Extended Forecast Discussion NWS Weather Prediction Center College Park MD 145 AM EDT Sat Sep 14 2019 Valid 12Z Tue Sep 17 2019 - 12Z Sat Sep 21 2019 ...Overview and Guidance Evaluation/Preferences... Latest models and ensemble members show a wide range of solutions with embedded systems over time in a pattern with average to below average predictabililty. Accordingly, the WPC medium range product suite was primarily derived from a composite blend of the more run to run consistent GEFS/ECMWF ensemble means along with the National Blend of Models. ...Weather Highlights/Threats... "Humberto" is forecast to deepen to hurricane stength over the next few days, but an increasingly offshore NHC track now only supports limited medium range rains/enhanced winds to coastal FL/GA/SC/NC before it turns eastward out to sea early next week. In the Pacific Northwest, a cooling surface front and subsequent upper trough will bring a widespread chance of rain (some very high elevation snow) to the region early in the week. This will spread through the northern/central Great Basin/Rockies before exiting to the northern Plains/Upper Midwest where an increasingly active convection signature becomes evident with frontal system passage/height falls. Increased moisture inflow in advance of the fronts may lead to record high minimum temperatures. Meanwhile, expect some tap of subtropical moisture out of Mexico on southwest flow aloft down over the Southwest/Four Corners states. Strong ridging downstream over the east-central U.S. may favor well-above average temperatures next week with some near record Deep South heat. In the western Gulf of Mexico, a trough/wave associated with an upper low favors a chance of rainfall, potentially locally heavy, over southeastern/coastal Texas next week. Weak steering aloft may allow this area of rain to persist through late 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