725 FXUS01 KWBC 170827 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 425 AM EDT Wed Jun 17 2026 Valid 12Z Wed Jun 17 2026 - 12Z Fri Jun 19 2026 ...Potential Tropical Cyclone One is expected to bring heavy rainfall across the Gulf Coast states during the next couple of days... ...Severe thunderstorms are expected to impact the Midwest to the Ohio Valley today... ...Heat and humidity return to the Mid-Atlantic on Thursday with severe thunderstorms possible for portions of the Ohio Valley, Northeast and Mid-Atlantic... A relatively fast-moving weather pattern remains in store across the northern tier states as Potential Tropical Cyclone One (PTC1) develops and tracks northeastward near the Texas Gulf Coast. The interaction between the tropical moisture associated with PTC1 and the fast-moving weather pattern to the north continues to support a multiday heavy rainfall event across the Gulf Coast states. The center of PTC1 is forecast to track just off the Texas Gulf Coast today before making landfall over southwestern Louisiana this evening with tropical-storm-force winds expected near the coast where a Tropical Storm Warning is in effect. The heaviest rain is forecast to fall ahead of the track of PTC1 from the Texas Gulf Coast, through the Deep South toward the interior Southeast as the center of PTC1 is forecast to move further inland and dissipate over central Mississippi by Thursday morning. Generally 5 to 10 inches of rain with isolated higher totals near 20 inches, are forecast near and just north of the track of PTC1 where a moderate risk of flash flooding is anticipated. Although the center of PTC1 is forecast to dissipate by Thursday morning, the remnants of PTC1 are expected to continue tracking farther eastward through the Southeast from Thursday to Friday morning. The Weather Prediction Center will continue to monitor the heavy rainfall potential associated with the remnants of PTC1. Meanwhile, a severe weather outbreak is in store today for portions of the Mid-Mississippi and Ohio Valleys, particularly across parts of central Illinois and northwestern Indiana. A strong mid-level trough and an associated jet streak will move eastward, reaching the Great Lakes while a strong surface low-pressure system approaches the region by the evening hours. With a strong concurrent influx of moisture expected, thunderstorms will develop during the afternoon and evening. Some thunderstorms are likely to be severe, carrying a risk of large hail, damaging winds, and potentially intense tornadoes. Winds could reach up to 80 mph in some areas, with up to 2.5-inch hail expected. As a result, the Storm Prediction Center (SPC) has outlined a Moderate Risk (level 4/5) of severe weather for central Illinois and northwestern Indiana for today. At the same time, rainfall will be heavy at times and will bring the possibility of scattered flash flooding. Consequently, there is also a Slight Risk of excessive rainfall for much of the Midwest and lower Great Lakes, with a Moderate Risk south of Lake Michigan. By Thursday, a relatively deep low pressure system for June will move through the Great Lakes and into Quebec, Canada. Increasing southerly flow will bring heat and humidity back to the Mid-Atlantic on Thursday with severe thunderstorms possible for portions of the Ohio Valley, Northeast and Mid-Atlantic ahead of the cold front trailing from the low center. Temperatures are forecast to soar well up into the 90s into lower 100s in the Mid-Atlantic where record high temperatures will be challenged on Thursday. By Friday morning, the cold front will be moving off the New England coast with cool air ushered into the Northeast and the Great Lakes. The West will generally be quiet through the next couple of days with highs reaching 100 in the Great Basin, 110s in the Desert Southwest. Triple digit temperatures are also forecast for the central to southern High Plains before the arrival of a cold front from the north by Thursday. Kong/Blanco-Alcala Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$