Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 316 PM EDT Sat Jul 26 2014 Valid 00Z Sun Jul 27 2014 - 00Z Tue Jul 29 2014 ...Another Canadian high pressure cell will bring cooler air south and eastward across much of the eastern half of the US by late Monday and early Tuesday... ...The leading edge of the latest summer cool front will again increase chances for heavy rainfall and flash flooding and severe weather across the Midwest/Ohio Valley/Central Appalachians/Mid Atlantic and Northeast later this weekend and on Monday... ...Monsoonal moisture will continue to fuel afternoon showers and thunderstorms across the Southwest and Central Rockies... The summer pattern so far of trough in the East and Ridge out West will be reinforced over the next few days as a potent upper level disturbance over southwest Canada drifts southeastward and drags a surge of cooler air across much of the eastern half of the US by later Monday and early Tuesday. A complex area of fronts and relatively weak low pressure systems will gradually usher in the cooler air across the Midwest into the Ohio Valley before becoming a well defined cold front and low pressure system moves across the Eastern US by Monday. Scattered showers and some heavy thunderstorms are likely ahead of the front and severe weather is again a possibility with strong winds, hail and isolated tornadoes possible. Behind the cold front...another Canadian high pressure cell will build and head southeastward toward the North Central States providing very comfortable temperatures for late July. This air mass should also end the current heat spell over Kansas and Oklahoma early in the week with an increasing chance of showers and much cooler temperatures. As the upper ridge currently responsible for the heat across the central and Southern Plains pulls westward across the Southwest...monsoonal moisture circulating around the upper High will interact with the front along the eastern slopes of the Rockies and could generate more heavy rainfall in isolated storms across the Southwest as well as upslope flow across eastern Colorado and northeast new Mexico and north Texas by late Monday and Tuesday. Kocin Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php