232
FXUS63 KIWX 171854
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
254 PM EDT FRI JUL 17 2026
KEY MESSAGES
- SMOKE FROM CANADIAN WILDFIRES WILL CONTINUE TO BRING PERIODS
OF POOR AIR QUALITY AND REDUCED VISIBILITY THROUGH AT LEAST
MONDAY.
- SLIGHT CHANCE FOR SEVERE THUNDERSTORMS TOMORROW (SAT)
AFTERNOON WITH DAMAGING WINDS THE MAIN THREAT.
- ADDITIONAL CHANCES FOR SEVERE THUNDERSTORMS MONDAY-TUESDAY.
- TEMPERATURES COOL OFF BY SUNDAY, BECOMING MORE SEASONABLE FOR
MID-JULY.
DISCUSSION
ISSUED AT 236 PM EDT FRI JUL 17 2026
CANADIAN WILDFIRE SMOKE WILL CONTINUE TO BRING MAJOR AIR
QUALITY IMPACTS TO THE GREAT LAKES REGION FOR THE NEXT SEVERAL
DAYS. EPA SENSORS ACROSS THE AREA HAVE BEEN SAMPLING VERY
UNHEALTHY TO HAZARDOUS PM2.5 DUE TO THE SMOKE. IT IS ADVISED TO
STAY INDOORS AS MUCH AS POSSIBLE IN THESE CONDITIONS. SHOWERS
AND THUNDERSTORMS, COUPLED WITH SOUTHWEST 850MB FLOW (THEN
BECOMING WEST TONIGHT), WILL HELP TO NUDGE THE SMOKE SLOWLY OFF
TO THE NORTHEAST AND EAST. THIS WILL BRING SOME RELIEF FOR
TOMORROW, BUT MOST AREAS ARE STILL EXPECTED TO REMAIN UNHEALTHY
FOR SENSITIVE GROUPS. AN UPPER LEVEL TROUGH MOVING THROUGH THE
GL TOMORROW NIGHT WILL RESTRENGTHEN THE SMOKE CONVEYER BELT, FOR
A LACK OF BETTER WORDS, AND SUNDAY WE COULD HAVE REINVIGORATED
SMOKE IMPACTS. MONDAY, WEAK LOW-LEVEL WINDS FROM HIGH PRESSURE
OVER LAKE ERIE WILL KEEP SUNDAY'S SMOKE HANGING AROUND.
UNFORTUNATELY, THE NICE BREAK FROM SEVERE WEATHER LOOKS TO COME
TO AN END. FOR TODAY, A MARGINAL RISK FOR SEVERE STORMS (STRONG
WINDS IS THE MAIN THREAT WHERE MIXED LAYER LAPSE RATES ARE THE
STRONGEST) WILL BE IN PLACE FOR AREAS GENERALLY FORT-WAYNE
SOUTHWARD. AS OF THIS WRITING, MORE ROBUST CONVECTION HAS
INITIATED OVER LAFAYETTE, IN AND THIS WILL CONTINUE TO WORK ITS
WAY EAST-NORTHEAST. THERE IS PLENTY OF INSTABILITY FOR SHOWER
AND THUNDERSTORM GROWTH TODAY, SO WE EXPECT A GOOD MAJORITY OF
THE CWA TO GET WETTING RAIN.
THE MID/UPPER LEVEL TROUGH THAT EVENTUALLY BRINGS MORE SMOKE
DOWN WILL BE MOVING THROUGH ONTARIO AND QUEBEC ON SATURDAY. A
COLD FRONT WILL DRAG SOUTH THROUGH THE DAY. AHEAD OF THIS, 850MB
FLOW WILL INCREASE TO AROUND 25-30KT AND CAPE VALUES ON THE
ORDER OF 2500-3000 J/KG WILL PROMOTE A LINE OF SHOWERS AND
THUNDERSTORMS PROPAGATING SOUTH AND SOUTHEAST THROUGH THE
AFTERNOON TO EARLY EVENING HOURS. WHILE DAMAGING WINDS WILL BE
THE PRIMARY THREAT, LOW-LEVEL HELICITY WILL BE MARGINALLY
ADEQUATE (75-100 M^2/S^2)) TO PRODUCE A QUICK SPIN-UP TORNADO.
THE GOOD NEWS IS THAT AFTER TOMORROW, WE CAN SAY GOODBYE TO
TEMPS IN THE 90S FOR THE UPCOMING WEEK AS WE RETURN TO A MORE
NORMAL TEMPERATURE PATTERN. ACTUALLY, WELL BELOW AVERAGE TEMPS
ARE EXPECTED ON WEDNESDAY-THURSDAY WITH TEMPS IN THE 70S. THIS
WILL BE IN THE WAKE OF A POTENT SYSTEM THAT WILL BRING THE
CHANCE FOR SEVERE WEATHER TO OUR AREA MONDAY AND TUESDAY AS THE
STORM PREDICTION CENTER HAS OUR AREA UNDER A D4/D5 SLIGHT RISK.
STAY TUNED TO SPC.NOAA.GOV FOR THE LATEST ON THAT.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 111 PM EDT FRI JUL 17 2026
TWO FOLD CHALLENGE WITH TAFS MAINLY IN THE FIRST 6 TO 12 HOURS.
THE FIRST IS THE LARGE PLUME OF SMOKE PERSISTING ACROSS THE
AREA. A WARM FRONT, LOCATED TO THE SW OF BOTH LOCATIONS, IS SET
TO WORK NE OVER THE NEXT SEVERAL HOURS AND SHOULD BEING TO
EITHER BREAK UP OR PUSH AND SMOKE TO THE NE. AT THE SAME TIME, A
MODERATELY UNSTABLE ATMOSPHERE IS LOCATED SOUTHWEST OF THE FRONT
WITH SCATTERED SHOWERS AND STORMS ALREADY DEVELOPING ACROSS
CENTRAL IN. A FEW SHOWERS EXISTED NORTH OF THE FRONT, BUT ARE
STRUGGLING TO INTENSIFY. HAVE MADE SOME MINOR CHANGES TO THE
TAFS TO KEEP THE SMOKE IN A BIT LONGER AND CONFINE CONVECTIVE
CHANCES TO ALONG AND SOUTH OF THE FRONT. LEFT AS A PROB30 GIVEN
CONCERNS FOR COVERAGE AT THIS POINT. AFTER SUNSET, STORM
COVERAGE SHOULD WIND DOWN WITH THE WARM FRONT WELL NORTH OF THE
AREA.
EVENTUALLY A COLD FRONT IS EXPECTED TO DROP SOUTH DURING THE
AFTERNOON AND EVENING HOURS SATURDAY WITH BETTER CHANCES FOR A
LINE OF SHOWERS AND STORMS. THIS LOOKS TO WAIT TILL AFTER 18Z SO
NO POPS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...AIR QUALITY ALERT UNTIL MIDNIGHT EDT /11 PM CDT/ SATURDAY
NIGHT FOR INZ005>009-012>015-017-018-020-022>027-032>034-
103-104-116-203-204-216.
OH...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR OHZ001-002-
004-005-015-016-024-025.
MI...AIR QUALITY ALERT UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR
MIZ078>081-177-277.
MARINE...DENSE SMOKE ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-
046.
DISCUSSION...NORMAN
AVIATION...FISHER
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