089
FXUS63 KIWX 231807
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
207 PM EDT THU JUL 23 2026
KEY MESSAGES
- TRENDING WARMER INTO THE WEEKEND. HOT AND HUMID WITH HIGHS IN
THE UPPER 80S TO LOW 90S BY SUNDAY AND MONDAY.
- PRIMARILY DRY THIS WEEKEND BUT THERE IS A 20% CHANCE OF
SHOWERS AND THUNDERSTORMS BOTH SATURDAY AND SUNDAY.
- BEST CHANCE FOR STORMS IN THIS 7-DAY FORECAST IS SUNDAY NIGHT
AND AGAIN MONDAY (30-60% CHANCE).
DISCUSSION
ISSUED AT 206 PM EDT THU JUL 23 2026
BEAUTIFUL CONDITIONS THIS AFTERNOON; FAIR WEATHER CUMULUS AND
TEMPERATURES IN THE 70S. THIS IS COURTESY OF A TROUGH DEPARTING THE
NORTHEAST US WITH EXPANSIVE HIGH PRESSURE AT THE SURFACE. THIS
SURFACE HIGH SHIFTS EAST OVER THE NEXT 24-48 HOURS AS VAST
RIDGING OVER THE ROCKIES BUILDS IN. SOUTHERLY RETURN FLOW, AND
RISING HEIGHTS ALOFT, PERMIT TEMPERATURES TO STEADILY WARM IN
SUBSEQUENT DAYS. WE CANNOT COMPLETELY RULE OUT STRAY SHOWERS OR
STORMS SATURDAY AFTERNOON (20% CHANCE) AS THE WESTERN US RIDGE
SPILLS INTO WESTERN INDIANA AND EVEN CENTRAL MICHIGAN THIS
WEEKEND. THERE SOME SOME INDICATIONS OF POSSIBLE SEVERE STORMS
SUNDAY EVENING AS WELL AMID A HIGHLY UNSTABLE ENVIRONMENT,
INCREASING SHEAR, AND APPROACHING 70-KNOT 500MB JET.
A SIMILAR SETUP BREWS MONDAY NIGHT INTO TUESDAY AS AN UPPER-LEVEL
LOW DROPS OVER THE UPPER GREAT LAKES. RECENT SLIGHT-RISK SEVERE
WEATHER DAYS HAVE BEEN HIGHLY CONDITIONAL, AND THIS ONE APPEARS NO
DIFFERENT. AS A RESULT, DETAILS ARE SPARSE. AS MENTIONED IN THE
PREVIOUS DISCUSSION, HOT AND HUMID CONDITIONS WILL RETURN BY
MONDAY WITH HIGHS IN THE 90S (NEAR-90 SUNDAY) AND DEW POINTS IN
THE 70S. BEYOND THIS SYSTEM, ENERGETIC NORTHWEST FLOW CONTINUES
THROUGH THE MIDWEST ON THE FRINGE OF AN UPPER-ELVEL RIDGE NOW OVER
THE FOUR CORNERS REGION. HOWEVER, THIS FLOW WILL NEED TO
COMPETE WITH EASTERN GREAT LAKES HIGH PRESSURE.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 128 PM EDT THU JUL 23 2026
DIURNAL VFR CU CONTINUES TO EXPAND IN COVERAGE EARLY THIS
AFTERNOON AND SHOULD GRADUALLY DISSIPATE TOWARD SUNSET WITH LOSS
OF STEEPER LOW LEVEL LAPSE RATES. A LAKE BREEZE IS ALSO
AUGMENTING THIS CU FIELD BUT APPEARS TO BE ANCHORED FAIRLY CLOSE
TO THE SHORE. WITH LIMITED LAKE/LAND THERMAL DIFFERENTIALS, THIS
LAND BREEZE MAY NOT EXHIBIT SIGNIFICANT INLAND PENETRATION THIS
AFTERNOON AND BE ON THE WEAKER SIDE, BUT WOULD EXPECT
TRANSITION TO LIGHT NORTHERLY WINDS AT KSBN MID-LATE AFTERNOON
AS THIS BOUNDARY SINKS SOUTHWARD. OTHERWISE, VFR CONDITIONS
SHOULD CONTINUE THROUGH THE REMAINDER OF THE PERIOD WITH SOME
INCREASE IN HIGH CLOUDINESS LATER TONIGHT HELPING TO LIMIT
SHALLOW PATCHY FOG POTENTIAL. WINDS WILL REMAIN LIGHT ON FRIDAY
AS LITTLE MOVEMENT IN THE SFC ANTICYCLONE IS EXPECTED THIS
PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...BROWN
AVIATION...MARSILI
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