA,
POTENTIALLY LEADING TO RAPID ONSET DROUGHT AND AN ELEVATED FIRE
WEATHER RISK. THE PERIOD BEGINS WITH WEAK TROUGHING OVER THE GREAT
LAKES REGION AND A BUILDING RIDGE OVER THE CENTER CONUS. THE UPPER
RIDGE AXIS BUILDS AND CONTINUES EASTWARD THROUGH THE WEEK STRETCHING
FROM LAKE SUPERIOR TO EASTERN TEXAS BY SUNDAY. LONG RANGE GUIDANCE
HAS BEEN CONSISTENT IN SHOWING THIS PATTERN DEVELOPING FOR QUITE
SOME TIME, WITH WELL ABOVE AVERAGE 500MB HEIGHTS AND 850MB
TEMPERATURES MAKING FOR A HIGH CONFIDENCE FORECAST FOR HOT AND DRY
CONDITIONS THROUGH AT LEAST NEXT WEEKEND.
THE WARMING TREND BEGINS ON TUESDAY AS SURFACE HIGH PRESSURE MOVES
OFF TO THE NORTHEAST, SWITCHING LOW LEVEL FLOW TO THE SOUTHEAST AND
BRINGING A WARMER AIRMASS NORTHWARD INTO THE STATE. HIGH PRESSURE
WILL CONTINUE TO BE THE DOMINANT WEATHER INFLUENCE AT THE SURFACE
THROUGH THE REST OF THE WEEK, KEEPING THE ATMOSPHERIC PROFILE TOO
DRY TO SUPPORT ANY PRECIPITATION LOCALLY. A FRONT DOES PUSH THROUGH
LATE WEDNESDAY, BUT SUCH DRY ANTECEDENT CONDITIONS WILL LEAD TO
VIRTUALLY NO IMPACTS AS HIGH PRESSURE AND AN EVEN WARMER AIRMASS
ADVECT INTO THE REGION IN THE FOLLOWING DAYS. THIS DRY PATTERN IS
SUPPORTIVE OF LARGE DIURNAL RANGES, WITH TEMPERATURES QUICKLY
HEATING UP AFTER SUNRISE...AND THEN PLUMMETING AFTER SUNSET. HIGH
TEMPERATURES GET A LITTLE WARMER EACH DAY THIS WEEK, STARTING OUT IN
THE UPPER 70S TO LOW 80S TUESDAY, THEN BY FRIDAY AND SATURDAY HIGHS
APPROACH THE 90 DEGREE MARK IN MANY SPOTS. LOWS ON THE OTHER HAND
REMAIN AT OR BELOW NORMAL FOR THIS TIME OF YEAR... IN THE UPPER 40S
TUESDAY MORNING AND MODERATING INTO THE UPPER 50S/LOW 60S BY THE END
OF THE WEEK.
FORECAST CONFIDENCE SOMEWHAT DECREASES TOWARD THE END OF THE PERIOD
AS LONGER RANGE GUIDANCE AND ENSEMBLES STRUGGLE TO RESOLVE HOW THIS
PATTERN EVOLVES AS WEAK STORM SYSTEMS RIDE UP AND OTHER THE RIDGE.
WHILE HIGHER CONFIDENCE EXISTS IN A HOT AND DRY FORECAST CONTINUING
INTO THE FOLLOWING WEEK, IT IS WORTH MENTIONING THAT SOME LONGER
RANGE GUIDANCE (ECMWF AND ECMWF AI) HAS BEEN CONSISTENT IN SHOWING
THE POTNETIAL FOR A WAVE AND ASSOCIATED CONVECTION TO RIDE OVER THE
RIDGE INTO INDIANA SATURDAY EVENING THROUGH SUNDAY. HAVE INTRODUCED
A SLIGHT CHANCE (20%) OF STORMS FOR THIS TIMEFRAME TO ACCOUNT FOR
THIS THREAT. CONFIDENCE REMAINS LOW ON THE EXACT MESOSCALE DETAILS
THIS FAR OUT, BUT THERE IS ENOUGH CONFIDENCE IN A PATTERN SUPPORTING
A THUNDERSTORM COMPLEX IN THE REGION TO ADD POPS FOR THIS WEEKEND.
DESPITE THE SLIGHT RISK OF STORMS, THERE IS MODERATE TO HIGH
CONFIDENCE IN HIGHS STILL REACHING THE 90 DEGREE MARK FOR SEVERAL
DAYS IN A ROW, ESPECIALLY FOR WESTERN AND SOUTHERN INDIANA THIS
WEEKEND INTO THE FOLLOWING WEEK. CPC CONTINUES TO PLACE THE ENTIRE
OHIO VALLEY AND MIDWEST IN A RISK FOR EXTREME HEAT IN THE SEPT 15-
18TH TIMEFRAME...WILL BE WATCHING THIS TIMEFRAME CLOSELY AND
UPDATING THE FORECAST AS NEEDED.
AVIATION (12Z TAF ISSUANCE)
ISSUED AT 549 AM EDT MON SEP 8 2025
IMPACTS:
- NONE.
DISCUSSION:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH CLEAR SKIES
OUTSIDE OF A FEW DIURNALLY DRIVEN CU CLOUDS THIS AFTERNOON. WINDS
WILL BE LIGHT AND VARIABLE THROUGH TOMORROW WITH A GENERALLY
NORTHEASTERLY TO EASTERLY DIRECTION.
FIRE WEATHER
ISSUED AT 255 AM EDT MON SEP 8 2025
THE LACK OF ANY SIGNIFICANT RAINFALL OVER THE LAST SEVERAL WEEKS HAS
RESULTED IN ABNORMALLY DRY AND MINOR DROUGHT CONDITIONS TO DEVELOP
ACROSS INDIANA. WITH LITTLE TO NO RAIN IN THE FORECAST FOR THE NEXT
7 DAYS, CONFIDENCE IS INCREASING IN AN ELEVATED FIRE WEATHER THREAT
EACH AFTERNOON AS DAILY MIN RH VALUES FALL INTO THE 20% RANGE.
LOWERED AFTERNOON DEW POINTS EACH DAY THROUGH NEXT SATURDAY TO THE
NBM10TH PERCENTILE TO ACCOUNT FOR SUCH DRY CONDITIONS AND AFTERNOON
MIXING BRINGING DOWN EVEN DRIER AIR TO THE SURFACE. THE ONE FACTOR
KEEPING THE FIRE WEATHER THREAT LOWER IS THE LACK OF WIND. DESPITE
DEEP MIXING, VERY WEAK LOW LEVEL FLOW SHOULD KEEP WINDS UNDER 10 KTS
THROUGH THE PERIOD. IT IS WORTH NOTING THAT CPC HAS PLACED THE
MAJORITY OF THE MIDWEST AND MID MISSISSIPPI VALLEY IN A SLIGHT RISK
FOR EXTREME HEAT FOR SEPT 15-18TH. IF NO APPRECIABLE RAINFALL IS
OBSERVED THIS WEEKEND, THE FIRE WEATHER THREAT MAY CONTINUE TO
INCREASE AND PERSIST INTO MID MONTH. WILL CONTINUE TO MONITOR THE
EXTENDED FORECAST FOR INCREASING FIRE WEATHER CONCERNS.
IND WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...MELO
SHORT TERM...WHITE
LONG TERM...CM
AVIATION...WHITE
FIRE WEATHER...CM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page