Extended Forecast Discussion NWS Weather Prediction Center College Park MD 300 AM EDT Wed Jun 03 2020 Valid 12Z Sat Jun 06 2020 - 12Z Wed Jun 10 2020 ...Gulf Coast to Mid-South Excessive Rainfall Threat with Tropical Storm Cristobal... ...Overview and Guidance/Predictability Assessment... Model and ensemble forecast clustering has improved significantly over the nation from this weekend into early-mid next week, bolstering forecast confidence in both the overall pattern amplification and an emerging threat from Tropical Storm Cristobal. WPC medium range products have been primarily derived from a blend of the latest GFS/ECMWF and National Blend of Models. This maintain good continuity. ...Weather/Hazard Highlights... Deep tropical moisture inflow will fuel a threat for heavy rainfall over the central and eastern Gulf Coast/FL ahead of Cristobal this weekend, reaching a frontal zone draped over the Southeast. Cristobal approach and landfall should increasingly focus heavy rains along its track across the Mid-Lower MS/Lower OH Valleys early-mid next week. Please refer to updates from the NHC on Cristobal. Meanwhile, a southern stream low/trough will finally eject northeastward over the West Sat and spawn Canadian Prairie cyclogenesis by Sun. This will occur as an amplified mid-upper latitude upper trough digs inland into the West. Maximum temperatures will drop to 10-20 degrees below normal from the Intermountain West to Northern/Central Rockies as a wavy frontal system pushes eastward across the western half of the nation Sat-next Wed. Locally enhanced precipitation is possible along and behind the system across the unsettled West to include some elevation snows from the Cascades/Sierra to the Northern Rockies given trough depth. Lead above normal temperatures are forecast to persist in the Plains over the weekend. In particular, the south-central High Plains should have some maximum temperatures 15+ degrees above normal. Energies reaching the n-central U.S. next week may support enhanced moisture inflow and convection/rains. 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