Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 407 AM EDT Wed Jun 07 2017 Valid 12Z Wed Jun 07 2017 - 12Z Fri Jun 09 2017 ...Cool weather continues over much of the eastern U.S. as heavy rain moves across southern Florida today... ...Warm weather returns to the northwestern U.S. before significant rain moves into the West Coast... It appears that a large-scale shift in the weather pattern is in store over the continental U.S. during the next few days as a cut-off low in the Northeast retreats into the Canadian Maritimes while a cut-off low develops off the Pacific Northwest. An upper-level ridge that is bringing warmer than normal temperatures with scattered thunderstorms in the Rockies will begin to break down as an amplifying upper-level trough over the northeastern Pacific develops into a cut-off low and moves towards the Pacific Northwest. Widespread rain along with strengthening winds is expected to reach the Pacific Northwest down into northern California on Thursday ahead of a strong cold front. The cold front should penetrate inland rather rapidly. and the lead low pressure center could reach the northern High Plains by Friday morning. Expect widespread rain with afternoon thunderstorm to continue over the Pacific Northwest on Thursday before tapering off a bit Thursday night and early on Friday. Temperatures will fall below normal behind the strong cold front. Over the eastern U.S., a broad upper-level trough has been bringing cool and unsettled weather over much of the eastern U.S. The upper trough is forecast to develop into a closed low over the Northeast by Friday morning. Cool and showery conditions are expected to continue over New England today while overcast and cool weather should prevail down the East Coast with showers possible along the Appalachians. Farther to the South, more substantial showers and thunderstorms are continuing across the Deep South into the Southeast and down the Florida Peninsula. In addition, tropical moisture to the south of an elongated low pressure system is bringing heavy rainfall across southern Florida. The low pressure system is forecast to slide off the southeast U.S. coast and intensify rapidly off New England by Friday morning. The associated rain will gradually taper off over the Southeast on Thursday although showers and thunderstorms will continue to linger over Florida. Elsewhere, a weakening front will bring scattered thunderstorms from the northern Plains eastward into the upper Midwest and the Great Lakes through Friday morning. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php