202 FXUS63 KAPX 290718 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 318 AM EDT Mon Jun 29 2026 .KEY MESSAGES... - Showers and thunderstorms this morning, best potential NW lower MI, then eastern UP into the early afternoon. - Hot and humid conditions through this week, heat indices between 95F to 105F Tuesday through Thursday. - Periodic thunderstorm chances through this upcoming week, a few periods of stronger storms possible. && .DISCUSSION... Issued at 247 AM EDT Mon Jun 29 2026 Pattern Synopsis and Forecast: Showers and thunderstorms are expected to develop this morning within a warm and moist advection regime, with instability axis northwest to southeast across the Upper Midwest nosing into western MI. The best elevated instability and moisture will be across northwest lower Michigan (where the current Marginal risk for severe weather lies). Moderate amounts of shear could result in some elevated hailers, although some of the convective allowing models are showing a convective complex congealing over Lake Michigan/Wisconsin and clipping the Marginal risk across our area this morning, which could produce strong winds in some places. Given the instability, shear, and moist airmass, locally heavy rain, localized hail, and strong winds will be the primary concerns this morning, with some showers and storms lingering through the day. Current radar imagery is not quite as robust in WI as some of the previous guidance suggested, so worth monitoring as the POP fcst may be a little off. Heat will generally be the focus the rest of the week. 596-597 dam upper high builds across the Southeast and Ohio Valley, with anomalous heights across northern MI. Most recent model guidance runs do show this upper high slowly meandering eastward with time through the end of the week, which continues the theme of uncertainty in regards to the heat. That being said, it will be hot and very humid, especially for northern MI, this entire week, so regardless, heat stress will be high and compounded with time. After the showers and storms today, a pretty hot day is expected with heat indices in the 80s and 90s, hottest GTB and southwest (thought about an advisory for that region but with the uncertainty and the focus being Tuesday, twas will forego). Hottest day appears to be Tuesday, with heat indices in the mid 90s to triple digits. Then we watch how much convection on Wednesday and Thursday tries to impact the high temperatures. Current forecast has highs well into the 90s most areas both Wednesday and Thursday with heat indices in the mid 90s to mid 100s. Heat is a compounding hazard, and so several days of heat indices near 100F may mean more than a single day of a heat index 105F. Because of this, Extreme Heat Watches have been issued for all of northern lower MI, the hottest temperatures and heat indices being across northeast lower MI. Whether some sections of this will be upgraded to Advisories or Warnings, will be up to the day crew most likely. The message remains the same regardless, heat stress will be high this week due to the heat and humidity. Check on those sensitive to heat, outside workers, and pets. Investigating the other convective threats through the week yields modest southwest flow overspreading the Upper Midwest, including northern MI, overtop of this moist and unstable airmass. As the high pressure slides to the east, this may open the door for subtle perturbations and convective complexes to ride the northern periphery of the ridge, resulting in showers and thunderstorms across northern MI. Given the amount of instability, expected convection upstream, and increased flow aloft, there could be severe threats at times for sure. Current guidance indicates the later Tuesday time frame and the Thursday to Friday being potentially active. As far as Tuesday is concerned, a Marginal risk (level 1 of 5) for severe thunderstorms is forecast, with portions of the Eastern UP in a Slight risk (level 2 of 5). Thus, isolated severe storms are possible during this time frame. Looking at the later Tuesday and Tuesday night time frame mostly. Moderate shear and plentiful instability is usually a hail/wind risk, especially if any bowing segments or mesoscale convective complexes can push into northern MI. Many details to hash out beyond that in regards to convection. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 1146 PM EDT Sun Jun 28 2026 Increasing clouds tonight, and some showers/embedded TSRA will push across the area late tonight into Monday morning. Most of this rain will be light, and will fall out of a VFR cloud deck. But brief restrictions are possible during any heavier rain bursts. MBL has the best chance for MVFR cigs to linger for a few hours. And the best chance of TSRA is at TVC/MBL. E to se winds will be breezy at times. && .APX WATCHES/WARNINGS/ADVISORIES... MI...Extreme Heat Watch from Tuesday afternoon through Thursday evening for MIZ016>018-020>036-041-042-097>099. MARINE...Small Craft Advisory from 11 AM this morning to 11 PM EDT this evening for LHZ345>348. Small Craft Advisory from 6 AM this morning to 8 AM EDT Tuesday for LMZ344>346. && $$ DISCUSSION...JLD AVIATION...JZ