Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 PM EDT Tue Oct 07 2014 Valid 00Z Wed Oct 08 2014 - 00Z Fri Oct 10 2014 ...Showers and thunderstorms will spread from the Ohio/Tennessee Valley to the Mid-Atlantic/Northeast on Tuesday into Wednesday morning... ...Tropical moisture from Simon expected to bring heavy rain to portions of the Southwest beginning on Tuesday... Mid level shortwaves rotating around a deep upper low over eastern Canada will bring wet weather to the Ohio Valley, Mid Atlantic, and Northeast. This afternoon, severe weather is possible across northern Kentucky, Southern Ohio, and West Virginia with thunderstorms developing in a strongly sheered environment. Even with surface temperatures on the cool side, strong dynamics taking place in the mid and upper levels with generate enough ascent for strong to severe storms to take hold. With the mid level shortwave moving rapidly around the deep upper low, showers will move across the Mid Atlantic and Northeast tonight before exiting New England hastily tomorrow morning. Some lake effect or lake enhanced showers could develop downwind of the Great Lakes after the frontal passage as much colder air moves in aloft. Tropical moisture from Simon is already making its way into the Desert Southwest. Showers and thunderstorms will continue across the region over the next 48 hours as the circulation associated with Simon moves inland and dissipates. The bulk of the precipitation should fall across Arizona, with the highest amounts over the higher terrain of central Arizona. Flash flooding is possible across much of central and southern Arizona today. Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php