Extended Forecast Discussion NWS Weather Prediction Center College Park MD 259 AM EDT Fri Sep 13 2019 Valid 12Z Mon Sep 16 2019 - 12Z Fri Sep 20 2019 ...Potential Tropical Cyclone NINE Threatens the Southeast U.S. Coast... ...Overview and Guidance Evaluation/Preferences... The latest deterministic models and ensembles offer a reasonably similar larger scale pattern evolution into much of next week, but really show a wide range of solutions with embedded systems over time. This is especially evident with Potential Tropical Cyclone NINE. In order to produce a medium range product suite consistent with the latest NHC track and intensity forecast, blended the more run to run consistent GEFS/ECMWF ensemble means for larger scale flow and then applied significant "NINE" manual adjustments. ...Weather Highlights/Threats... "NINE" is forecast to bring numerous showers and thunderstorms along its uncertain track. The current track offers a heavy rain/weather threat for coastal FL/GA/SC/NC. Amplified upper low/trough passage and surface system genesis will support widespread rains (and some mountain snows) across the Pacific Northwest before spreading south into CA and inland across the Great Basin and northern Rockies next week. Southerly flow east of the upper trough looks to revive monsoonal showers/storms into the Four Corners region. Ample convective potential should also reach the n-central U.S. with system/height fall progression into mid-later next week. While western to n-central U.S. system development and progression provides widespread cooling and unsettled weather, lead amplified upper ridging will result in above average temperatures from the Plains to the east-central states next week. Warm overnight temperatures will offer max chance of approaching record values over the n-central U.S. and in humid air from the central Gulf Coast to the coastal Southeast closer to "NINE". 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