Wet weekend in store for portions of the Central/Southern Plains andadjacent Rockies...A pair of frontal systems will bring shower and storm chances from theGreat Lakes to the Mid-Atlantic this weekend...Above average temperatures will spread across the West andnorth-central U.S. this weekend...A wet weekend is in store for portions of the Central/Southern Plains andadjacent Rockies as a cooler, moist airmass has settled in north of afrontal boundary stalled out just south of the U.S.-Mexico border.Scattered, lighter showers through Friday evening/early Saturday willbecome more widespread and heavier through the day Saturday, with isolatedflash flooding possible. Higher elevations of the central Rockies will seesome snow, though accumulations should remain much lighter compared to thepast couple of days. Then, on Sunday, the boundary will lift backnorthward through Texas and into the Lower Mississippi Valley as a warmfront, bringing deeper moisture, higher instability, and the potential formore intense downpours. A Slight Risk of Excessive Rainfall (level 2/5)has been issued for portions of central/eastern Texas into the LowerMississippi Valley for the risk of scattered flash flooding, particularlywhere antecedent conditions remain wet due to recent heavy rainfall ineastern Texas. To the east, shower and thunderstorm chances will taper off along the EastCoast Friday evening as a cold front pushes offshore, lingering longestacross Florida. Another frontal system dropping southeast from Canada willbring some scattered showers and thunderstorms to the Upper Midwest/GreatLakes overnight Friday, then spreading into the Upper OhioValley/Appalachians and Mid-Atlantic during the day Saturday. Storms willdiminish overnight Saturday as this system departs the East Coast as well.Yet another system is forecast to follow in its wake, bringing somerenewed scattered storm chances to the Great Lakes Sunday. Other areas ofthe country should remain mostly dry through the weekend.An upper-level ridge building over the West Coast and eastward into thenorth-central U.S. is expected to lead to widespread well-above averagetemperatures across those regions this weekend. Forecast highs Saturdayfrom California northward into the Pacific Northwest will range in the 80sto low 90s. The focus for warmer temperatures will shift more into theInterior West/Great Basin Sunday. While not quite as warm, temperaturesthrough the northern Rockies into the northern Plains will still be wellabove average, with highs in the 70s to low 80s expected. These warmertemperatures will spread into the Midwest by Sunday. In contrast, cooler,below average temperatures are expected most elsewhere across the easternand central U.S. following the frontal passage. Forecast highs range fromthe 50s and 60s in New England and the Mid-Atlantic, the 70s to low 80sacross the Southeast, and 60s and 70s into the Central/Southern Plains.Areas of south Texas and Florida will remain warmer, with 80s and some 90sforecast.