Extended Forecast Discussion NWS Weather Prediction Center College Park MD 158 AM EST Sun Nov 13 2022 Valid 12Z Wed Nov 16 2022 - 12Z Sun Nov 20 2022 ***It will feel more like January across much of the U.S. with widespread subfreezing high temperatures expected across the north-central states*** ...Synoptic Overview... A rather cold pattern is expected to be in place across much of the nation for the middle of the week into next weekend with broad cyclonic flow aloft around a deep upper level trough centered near the north-central U.S. and extending to Hudson Bay. Multiple reinforcing cold fronts/shortwaves will help to maintain this pattern, and a strong upper ridge axis should prevail just off the West Coast. A well organized storm system will be exiting the Northeast late on Wednesday, with coastal rain and inland snow expected, followed by lake effect snow downwind of the Great Lakes ...Guidance and Predictability Assessment... The latest guidance is showing an active pattern with multiple shortwaves initially within the northern and southern streams that transition to a broad and phased trough over much of the nation. Overall, there is good synoptic scale agreement with the broad cyclonic flow expected over the north-central states, but there is still notable spread on the timing, location and strength of individual shortwave features that increase beyond Wednesday, with the 00Z GFS becoming stronger with the next southern stream system crossing the southern Plains and then the Gulf Coast region for late in the week. The CMC has trended closer to the model consensus compared to its previous 12Z run, which was an outlier solution across the western U.S. when compared to the ensemble guidance. The WPC forecast was primarily based on a mainly GFS/ECMWF/UKMET model blend through about Wednesday, followed by increasing the inclusion of the GEFS and EC ensemble means to account for the greater model differences going into the end of the week and into next Saturday. In terms of QPF, a blend of about 25% GFS/25% CMC/50% NBM was used as a baseline for the Great Lakes region to add more detail to the expected lake effect snowfall. ...Weather/Hazard Highlights... There will be two main things making weather headlines going into next week. The first will be an organizing storm system near New England by midweek that is forecast to produce widespread rain across much of the Mid-Atlantic and into coastal portions of the Northeast, and accumulating snow for interior portions of New England. Strong cold air advection over the Great Lakes is expected to produce lake effect snow for several days, and some of this snow could be locally heavy at times. The other noteworthy aspect of the extended forecast will be the widespread anomalous cold weather across a great deal of the nation for the entire forecast period, especially from Montana and Wyoming eastward to the Midwest where afternoon highs could be running on the order of 15-30 degrees below typical mid-November averages. Some daily record lows are also within the realm of possibility for these areas. The exceptions to the cold weather will likely be across the Florida Peninsula with readings near or slightly above average. Hamrick Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation, experimental excessive rainfall outlook, 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/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml