864  
FXUS63 KIWX 150932  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
532 AM EDT THU MAY 15 2025  
   
KEY MESSAGES  
 
- INCREASING CONFIDENCE IN SEVERE THUNDERSTORMS THIS EVENING.  
ALL HAZARDS ARE POSSIBLE, BUT LARGE HAIL FROM DISCRETE  
SUPERCELLS FOLLOWED BY DAMAGING WIND GUSTS FROM LINEAR  
SEGMENTS ARE THE PRIMARY HAZARDS.  
 
- VERY WARM TODAY WITH NEAR RECORD HIGH TEMPERATURES  
APPROACHING 90 DEGREES.  
 
- ON FRIDAY EVENING, ANOTHER ROUND OF SEVERE THUNDERSTORMS ARE  
POSSIBLE.  
 
 
   
DISCUSSION  
 
ISSUED AT 305 AM EDT THU MAY 15 2025  
 
DRY WEATHER IS EXPECTED DURING THE DAY DESPITE AN ADVANCING  
WARM FRONT MIDDAY. FORECAST SOUNDINGS DEPICT A STOUT DRY LAYER  
STOP A CAPPING INVERSION. THIS CAP DOES PERMIT STEEP LOW-LEVEL  
LAPSE RATES, BUT AN ABSENCE OF UPPER-LEVEL SUPPORT AND A DEEP  
MOISTURE COLUMN PRECLUDE DAYTIME POP-UP STORMS. INSTEAD, THE  
PRIMARY DRIVER OF STORMS THIS EVENING WILL BE AN APPROACHING  
COLD FRONT / DRYLINE FROM ILLINOIS. CAMS HAVE COME INTO FAIRLY  
STRONG AGREEMENT THAT STORMS WILL OVERCOME THE CAP AND ERUPT  
OVER EASTERN IL AND TRACK EAST- NORTHEAST. THIS CAP IS THE ONLY  
REMAINING PIECE OF UNCERTAINTY AND THERE ARE STILL A COUPLE OF  
MODELS THAT STEER CONVECTION ELSEWHERE, BUT THESE SOLUTIONS SEEM  
TO BE OUTLIERS. THE BEST 500-MB JET DYNAMICS ARE FOCUSED ACROSS  
NORTHERN IL AND MUCH OF WI WHICH DOES RAISE SOME QUESTIONS AS  
TO HOW FAR EAST STORMS CAN SUSTAIN THEMSELVES, BUT CAMS SUGGEST  
DISCRETE IL STORMS AND NORTHWEST IN STORMS WILL CONGEAL INTO A  
LINE WITHIN OUR FORECAST AREA. ALL HAZARDS REMAIN POSSIBLE,  
THROUGH IT SHOULD BE NOTED THAT LOW-LEVEL HODOGRAPHS ARE  
SOMEWHAT FLAT, AND THAT LCLS NEAR 1000M AREA COULD BE A TOUCH  
ELEVATED FOR A TRUE TORNADO RISK.  
 
OTHERWISE, VERY WARM THIS AFTERNOON WITH HEAT INDICES IN THE LOW-90S  
AND AIR TEMPERATURES APPROACHING 90, ESPECIALLY ALONG AND WEST OF US  
31.  
 
ON THE HEELS OF THIS EVENING'S SEVERE WEATHER RISK IS INCREASING  
CONCERN FOR SEVERE STORMS FRIDAY EVENING. A STOUT 500-MB JET RACES  
IN ACROSS IL AND IN AHEAD OF AN ADVANCING UPPER-LEVEL TROUGH AND  
COLD FRONT. OUR ATMOSPHERE WILL HAVE TO RECOVER FROM THRUSDAY'S  
STORMS IN ORDER TO ACCOMMODATE THE FRIDAY RISK. ADDITIONALLY, DEW  
POINTS ARE FORECAST TO BE HIGHLY VARIABLE NORTH TO SOUTH WHICH WILL  
LIMIT THE SEVERE RISK ACCORDINGLY. MANY DETAILS TO SORT OUT OVER THE  
NEXT 24 HOURS, BUT, DAMAGING WIND APPEARS TO BE THE PRIMARY RISK.  
YET, ALL HAZARDS REMAIN ON THE TABLE.  
 
NOTABLY COOLER AND DRYING OUT FOR THE WEEKEND BEFORE A SERIES OF  
SYSTEMS NEXT WEEK BRING RENEWED SHOWER AND STORM CHANCES.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/  
 
ISSUED AT 523 AM EDT THU MAY 15 2025  
 
AREAS OF FOG HAVE FORMED ONCE AGAIN NEAR THE INDIANA AND OHIO  
BORDER FOR THE 3RD CONSECUTIVE MORNING. FT WAYNE WAS JUST SOUTH  
OF THE VERY LOW VISIBILITIES THAT WERE BEING REPORTED AT SMD AND  
GWB. KEPT THE LOWER CEILINGS AND VISIBILITIES OUT OF THE FWA TAF,  
BUT THERE IS A CHANCE THESE COULD BE BRIEFLY LOWER BEFORE 15Z.  
OTHERWISE, STORMS ARE NOT EXPECTED TO DEVELOP UNTIL AFTER 00Z.  
PLACED SOME STRONGER WINDS IN THE TAF GIVEN THE POTENTIAL FOR  
THE CAP TO BREAK WITH A LARGE AMOUNT OF CAPE AVAILABLE.  
CONDITIONS SHOULD BE VFR AFTER THE STORMS MOVE OUT OF THE AREA  
BY 07Z.  
 
 
   
IWX WATCHES/WARNINGS/ADVISORIES  
 
IN...NONE.  
OH...NONE.  
MI...NONE.  
MARINE...NONE.  
 
 
 
 
 
DISCUSSION...BROWN  
AVIATION...SKIPPER  
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