624
FXUS63 KIWX 051649
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1249 PM EDT FRI JUN 5 2026
KEY MESSAGES
- BREEZY WITH AN ISOLATED SEVERE THUNDERSTORM POSSIBLE THIS
AFTERNOON. CONFIDENCE IN SEVERE STORMS OCCURING IS LOW.
- PERIODIC CHANCES (60-90 PERCENT) FOR SHOWERS AND THUNDERSTORMS
SATURDAY INTO SATURDAY EVENING. THERE IS A MARGINAL TO SLIGHT
RISK FOR SEVERE STORMS, BEST POTENTIAL IN NW OHIO. DAMAGING
WINDS AND LARGE HAIL ARE THE MAIN THREATS. CONFIDENCE IN
SEVERE WEATHER OCCURRING IS MEDIUM.
- HUMID THROUGH EARLY NEXT WEEK WITH HIGH TEMPERATURES IN THE
80S. THERE ARE CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
THE PERIOD, BEST CHANCES (30-60 PERCENT) SOUTHWEST ON SUN/MON,
THEN BECOMING MORE WIDESPREAD (55-70 PERCENT) TUESDAY.
DISCUSSION
ISSUED AT 536 AM EDT FRI JUN 5 2026
NO MAJOR CHANGES FROM PREVIOUS DISCUSSION BEYOND THE ADJUSTMENT OF
TODAY'S MARGINAL RISK TO AREAS WEST OF I 69. SATURDAY'S RISK REMAINS
THE SAME. CONFIDENCE IS STILL LOW WITH MODELS VARYING QUITE A BIT IN
REGARDS TO THE AVAILABLE INSTABILITY/MOISTURE EARLIER ON IN THE
AFTERNOON. WE COULD SEE SOME SHOWERS/STORMS BETWEEN 11-3PM NEAR LAKE
MI AND IN OUR FAR WESTERN CWA--HOWEVER THE BEST CHANCES ARRIVE
CLOSER TO 4-6 PM EDT DEPENDING ON THE MODEL. INGREDIENTS FOR SEVERE
IN TERMS OF THE BEST MOISTURE, SURFACE INSTABILITY, AND SHEAR COME
TOGETHER CLOSER OR SHORTLY AFTER SUNSET WITH AMPLIFICATION OF LLJ
AND SHARPER WAVE. THE HRRR (WHICH SEEMS TO BE DOING REASONABLY WELL
AS OF THIS WRITING IN TERMS OF PLACEMENT OF CURRENT PRECIP) BRINGS
AN INITIAL BATCH OF SHOWERS/ISOLATED STORMS BETWEEN 4-8PM ET THAT
DECAY RAPIDLY AS THEY PROGRESS EASTWARD (STOPPING SHORT OF I 69).
BEHIND THAT WITH THE STRONGER WAVE AROUND 8 PM-1 AM ET ANOTHER BATCH
COMES IN NEAR LAKE MI AND CONTINUES EASTWARD, BUT INTENSITY WANES
AND IT BECOMES MORE SCATTERED CONVECTION UNTIL THE LLJ REALLY
FOCUSES LATER OVERNIGHT...WHICH WOULD BE LESS SEVERE AND MORE OF A
HEAVY RAIN/LIGHTNING THREAT. THE BEST MID LEVEL LAPSE RATES COME IN
AFTER SUNSET IN THE WEST, AND THAT IS USUALLY WHAT WE NEED IN ORDER
TO HAVE A SEVERE THREAT (7-8C/KM VS 5-6C/KM EARLIER IN DAY). STILL
AS PREVIOUS DISCUSSION MENTIONED, WE DO HAVE DCAPE THAT DEVELOPS IN
THE AFTERNOON SO IF STORMS MANAGE TO DEVELOP EARLY ENOUGH AND MOVE
INTO THAT ENVIRONMENT, WE COULD SEE SOME DAMAGING WINDS AND LARGE
HAIL.
SATURDAY STILL LOOKS LIKE A REASONABLE SEVERE WEATHER THREAT, WITH
OUR ENTIRE AREA IN EITHER A MARGINAL OR SLIGHT RISK FOR SEVERE
WEATHER (SLIGHT RISK REMAINS IN NW OH). STILL THINKING MEDIUM
CONFIDENCE AS WE HAVE SOMEWHAT MORE FAVORABLE TIMING BUT THERE ARE
MANY QUESTIONS REGARDING THE EXTENT OF MORNING CONVECTION/HOW FAST
WE CAN CLEAR THAT AND ASSOCIATED CLOUD DEBRIS TO REGAIN SOME
INSTABILITY. WHERE EXACTLY STORMS FIRE (WHAT LINGERING BOUNDARIES
REMAIN, WHAT HEATING DIFFERENTIALS DEVELOP BETWEEN CLEARING/CLOUDS)
AND HOW WIDESPREAD THEY GET IS STILL IN QUESTION. WE DO HAVE BETTER
DYNAMICS AND AN INCOMING COLD FRONT WITH THIS SET UP (TOWARDS THE
LATER AFTERNOON/EVENING), WITH SFC CAPE AROUND 1000-1500 J/KG OR
MORE AND 0-6KM SHEAR OF AROUND 35-40KTS DEPENDING ON THE MODEL. AS
SPC'S DISCUSSION FOR THE OUTLOOK ALLUDES TO, THIS COULD GIVE US MORE
ORGANIZED STORM MODES LIKE BOWING LINE SEGMENTS AND SUPERCELLS
(MAYBE)-WHICH CAN GIVE US THE GREATER WIND/HAIL THREAT. THE TORNADO
THREAT IS EAST OF OUR AREA INTO OHIO AT THIS POINT. OF COURSE, HEAVY
RAIN AND FREQUENT LIGHTNING ARE ALSO THREATS. ONE ITEM OF CONCERN IS
WE SEEM TO LOOSE OUR STEEPER MID LEVEL LAPSE RATES AS WE GO INTO THE
LATE AFTERNOON/EVENING (STILL AROUND 6-7C/KM IN NW OH AT TIMES).
DESPITE THIS, STILL THINK WE HAVE A DECENT SHOT AT STRONG/SEVERE
STORMS.
LATER THIS WEEKEND INTO EARLY NEXT WEEK IS TRICKY AS IT WILL DEPEND
ON HOW THE UPPER LEVEL RIDGE/OMEGA BLOCK DEVELOPS AND WHERE EXACTLY
OUR COLD FRONT ENDS UP ON SUNDAY (COULD BE FAR ENOUGH SOUTHWEST THAT
IT'S OUT OF OUR AREA AND WE END UP DRY). A WARM FRONT LIFTS NORTH
THROUGH TUESDAY WHICH WILL BRING US BETTER POTENTIAL FOR
PRECIPITATION AND STORMS INTO THE EVENING, THEN A DECAYING SURFACE
LOW/COLD FRONT THROUGH WEDNESDAY. HAVE A BROAD RANGE OF POPS, WITH
THE BEST CHANCES IN THE FAR WEST AND SOUTH SUN-MON, AND THEN
EXPANDING CWA-WIDE FOR TUE/WED (45-70%). IT WILL BE HUMID WITH HIGHS
IN THE 80S (SOME LOCATIONS IN MID-UPPER 80S, APPROACHING 90).
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1249 PM EDT FRI JUN 5 2026
A BROKEN LINE OF SHOWERS HAS A HISTORY OF PRODUCING LIFR
VISIBILITY, DESPITE THEIR MEAGER APPEARANCE ON RADAR. KSBN WILL
SEE A BRIEF BREAK IN THE RAIN BEFORE MORE SHOWERS ARRIVE FROM
NORTHEAST ILLINOIS. BEYOND 00Z, THE FORECAST IS UNCERTAIN BUT
TRENDS SUGGEST AN EAST-WEST ORIENTED AREA OF SHOWERS AND STORMS
DEVELOP PERHAPS JUST SOUTH OF SBN, BUT NEAR OR JUST NORTH OF
KFWA. THIS LINE THEN DRIFTS SSE THROUGH DAYBREAK SATURDAY. I'VE
OPTED TO CONTINUE A PROB30 AT KSBN TO ACCOUNT FOR THIS -TSRA,
WHILE OPTING FOR A HIGHER CONFIDENCE TEMPO AT KFWA.
A DRYING TREND IS ANTICIPATED AFTER 12Z, ESPECIALLY AT KSBN.
ADDITIONAL -TSRA IS POSSIBLE NEAR 18Z OR BEYOND AT KFWA,
DEPENDING ON PREVIOUS EVOLUTION OF -TSRA.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-
046.
DISCUSSION...MCD
AVIATION...BROWN
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