Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 403 PM EDT Thu Aug 03 2017 Valid 00Z Fri Aug 04 2017 - 00Z Sun Aug 06 2017 ...Excessive heat across the West Coast expected to continue... ...A strong cold front sweeping the eastern U.S. to bring showers and thunderstorms with it... ...Heavy rainfall expected across the Gulf Coast... The upper level ridge that has been centered over the West Coast will continue to bring oppressive heat for the rest of today and lasting until Friday. By Saturday, the upper ridge will begin to weaken--which will help alleviate the dangerous heat plaguing the Pacific Northwest. In the meantime, excessive heat warnings and heat advisories will remain in effect from the Pacific Northwest through central California/northwestern Nevada through Friday evening. Meanwhile, a strong cold front will continue moving eastward into the Mississippi Valley and toward the Ohio/Tennessee Valleys. The surface low associated with this front will move from the Upper Midwest into the Upper Great Lakes by early Friday morning. Heavy rainfall and severe weather can be expected around this low for the rest of tonight and into Friday morning. As the front stretches from the lower Great Lakes to the southern Plains, showers and thunderstorms will fire off ahead of this boundary. There is a possibility of severe weather primarily for the lower Great Lakes and Ohio Valley region on Friday. By Saturday, the front reaches the East Coast--with most of the precipitation occurring in the Northeast. Behind the front, much cooler temperatures can be expected for the entire region east of the Rockies. A frontal boundary along the Gulf Coast will act as a focal point for convection across this region over the next few days. Daytime heating will lead to instability and combining this with moisture from the Gulf of Mexico will lead to an increase in thunderstorms in the afternoon and early evening. Some of these thunderstorms are capable of producing heavy downpours and which could lead to flash flooding. In addition, a warm front attached to a surface low will begin lifting northward across the Carolinas, which may generate showers and thunderstorms along the coastline; however, the heaviest rainfall will remain offshore. In the Desert Southwest and central/southern Rockies, monsoonal moisture along with assistance of daytime heating will also lead to typical afternoon thunderstorms through the short term period. As a frontal boundary begins to drop southward over the northern and central Rockies, convection will begin to develop east of the Rockies on Saturday morning. These thunderstorms are expected to progress eastward into the central Plains throughout the day--leading to potential heavy rainfall in eastern portions of the southern Plains. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php