Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
476 FXUS02 KWBC 020815 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 315 AM EST Mon Mar 2 2026 Valid 12Z Thu Mar 05 2026 - 12Z Mon Mar 09 2026 ...Emerging East-Central U.S. Heavy Rainfall Pattern late week... ...Guidance/Predictability Assessment... Guidance solutions aloft are now much better clustered overall for later this week and the weekend outside of small scale variances compared to the last few cycles, bolstering forecast confidence. However, the ejection timing of a southern stream Baja closed low does remain varied in guidance. The ECMWF offer the slowest model solution compared to the slightly faster GFS and even faster Canadian. Prefer a solution on the slower side of the full envelope given nature of separted closed lows. The EC-AIFS seems reasonable in between the ECMWF and GFS for this system. Otherwise, otherwise prefer well clustered GFS/ECMWF/Canadian/UKMET/EC-AIFS blend Thursday into Saturday before pivoting more toward the GEFS/ECMWF ensemble means and EC-AIFS as uncertainty grows into loneer time frames. This plan maintains good WPC product continuity in line with the National Blend of Models and favorable newer 00 UTC guidance cycle trends. ...Weather/Hazards Highlights... A split upper flow pattern will dominate the nation this week. A lead southern stream upper trough and frontal system will eject through the Midwest then Northeast Thursday/Friday and pooling moisture may fuel areas of moderate rains. Overrunning moisture into cold Canadian high pressure sliding into the U.S. northern tier 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 may also support an ice/freezing rain transition zone to monitor. Heavy rain/runoff threats from the south-central U.S. northeastward into the east-central U.S. should re-emerge for late week/weekend. Runoff threats may build with each round of rain given a repeating pattern with some cell training potential. Accordingly, introduced a WPC Day 5/Friday Excessive Rainfall Outlook Marginal Threat area from the South-central Plains to the Mid-Mississippi Valley given wavy frontal translation and convective potential to lead into a protracted wet period at least through this weekend to also monitor. Meanwhile upstream, an amplified upper trough will dig sharply southeastward through the West into Thursday/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. While recent guidance trends dig an increasing southern stream detached upper low/trough through the Southwest into Baja next weekend. Additional flow from the northeast Pacific may also work back into the Northwest to renew moderate precipitation this weekend and continued northern stream energy translation into cyclonic upper flow downstream into the northern tier could also allow for some cooler airmass intrusions to interact with the northern fringe of the aforementioned expanding southern stream precipitation area. In this pattern, amplified Southeast/Atlantic upper ridging and significant springtime warming will build and linger over the South/Southeast and East-central/Eastern U.S. to the south of lead cold damned high pressure over the Mid- Atlantic/Northeast late this week moderates and loses southward influence. 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 $$