556
FXUS63 KIND 271330
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
930 AM EDT SUN SEP 27 2026
KEY MESSAGES
- MOSTLY SUNNY SKIES THIS WEEKEND WITH SEASONABLE TEMPERATURES.
- PATCHY FOG POSSIBLE EACH MORNING THROUGH TUESDAY MORNING.
- DRY CONDITIONS PERSIST THROUGH TUESDAY, WITH THE NEXT CHANCE FOR
RAIN ARRIVING WEDNESDAY AND THEN CONTINUING INTO THE WEEKEND.
FORECAST UPDATE
ISSUED AT 930 AM EDT SUN SEP 27 2026
FORECAST IS IN GOOD SHAPE THIS MORNING. PATCHY FOG HAS MIXED OUT,
AND ONLY SOME SCATTERED CIRRUS WAS ACROSS THE FAR WESTERN FORECAST
AREA.
SOME ADDITIONAL HIGH CLOUDS WILL DRIFT ACROSS MAINLY THE WESTERN
FORECAST AREA TODAY. SUNSHINE AND A DRY ATMOSPHERE WILL PROMOTE
MIXING, WHICH WILL DROP DEWPOINTS THIS AFTERNOON AND ALLOW HIGHS
MAINLY IN THE MID 70S.
TWEAKED HOURLY FORECASTS TO MATCH TRENDS IN OBSERVATIONS BUT
OTHERWISE MADE NO CHANGES TO THE FORECAST.
DISCUSSION (TODAY THROUGH SATURDAY)
ISSUED AT 243 AM EDT SUN SEP 27 2026
THE OVERALL SYNOPTIC PATTERN OVER THE CONUS FEATURES SPLIT FLOW
ACROSS THE PLAINS WITH A DEEP CUT OFF LOW OVER THE MID-ATLANTIC.
INDIANA IS WITHIN A BROAD AREA OF SUBSIDENCE DUE TO UPPER-LEVEL
RIDGING AND SURFACE HIGH PRESSURE. A TROUGH IS MOVING ASHORE OVER
CALIFORNIA AS OF THIS WRITING, AND MAY BECOME AN IMPORTANT FEATURE
NEXT WEEK.
TODAY THROUGH TUESDAY
THE WEATHER FOR THE NEXT SEVERAL DAYS IS NOT ANTICIPATED TO BE THAT
DIFFERENT ON A DAY TO DAY BASIS. SURFACE HIGH PRESSURE IS IN CONTROL
AND WILL PROVIDE CLEAR SKIES AND LIGHT NORTHERLY WINDS. WITH IDEAL
RADIATIVE HEATING/COOLING CONDITIONS, A LARGE DIURNAL SPREAD IN
TEMPERATURES IS LIKELY. LOW TEMPERATURES IN THE 40S TO NEAR 50 WILL
RAPIDLY REBOUND INTO THE 70S EACH AFTERNOON.
CONDITIONS ALSO FAVOR NOCTURNAL FOG DEVELOPMENT. FOG SHOULD BE
PATCHY IN NATURE, CONFINED MAINLY TO RURAL AREAS AND FOG-PRONE
LOCATIONS ALONG RIVERS. LOCALLY DENSE FOG IS POSSIBLE AT TIMES.
WEDNESDAY THROUGH FRIDAY
BY ABOUT WEDNESDAY A CHANGE IN THE OVERALL WEATHER PATTERN APPEARS
LIKELY. SURFACE HIGH PRESSURE SLIDES EASTWARD ALLOWING WINDS TO
BECOME SOUTHWESTERLY. WARM AIR ADVECTION TAKES HOLD POTENTIALLY
BRINGING TEMPERATURES BACK INTO THE 80S.
TO OUR WEST, ENSEMBLE GUIDANCE SHOWS THE CALIFORNIA TROUGH, NOW CUT
OFF FROM THE LARGER SCALE FLOW, EJECTING INTO THE PLAINS.
SIMULTANEOUSLY, HURRICANE POLO LIFTS NORTH AND BECOMES ABSORBED BY
THE UPPER LOW...CONTRIBUTING ITS MOISTURE TO THE LARGER SYSTEM.
GUIDANCE IS A BIT MIXED ON WHAT HAPPENS NEXT, BUT TRENDS HAVE BEEN
TOWARDS INCREASING PRECIPITATION CHANCES IN THE WEDNESDAY NIGHT
THROUGH FRIDAY TIMEFRAME. THE EMERGING SYSTEM SHOULD CAUSE A
BAROCLINIC ZONE OVER THE PLAINS TO TIGHTEN, WHICH WILL FOCUS
PRECIPITATION POTENTIAL IN A SW TO NE BAND. UNFORTUNATELY, GUIDANCE
CAN DO POORLY WITH CUT OFF UPPER-LEVEL LOWS AND IS SOMETIMES TOO
FAST BRINGING THEM EASTWARD. SHOULD THE SAME MODEL BIAS OCCUR, A
SLOWER ARRIVAL TIME AND DELAYED PRECIP CHANCES COULD BE SEEN IN
LATER FORECAST UPDATES.
SATURDAY ONWARD
DETAILS BECOME MURKY AT THIS POINT BUT GLOBAL MODELS TEND TO KEEP
THE BAROCLINIC ZONE IN THE REGION THROUGH THE WEEKEND. AS SUCH, WE
WILL RETAIN AT LEAST CHANCE POPS THROUGH SUNDAY. THEREAFTER,
GUIDANCE SHOWS A MORE PROGRESSIVE FLOW PATTERN TAKING HOLD WHICH
ALLOWS THINGS TO BEGIN MOVING EASTWARD. A RETURN TO DRY WEATHER IS
POSSIBLE EARLY NEXT WEEK.
AVIATION (12Z TAF ISSUANCE)
ISSUED AT 620 AM EDT SUN SEP 27 2026
IMPACTS:
- PATCHY FOG POSSIBLE OVERNIGHT INTO SUNDAY MORNING, AGAIN ON MONDAY
MORNING.
DISCUSSION:
PREDOMINATELY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS
WILL DIMINISH OVERNIGHT WHICH MAY ALLOW FOR PATCHY FOG TO FORM NEAR
THE OUTLYING TAF SITES UNDERNEATH MOSTLY CLEAR SKIES. THE GREATEST
CONFIDENCE IN FOG DEVELOPMENT IS NEAR LAF. THE URBAN HEAT ISLAND
EFFECT SHOULD KEEP KIND VFR.
WILL CONTINUE TO USE A TEMPO FOR MVFR FOG AT ALL BUT KIND. WIND
DIRECTION WILL MOSTLY REMAIN AROUND 360-030 DEGREES THROUGH THE
PERIOD.
SIMILAR CONDITIONS MAY ALLOW FOR RENEWED FOG POTENTIAL MONDAY
MORNING.
IND WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...50
AVIATION...50/ECKHOFF
DISCUSSION...ECKHOFF
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