902 FXUS02 KWBC 032000 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Sun May 3 2026 Valid 12Z Wed May 06 2026 - 12Z Sun May 10 2026 ...General Overview... A broad upper-level closed low anchored over eastern Canada will continue to drive broad cyclonic flow and repeated trough reinforcement across central and eastern U.S. next week. This pattern will bring a stretch of cool, unsettled weather across the area. The associated cold front will continue to move south- southeast and produce showers and thunderstorms across eastern U.S., with potential flooding concerns for the interior Southeast. Furthermore, a southern stream upper trough/closed low moving across the Southwest could bring increasing chances of heavy rain up across the southern Plains and toward the lower Mississippi Valley later this week. Meanwhile, above normal temperatures will continue across much of the western U.S. ...Guidance/Predictability Assessment... The latest model guidance continues to show a trend toward faster eastward progression of the upper trough and cold front across the Northeast with more southward penetration of post-frontal cold air intrusion across the Great Lakes through the latter portion of the week. Meanwhile, model timings remain reasonably good regarding the upper low forecast to slowly move inland near the U.S.-Mexican border later this week before being ejected into the southern Plains this weekend. The GFS exhibits the typically faster ejection bias with this southern stream trough relative to the slower ECMWF and CMC solutions. Nevertheless, model consensus has trended toward faster northward intrusion of Gulf moisture into the southern Plains to the west of the lower Mississippi Valley Friday and into the weekend. Meanwhile, the wet snow across the central High Plains on Wednesday remains on track to taper off on Thursday. Therefore, the WPC forecast charts were based on a consensus of the 06Z GFS/GEFS, 00Z ECMWF/EC mean, and 00Z CMC/CMC, with increasing proportions from the ensemble means for the latter portion of the forecast period. ...Weather/Hazards Highlights... A broad upper-level low hovering over eastern Canada through the medium-range period will bring a series of shortwaves converging near the base of the mean trough. This pattern will bring a cold front to progress steadily through the eastern and southern U.S. through the latter portion of the week. It appears that the dynamic forcings associated with the front and upper trough will converge with the highest moisture content from the Gulf to support heavy rainfall and possibly strong thunderstorms across the Deep South to the southern Appalachians later on Wednesday to early on Thursday. A Slight Risk of heavy rainfall has been introduced across the interior Southeast where the forcings appear greatest based on current model guidance. Much of the eastern U.S. will likely receive rainfall from this cold front before the front swings off the East Coast behind a low pressure wave on Friday. The cold air behind the front will bring widespread below normal temperatures across the eastern two-thirds of the country through late this week, with frost/freeze conditions across the northern/central Plains to the Great Lakes Wed-Thu, and the northern borders of New England Fri-Sat. With the cold temperatures, there is a slight chance for some mixed precipitation over some isolated higher- elevation areas near the Upper Midwest/Great Lakes but impacts will be minimal. Over northern/central Plains into the Great Lakes, temperatures will drop 15-20 degrees below average by midweek. The ongoing wet snow across the central High Plains to the Front Range early on Wednesday will gradually taper off and end by early on Thursday. By the weekend, a moderating trend will spread above normal temperatures into the Plains and head eastward. Over the western U.S., the Pacific upper low/trough will continue to move across the Southwest early in the period, then gradually ejects into the Plains. This will be bring some low elevation showers and possible thunderstorms, as the wet snow blankets the Front Range to the central High Plains on Wednesday. The cold front will bring 15-25 degrees below normal temperatures across the Four Corners on Wednesday. The frontal system and shortwave energy will also bring some gusty winds across Rockies/Plains on Wednesday. Over the Pacific Northwest, a ridge will push inland, bringing a warming trend. As the ridge continues to move eastward, above normal temperatures will return across much of western U.S. later next week. Kong/Oudit Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast, excessive rainfall outlook, winter weather outlook probabilities, heat indices and Key Messages are at: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw $$