671
FXUS63 KIWX 301801
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
201 PM EDT SUN AUG 30 2026
KEY MESSAGES
- CHANCES FOR SCATTERED SHOWERS CONTINUE INTO TONIGHT, WITH
MAINLY DRY CONDITIONS TO FOLLOW MONDAY THROUGH WEDNESDAY.
- HOTTER AND MORE HUMID CONDITIONS BUILD THROUGH MIDWEEK,
PEAKING TUESDAY INTO WEDNESDAY WHEN AFTERNOON HEAT INDICES
MAY REACH UP TO NEAR 100 DEGREES.
DISCUSSION
ISSUED AT 200 PM EDT SUN AUG 30 2026
SHOWERS ASSOCIATED WITH A SHORTWAVE AND ELEVATED WAA WILL DRIFT OFF
TO THE EAST-SOUTHEAST BY ~19Z. ANOTHER UPSTREAM LOW AMPLITUDE,
CONVECTIVELY AUGMENTED, SHORTWAVE FOLLOWS EAST INTO THE LOWER GREAT
LAKES LATE THIS AFTERNOON INTO THIS EVENING WITH ADDITIONAL
SHOWERS EXPECTED, MAINLY ALONG/NORTH OF US 24.
MONDAY COULD VERY WELL BE SIMILAR TO TODAY WITH CLOUDS AND SHOWERS
AROUND AS MOISTURE CONTINUES TO STREAM IN ON THE NORTHERN PERIPHERY
OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTHERN PLAINS AND MID MS
RIVER VALLEY. HOWEVER, THIS HEAT DOME WILL BE GRADUALLY BUILDING
NORTHWARD WHICH WOULD ORIENT THE LOW LEVEL JET CORE AND ASSOCIATED
MOISTURE TRANSPORT MORE OFF TO THE THE NORTH-NORTHWEST WHEN COMPARED
TO TODAY. OPTED TO INTRODUCE SOME LOW-END POPS FAR NORTH TO ACCOUNT
FOR THE CLOSE PROXIMITY AND LATEST MODEL GUIDANCE. ONGOING SOUTHERLY
FLOW IN THE LOW LEVELS (SFC DEWPOINTS NEARING 70F), IN COMBINATION
WITH ANY FILTERED SUNSHINE, MAY PUSH AFTERNOON HEAT INDICES WELL
INTO THE 90S OTHERWISE BY MONDAY AFTERNOON, BEST CHANCES ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA.
NEAR ADVISORY LEVEL HEAT/HUMIDITY BECOMES THE PRIMARY CONCERN INTO
TUESDAY AND WEDNESDAY AS THE IMPRESSIVE ~596 DAM 5H RIDGE DRIFTS
EAST OVER THE OH VALLEY. HIGHER CONFIDENCE IN PEAK PM HEAT INDICES
NEARING 100F CONTINUES TO BE ALONG AND SOUTH OF THE US 30 CORRIDOR
EACH DAY. NORTHERN PORTIONS MAY STRUGGLE WITH CONVECTIVE CLOUD
DEBRIS (THUS SLIGHTLY COOLER) FROM WHAT SHOULD BE A PERIODICALLY
STORMY PATTERN NORTH OF THE AREA. THE NBM CONTINUED WITH ITS DRY
FORECAST EACH DAY, BUT WOULD NOT BE SURPRISED IF AT LEAST A LOW POP
IS INTRODUCED IN THE NORTH AT SOME POINT.
MODELS CONTINUE TO BREAK DOWN THE UPPER RIDGING FOR THE SECOND HALF
OF THE WEEK WHICH SHOULD BRING SLIGHTLY COOLER TEMPS AND PERIODIC
CHANCES (20-40%) FOR CONVECTION AS SEVERAL SHORTWAVES AND A FRONTAL
BOUNDARY DROP THROUGH IN DEVELOPING NORTHWEST FLOW ALOFT.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 143 PM EDT SUN AUG 30 2026
WARM AIR ADVECTION AND MOISTURE CONVERGENCE ON THE NORTHERN SIDE
OF A RIDGE OF HIGH PRESSURE IS AIDING IN RECURRING SHOWERS
MOVING GENERALLY FROM NORTHWEST TO SOUTHEAST, WITH SURFACE WINDS
OUT OF THE SOUTH. WHILE THIS HAS MAINLY PUSHED OUT OF THE AREA,
THUNDERSTORMS IN FAR SE WISCONSIN AND NE ILLINOIS WILL PUSH
ACROSS S. LAKE MICHIGAN OVER THE NEXT SEVERAL HOURS. HAVE TEMPOS
IN FOR SBN TO ACCOUNT FOR -TSRA AND MVFR VSBYS. DRY AIR OFF THE
SURFACE SHOULD INHIBIT LOW CIGS WITH MAINLY A MIDLEVEL
CLOUDBASE. THESE SHOULD WEAKEN AS THEY PUSH SW, CONSEQUENTLY
HAVE SHOWERS IN THE FORECAST FOR FWA.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...STEINWEDEL
AVIATION...NORMAN
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