Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 309 AM EDT Mon Sep 09 2013 Valid 12Z Mon Sep 09 2013 - 12Z Wed Sep 11 2013 ...Areas of flash flooding and severe weather are possible from the Northern High Plains east into the Upper Midwest... ...Heavy showers and thunderstorms will promote a risk of flash flooding across the Southwest as monsoonal moisture persists... ...Cool weather initially over the Northeast will give way to a warming trend by the middle of the week as hot and dry weather continues for most of the South... The slow-moving upper low over the Pacific Northwest will move east and steadily weaken today and Tuesday while crossing the Northern Plains and Upper Midwest. Nevertheless, numerous showers and thunderstorms exiting out across the Dakotas this morning will advance into the Upper Midwest later today and tonight. The region will remain unsettled with at least regional threats of flash flooding and severe weather through tonight and early Tuesday. This area should begin to dry out somewhat and see more tranquil weather by the middle of the week as finally an area of surface low pressure associated with the broader system aloft exits the region. Farther southwest back through the Central and Southern Rockies and into the Desert Southwest, the concern over the next few days will be heavy showers and thunderstorms as a well-defined feed of monsoonal moisture becomes even more entrenched and concentrated over the area. In fact, there is expected to be an elevated threat of flash flooding given the degree of anomalous moisture and enhanced instability over the region and especially over the higher terrain. This will tend to keep temperatures somewhat cooler, but there will be locally heavy rainfall across the region. Hot weather should persist across the Southern Plains and into the Lower Mississippi Valley through the middle of the week, as a front settling down through the Central Plains and Midwest is expected to stall out and not make it down into southern tier of the nation. Dry conditions will persist for most areas, but some scattered showers and thunderstorms are expected for South Texas and the Lower Rio Grande Valley with some moist onshore flow in off the Gulf of Mexico. Elsewhere, initially cool conditions across the Northeast will give way to a warming trend as high pressure moves off the East Coast and a southwest return flow sets up. Some of the very warm to hot temperatures currently focused over the Midwest will advance across the Ohio Valley and into the Mid-Atlantic by Wednesday. These areas should remain dry, but it should become unsettled for New England as a warm front moving back through the region and a surface low arriving across the Great Lakes region helps to focus showers and thunderstorms across the region. Orrison Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php