Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EDT Sat Jun 04 2022 Valid 12Z Tue Jun 07 2022 - 12Z Sat Jun 11 2022 ...Overview and Sensible Weather/Threat Highlights... Expect summer heat into the South with parts of Texas in particular expected to endure near record heat with daytime highs as much as 15 to 20 degrees above normal through much of next week. Steadily progressive shortwaves embedded within near zonal flow overtop U.S. southern tier upper ridging through through midweek should offer a broadly active convective weather pattern from the Rockies to the East/Northeast as locally heavy rainfall and strong thunderstorms tend to focus near and along a wavy frontal boundary, with plenty of moisture and instability available. Exact locations of heaviest rain will remain extremely difficult to pinpoint given the convective nature of this activity. Convective clusters and repeat/training cells could produce local runoff issues with perhaps the strongest signal from the Central Plains to the Mid-South and later next week upper trough amplification may refocus and better organize convective rainfall potential in this susceptable area and vicinity. Meanwhile, much of the west should stay dry until late next week when a Pacific system approaching the coast brings a period of rainfall to the Pacific Northwest, while lead upper ridge amplification also favoring the building of excessive heat across the interior valleys of California and the Desert Southwest late week into next weekend. ...Model Guidance Evaluation/Preferences... Guidance continues to show above average agreement and predictability with the mid-larger scale flow evolution through next midweek in a pattern with relatively zonal flow. There remain some questions in the smaller scale details which likely will take until the short range to resolve. However, a general model composite of the latest GFS/ECMWF/UKMET/Canadian runs seemed to provide a good forecast basis for days 3/4 (Tuesday/Wednesday) along with the National Blend of Models and WPC continuity. Models and ensembles are increasingly showing a signal for a more amplified flow pattern by later next week, albeit in a pattern with moderately increasing forecast spread. WPC products for days 5-7 (Thursday-next Saturday) were primarily derived from a compoiste blend of best clustered guidance from the GEFS/ECENS ensemble means and National Blend of Models along with deterministic guidance from the GFS/ECMWF for added system definition. This maintained good WPC product continuity. 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, 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