Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 335 PM EDT Mon Oct 20 2014 Valid 00Z Tue Oct 21 2014 - 00Z Thu Oct 23 2014 ...Heavy rain expected across the Northwest, Northeast, and Florida Keys over the next few days... The most active region this period continues to be the Pacific Northwest, where an onshore fetch continues relatively unabated for the next few days. Thunderstorms with heavy rainfall are anticipated with each fresh cold front passage, with total accumulations of 5-7" slated over the next few days -- with locally heavier amounts -- per Weather Prediction Center (WPC) rainfall forecasts. Across the higher elevations of north-central Washington, southwest Montana, and central Idaho, measurable snowfall is expected across higher elevations, including portions of the Cascades and Anaconda ranges. Portions of southern New Mexico and western Texas continue to be under the threat for scattered thunderstorms each afternoon and evening through Wednesday as an upper level disturbance and its associated cold pool aloft combine with daytime heating to destabilize the atmosphere and lure Gulf of Mexico moisture up the Rio Grande. The Northeast will become a new focus for showers and thunderstorms from Tuesday into Thursday as a coastal low meanders offshore the northern Mid-Atlantic States, coupling with a strengthening upper level low moving in from the west-northwest as it deepens. Thunderstorms with moderate to heavy rainfall are expected due an increasingly onshore flow from the Atlantic across New England and the northernmost Mid-Atlantic states, with a general 1-2" of rain -- with locally higher amounts -- expected over the next few days. Inflow into the vicinity of a weak stationary front to the east of a developing monsoon depression between the Bay of Campeche and the northwest Caribbean sea is expected to spawn thunderstorms with heavy rainfall across the Florida Keys -- 2-3" of rain are forecast by WPC, with locally higher amounts possible. The National Hurricane Center (NHC) indicates a low moving across the Bay of Campeche has a 50/50 chance of becoming a tropical cyclone by midday Wednesday -- see the latest tropical weather outlooks from NHC for more on this system's potential for tropical cyclone development. Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php