Extended Forecast Discussion NWS Weather Prediction Center College Park MD 231 AM EDT Sat Jun 19 2021 Valid 12Z Tue Jun 22 2021 - 12Z Sat Jun 26 2021 ...Heat intensifies from the interior Northwest to the Plains next week... ...Guidance/Predictability Evaluation... A composite blend of well clustered model solutions of the 18 UTC GFS and 12 UTC ECMWF/UKMET/Canadian seem to offer a good basis for the day 3-5 (Tuesday-Thursday) forecast period in a pattern with above average continuity and predictability. Model continuity begins to suffer into days 6/7 and the WPC product suite was instead mainly derived from still compatible GEFS/NAEFS/ECENS means and National Blend of Models in a period with slowly growing forecast spread and uncertainty. 00 UTC guidance remains in line. ...Weather Highlights/Hazards... Record-breaking and dangerous heat now over the Southwest/California is expected to return to seasonal next week. However, heat will intensify from the interior Northwest to the north-central Great Basin/Rockies and Plains where some record values may build. In the wake of wet "Three", well organized convective rains and lingering runoff issues are expected for the Gulf Coast states and the Eastern Seaboard Tuesday with frontal passage. Some activity will linger over the Southeast/Florida into later next week with the stalling front. Digging upper energy, instability and frontal support upstream may combine to favor an emerging late week strong convection/rain threat for the Midwest. 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, 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/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml