Extended Forecast Discussion NWS Weather Prediction Center College Park MD 1200 PM EDT Thu May 31 2018 Valid 12Z Sun Jun 03 2018 - 12Z Thu Jun 07 2018 ...Guidance/Uncertainty Assessment... Model and ensemble guidance offer a reasonably similar larger scale pattern over the nation as highlighted aloft by significant troughs into the Northwest and downstream over the East sandwiching an amplified/hot s-central us ridge. Recent guidance has trended a bit toward a bit more amplitude and pattern longevity. This trend seems reasonable. The depiction and interactions of a multitude of mid-smaller scale systems embedded with the flow however is proving to be quite problematic days 3-7 and forecast uncertainty with these is producing significant run to run model issues. Accordingly, the WPC medium range product suite was primarily derived from a composite blend of the 00 UTC GEFS/NAEFS/ECMWF ensemble means. ...Weather Highlights and Threats... Shortwaves reinforcing an upper trough in the East should support a lingering surface front from the western Atlantic and Southeast to the southern plains that should maintain some focus for deeper moisture pooling and some heavier local convective downpours next week, albeit with main low genesis offshore. Upstream, an amplifying trough position over the Northwest should generate some late season rainfall and some cooling. A less certain stream of ejecting energy/height falls will also support an extended pattern favorable for locally heavy convection/rainfall over the Plains/Midwest with low/front genesis. WPC medium range forecasts of 500 mb heights, surface systems, weather grids, quantitative precipitation, and winter weather outlook probabilities can be found at: http://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif http://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif http://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html http://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml http://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 Schichtel