Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Sat Aug 28 2021 Valid 12Z Sat Aug 28 2021 - 12Z Mon Aug 30 2021 ...There is an Enhanced Risk of severe thunderstorms and a Slight Risk of excessive rainfall over parts of the Upper Mississippi Valley through Sunday morning... ...Hurricane IDA is forecast to intensify while moving toward the Central Gulf Coast, having amongst other hazards, there will be a High Risk of excessive rainfall on Sunday into Monday... ...Uncomfortable and potentially dangerous heat throughout much of the Southwest and parts of the Midwest... A front extending from the northern Mid-Atlantic westward to the Great Lakes then into the Great Basin has a wave of low pressure over South-Central Canada will pull the front northward into Canada on Sunday. On Monday, the trailing front will extend from the Lower Great Lakes westward to another wave of low pressure over the Northern High Plains. The system will produce showers and thunderstorms along and near the boundary from the Northern High Plains to the Great Lakes, as some of the storms will be very energetic. As a result, the SPC has issued an Enhanced Risk of severe thunderstorms over the Upper Mississippi Valley through Sunday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. There is a 10% or greater probability of 65 knots or greater wind gusts over parts of the Upper Mississippi Valley. Additionally, the WPC has issued a Slight Risk of excessive rainfall with these thunderstorms. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable through Sunday morning. The severe thunderstorm threat decreases to a marginal threat on Sunday into Monday. The excessive rainfall threat also diminishes over the Upper Midwest on Sunday into Monday morning. Over the Gulf Coast, tropical moisture and upper-level impulses will produce showers and thunderstorms along the Gulf Coast into the Southeast on Saturday. Furthermore, Hurricane IDA is forecast to intensify while moving toward the Central Gulf Coast, having amongst other hazards, there will be a High Risk of excessive rainfall on Sunday into Monday. Ida is currently forecast to make landfall over the Louisiana Coast on Sunday evening. Check with the NHCâ€s latest bulletin for the most up-to-date track and intensity of IDA. IDA will produce heavy rain over parts of the Central Gulf Coast on Sunday. Therefore, the WPC has issued a High Risk of excessive rainfall over the Central Gulf Coast on Sunday into Monday. Severe, widespread flash flooding is expected with IDA. Areas that normally do not experience flash flooding will flood. Lives and property are in great danger on Sunday into Monday. The excessive rainfall threat continues on Monday into Tuesday with a Moderate Risk of excessive rainfall over parts of the Lower Mississippi Valley. There is also a Slight Risk of severe thunderstorms with landfalling hurricanes with the main hazard of a few tornadoes on Sunday into Monday. Elsewhere, upper-level impulses and diurnal heating will produce showers and thunderstorms over parts of the Southwest into the Southern High Plains from the late afternoon into the late evening on Saturday and Sunday. Additionally, heat will also produce hazards. Heat Advisories are posted over parts of the Great Lakes and the Middle Mississippi Valley, where high temperatures are forecast in the upper 80s to low 90s. Moreover, many areas of the Midwest will have the possibility of record high minimum temperatures on Saturday and Sunday morning. In the Southwest, highs in the 110s are expected on Saturday, and an Excessive Heat Warning remains in effect for the area through Saturday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php