Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EDT Tue Sep 17 2019 Valid 12Z Fri Sep 20 2019 - 12Z Tue Sep 24 2019 ...Gulf of Mexico disturbance offers a Texas to Midwest heavy rainfall threat... ...Overview and Guidance Evaluation/Preferences... Models and ensembles again offer a reasonably similar and amplified larger scale pattern over the lower 48 and vicinity for much of the upcoming medium range period. Forecast spread and uncertainty for even mid-scale embedded features remains mostly improved, bolstering overall forecast confidence to above normal levels. The WPC medium range product suite was primarily derived from a composite blend of the latest and fairly well clustered GFS/ECMWF, GEFS/ECMWF ensemble means and the National Blend of Models. ...Weather Highlights/Threats... A slow moving disturbance is expected to reach TX by midweek. This system offers a significant threat of locally excessive rainfall. Deep tropical moisture will fuel a heavy rainfall/runoff threat across eastern TX into Fri. Expected northward lifting and entrainment into the flow with approaching mid-latitude upper trough energy from the West and surface front proximity will likely then focus heavy weekend convection/runoff issues with cell training from the east-central Plains to the Mid-MS Valley/Midwest. Overtop, the aforementioned and amplified upper trough will lift northeastward from the unsettled and cooled West/Rockies to the north-central U.S. This supports an organized convective focus with locally heavy downpours and severe thunderstorms risk Friday into Saturday as per SPC. Deepened lead moisture may also support some record high minimum temperatures. Guidance is now in better agreement in showing the reloading of upper trough energies back into an again unsettled West Sunday/Monday with widespread precipitation over the Northwest shifting across the north-central Great Basin/Rockies, reaching the Plains earlu next week. Schichtel Additional 3-7 Day Hazards information can be found on the WPC medium range hazards 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