Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 239 AM EST Tue Dec 22 2015 Valid 12Z Tue Dec 22 2015 - 12Z Thu Dec 24 2015 ...Rain and mountain snow expected to continue over much of the western U.S. through Christmas Eve... ...Widespread warm temperatures expected east of the Rockies... ...Numerous showers and thunderstorms are likely from the Gulf Coast to the northeast states... The next two days will be featured with a progressive flow pattern aloft that will result in rapidly moving shortwave disturbances from west to east across the northern U.S. In addition, ridging aloft and at the surface is expected to develop over the eastern U.S., and a trough over the western U.S. A series of storm systems and onshore flow will continue to affect the Pacific Northwest. Periods of coastal rain and heavy mountain snow can be expected, with the greatest amounts likely over the Cascades and northern and central Rockies where amounts in excess of one foot are likely at the highest elevations. Widespread rainfall is also in the forecast from the Gulf Coast to the Ohio Valley where amounts on the order of 1 to 3 inches is likely. A few strong to severe thunderstorms will be possible across the Deep South. Temperatures are forecast to approach near record levels for the middle of the week east of the Mississippi River. Large scale southerly flow from the Gulf of Mexico will result in spring-like warmth and humidity all the way to the Great Lakes and parts of New England going through Thursday. Upper level ridging will also help in keeping temperatures well above average. Expect widespread 60s and 70s for daytime highs, and 50s and 60s for overnight lows for much of the eastern U.S. through Thursday. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php