Extended Forecast Discussion NWS Weather Prediction Center College Park MD 255 PM EDT Sat Jun 25 2022 Valid 12Z Tue Jun 28 2022 - 12Z Sat Jul 02 2022 ...Pattern Overview and Weather/Hazard Highlights.. An upper ridge will remain in place over the southern half of the CONUS throughout next week while fast flow across the northern tier will be accompanied by periodic shortwave troughs embedded in the flow. At the start of the period, a shortwave trough will force a surface front southeastward along the East Coast and Gulf Coast, becoming stalled/draped along the Gulf Coast throughout much of next week. This boundary may act as the focus for deeper moisture and an increased coverage of locally heavy downpours. Elsewhere, another shortwave trough passes through the Northern Plains and Great Lakes mid to late week, bringing periodic chances for stronger convection and locally heavy rainfall. Ahead of that trough passage, much above normal temperatures will progress from the Rockies to the Plains and eventually the Northeast by the end of the upcoming work week. ...Guidance Evaluation/Predictability Assessment... The available deterministic and ensemble guidance showed very good agreement and clustering with the overall synoptic pattern for next week, giving way to above normal predictability and confidence. The medium range forecast blend was composed of a near equal weight of the 06Z GFS, 00Z ECMWF/CMC/UKMET for days 3-5 followed by inclusion of the ECENS/GEFS means for days 6-7 where typical forecast spread was noted. Across the northwest Gulf, the trailing frontal boundary likely to be draped in the region may eventually act as a focus for low pressure formation. The GFS has been more bullish with this scenario with the low drifting slowly westward toward the Texas coast. While the 12Z GFS has backed off somewhat in this scenario, some development is possible and could bring a focus for heavier rainfall. Guidance solutions seem reasonably well clustered well into medium range timescales in a pattern with above normal predictability with the mid-larger scale pattern evolution. The WPC medium range product suite was primarily derived from a composite blend of the 18 UTC GFS and 12 UTC ECMWF/UKMET/Canadian models along with the 01 UTC National Blend of Models (NBM) for days 3-5 (Tue-Thu). The GFS/ECMWF stay most compatible with GEFS/ECMWF ensemble means into days 6/7 (next Friday/Saturday), so that composite blend was utilized for that period along with the NBM. WPC product continuity is good and individual system forecast differences seem well addressed by the blending process, consistent with predictability. 00 UTC guidance seems overall in line. Taylor 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, experimental excessive rainfall outlook, winter weather outlook probabilities and heat indices 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