Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 AM EDT Fri Mar 18 2016 Valid 12Z Fri Mar 18 2016 - 12Z Sun Mar 20 2016 ...Severe thunderstorms and locally heavy rain possible across portions of the Gulf Coast states... ...Heavy snow possible for portions of the Wyoming and Colorado Rockies as well as the Front Range... ...Colder temperatures on the way for much of the central and eastern U.S. by Saturday... Showers and thunderstorms will continue to develop along a nearly stationary boundary spanning from central Texas to the Southeast into the weekend. Some of the storms over the Gulf states may turn severe this afternoon and evening. The Storm Prediction Center has highlighted this region as having a slight risk for severe weather. Locally heavy rainfall will be possible for portions of Texas, Louisiana, Mississippi, Alabama and western Florida. Please refer to products issued by SPC for further details on the severe weather threat. A wave of low pressure will develop along the front on Saturday over the lower Mississippi Valley; which in turn, with help maintain convective initiation over the Gulf states. Multiple rounds of showers and thunderstorms could potentially track slowly over the same region, yielding 1 to 3 inches of rain, with locally higher amounts, across much of the Gulf Coast through by Saturday night. A vast portion of the central and eastern U.S. will have a significant drop in temperatures over the next few days. Colder air will spill into the area as two cold fronts plunge south and east. The first cold front push through the lower Great Lakes and into the Ohio Valley today, with a mix of rain and show showers possible ahead of and along the front. The rain will transition over to snow for the Northeast today. Snowfall accumulations are expected to be fairly light, with 1 to 3 inches possible at the higher elevations of the Northeast as well as the central Appalachians. The second frontal system will track across the Central Plains and portions of the Rockies through the day. This system will bring the potential for heavy snow to portions of the Colorado and Wyoming Rockies as well as the Front Range. Snowfall amounts of 6 to 12 inches are possible, with 1 to 2 feet possible at the highest elevations. Several Winter Weather Advisories and Winter Storm Warnings are in effect today in Wyoming and Colorado. A mix of rain and snow will also fall across portions of the central plains as colder air moves into that region behind the front. Portions of central Kansas also have Winter Weather Advisories in effect. In the wake of the frontal passage, afternoon high temperatures for Saturday are forecast to be 5 to 10 degrees below average across much of the central and eastern U.S., with some areas of the Southern Plains 10 to 20 degrees below average. The Pacific Northwest will have rain through most of the weekend as a Pacific cold front approaches the coast. Accumulations of 1 to 2 inches will be common for coastal areas from Washington to northern California. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php