FXUS02 KWBC 190831 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 431 AM EDT Thu Mar 19 2026 Valid 12Z Sun Mar 22 2026 - 12Z Thu Mar 26 2026 ...Anomalous early season heat wave abating somewhat early next week but appears to rebuild midweek... ...Overview... The medium-range forecast period should feature an anomalous upper high hovering near the southwestern border of the U.S. while brief ridging early next week in the eastern U.S. will be replaced by broad troughing midweek. In the West, stronger ridging appears to be the current model trend early next week before significant troughing reaches the Pacific Northwest and advances farther southeast into the western U.S. from midweek onward. ...Guidance/Predictability Assessment... Within the general theme of an anomalous upper high over the Southwest and broad troughing in the East, deterministic solutions from the global models have been ejecting waves too fast eastward from the Rockies toward the eastern U.S. Case in point is the frontal wave across the central U.S. on Sunday. All global models including the AI outputs from previous days have been ejecting this wave way too fast to the east. The latest model guidance has been trending toward more ridging in the Great Plains this weekend. The downstream implication is for the warm front to be farther north, together with warmer conditions over the eastern U.S. and slower ejection of the low pressure wave across the Northeast on Monday. It appears that all deterministic models including the AIs offer skillful guidance from about Day 5 onward for the eastern two-thirds of the country excluding the southern tier states. Across the West, stronger ridging appears to be the current model trend early next week before significant troughing reaches the Pacific Northwest and advances farther southeast into the western U.S. from midweek onward. The stronger ridge advertised by the EC mean from the Southwest to the Rockies appears to be a viable solution because both the GEFS and CMC means are trending toward a stronger ridge but lagging behind the EC mean solution. Given the uncertainty noted above, the best course of action is to use the consensus of the latest ensemble means from the GEFS, ECMWF, and CMC mean. The NBM's QPF was closer to the GEFS mean for the wave crossing the Northeast Sunday-Monday, which is the preferred solution assuming a slower wave speed compared with the EC mean which contains solutions with a more southern track across the Appalachians. ...Weather/Hazards Highlights... The medium-range forecast period will begin on Sunday with the record-breaking early season heatwave in the western U.S. abating a bit due to cold air intruding into the northern and central Plains. Thereafter, more widespread high temperatures 20 to 30+ degrees above normal appear to return over the western U.S. on Wednesday as a rather strong cold front penetrates inland through much of the western U.S. and into the northern Plains by around Thursday. Numerous record high temperatures will likely be broken once again across the Southwest followed by the southern Plains. Across the central Plains to the Midwest, recent model trends are indicating stronger ridging across the southern Plains on Sunday. This translates to a stronger and farther northward placement of the warm front across the Midwest and a stronger surge of the cold air down the northern and central Plains. Wintry precipitation could affect New England particularly the interior sections with the passage of the low pressure wave, with the models trending toward a slower ejection of the wave. This would keep a wintry mix farther inland and rain farther south across the Mid-Atlantic although the details are far from certain. There will likely be a brief warm-up for the East Coast region this weekend ahead of the strong cold front, with highs expected to be well into the 60s and 70s for many areas. Highs should return to slightly below normal levels by Monday and Tuesday as a Canadian surface high builds in from the north. Across the Pacific Northwest, with the approach of a deep upper trough early next week, a return of rain and mountain snow is likely, with Tuesday to Wednesday being the time period of receiving the heaviest precipitation. The Sunshine State could see some showers and thunderstorms linger near the east coast due to the cold front becoming stationary in the vicinity. Kong 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 $$