806
FXUS63 KIWX 170042
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
842 PM EDT SAT MAY 16 2026
KEY MESSAGES
- VERY WARM THROUGH AT LEAST TUESDAY WITH HIGHS NEAR OR ABOVE 80
AND A MUGGIER FEEL TO THE AIR.
- THUNDERSTORM CHANCES INCREASE MONDAY INTO TUESDAY. LOCALLY
HEAVY RAINFALL AND DAMAGING WIND GUSTS ARE POSSIBLE, PRIMARILY
DURING THE AFTERNOON AND EVENING HOURS.
UPDATE
ISSUED AT 838 PM EDT SAT MAY 16 2026
WARM AND MUGGY AIR HAS SETTLED INTO THE AREA WITH DEWPOINTS IN
THE 60S (EVEN SOME MID TO UPPER 60S WHERE RAINFALL OCCURRED
EARLIER TODAY). CONVECTION WELL SOUTH OF THE AREA WAS WEAKENING
WITH LOSS OF DAYTIME HEATING, WITH THE PRIMARY FOCUS WELL TO THE
WEST ACROSS PORTIONS OF IA AND NORTHERN MO. EASTERLY MOVEMENT
OF THE AREA HAS BEEN QUITE SLOW AS S TO SE LLJ KEEPS THE
STRONGER CELLS ROOTED IN THE AREA GENERAL AREA. WITH TIME THE
FLOW SLOWLY SHIFTS, BUT THE STRONGEST FLOW REMAINS DISPLACED
WELL WEST OF US AND NOSES SOMEWHAT TO THE NE INTO PORTIONS OF WI
TOWARDS MORNING. WHILE I SUSPECT LATE TONIGHT WILL BE
COMPLETELY DRY. I WILL LEAVE SOME TOKEN 15 POPS IN THE FAR WEST
AND NORTH AS THE AREA OF SHOWERS AND STORMS POSSIBLY CLIP THESE
AREAS.
DISCUSSION
ISSUED AT 144 PM EDT SAT MAY 16 2026
THIS MORNING'S SHOWERS AND THUNDERSTORMS HAVE SHIFTED EAST AND SKIES
HAVE CLEARED NICELY AS OF MIDDAY. A NARROW AREA OF CUMULUS IS NOTED
ALONG THE US 30 CORRIDOR, PERHAPS AN INDICATOR OF AN OUTFLOW
BOUNDARY. UPPER-LEVEL SUPPORT FOR ANY AFTERNOON OR EVENING
THUNDERSTORMS IS GENERALLY NON EXISTENT, WITH 500 MB AND 850 MB
JETS LOCATED WELL TO OUR NORTH AND SOUTHWEST, RESPECTIVELY. THUS,
DESPITE SURFACE CAPE SWELLING TOWARD 1,500 J/KG THIS AFTERNOON, THE
MODEST TRIGGER OF A LINGERING OUTFLOW BOUNDARY LEAVES MUCH TO
BE DESIRED FOR RENEWED STORM CHANCES. CAN'T COMPLETELY RULE OUT
AN ISOLATED STORM BEFORE SUNSET (20-30% CHANCE) BUT OVERALL,
NOT IMPRESSED AND HAVE COORDINATED WITH SPC TO REDUCE THE EXTENT
OF THE MARGINAL SEVERE WEATHER RISK TODAY.
TONIGHT, ORGANIZED CONVECTION IS EXPECTED OVER MO, IA, AND
EVENTUALLY INTO IL. LIKE YESTERDAY, HOW THIS EVOLVES OFFERS
UNCERTAINTY. HOWEVER, USING THE SAME SYNOPTIC METHODOLOGY AS
YESTERDAY, THE OVERNIGHT PERIOD APPEARS TO BE PRIMARILY DRY.
TOWARD SUNRISE, 500MB FLOW IMPROVES OVER IL AND COULD BE A
FORCING MECHANISM TO SUSTAIN ANY ONGOING CONVECTION THERE. YET,
DESPITE THE SYNOPTIC FORCING, INSTABILITY VALUES OF ONLY 500
J/KG WILL BE A LIMITING FACTOR WHILE SHEAR IMPROVES TO 30
KNOTS.
A WARM FRONT, CURRENTLY RUNNING EAST/WEST THROUGH LAFAYETTE, LIFTS
NORTH EARLY SUNDAY MORNING AS WELL, BUT GIVEN THE DEARTH OF
INSTABILITY, HIGH RESOLUTION GUIDANCE DOES LITTLE IN TERMS OF ANY
CONVECTION ALONG THE FRONT. THUS, HAVE MAINTAINED ONLY A 20% CHANCE
OF SHOWERS AND THUNDERSTORMS TO BLEND WITH NEIGHBORS. SUNDAY
APPEARS PRIMARILY DRY AND WARM.
MONDAY AND TUESDAY REMAIN MURKY BUT FEATURE FAVORABLE SEVERE
WEATHER INGREDIENTS. THE PRIMARY QUESTION IS WHETHER OR NOT
CONVECTION FIRES MONDAY AFTERNOON FROM A PREFRONTAL TROUGH THAT
LIFTS IN. SHOULD THIS TROUGH BECOME THE FOCUS FOR SEVERE STORMS,
DAMAGING WIND GUSTS APPEAR TO BE THE PRIMARY HAZARD VIA STEEP
LOW- LEVEL LAPSE RATES. AFTERNOON STORMS WOULD THEN SQUASH THE
OVERNIGHT SEVERE RISK. THE SLOW-MOVING COLD FRONT CREEPS THROUGH
OUR AREA TUESDAY SERVING AS A CONTINUED FOCUS FOR SEVERE
STORMS. HOWEVER, PLENTY OF CLOUD DEBRIS IS EXPECTED THROUGHOUT
THE DAY OWING TO ANY PRECEDING CONVECTION. THIS WILL LIMIT
INSTABILITY VALUES. HEAVY RAIN RATES OF AT LEAST 1" PER HOUR
REMAIN A CONCERN EARLY THIS WEEK. OVERALL, ENTERING A PERIOD OF
ACTIVE WEATHER THAT WILL REQUIRE TAKING THINGS ONE DAY AT TIME
OWING TO MESOSCALE NUANCES.
COOLER BEHIND THE FRONT WITH HIGHS SOME 20-DEGREES COOLER; ONLY IN
THE MID-60S WEDNESDAY AND THURSDAY. HIGH PRESSURE WEDNESDAY AND
THURSDAY BECOMES DISPLACED OVER THE EASTERN GREAT LAKES FOR NEXT
WEEKEND.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 642 PM EDT SAT MAY 16 2026
FEW TO SCT CU WILL QUICKLY DISSIPATE WITH ONLY REMAINING CLOUDS
BEING OF THE MID TO HIGH VARIETY AS THE GREATEST CHANCES FOR
SHOWERS AND STORMS REMAIN WELL SOUTH OF BOTH SITES CLOSER TO THE
OHIO RIVER AND WELL TO OUR WEST ACROSS PORTIONS OF MO, IA AND
EVENTUALLY IL LATER TONIGHT. CAMS STILL VARYING GREATLY IN
SOLUTIONS WITH SOME WEAKENING SHOWERS POSSIBLE CLOSER TO KSBN OR
KFWA, BUT SETUP MUCH LESS FAVORABLE FOR ANYTHING TO SURVIVE INTO
THE AREA TONIGHT SO TAFS HAVE BEEN LEFT DRY AND VFR.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
UPDATE...FISHER
DISCUSSION...BROWN
AVIATION...FISHER
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