886 FXUS02 KWBC 231931 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 331 PM EDT Thu Apr 23 2026 Valid 12Z Sun Apr 26 2026 - 12Z Thu Apr 30 2026 ...A low pressure system will cause heavy rain and severe weather across the central U.S. Sunday and east-central U.S. Monday... ...Overview... Into early next week, an amplified and progressive spring pattern continues across the lower 48, as a surface low moves through the north-central U.S., supporting heavy rain and severe weather in the Plains and Mississippi Valley. The cold front should press across the East into Tuesday-Wednesday and bring rain chances there, though showers and thunderstorms are also forecast to linger across the south-central to southeastern U.S. as a front stalls south of a broad upper trough anchored in south-central Canada. Meanwhile, a southern stream upper low will make its way into California around midweek and bring chances for low elevation rain and mountain snow across the Intermountain West/Rockies into the Plains. ...Guidance/Predictability Assessment... As the period begins Sunday, troughing aloft will move quickly across the Intermountain West into the central Plains rounding the base of a persistent south-central Canada upper low, supporting a surface low pressure system. Recent model guidance remains reasonably agreeable with this system, and a multi-model blend like the NBM seems to represent the pattern well. This holds as the surface low tracks into the Upper Midwest/Great Lakes by Tuesday. Farther east, there are some model discrepancies with a shortwave over the Northeast and a surface low in the western Atlantic early next week, which would affect rain chances and potential winds across coastal areas of the Northeast. Of the 12Z models, the CMC seems to linger the farthest west (for more effects in the Northeast), but does have some support from the AI guidance. Farther west, there is good agreement for ridging across the Northwest, but a southern stream low/trough shows uncertain timing coming into California and the Southwest around midweek. With the 00/06Z model cycle, the ECMWF tracked this feature more quickly into the coast compared to the GFS/CMC and EC-AIFS/AIGFS. However, the faster track had support from most ensemble members (including CMCE and GEFS) and some of the other EC-based AI models. The 12Z model guidance has indeed trended faster than earlier runs of the CMC/GFS, for better model convergence now. As the period progressed, the WPC forecast used just over half ensemble means for Days 6-7 due to model differences with the western low. ...Weather/Hazards Highlights... Upper troughing moving across the Intermountain West will support lower elevation rain and terrain enhanced snow across the Great Basin/Rockies and northern High Plains Sunday and Monday, with a little lingering into Tuesday as another front comes through. This energy will also set up a potent surface low pressure in the central U.S. that should serve as a focus for heavy rain and thunderstorms, including organized convection. Above average moisture and instability are forecast to advect well north from the Gulf across the Plains and Mississippi Valley, while a coupled jet structure provides upper level support. Severe weather could be a significant threat per the Storm Prediction Center. Additionally, Marginal Risks of flash flooding are in place for the central U.S. for Day 4/Sunday and slightly east into the Mississippi/Ohio Valley and Mid-South by Day 5/Monday. These were expanded somewhat from the previous issuances because of the widespread instability and moisture potentially causing isolated flooding from high rain rates despite dry conditions in many areas. Meanwhile, high winds and conditions favorable for fire weather are likely in the Southwest/High Plains early next week on the backside of the system. The cold front associated with the surface low should track across the Eastern Seaboard Tuesday into Wednesday and spread rain and thunderstorms there. Additionally, convection is forecast to linger in the south-central to southeastern U.S. into Tuesday as a frontal system meanders. Then the upstream southern stream low will spread some light to moderate precipitation to California, the Southwest, and Four Corners states by Wednesday, including snow in higher elevations of the central Rockies. This feature will provide more support for renewed precipitation in the south-central Plains to Lower/Middle Mississippi Valley and Mid-South on Wednesday into Thursday. Warmer than average temperatures are likely to the south of the primary storm track across the southern Plains through midweek, and ahead of the cold front into the Mississippi and Ohio Valleys early next week. Temperatures in the 90s will be common across Texas. Meanwhile, below average temperatures continue for much of the West and northern/central Plains under the troughing through Monday, and shifting into the north-central U.S. through midweek. Most areas could moderate to near or below average conditions by mid to late next week. 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, excessive rainfall outlook, winter weather outlook probabilities, heat indices and Key Messages are at: 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 $$