Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Thu Aug 24 2017 Valid 00Z Fri Aug 25 2017 - 00Z Sun Aug 27 2017 ...Tropical Storm Harvey continue to strengthen while bringing extremely heavy rain over the Western Gulf Coast... ...Heavy rain possible over South Florida and parts of the Upper Mississippi Valley... The National Hurricane Center is forecasting Hurricane Harvey to move northwestward over the Western Gulf of Mexico moving into the Western Gulf Coast overnight Friday. The storm will produce showers and thunderstorms over parts of the Western Gulf Coast overnight Thursday. Extremely heavy rain will develop over parts of the Western Gulf Coast Friday into Saturday. Additionally, upper-level energy near Southern Florida will aid in producing showers and thunderstorms over the region through Saturday. In addition, a stationary front extending from the Southeast westward across the Gulf Coast State that will linger north of Harvey through Saturday. Showers and thunderstorms will develop along and near the boundary over the Western Gulf Coast/Southern Plains eastward to the Southeast also through Saturday. Meanwhile, a front over the Northern High Plains/Northern Rockies into parts of the Great Basin that will be quasi-stationary through Saturday. A warm front will develop over parts of the Northern Plains into parts of the Middle Mississippi Valley Friday into Saturday. The system will produce showers and thunderstorms over parts of the Upper Mississippi Valley into parts of the Northern/Central Plains into parts of the Northern Rockies/Northern High Plains A wavy front along the central and western Gulf Coast region will stall along these areas by this afternoon and stays put through Saturday. This boundary will act as a focal point for setting off convection across these coastal areas. The boundary will also stall across the Carolinas, which will bring heavy rainfall to coastal areas of those states. However, by early Friday morning, the front will begin to move offshore. As a result, most of the precipitation will also move off into the Atlantic. With an upper-level trough coming in from the west and sufficient moisture in place, the Southern Rockies can expect showers and thunderstorms over the next few days. A slight risk of flash flooding for this region will be in place as some of these thunderstorms will be capable of producing heavy downpours. Farther north, a cold front will move across the Pacific Northwest and Northern Rockies on Thursday--bringing light showers to these regions. As the front sweeps across the Northern High Plains, showers and thunderstorms will develop ahead of the front and will spread across the northern Plains in addition to the Upper Midwest by Saturday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php