013
FXUS63 KIWX 050937
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
537 AM EDT FRI JUN 5 2026
KEY MESSAGES
- BREEZY WITH INCREASING CHANCES (40-90 PERCENT) FOR SHOWERS AND
STORMS TODAY INTO TONIGHT, HIGHEST CHANCES WEST OF I 69 TODAY
THEN SPREADING EASTWARD OVERNIGHT. THERE IS A MARGINAL RISK
FOR STRONG TO SEVERE STORMS BETWEEN 4PM AND 1AM ET, WITH
DAMAGING WINDS AND LARGE HAIL THE MAIN THREATS. CONFIDENCE IN
SEVERE WEATHER OCCURRING IS LOW.
- PERIODIC CHANCES (60-90 PERCENT) FOR SHOWERS AND THUNDERSTORMS
SATURDAY INTO SATURDAY EVENING. THERE IS A MARGINAL TO SLIGHT
RISK FOR STRONG TO SEVERE STORMS IN THE AFTERNOON AND EVENING,
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 /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 155 AM EDT FRI JUN 5 2026
PREDOMINANTLY VFR CONDITIONS AT THE TERMINALS THIS PERIOD
OUTSIDE OF THUNDERSTORM ACTIVITY WHERE WE COULD SEE BRIEF DROPS
TO MVFR/IFR. UPSTREAM OBSERVATIONS INDICATE SCT/BKN CLOUD DECKS
AROUND 5-6KFT AS OF THIS WRITING, IN ADDITION TO CLOUDS AROUND
25-30KFT. HIGH PRESSURE CONTINUES TO SINK SOUTHEASTWARD THROUGH
THE PERIOD, WITH A TROUGH APPROACHING FROM THE WEST. TIGHTENING
PRESSURE GRADIENT AND DECENT MIXING THIS AFTERNOON SHOULD GIVE
US SW WINDS GUSTING TO AROUND 25-30KTS AT TIMES. OTHERWISE, AS
THE TROUGH MOVES THROUGH THIS AFTERNOON INTO THE OVERNIGHT,
WE'LL SEE ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS. WITHIN
THUNDERSTORMS, MVFR/IFR CONDITIONS ARE POSSIBLE. IT'S POSSIBLE
WE SEE SCATTERED SHOWERS AHEAD OF THE MAIN TROUGH (15Z-18Z) AT
KSBN WITH WAA ONGOING AND STRENGTHENING MOISTURE ADVECTION, SO
ADDED VCSH FOR THAT TIME. MORE IMPACTFUL SHOWERS AND ANY T-STORM
ACTIVITY LOOKS TO HOLD OFF UNTIL AT LEAST 18Z, MORE LIKELY 20Z
(MODELS ARE QUITE VARIABLE). INTERMITTENT ACTIVITY OCCURS THEN
THROUGH THE OVERNIGHT. HANDLED WITH PROB30S FOR T-STORM ACTIVITY
GIVEN LOWER CONFIDENCE. EVEN LESS CERTAINTY AT KFWA AS MODELS
SUGGEST THE PRECIPITATION/STORM ACTIVITY LOOKS TO STRUGGLE WITH
EASTWARD PROGRESSION FROM KSBN. HAVE VCSH STARTING AROUND 21Z,
BUT IT LOOKS LIKE MORE IMPACTFUL WEATHER AND STORM DEVELOPMENT
IS MORE LIKELY AFTER 00Z (MODELS SUGGEST DEVELOPMENT NEARLY
OVERHEAD AROUND 1Z). HAVE VCTS STARTING AT 00Z WITH PROB 30S TO
HANDLE ANY STORMS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS
EVENING FOR LMZ043-046.
DISCUSSION...MCD
AVIATION...MCD
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