Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Tue Oct 17 2017 Valid 00Z Wed Oct 18 2017 - 00Z Fri Oct 20 2017 ...Heavy rain possible over parts of the Pacific Northwest... ...Heavy rain possible over the central-northeastern Florida Coast... A front extending from the Northern Rockies southwestward into the Pacific Northwest will move eastward to the Great Lakes/Middle Mississippi Valley into the Central Plains by Thursday. Moisture will be lacking with the boundary so there will be a dry frontal passage along the length of the front from the Northern High Plains to the Great Lakes/Central Plains through Thursday. In the meantime behind the front, onshore flow will stream moisture into the Pacific Northwest on strong low-level wind through Thursday morning when the strong low-level wind decreases. The flow will aid in producing rain over parts of the Pacific Northwest into parts of the Northern Rockies ending overnight Tuesday when upper-level ridging moves over the Pacific Northwest/Northern Rockies. Meanwhile, a stronger front over the Eastern Pacific moves close to the Northwest Coast by Thursday morning. A deep upper-level trough associated with the boundary will begin to move over the Pacific Northwest on Wednesday afternoon and becoming stronger as the front approaches. The approaching upper-level trough and onshore flow will aid in producing rain over parts of the Northwest Coast on Wednesday. The rain will become heavy by Wednesday evening over the Northwest as the rain moves farther inland into the Northern Intermountain Region by Wednesday evening. Overnight Wednesday, the heavy rain will move southward along the Pacific Northwest Coast approaching Northern California by Thursday. ...more to follow... Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php