Overview
- Persistent wildfire smoke has prompted official Air Quality Advisories across parts of the Midwest, with PM2.5 levels reaching Unhealthy to Very Unhealthy and sensitive groups advised to stay indoors and check AirNow guidance.
- The Storm Prediction Center has placed large portions of southeast Wisconsin and south‑central Pennsylvania under an Enhanced (level 3 of 5) severe‑weather outlook for Tuesday, signaling a meaningful chance of numerous severe storms.
- Forecasters say the main hazards in the expected storms are damaging straight‑line winds, large hail and heavy downpours that could trigger flash flooding, with isolated tornadoes possible in the strongest cells.
- Meteorologists warn storm timing is conditional because morning convection can reduce or leave ingredients in place for a stronger late‑day event, so evening windows from mid‑afternoon into the night will be critical to monitor.
- The interior West faces a Heat Advisory including the Denver metro where highs near 98–102°F are expected, and forecasters note monsoonal moisture will return mid‑ to late‑week, increasing afternoon storm chances in mountain areas.