Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 AM EDT Mon Aug 15 2022 Valid 12Z Mon Aug 15 2022 - 12Z Wed Aug 17 2022 ...There is a Slight Risk of excessive rainfall over parts of the Central/Southern Rockies, Great Basin, and Southwest through Wednesday morning... ...There is a Slight Risk of excessive rainfall over parts of southern Texas through Tuesday morning and over parts of the Middle Mississippi Valley from Tuesday into Wednesday morning... ...There is a Slight Risk of severe thunderstorms over parts of the southern Mid-Atlantic through Tuesday morning... ...There is a Heat Advisory over parts of the Southern Plains/Lower Mississippi Valley on Monday and an Excessive Heat Watch over parts of the West Coast on Tuesday... Monsoonal moisture and upper-level impulses will aid in producing diurnal showers and thunderstorms with heavy rain over parts of Colorado, Utah, Arizona, and New Mexico through Wednesday morning. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of the Central Rockies, Great Basin, and Southwest through Tuesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. Furthermore, on Tuesday into Wednesday morning, the Slight Risk s aerial coverage will be move to parts of the Central/Southern Rockies, Great Basin, and Southwest. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. Meanwhile, an upper-level low over parts of southern Texas and Northeastern Mexico will slowly move westward into North-Central Mexico by Wednesday. Tropical moisture and the energy will aid in producing showers and thunderstorms with heavy rain over southern Texas into Tuesday. Therefore, the WPC has issued a Slight Risk of excessive rainfall mainly along the Rio Grande in southern Texas through Tuesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. Elsewhere, a weak front over the Ohio Valley will move southeastward into South Carolina and America s Georgia by Wednesday. The system will produce showers and thunderstorms, with some storms becoming severe and the possibility of heavy rain over the region. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the southern Mid-Atlantic through Tuesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. In addition, the WPC has issued a Marginal Risk of excessive rainfall over parts of the Central Appalachians and the Virginia/North Carolina Piedmont into Tuesday morning. The associated heavy rain will create localized areas of flash flooding, affecting areas that experience rapid runoff with heavy rain over these areas. Additionally, tropical moisture and a weak front will aid in producing showers and thunderstorms with the possibility of heavy rain over Southern Florida through Tuesday morning. Therefore, the WPC has issued a Marginal Risk of excessive rainfall over a small area of the southeastern Florida Peninsula through Tuesday morning. The associated heavy rain will create localized areas of flash flooding, affecting areas that experience rapid runoff with heavy rain. The threat of excessive rainfall ends on Tuesday over Florida. Furthermore, moisture pooling along the front over the Middle Mississippi Valley will aid in producing showers and thunderstorms with heavy rain on Tuesday. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of the Middle Mississippi Valley from Tuesday through Wednesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. Lastly, upper-level ridging over the Central Plains will contribute to a heat low developing over parts of the Central Plains on Monday into Tuesday. As a result, the temperatures will climb into the mid to upper nineties to low hundreds over parts of the Southern Plains/Lower Mississippi Valley prompting Heat Advisories. Moreover, on Tuesday, upper-level ridging will build into the Great Basin, allowing temperatures to rise into the mid-to-upper hundreds over parts of California, prompting an Excessive Heat Watch over the Sacramento and San Joaquin Valleys starting and over parts of the Pacific Northwest on Wednesday. Ziegenfelder Graphics are available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php