Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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245 FXUS02 KWBC 030714 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 214 AM 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 unsetled 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 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... Forecast spread and uncertainty has decreased significantly over the last several guidance cycles for much of the nation through medium range time scales, bolstering forecast confidence. A composite of well clustered output of the GFS/ECMWF/UKMET/Canadian models, ensemble means and machine learning guidance provides a solid forecast basis in line with the National Blend of Models. ...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. 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 $$