Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 250 PM EST Fri Jan 27 2017 Valid 00Z Sat Jan 28 2017 - 00Z Mon Jan 30 2017 ...High pressure will remain the dominating feature across the U.S. through this weekend... ...Possible monthly and all time high pressure records may be reached or exceeded in California and the Great Basin... Strong northwest flow has taken hold across much of the central and eastern continental U.S. Friday, with generally dry and benign weather expected through the weekend. The caveat to this will be for areas downwind of the Great Lakes, where lake effect snow bands will likely develop. A reinforcing cold front will drop south across the Great Lakes region by Saturday morning, enhancing the surge of cold air over this region. The heaviest snow will occur east of Lake Erie and Lake Ontario, where lake effect snow warnings remain in effect. Some localized areas could see snow amounts in excess of a foot. Northwest flow may also create some upslope snow showers in parts of the central and northern Appalachian Mountains through this weekend as well. A winter weather advisory is already in effect for parts of the northern Appalachians through Friday night. Across the Intermountain West, a large dome of high pressure and light winds will result in some of the coldest conditions across the continental U.S., especially during the overnight periods. Generally clear to partly cloudy skies and subsidence aloft should deter any snow across the region. Additionally, a strong inversion developing across this region could lead to deteriorating air quality for valley locations. This area of high pressure will continue to build across the far western U.S. In fact, portions of California and the Great Basin could reach or even break monthly high pressure records for January. A few locations in California are also very close to reaching their all time highest pressure records. This type of a pattern will cause any approaching northern Pacific weather systems to deflect northward before reaching the western coast. Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php