Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
416 FXUS02 KWBC 032000 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 PM EST Tue Mar 3 2026 Valid 12Z Fri Mar 06 2026 - 12Z Tue Mar 10 2026 ...Heavy rain/flooding and severe weather expected in the south- central U.S. late week through the weekend... ...Overview... Shortwave trough energy will eject through the Northeast Friday and promote precipitation including wintry weather into a cold air dammed airmass. Well behind this feature, broader troughing is forecast to dive through an unsettled West late week and split off a southern stream upper low near northern Mexico by the weekend. This pattern will advect ample moisture and instability especially into the Central U.S. in a channel stuck between western U.S. troughing and South/Southeast/East upper ridging. This will fuel a corridor of widespread thunderstorms with severe and flooding potential with repeat focus over the south-central U.S. and vicinity as enhanced by wavy frontal systems. Additionally, expect unseasonably warm pre-frontal temperatures to include some widespread record values in the eastern half of the U.S. under the downstream upper ridge. ...Guidance/Predictability Assessment... The general pattern of persistent troughing across the northern tier, ridging in the East/Southeast and troughing in the Southwest/northwest Mexico is captured well by the latest guidance. There`s some uncertainty with the timing/location of the southern stream cut-off low, which will be responsible for thunderstorm activity across the Southern Plains and Mississippi Valley this weekend. The NBM has trended slightly more progressive with the axis of QPF over the Southern Plains/Lower Mississippi Valley this weekend. Varying composite blends were utilized to depict a reasonable middle ground solution, while maintaining continuity across the lower 48. ...Weather/Hazards Highlights... A shortwave trough and wavy frontal system will eject from the Midwest through the Northeast into Friday and pooling moisture may fuel lingering areas of moderate rains. Farther north, overrunning moisture into cold dammed Canadian high pressure as driven by more progressive northern stream energies should also support some snow from northern portions of the Upper Midwest/Great Lakes to the Interior Northeast where conditions also support an ice/freezing rain transition zone to monitor. Upstream, an amplified upper trough will dig sharply southeastward through the West into Friday and bring unsettled and cooling flow along with a widespread moderate precipitation focus out from the Pacific Northwest through the north-central Intermountain/Rockies to include terrain enhanced snows. A split upper flow pattern should become dominant as this energy separates into the southern stream and stalls near Baja California into the weekend and early next week. With the western trough and upper low pattern, Pacific and Gulf moisture will flow into the Central U.S. along with instability, while a wavy front is in place. Runoff threats may build with each round of rain given a repeating pattern with some cell training potential. Marginal Risk areas for the threat of excessive rainfall for flooding/runoff are in place for portions of the south-central Plains into the Mid-Mississippi Valley and vicinity Day 4/Friday and especially by Day 5/Saturday with a protracted wet period at least through this weekend to monitor. SPC is also highlighting severe weather potential. More modest precipitation should spread into the Northeast, mostly in the form of rain, though the northern fringe may see wintry weather. In this pattern, amplified Southeast U.S./Atlantic centered upper ridging significant springtime warming will build over the central and eastern U.S. late week, lasting in the East into early next week. Temperatures will be 20-30 degrees above average, with 80s reaching as far north as parts of the Ohio Valley and Mid-Atlantic. Daily records could become widespread. Kebede/Schichtel 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 (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: 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 $$