524
FXUS63 KIND 241931
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
231 PM EST WED DEC 24 2025
KEY MESSAGES
- DENSE FOG ADVISORY TONIGHT FROM 10 PM UNTIL 11 AM THURSDAY
- CLOUDY AND DREARY CONDITIONS FOR CHRISTMAS, TURNING WARMER TOWARDS
THE WEEKEND
- TRANSITION BACK TO MUCH COLDER CONDITIONS NEXT WEEK
SHORT TERM (THIS EVENING THROUGH THURSDAY)
ISSUED AT 231 PM EST WED DEC 24 2025
REST OF TODAY AND TONIGHT.
MAIN FOCUS FOR THE SHORT TERM PERIOD WILL BE TRACKING THE
DRIZZLE/LIGHT RAIN TONIGHT AND THE RETURN OF DENSE FOG ACROSS
CENTRAL INDIANA. AS OF EARLY THIS AFTERNOON, MOST OF CENTRAL INDIANA
IS UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES, BUT THIS WILL RAPIDLY
BEGIN TO CHANGE TOWARDS THE EVENING HOURS AS HIGHER CLOUDS ADVECT IN
FROM THE WEST AND A SURGE OF MOISTURE MOVES IN FROM THE SOUTHEAST AS
WINDS GRADUALLY BEGIN TO RAMP UP. A FEW LIGHT SHOWERS WILL BE
POSSIBLE LATE THIS AFTERNOON AND EVENING, MAINLY ACROSS SOUTHWESTERN
INDIANA ASSOCIATED WITH WEAK LIFT IN THE HIGHER CLOUDS BUT COVERAGE
WILL BE FAIRLY MINIMAL WITH AMOUNTS GENERALLY NO HIGHER THAN A FEW
HUNDREDTHS OF AN INCH.
SATURATION NEAR THE SURFACE IS THEN EXPECTED TOWARDS MIDNIGHT WITH
DRIZZLE BECOMING THE PREDOMINANT PRECIPITATION TYPE AS CLOUD BASES
DROP TO JUST A COUPLE HUNDRED FEET. WIDESPREAD FOG IS EXPECTED
TONIGHT WITH DENSE FOG LIKELY ALONG THE WARM FRONT WHERE WINDS WILL
BE NEAR CALM. CONFIDENCE ON THE EXACT LOCATION OF THE WARM FRONT
REMAINS SOMEWHAT LOW WITH THE AXIS OF LONG-LASTING DENSE FOG LIKELY
ONLY A FEW COUNTIES FROM NORTH TO SOUTH. THERE SHOULDN'T BE MUCH
NORTH TO SOUTH MOVEMENT WITH THE FRONT WHICH COULD KEEP FOG AROUND
FOR MUCH OF THE NIGHT WHERE IT DOES FORM. AFTER CONSULTING WITH
NEIGHBORING OFFICES, WE DECIDED TO GO WITH A DENSE FOG ADVISORY
ALONG AND NORTH OF I-70 WHERE CONFIDENCE IN THE DENSE FOG IS
GREATEST. A SOUTHERLY EXPANSION MAY BE NEEDED AND WILL BE LOOKED AT
THROUGH THE EVENING.
THURSDAY.
OTHER THAN SOME RESIDUAL FOG DURING THE MORNING HOURS, QUIET ALBEIT
DREARY WEATHER IS EXPECTED FOR MUCH OF THE DAY WITH LIGHT
NORTHEASTERLY WINDS IN THE AFTERMATH OF THE EXITING LOW. SOUTHERLY
SURFACE FLOW NOW LOOKS TO REMAIN SOUTH OF THE FORECAST AREA WHICH
SHOULD KEEP THE WARMER 60S CLOSER TO THE OHIO RIVER. A FAIRLY
NOTABLE NORTH TO SOUTH TEMPERATURE GRADIENT IS LIKELY WITH A
POTENTIAL 15-20 DEGREE SWING BETWEEN NORTH CENTRAL INDIANA AND THE
OHIO RIVER. THERE MAY BE SOME LINGERING DRIZZLE, BUT WITH THE FLOW
BECOMING NORTHERLY, ISENTROPIC LIFT LOOKS MINIMAL WITH ANY FORCING
ABOVE THE CLOUD LAYER.
LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 231 PM EST WED DEC 24 2025
CHRISTMAS NIGHT THROUGH FRIDAY...
A WEAK FRONTAL BOUNDARY SHOULD REMAIN POSITIONED OVER THE OHIO
VALLEY, STILL LOOKS TO BE ORIENTED OVER INDIANA AND GUIDANCE HAS
BEEN WAVERING THE LAST FEW DAYS, BUT WITH THE BROAD SURFACE RIDGE
DISPLACED TO THE NORTH THIS SHOULD KEEP THE BOUNDARY JUST SOUTH OF
THE INDY METRO AREA THROUGH CHRISTMAS NIGHT; HOWEVER, THE UPPER
LEVEL JET STRUCTURE STILL SUPPORTS A PROGRESSIVE PATTERN SETUP. THIS
INDICATES THE BOUNDARY WILL QUICKLY LIFT NORTH AND TURN LOW-LEVEL
FLOW SOUTHEASTERLY TO SOUTHERLY AS IT LIFTS NORTH OF CENTRAL IN.
GUIDANCE STILL INDICATES A WEAK MID-LVL SPEED MAX TO DEVELOP ACROSS
THE CENTRAL PLAINS EARLY FRI, AND APPEARS TO EXPAND A PRECIP
FOOTPRINT ACROSS THE OHIO VALLEY FRI MORNING. BUT THE CAVEAT TO
LINGERING PRECIP IS THAT THE SURFACE LOW LOOKS BE LACKING IN A
ISALLOBARIC GRADIENT, INDICATING THAT LOW CEILINGS COULD DEVELOP
MIDDAY WITH A PERSISTENT STRATUS DECK UNDER A LIGHT SOUTHERLY MOIST
FLOW. GUIDANCE CONTINUES TO INDICATE TEMPS IN THE 60S, BUT IF CLOUD
COVER IS SUBSTANTIAL THIS COULD BE REDUCED DUE TO THE ABUNDANCE OF
SOLAR BLOCKING AND KEEP TEMPS IN THE UPR 50S.
FRI NGT INTO SAT... MID-LVL HEIGHT RISES SHOULD SLIDE EAST OVER
INDIANA, WHICH WILL FURTHER REDUCE THE PRESSURE FIELDS WITHIN THE
BOUNDARY LAYER. THAT INDICATES THAT WE COULD HAVE ANOTHER PERIOD OF
SOME PATCHY FOG, WITH MILD TEMPS GIVEN THE LACK OF ANY COLD AIR
ADVECTION BLEEDING BACK INTO INDIANA. SAT SHOULD FEATURE ANOTHER
MILD DAY WITH THE BOUNDARY TRYING TO SAG SOUTH YET AGAIN, BUT THE
LACK OF A FORCING MECHANISM IN THE UPPER LEVELS SHOULD KEEP THIS
FEATURE DISPLACED TO THE NORTH.
SUN THROUGH WED...THEN HEIGHTS CONTINUE TO RISE MARGINALLY LATE SAT
NGT, SETTING SUN UP TO BE ANOTHER VERY MILD DAY UNDER STRONGER
SOUTHERLY FLOW AS THE UPSTREAM TROUGH DIGS INTO THE SOUTHWEST CONUS.
THIS WILL FURTHER AMPLIFY THE DOWNSTREAM RIDGE OVER OHIO VALLEY.
ENSEMBLES CONTINUE TO FAVOR A SYSTEM DEVELOPING ACROSS THE FOUR-
CORNERS REGION SUN EJECTING INTO THE SOUTHERN PLAINS AND POSSIBLY
FURTHER DEVELOPING WITH THE INCREASING FLOW OF WARM/MOIST AIR FROM
THE WEST GULF. THIS SHOULD BE A PROGRESSIVE SETUP AND QUICKLY PUSH
INTO THE OHIO VALLEY BY LATE SUN INTO MON. CURRENT INDICATIONS ARE
THAT THIS WILL BE A MAINLY RAIN SYSTEM BUT COLD AIR ADVECTION WILL
BE POURING IN FROM THE NORTHWEST MON, AS THE SETUP TURNS TO A
TYPICAL WINTER NORTHWEST FLOW. THIS THEN APPEARS TO BE THE MAIN
FEATURE HEADING INTO THE FINAL DAYS OF THE YEAR WITH MUCH MORE OF A
TYPICAL LATE DEC SETUP OF COLD TEMPS AND PERIODIC CHANCES FOR SOME
SNOW SHOWERS.
AVIATION (18Z TAF ISSUANCE)
ISSUED AT 1204 PM EST WED DEC 24 2025
IMPACTS:
-LIFR TO VLIFR CIGS/VSBYS TONIGHT, MAINLY AFTER 06Z
-IFR CONDITIONS PERSIST AFTER 14Z THROUGH MUCH OF TOMORROW
DISCUSSION:
AREAS OF FOG TONIGHT WITH PERIODS OF DENSE FOG WILL BRING LIFR TO
VLIFR CONDITIONS TO MUCH OF CENTRAL INDIANA. CONFIDENCE IN THESE
CONDITIONS IS HIGHEST AT LAF WITH PERIODS OF DRIZZLE ALSO EXPECTED
THROUGH MUCH OF THE NIGHT. THESE CONDITIONS ARE LIKELY TO CONTINUE
THROUGH AT LEAST 12Z WITH SOME IMPROVEMENT TOWARDS 14Z. IFR CIGS
WILL STICK AROUND THROUGH MUCH OF THE DAY WITH THE POTENTIAL TO
PERSIST ALL THE WAY THROUGH TOMORROW NIGHT. WINDS WILL GENERALLY
REMAIN SOUTHEASTERLY TODAY AT 8-12KTS BEFORE BECOMING LIGHT AND
VARIABLE AFTER 06Z.
IND WATCHES/WARNINGS/ADVISORIES
DENSE FOG ADVISORY FROM 10 PM THIS EVENING TO 11 AM EST THURSDAY
FOR INZ021-028>031-035>049.
SHORT TERM...WHITE
LONG TERM...BEACH
AVIATION...WHITE
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