Extended Forecast Discussion NWS Weather Prediction Center College Park MD 306 AM EDT Wed Sep 30 2020 Valid 12Z Sat Oct 03 2020 - 12Z Wed Oct 07 2020 ...Hot and dry conditions for the West... ...Heavy rainfall threat for Florida... ...Overview and Guidance/Predictability Assessment... An amplified upper-level mean pattern with a western U.S. ridge and central/eastern U.S. trough will support warmth in the West and generally cooler than normal temperatures from the central to eastern states into next week before moderating. The models are reasonably good agreement regarding the large-scale pattern, but continue to suffer from continuity issues will the timing and flow separation of embedded smaller scale systems days 3-7. The WPC medium range product suite was primarily derived from a blend of the GEFS mean and the ECMWF ensemble mean that was weighted more heavily to better maintain WPC continuity. ...Weather/Hazard Highlights... An amplified upper ridge over the West offers hot and dry conditions with associated fire risks. Expect temperatures to reach 5-15 degrees F above normal from California/Arizona/Nevada through the Northwest and some spotty record values are possible. Fronts with multiple but uncertain waves will provide focus for rainfall up the full Eastern Seaboard along with unsettled maritime conditions. Coastal areas could see some heightened rainfall totals, especially from the Carolinas through Northeast early next week. Trailing fronts will tend to stall over south-central Florida where periods of heavy rain/runoff issues are likely this weekend into next week. Amplification and reinforcement of the east-central U.S. upper trough favors deep tropical moisture influx into Florida associated with a western Caribbean wave/disturbance to fuel some excessive multi-day totals. Cold air aloft will meanwhile provide instability for scattered showers under the upper trough. One of the stronger embedded waves expected to drop into the central then east-central U.S. may some locally moderate rain through the east-central U.S.. Cold air surges will support weekend temperatures of 5-15 degrees F below normal for much of the central to eastern U.S.. 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