Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 1203 PM EST Sat Mar 04 2017 Valid 00Z Sun Mar 05 2017 - 00Z Tue Mar 07 2017 ...Heavy snow possible over the Cascades, Sierras, and the Intermountain West... ...Well above normal temperatures for the Central and Northern Plains... ...Heavy rain possible across South Texas today and tonight... A cold front that moved onshore across the Pacific Northwest yesterday will continue to move slowly inland today, pushing across northern California and eventually through the Great Basin and much of the Rockies. Onshore flow behind the front will direct moisture into the mountains of the Pacific Northwest and California over the next few days. The slow motion of the front will lead to a prolonged period of moderate to heavy snow in these areas, as well as inland across the Intermountain West and into the Rockies by Sunday. Winter Weather Advisories and Winter Storm Warnings are in effect for portions of the Intermountain West, Pacific Northwest, and California for heavy snow. While the cold front is pushing across the Pacific Northwest, west to southwesterly flow sweeping off the Continental Divide will lead to a warming and drying trend across much of the Central and Northern Plains. Temperatures will soar to as much as 20 to 30 degrees above normal, continuing the springlike thermal seesaw. Strong high pressure protects the eastern U.S. in the form of a cold air wedge east of the Appalachians, leading to below normal temperatures into Monday before warmer air slowly erodes the wedge. On the western edge of this high pressure, strong return flow will be present, with a deep layer of warm and moist air already present across southern Texas. A disturbance aloft will interact with this moist and unstable airmass, sparking showers and thunderstorms across southern and eastern Texas. These will spread eastward into the Lower Mississippi Valley Sunday, and then northward up the Mississippi Valley and into the Upper Great Lakes during the day Monday. We continue to carry a slight risk for excessive rainfall and flash flooding across southern Texas for today into tonight. Roth/Wix/Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php