382 FXUS02 KWBC 041956 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EDT Thu Jun 4 2026 Valid 12Z Sun Jun 07 2026 - 12Z Thu Jun 11 2026 ...East-central to Southeast U.S. heavy convective rainfall/runoff pattern next week as unsettled wet weather works over the West... ...Overview... Southern stream shortwave energy riding slowly on/into the western periphery of an amplifying upper ridge settling over the East will pool deep moisture/instability to fuel ample and repeat thunderstorm and heavy rainfall activity from the Southern Plains and Lower/Mid Mississippi Valley to the Ohio/Tennessee Valleys, eventually linking with deep moist activity with a slow frontal push into the Southeast next week on the backside of a western Atlantic amplified upper trough. Meanwhile, protracted mean upper troughing over the West will periodically be reinforced to offer cooling and moderate Northwest through Rockies precipitation. ...Guidance/Predictability Assessment... Guidance offers a reasonably similar pattern evolution through medium range time scales despite numerous embedded smaller scale system variances, especially within amplified mean upper troughs over the West Coast/West and off the East Coast. A guidance composite seems to produce a solid forecast basis for early next week, but favor a GEFS/ECMWF ensemble mean blend mid-later next week to mitigate variances and maintain flow on the more amplified side of the full envelope of solutions given trends/history. It is also important to note that the GFS also shows more tropical interaction up into Florida Days 6/7 that is not supported by NHC. ...Weather/Hazards Highlights... Surface low pressure systems and meso-boundaries through the Plains will further focus scattered showers/thunderstorms from the eastern Plains and Mississippi Valley Sunday and Monday. Day 4/Sunday and Day 5/Monday Marginal Risks of excessive rainfall are in place and will be monitorred for upgrade given favorable conditions once local details show a stronger signal in guidance. The threat for excessive rainfall also shifts into the Tennessee Valley on Monday, due to persistent moist southerly flow into the Central and Southern U.S.. The lingering upper low/trough may also spread convective rainfall over the Ohio Valley through midweek. This activity may link with an ongoing focus for moderate to heavy showers/thunderstorms along/south of a slow moving cold front slated to slip down the Eastern Seaboard next week. The signal for a heavy rainfall/runoff threat growis for the Southeast/Florida. A pair of deep mid-level lows will bring rainfall to the Pacific Northwest on Sunday and Monday and lingering with cooling into mid- later next week while spreading moisture, supported by the second reinforcing low, into the Northern Rockies and Northern Plains again by Tuesday/Wednesday along with a severe threat as per SPC. 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, 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 $$