842 FXUS01 KWBC 200749 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 348 AM EDT Mon Jul 20 2026 Valid 12Z Mon Jul 20 2026 - 12Z Wed Jul 22 2026 ...High concentrations of Canadian wildfire smoke to affect the Great Lakes area over the next few days... ...A strong southeastward moving frontal system to support active thunderstorms from the Northern Plains to the Mid-Atlantic... ...T.D. Two to bring heavy rain threats to the northeast Gulf coast... ...Monsoonal thunderstorms to continue over the next few days from the Southwest into the Great Basin... ...Hazardous heat builds from the Northern Plains into the Lower Mississippi Valley... There is no let up in air quality issues over the next few days downwind of the ongoing Canadian wildfires across western portions of Ontario. The latest smoke models are focusing the highest concentrations of smoke across the Great Lakes today, followed by another shot of smoke moving south on Tuesday across this area in the wake of a strong frontal system pushing east. Air quality alerts are currently in effect across the Great Lakes into portions of the Midwest, with this likely to continue over the next few days. Air quality issues are also expected across portions of the Pacific Northwest into the Northern Rockies due to wildfires across this area. Air quality alerts are currently in effect across eastern Oregon into northern Idaho. The same frontal system will focus widely scattered severe thunderstorms and some flash flooding today and tomorrow across portions of the Midwest, Northeast, and Mid-Atlantic. Meanwhile, T.D. Two is forecast to gradually strengthen over the next 48 hours as it meanders westward toward the central Gulf Coast. Much of the precipitation with this storm is still expected to remain just offshore, although flash flooding certainly remains a threat with this system as the outer bands of T.D. Two approach the I-1O corridor from northwest Florida to southeast Louisiana. See the latest NHC advisories for additional and updated information on this storm. In the West, an active monsoonal pattern will persist across the Southwest and Great Basin for at least the next three days. Scattered flash flooding remains the foremost concern with this activity owing to the plentiful moisture available for the daily thunderstorms to tap into. While cooler air is expected behind the aforementioned cold front, building mid to upper-level heights across the Central Rockies and Plains will continue to support much above average temperatures early this week across much of the Plains, Lower Missouri Valley, and Lower Mississippi Valley. Heat indices in these region are expected to approach 110-115 degrees today and tomorrow, where a swath of Heat Advisories are in effect. Asherman/Oravec Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$