859 FXUS63 KIWX 011645 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1245 PM EDT Sun Jun 1 2025 .KEY MESSAGES... -Partly to mostly clear skies and dry conditions expected through Tuesday. Canadian wildfire smoke will remain elevated over the area through at least Monday. Minimal, if any, impacts to air quality as smoke should remain aloft. -High temperatures today will be in the upper 60s and low to mid 70s, then rise into the mid to upper 80s by Tuesday and Wednesday. Highs fall back into the 70s and low 80s Thursday into next weekend. -Rain chances return Tuesday night, and persist through the end of the work week. The best potential is Wednesday into Thursday night (45 to 85 percent). There are chances for thunderstorms as well, particularly Wednesday afternoon into Friday evening. && .DISCUSSION... Issued at 359 AM EDT Sun Jun 1 2025 Dry conditions with partly to mostly sunny skies (outside of the wildfire smoke aloft) will persist through Tuesday thanks to high pressure at the surface and a building ridge aloft. Temperatures today will be in the 60s and low to mid 70s, warmest inland and along/south of US 24. Lows tonight will drop back into the 40s. As the ridge builds in through Tuesday, highs will climb towards the mid to upper 80s. By Tuesday night, the upper ridge will shift eastward as a broad trough fills in the central CONUS (stemming from an upper low over the Canadian Prairies). A cold front will make a run eastward into the ridge, reaching just west of our CWA by Wed AM and eventually exiting by Friday morning. The front will likely stall somewhere over our CWA between Wednesday night and Thursday before it eventually is forced eastward by another shortwave rippling through the edge of the weakening ridge (ECMWF brings a weak surface low up along the front, but other guidance is inconsistent with this). For now have 40-85 percent chances Wed, then widespread 60-80 percent Wed night into Thu, tapering off from NW to SE Thu PM-Friday. Have the best potential for thunder along the front and during daytime hours. Moisture transport during the Tue night-Thu night period is right off the Gulf into our CWA, with a 35-45 kt LLJ in place parallel to our potentially stalled frontal boundary. We could see periods of heavy rain with this, and WPC has us in a marginal risk for the Excessive Rainfall Outlook for Tuesday night-Friday morning accordingly. Severe weather is not expected at this point. Highs on Wednesday are somewhat challenging as the ridge is exiting eastward and there are timing differences re: the progress of the cold front. Have mid to upper 80s still generally along and south of US 24 and east of US 31, warmest east of I 69. Further north and west highs will likely be in the upper 70s and low 80s-coolest near Lake MI. Have lower confidence in pops beyond thursday night because of model disagreement-but mainly with respect to timing/exact placement of precipitation vs. the potential for overall precipitation. There will be periods of rain and perhaps some thunderstorms beyond Thu night-so left the consensus pops for now (20-50 percent, highest Fri and then again on Sun afternoon). Highs will be in the mid to upper 70s. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1243 PM EDT Sun Jun 1 2025 No flight concerns through the period with little in the way of cloud cover or winds to deal with. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...MCD AVIATION...Fisher