Extended Forecast Discussion NWS Weather Prediction Center College Park MD 1132 AM EDT Fri Nov 01 2019 Valid 12Z Mon Nov 04 2019 - 12Z Fri Nov 08 2019 1530 UTC Update... Overall, the large scale pattern across the CONUS shows above average predictability during the medium range. A building ridge from the northeastern Pacific north across Alaska toward the Arctic will favor a persistent and broad upper trough across the north central/northeastern U.S. Changes to the ongoing forecast were minor, and the forecast was updated to reflect a blend of the latest deterministic guidance (00Z ECMWF/UKMET/06Z GFS), with more weight toward the ECENS/GEFS ensemble means by late next week. The previous discussion follows below. Ryan Previous Discussion (issued at 0621 UTC)... ...Pattern Overview/Weather Threats and Guidance Assessment... Broad cyclonic flow aloft will dominate much of the lower 48 next week as a series of impulses reinforce a central North American mean upper longwave trough. This trough may gradually shift eastward as east Pacific upper ridging grudgingly work into a dry West Coast. The pattern will favor the spread and periodic reinforcement with colder than normal airmasses from the Rockies and Central U.S. to the East as post-frontal high pressure cells spill down from Canada. Moisture will be mainly limited across the mid-higher latitudes, but the passage of several clipper lows should support modest snow/rain swaths over the U.S. northern tier from the Rockies through the Great Lakes/Northeast where activity will be prolonged by lake effect. Moisture may sufficiently feed into/over a wavy lead front to fuel some moderate rains for FL and the coastal Southeast/Carolinas early next week, then back over the southern Plains mid-later next week where cooled temperatures offer some risk of a light icy coating on the far northern periphery of return flow with secondary frontal passages. The WPC medium range product suite was primarily derived from a composite blend of the quite compatable latest GEFS/ECMWF ensemble means in lue of reliance on deterministic models that show more run to run continuity issues with the timings/amplitudes of embedded weather systems. 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