Extended Forecast Discussion NWS Weather Prediction Center College Park MD 219 AM EDT Mon Mar 11 2019 Valid 12Z Thu Mar 14 2019 - 12Z Mon Mar 18 2019 ...Heavy snow/wind threat to exit the North-Central U.S. Thursday... ...Heavy rain threat in the Southeast Thursday... ...Overview and Guidance Assessment/Preferences... Upper pattern will be driven by ridging over southwestern Canada which supports broad troughing in the eastern half of the lower 48. A robust central-eastern system will exit off the east coast late Friday into Saturday (but linger in south Florida) as the pattern will turn much quieter by next Sunday/Monday. The models/ensembles show reasonable clustering through the period and a blend of the GFS/ECMWF with their ensemble means offered a good starting point that kept in line with continuity. ...Weather Highlights and Hazards... Low pressure over Iowa Thursday morning will bring wind-driven snow to the Upper Midwest and then Great Lakes as it exits through Ontario and Quebec on Friday. To the south, influx of Gulf moisture will support a continued threat for heavy rainfall and embedded convection from Alabama/Mississippi eastward as the cold front continues to move eastward and southward. Mild air drawn northward ahead of the front will be replaced by much cooler temperatures (5-10 degrees below average) that will finally exit out of the west and focus on the central states. By Sat-Mon, high pressure will be in control of much of the lower 48 with a dry northwest flow out of Canada, supporting some lake-enhanced snows. 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