Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 257 AM EST Tue Jan 07 2014 Valid 12Z Tue Jan 07 2014 - 12Z Thu Jan 09 2014 ...Heavy precipitation possible for the Cascades... ...Freezing rain possible for parts of the Lower Mississippi Valley on Wednesday... ...Lake effect snow downwind from the Great Lakes... ...Temperatures will be 25 to 35 degrees below average for the Mid-Atlantic/Southeast to the Ohio/Tennessee Valleys into the Upper Midwest... Bitterly cold air over the eastern two thirds of the country will slowly moderate through Wednesday. In addition, as the cold air passes over the Great Lakes, the temperature difference between the water and air will aid in producing lake effect snow downwind from the Great Lakes through Wednesday evening. Meanwhile, upper-level energy over the Pacific Northwest will move southeastward to the Central Plains/Middle Mississippi Valley by Wednesday. Weak onshore flow will produce rain and higher elevation snow over parts of the Pacific Northwest that will increase to light to moderate by Wednesday evening. Additionally, the energy will trigger light snow over parts of the Northern/Central Rockies on Tuesday and Wednesday. Return flow around high pressure over the Central/Eastern Gulf Coast will stream moisture from the Gulf of Mexico over the Western Gulf Coast into the Middle Mississippi Valley, producing rain over Western Gulf Coast into parts of the Lower Mississippi Valley Wednesday morning into evening. Snow will also develop over parts of the Middle Mississippi Valley by Wednesday evening. Furthermore, an area of rain/freezing rain will develop over Eastern Oklahoma and Northwestern Arkansas on Wednesday evening. Elsewhere, Easterly flow off the Atlantic will produce light rain over the Southern tip of Florida from Tuesday evening into Wednesday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php