Extended Forecast Discussion NWS Weather Prediction Center College Park MD 257 AM EDT Mon Jun 06 2022 Valid 12Z Thu Jun 09 2022 - 12Z Mon Jun 13 2022 ...Overview and Sensible Weather/Threat Highlights... An energetic series of steadily progressing shortwaves within near zonal flow will act to locally enhance a broadly active convective weather pattern from the Rockies/Plains to the East into later this week as heavy rainfall and strong thunderstorms are fueled by moisture and instability pooling near a wavy frontal boundary. Exact locations of the heaviest rain will remain extremely difficult to pinpoint given the convective nature of this activity, though local flooding concerns may be possible within convective clusters and where cells repeat/train. The best signal for this would be from the central Plains to Mid-South Thursday/Friday (where SPC highlights a chance for severe weather as well). Upper ridging underneath across a warmed South will include near record daytime temperatures more than 10 degrees above normal across Texas into the weekend. The overall upper flow pattern by then looks to amplify, bringing a wavy frontal system and more widespread rains/convection across the East and heat moderation down across the Deep South. Much of the West should stay dry until late week and the weekend when Pacific system energies work inland to bring a period of enhanced moisture and rainfall to the Pacific Northwest and onward across the northern Intermountain West/Rockies. Downstream system progression would add enhanced convective potential to the northern Plains/Upper Midwest into early next week. Upper ridge amplification in advance of Pacific system energies will meanwhile favor building excessive heat across the interior valleys of California and the Desert Southwest late week into the weekend to include some local record values. ...Model Guidance Evaluation/Preferences... Guidance continues to show above average agreement and predictability with the mid-larger scale flow evolution into late week 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 but a general model blend of the GFS/ECMWF/UKMET/Canadian and NBM seems to provide a good starting point Thursday/Friday. Models and ensembles continue to increasingly show a signal/trends (including latest 00 UTC runs) toward more amplified flow into next weekend, though with increasing forecast spread. WPC products into days 5-7 (next weekend into next Monday increasingly weighed towards the GEFS/ECMWF ensemble means, with lesser input from the best matched GFS/ECMWF for better system definition. This also helped to maintain 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