Extended Forecast Discussion NWS Weather Prediction Center College Park MD 242 PM EDT Sun Jun 07 2020 Valid 12Z Wed Jun 10 2020 - 12Z Sun Jun 14 2020 ...Overview and Guidance/Predictability Assessment... The beginning of the extended period has an inland post-tropical Cristobal progged to weaken as it gets caught up in the northern stream and quickly tracks to eastward. Initially, the 00Z ECMWF/ensemble means and the 00Z GFS clustered well with the official NHC position. Also of note, the monthly pressure record may be tied or broken over northern Wisconsin and U.P of Michigan Wednesday through Friday due to the combination of Cristobal and a deep western trough producing a robust system out of the Upper Midwest into Ontario with a weakening cold front moving into the East. As the shortwave trough and the remnant energy/moisture from Cristobal moves toward the Northeast, ridging across the High Plains/central U.S. and the incoming trough near the West Coast will amplify, setting up an omega-type block through the end of the extended period. Overall, the models/ensembles agreed upon this evolution with the typical spread in timing and depth; relied more on the NAEFS, GEFS and EC ensemble in the later periods to a solution in the middle ground between the ECWMF and GFS. Ocean system near Bermuda may attempt to retrograde westward/northwestward toward the Mid-Atlantic/Northeast as either an occluded or subtropical entity, or perhaps just a weak surface trough. Cresting upper high would tug it back to the coast but incoming/reinforcing upper trough out of the Great Lakes/southern Ontario would then guide it back northward/northeastward (dependent on timing of each system). NHC will continue to monitor this system. ...Weather/Hazard Highlights... Warmer temperatures will spread from the Rockies into Plains as the ridge strengthens and the trough moves over the Northeast; with a vast portion of this area in the 80s and 90s, and parts of the Southwest climbing to 110s. Precipitation will follow Cristobal's path and the associated frontal system tracking to the East. Additional precipitation may develop along the trailing front and across the Gulf states/coast as the front eventually stalls there. As mentioned above, the potential retrograding front near the East Coast increases the forecast uncertainty for where rainfall will set up and how much. Ensembles do show an increase in rainfall farther north by next weekend into the Mid-Atlantic/Northeast. Minimal rainfall expected across the West with the leading front, however, as the trough digs closer to the Coast the chances will increase across portions of Washington and Oregon. Campbell 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