Extended Forecast Discussion NWS Weather Prediction Center College Park MD 136 AM EST Thu Jan 16 2020 Valid 12Z Sun Jan 19 2020 - 12Z Thu Jan 23 2020 ...Guidance/Predictability Assessment... Troughing in the eastern 2/5ths of the CONUS will gradually shift into the Atlantic next week as Pacific troughing moves into the Pac NW midweek. Ridging over the Rockies will weaken as it slips eastward to the Plains. The overall pattern will be much quieter than the short term in the East but remain active in the West with a main system on Tuesday. The models/ensembles were in good agreement to start the period and a deterministic consensus sufficed for Sunday with the exiting eastern system. Thereafter, the GFS and to an extent the GEFS mean diverged from the ECMWF-led cluster (including the UKMET/Canadian) with the eastern Pacific flow including a potential surface low offshore California late Sun/early Mon. Majority of ensembles suggest this is a low probability solution and was not included in the preference. By about next Tue, GFS became quicker in the West to lower heights (related to its earlier differences) and deeper with eastern troughing than most ensembles. Preferred the ECMWF/Canadian/ECMWF ensemble mean and somewhat the GEFS mean with the overall flow, which was closer to continuity. This should carry the western front through the Great Basin/northern Divide and to the southern Plains by the end of the period with rising heights in the East. ...Weather/Hazard Highlights... The eastern half of the CONUS will near to below normal temperatures next week behind the exiting Northeast system. With the front expected to push south of Florida, even the sunshine state will see high temperatures only in the 60s and low 70s at best all the way to the Keys. High temperature anomalies of 10-20F below normal will ease after Tuesday back toward more typical January values. Above normal temperatures will be limited to areas east of the Rockies. Precipitation will be limited in the East to around the Great Lakes and across Florida early in the period. Main western front will bring in modest lower elevation rain/higher elevation snow to WA/OR and northern/central CA with lighter amounts east of the Cascades/Sierra Tuesday, followed by lighter precipitation Wed-Thu. By next Wed-Thu, Gulf moisture may increase rain chances over Texas northward and northeastward as a front approaches the area from the northwest. 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