Extended Forecast Discussion NWS Weather Prediction Center College Park MD 228 AM EDT Sat Jun 06 2020 Valid 12Z Tue Jun 09 2020 - 12Z Sat Jun 13 2020 ...Heavy Rainfall Threat into the Upper Midwest/western Great Lakes next Tue from Cristobal... ...Overview... Upper pattern will again trend toward amplification with troughing along the east and west coasts with ridging building over the High Plains. Before that, the remnants of Cristobal will likely be lifting northward just ahead of a front before becoming absorbed late Tue into Wed. Off the East Coast, an ocean system will retrograde westward toward the Mid-Atlantic before being pushed back to the northeast as the cold front moves through. More precipitation and cooler temperatures will infiltrate parts of the Pac NW via a slow-moving front. ...Guidance/Predictability Assessment... Through the 12Z/18Z guidance, models and ensembles generally agreed on the pattern evolution with a few exceptions. The GFS remained quicker to lift Cristobal northward compared to the others, but once inland an increase in forward speed is quite certain. Off the East Coast, the Canadian remained farther east with the upper/sfc low but eventually came back into tolerance there. In the wake of Cristobal's demise/absorption, the ECMWF/Canadian were stronger with trailing upper troughiness and a preference toward the ensembles was preferred. Off the West Coast, GFS runs were slightly displaced from the ECMWF/Canadian-led consensus but were not unrealistic. Utilized the 12Z ECMWF most for added details to the ensemble means which were close to each other into next weekend. ...Weather/Hazard Highlights... Chilly temperatures over the Great Basin/Rockies on Tuesday will be replaced be warmer than normal temperatures Thursday onward as ridging builds over the area. Ahead of the front/Cristobal will be an area of warmer than normal temperatures to the Great Lakes into the Northeast until the front passes. Rainfall may be heavy over the Corn Belt to the western Great Lakes as Cristobal's remnants become absorbed into the front. Several inches of rain is possible. By later in the week, area of modest rainfall will decrease to the east with the weakening lead front. Secondary front may bring another chance for generally light rain. Over the Northwest, bouts of rainfall and some high elevation snow will accompany the front as it pushes inland. Fracasso 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