Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
989 FXUS02 KWBC 032000 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 PM EST Tue Nov 3 2026 Valid 12Z Fri Nov 06 2026 - 12Z Tue Nov 10 2026 ...Overview... Active weather will continue through Friday for portions of eastern U.S. as the initial upper trough and frontal systems continues to progress offshore. However, additional shortwave energy may reinforce troughing across the eastern states into early next week, supporting chances for additional showers and thunderstorm. Persistent troughing over Pacific Northwest will bring chances for precipitation into early next week. Farther south, a southern- stream trough will bring scattered showers and thunderstorm chances across the Southern Plains into western Gulf Coast through the weekend. ...Guidance/Predictability Assessment... Model dispersion is relatively high early in the medium range period (this weekend), versus later in the period (early next week), specifically over the Southwest. A digging, positively tilted trough over the Western U.S. will slow as the southern most portion stalls. The GFS suite and eventually the deterministic Canadian attempt to close off a mid-level feature over the Southwest which retrogrades into the Baja Eastern Pacific early next week. Therefore, a non-GFS suite based blend was favored through day 4. By day 5, the ensemble means are favored in the blend in an attempt to mitigate uncertainty around the trough frequency over the Central U.S.. ...Weather/Hazards Highlights... A series of shortwave disturbances will maintain an active weather pattern across the Pacific Northwest into early next week. Persistent cyclonic flow over the northeastern Pacific, combined with periods of enhanced onshore moisture transport, will support reoccurring precipitation along the Washington and Oregon Coast and across the Cascades. Some precipitation may extend inland across portions of the Northern Rockies/Intermountain west. Farther south, a southern-stream trough will progress eastward and interact with Gulf moisture, bringing periods of scattered showers and thunderstorms across portions of the southern Plains and western Gulf Coast through the weekend. An atmospheric river event may begin early next week as a long duration precipitation event is anticipated to arrive. The initial upper trough and associated frontal boundary will continue moving eastward toward the Atlantic coastline on Friday. Showers and thunderstorms will continue for portions of the Mid- Atlantic and Northeast, as moisture continues to pool along the boundary. Localized flash flooding will be possible for Friday as the frontal boundary may stall. WPC Excessive Rainfall Outlook has placed a Marginal Risk for portions of the Northeast coast. Following the frontal passage, surface high pressure should expand eastward from central U.S., promoting drier conditions across the Mississippi, Ohio, and Tennessee Valley. However, another shortwave trough dropping southeastward from the northern Plains could reinforce cyclonic flow across portions of eastern U.S. through the weekend, but the evolution of this disturbance remains uncertain. Furthermore, the potential for a secondary surface low to develop near the East Cost, may support additional showers along the coast. Further north, favorable low- level flow and cold-air advection behind the frontal system may support periods of light lake-effect showers downwind of the Great Lakes. Kebede/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 $$