711 FXUS02 KWBC 210732 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 232 AM EST Sat Feb 21 2026 Valid 12Z Tue Feb 24 2026 - 12Z Sat Feb 28 2026 ...Overview... An atmospheric river coincident with a wavy and slow-moving Pacific front will lead to heavy rain in northern/central California Tuesday, winding down Tuesday night into Wednesday. Unsettled weather is likely across the Intermountain West Tuesday and Wednesday and could get renewed in the Northwest through later week. Meanwhile, upper ridging will be in place across the southwestern U.S., leading to unseasonably warm temperatures there into the central U.S. through much of the week. Downstream, clipper systems could affect the north-central U.S. into midweek, and precipitation is forecast across the eastern third of the U.S. Wednesday-Thursday, including northern tier wintry weather. ...Guidance/Predictability Assessment... Model guidance begins the medium range period Tuesday with good overall agreement in a western ridge/eastern trough pattern. The most uncertain aspect of the forecast is with shortwaves that track across the northern tier and may dig to broaden troughing in the central U.S. in addition to the East. For example, GFS runs are more aggressive than other guidance with shortwave energy in the Great Lakes by midweek and moving into the Northeast by Thursday. This means the next shortwave moving from the Northwest across the north-central U.S. Thursday is slower in the GFS while other dynamical/AI models have it more progressive. These model differences are generally within reason for the medium range, but do cause differences in sensible weather like frontal timing and precipitation. Upper troughing is forecast to broaden even further late week, as additional energy moves into the northwestern and north-central CONUS. Thus the WPC forecast was based on a general model blend early in the period, with lessening proportions of the GFS due to its shortwave differences. Gradually increased the proportion of ensemble means as the forecast progressed, with means reaching half the blend by Day 7. ...Weather/Hazards Highlights... An atmospheric river will be ongoing across northern/central California on Tuesday, bringing anomalously high moisture in the form of precipitable water values over the 95th percentile. A Marginal Risk remains in place there for the Day 4/Tuesday ERO for flooding concerns. Some areas in the Sierra Nevada vicinity that just received multiple feet of snow could see rain with this warmer system. Precipitation, including higher elevation snow, is likely farther inland across much of the Intermountain West and Rockies on Tuesday and Wednesday. By later week, the Pacific Northwest and the northern Rockies should see increasing precipitation chances with the arrival of the next Pacific system. Downstream, the mean westerly flow will lead to high winds concerns across the Rockies and High Plains through much of next week, with fire weather a potential threat. Farther east, a couple of clipper systems are forecast to impact the central and northern U.S. Tuesday and Wednesday. Moderate snow is forecast to spread across the Great Lakes region, while lighter snow is forecast farther west across the northern Plains. Light rain is also possible for the central Plains/Mid-Mississippi Valley. Energies aloft combining with a surface frontal system will allow for increasing precipitation potential from the Mid-South through the Ohio Valley to Interior Northeast on Wednesday, and spreading into much of the Eastern Seaboard on Thursday. This precipitation would be snow for portions of the Northeast. The front clearing the coast into the western Atlantic should lessen precipitation chances by Friday, though some westerly flow light precipitation is possible in the Great Lakes region. Colder than average temperatures by 10 to 20 degrees are likely across the eastern U.S. into Tuesday under a chilly surface high pressure system. Temperatures should moderate after a cool Wednesday morning in Florida. Meanwhile much warmer than average temperatures will be increasing in coverage and magnitude underneath an upper ridge behind this system. The Southwest into the Plains can expect temperatures of 15 to 25 degrees above average, leading to highs in the 80s in Texas at times and over 90F in parts of the Desert Southwest. Tate 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 $$