272 FXUS02 KWBC 211859 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 259 PM EDT Sat Mar 21 2026 Valid 12Z Tue Mar 24 2026 - 12Z Sat Mar 28 2026 ...Anomalous early season heat wave Southwest to the South-Central U.S. abating somewhat early next week to slowly rebuild midweek... ...Overview... A difficult to time shortwave series will propagate over southern Canada and the U.S. northern tier next week. The most pronouced wave may focus locally moderate precipitation from the Pacific Northwest to a wintry Upper Midwest then Northeast/Mid-Atlantic Tuesday-Thursday, with additional waves to monitor on its heels. Meanwhile to the south, upper ridging will support gradual heat renewal from the Southwest to the Great Plains midweek, but will be followed by the digging of post-frontal moderating high pressure into later week down across the south-central and eastern U.S.. ...Guidance/Predictability Assessment... Latest models, ensembles and machine learning guidance solutions overall seem well clustered and a simple composite seems to provide a solid forecast basis through this period in a generally benign weather pattern with above normal predictabilty despite standard and lingering smaller scale system variances. This solution maintains reasonable WPC continuity in line with the NBM. ...Weather/Hazards Highlights... While not quite as anomalous as this past week, the main story for this medium range period next week will be for another period of well above average, widespread daily-record level warmth across portions of the western and central U.S. A prominent upper-level ridge will support renewed maximum temperatures upwards to 20-30 degrees above average, and widespread maximum and minimum temperature records are possible from the Southwest early next week to the Plains by midweek. This heatwave, combined with dry conditions and daily bouts of gusty, downsloping winds across the High Plains may lead to potential fire weather concerns on Tuesday and Wednesday. A more concentrated area of very strong winds is expected across the Northern Rockies and High Plains Wednesday as a deepening low in the lee of the Canadian Rockies passes by. A potent mid-latitude cyclone will move from the Northwest to the Canadian Maritimes next week. This system will bring moderately heavy rain over the Pacific Northwest Tuesday. Most of the precipitation from this will be in the form or rain since the shortwave aloft will be embedded within the broader Western ridge. Higher elevations of the Olympic and Cascade mountains will receive snowfall. The low pressure system will weaken while it tracks across the northern tier of the Central U.S., before reinvigorating over the Northeast/Canada. Cooled northern tier U.S. conditions should support some moderate rain south/snow north from the Upper Midwest/Great Lakes/Ohio Valley/Northeast into later next week, with subsequent waves adding some precipitation focus along the southward dropping front as temps cool late period. 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 $$