Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 423 PM EDT Thu Oct 15 2015 Valid 00Z Fri Oct 16 2015 - 00Z Sun Oct 18 2015 ...Strong cold front to bring significantly colder temperatures to the northern tier and eastern third of the US... ...An upper-level low will move over Southern California... The Great Lakes, New England and the Mid-Atlantic regions will have a significant cool down over the next couple of days as a trough moves through. This system will have strong support from the upper-level jet and will send a cold front through the Great Lakes/Ohio Valley tonight and into Friday morning. A secondary front will follow quickly on its heels as the colder air surges in. The Great Lakes region and New England will be impacted the most in terms of precipitation with this system. Many areas have forecast moisture amounts of 0.50 to 1 inch. With the lakes remaining open and warmer than the surrounding area, and a cold airmass moving through, localized higher amounts may be possible. Rain may even transition over to all snow, but whether it will stick or accumulate remains uncertain at this time. An old front will remain over the southern tip of Florida and over Gulf of Mexico through Saturday. Showers and thunderstorms are forecast to develop along this boundary, but remain mostly offshore. Amounts up to 3 inches will be possible over the next 3 days. An upper-level low just off the California Coast will move eastward to Southern California by Friday morning and start to weaken. The circulation around the upper-low will aid in drawing moisture from the Pacific over the Southwestern portion of the country. The moisture and upper-level energy will aid in producing showers and thunderstorms from Southern California to the Great Basin and parts of the Southern/Central Rockies by Friday. An approaching system over the Eastern Pacific will bring a plume of moisture into the Pacific Northwest by Friday evening. Scattered to widespread rain is expected for much of the West Coast from northern California to southwest Alaska. Vancouver Island will likely have the highest amount. Precipitation will range from 0.25 to 1.3 inches. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php