Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 324 AM EDT Wed Oct 18 2017 Valid 12Z Wed Oct 18 2017 - 12Z Fri Oct 20 2017 ...Heavy rainfall expected across the Pacific Northwest... ...Heavy snow possible across the Cascades and northern Rockies... ...Stormy weather continues for Florida... A frontal system will begin to approach the Pacific Northwest by this evening. Precipitation will increase throughout the day and into tonight. By Thursday, the strong cold front will begin pushing eastward over the Pacific Northwest and toward northern California with precipitation spreading farther east as a result. Once the front moves into the Central Great Basin, rainfall will also follow suit; however, due to onshore flow, showers and higher elevation snow will continue across the Pacific Northwest. There is a marginal risk for flash flooding in western Washington and northwestern Oregon on Thursday as a result of the heavy rainfall. On Thursday, snowfall will expand throughout the Washington and Oregon Cascades and parts of the northern Rockies--with some light snowfall in higher elevations of northern California. By Friday, snow will continue across the Cascades and throughout the northern Rockies. A stalled frontal boundary will linger near South Florida for the remainder of the week. Easterly flow will bring tropical moisture across the state while the stationary front will act as a focal point for continuing showers and thunderstorms through Friday. Most the heavy rainfall will be confined to the Atlantic coastline and the southern half of Florida--with a marginal risk of flash flooding is in place the central Atlantic coastline for Florida today. Showers and thunderstorms will approach the middle and southeastern Texas coast by Thursday evening. A disturbance aloft along with increasing moisture will give way to precipitation that will last through Friday. Meanwhile, high temperatures in the mid to upper 70s will be possible across the northern Plains on Thursday and Friday--which is 10-20 degrees above normal for this time of year. Because of the warm and dry conditions, elevated fire weather is possible on Wednesday and Thursday for portions of the northern High Plains. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php