724
FXUS63 KIWX 150956
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
556 AM EDT MON JUN 15 2026
KEY MESSAGES
- DRY AND COOL WEATHER PERSISTS TODAY AND TONIGHT.
- A MARGINAL RISK FOR SEVERE WEATHER EXISTS FOR TUESDAY WITH
DAMAGING WINDS AND HAIL THE MAIN THREATS.
- AN ENHANCED RISK FOR SEVERE WEATHER EXISTS FOR WEDNESDAY INTO
WEDNESDAY NIGHT. UNCERTAINTY STILL REMAINS WITH REGARD TO THIS
RISK.
- THERE'S A TREND BACK TOWARD DRY WEATHER FOR LATER THURSDAY
AND FRIDAY.
DISCUSSION
ISSUED AT 402 AM EDT MON JUN 15 2026
A BROAD MID LEVEL TROUGH REMAINS ACROSS THE AREA FOR THIS WORK WEEK.
THAT MEANS WE'LL BE TRACKING WAVES MOVING ACROSS THE AREA WITHIN IT.
THE FIRST SUCH WAVE PASSES THROUGH THIS MORNING ON THE LEADING EDGE
OF SURFACE HIGH PRESSURE, BUT IT'S SO DRY BEHIND THE COLD FRONT THAT
MINIMAL IMPACTS ARE EXPECTED FROM IT. IN FACT DEW POINTS HAVE FALLEN
INTO THE 40S AND 50S BEHIND THE FRONT AS THE HIGHER THETA-E AIR MASS
HAS VACATED THE AREA.
A WEAK THETA-E PLUME PUSHES THROUGH TUESDAY OUT AHEAD OF ANOTHER
FROPA AND ACCOMPANYING VORT MAX. DEW POINTS STRUGGLE TO REACH 60
DEGREES WITH A WEAK GULF CONNECTION LIMITING INSTABILITY SOME (THE
NORMAL ROBUST NAM ONLY SHOWING 500 TO 1500 J/KG OF MUCAPE), BUT
AMPLE SHEAR GREATER THAN 30 KTS REACHES THE AREA AFTER 21Z CLOSER TO
WHEN THE COLD FRONT SWINGS THROUGH. IT IS INTERESTING THAT BOTH THE
NAM AND THE HRRR INITIATE STORMS ALONG WHAT APPEARS TO BE A PRE-
FRONTAL TROUGH, AND THEN AGAIN CLOSER TO THE COLD FRONT WHICH WOULD
BEG THE QUESTION ABOUT DEBRIS CLOUDS CHOKE THE COLD FRONT'S
STORMS. THE NAM'S RH PLOTS WOULD INDICATE A LACK OF DEBRIS
CLOUDS, BUT IT IS SOMETHING TO KEEP AN EYE ON. GIVEN LONG,
MOSTLY STRAIGHT HODOGRAPHS AND AN EML PASSING THROUGH, THIS
WOULD BE CONDUCIVE TO HAIL AND GUSTY TO DAMAGING WIND. THERE ARE
POCKETS OF 200 UNITS OF HELICITY SHOWING UP ON THE NAM, BUT THE
HRRR HAS MUCH WEAKER HELICITY, WHICH WOULD MAKE SENSE IN AN
ENVIRONMENT WITH MORE WESTERLY WINDS INSTEAD OF SOUTHWEST WINDS.
ANOTHER MORE VIGOROUS WAVE FOLLOWS FOR WEDNESDAY AND ANOTHER VORT
MAX FORMS OUT IN FRONT OF IT AND HEADS EASTWARD ACROSS SOUTHERN
LOWER MI. STILL, THE MAIN QUESTION IS ABOUT THE WARM FRONT. WILL
THERE BE ENOUGH TIME FOR IT TO LIFT NORTH AND ALLOW FOR MAXIMUM
HEATING? THE NAM/ECMWF/GFS ALL SEEM TO BE KEEPING THE BETTER
INSTABILITY SOUTH OF THE AREA DURING THE DAYTIME. HOWEVER, THE NAM
FINALLY BRINGS SBCAPE INTO THE AREA AFTER 00Z. PERHAPS THAT'S ENOUGH
TO GET SOME STRONG STORMS INTO OUR SOUTH? IF THIS TREND IS REAL,
THEN ALL THREATS COULD BE ON THE TABLE. AT THIS POINT, DO APPEAR TO
PACK QUITE A BIT OF MOISTURE INTO THE AREA WITH PWATS REACHING 1.75
TO 2 INCHES AND PLENTY OF LARGE SCALE ASCENT TO SQUEEZE OUT THAT
MOISTURE. AN INTERROGATION OF THE AVAILABLE MODELS INDICATES A 20 TO
60 PERCENT CHANCE OF 2 INCHES OF RAIN IN 24 HOURS FROM WEDNESDAY
AFTERNOON INTO THURSDAY MORNING MAINLY SOUTH OF US-30 AND WEST OF I-
69. SO EVEN IF THE SYSTEM PASSES BY TO THE SOUTH, A GOOD SLUG OF
MOISTURE MAKES IT UP HERE IN CONJUNCTION WITH THE SURFACE LOW
PRESSURE SYSTEM.
THINGS TREND DRIER BETWEEN LATER THURSDAY AND FRIDAY NIGHT AS
SURFACE HIGH PRESSURE NOSES IN AND SLINKS BY TO OUR SOUTH. ANOTHER
WEAK WAVE ATTEMPTS TO BRING RAIN AND MAYBE SOME THUNDERSTORMS
SATURDAY.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 555 AM EDT MON JUN 15 2026
SURFACE HIGH PRESSURE AND DRY AIR ARE IN CONTROL OF THE WEATHER
TODAY WITH VFR CONDITIONS. STILL SOME PRESSURE GRADIENT LINGERING
ALLOWS FOR 10 KT SUSTAINED GUSTS IN SBN TAF WITH WEST WINDS SLOWLY
BACKING TOWARDS SOUTHWESTERLY BY THE END OF THE PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...ROLLER
AVIATION...ROLLER
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