FXUS02 KWBC 041804 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 204 PM EDT Sat Apr 4 2026 Valid 12Z Tue Apr 07 2026 - 12Z Sat Apr 11 2026 ...Pattern Overview... Split flow over the lower 48 next week will be highlighted by two main streams. In a steadily progressive northern stream, a leading upper trough over the northern third of the nation Tuesday will quickly exit as an energetic upstream upper trough progresses on it's heels from the Northwest U.S. Tuesday to the Northeast into Thursday/Friday. These will reinforce a wavy frontal boundary over the Gulf and Florida to prolong a wet pattern. Meanwhile, an eastern Pacific southern stream closed upper trough and system energy will slowly work inland to the West/Southwest with some showers by Friday/Saturday. Ample lead return flow development then over the central U.S. may portend a re-emerging heavy rainfall pattern by next weekend that has some signal evident beyond that into week 2 as per the Climate Prediction Center (CPC) that may offer broad moderate and high risk potential to monitor. ...Guidance/Predictability Assessment... Latest model and ensemble guidance continues to show good agreement on the large scale pattern across the CONUS next week, but with lingering uncertainty in the details and timing of systems. There are some minor timing differences with the northern stream shortwave which drives a decent surface system across the northern Rockies/Plains and Upper Midwest/Great Lakes midweek. After this, uncertainty remains initially with the timing of the southern stream upper low off the West Coast, and then how much of the low opens up as it enters the Southwest next weekend or stays intact. The better consensus suggests the upper low should more or less stay in tact/separate from the northern stream, but the GFS was much more sheared with this, likely in response to a stronger/more southward positioned upper low off the Northwest coast. The latest WPC guidance blend for the upper level and surface progs was primarily derived from a blend of the deterministic guidance for the first half of the period. Increased weighting of the ensemble means Days 6 and 7 to 60 percent of the blend to help mitigate the unresolvable aspects of the forecast in the West late period. This maintains good continuity with prior WPC guidance and is consistent with the NBM. ...Weather/Hazards Highlights... A wavy front is forecast to settle offshore into the Atlantic and Gulf next week, though it will still be passing over Florida and provide a focus for above average moisture there and possibly into Gulf Coastal areas. Consistent with WPC Day 3-7 Hazards products, the WPC Excessive Rainfall Outlook shows Marginal Risk areas on Day 4/Tuesday and Day 5/Wednesday for eastern coastal Florida. A wet pattern should persist given southern stream trough energy may be reinforced into later period with flow amplification. Farther north, the Northeast upper trough will allow for some lingering lower lake effect precipitation with a round of rain and snow passing over the Northeast Tuesday. Another swath of precipitation is possible in the north-central Plains to Mid-Upper Mississippi Valley. Meanwhile, some convection is possible in the Four Corners region into Tuesday with some southern stream waves aloft and above average moisture. Then as an upper low/trough moves toward and into the West, lift and pooled moisture should support some organized precipitation Wednesday into later next week, including higher elevation snow. The signal is increasing for return flow ahead of the Western trough to spread widespread moderate to heavy precipitation into the Plains and Midwest later next week. This may continue into week 2 as well per latest products from CPC. Following cold front passages and cooled Canadian high pressure settling next week, the central to eastern U.S. should see periods with below average temperatures. The West can expect above average temperatures by 10 to 20 degrees underneath upper ridging for the early part of the week. Above normal pre-frontal temperatures should spread into the High Plains by Tuesday and gradually farther southeast later next week as the ridge shifts east, while the West Coast can expect temperatures to cool as upper troughing and associated frontal systems work slowly inland. Santorelli/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 $$