Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Tue Aug 07 2018 Valid 00Z Wed Aug 08 2018 - 00Z Fri Aug 10 2018 ...Unsettled weather expected to shift across the south-central and eastern U.S. through much of the work-week... ...Excessive heat and air quality concerns will persist for much of the Western U.S. as well as across the Northeast and Southeast U.S.... ...Red Flag Warnings continue across southern California and the Cascades of Washington... ...Hurricane John will track northwest near the Baja California Peninsula... A slow moving cold front is currently stretching from the southern Plains northeast into Lowe Great Lakes and northeast. As it slowly continues to shift east and southeast, it will remain the focus for scattered to widespread showers and thunderstorms over the coming days, both along the front and areas to the south and east. The trailing end of the front will slow considerably across the central U.S. Slow storm motion along this portion of the front will increase the likelihood of heavy rainfall and flash flooding risk. WPC has therefore highlighted a portion of the Southern and Central Plains (including the Leeward side of the Central and Southern Rockies), as well as along the Ohio River and into the Middle Mississippi Valley as being in a slight risk of excessive rainfall. The remaining regions along the frontal boundary are in a marginal risk of excessive rainfall and flash flooding. Additionally, the Storm Prediction Center has also issued a slight risk for severe storms for the leeward portions of the Southern/Central Rockies. A Flash Flood Watch and Severe Thunderstorm Watch are currently in place for the lee side of the Central and Southern Rockies as well. The risk of excessive rainfall will slowly shift south with the front each day. Meanwhile, a ridge has settled over the Southwest, extending northward over much of the West, will keep hot and mostly dry conditions in place for the next the few days. This is resulting in rising temperatures and excessive heat across much of this region. Excessive Heat Warnings are in effect for much of the Southwest and southern California. Excessive Heat Watches and Advisories are also in effect for the Northern Great Basin and portions of the Pacific Northwest. Many locations will observe daily maximum temperature reading exceeding 100 degrees. These hot and dry conditions will maintain an elevated threat for the spread of wildfires. Red Flag Warnings are currently in place across Southern California as well as across the Cascades in Washington. Air Quality Alerts also continue across portions of the Southwest, California, and Northwest as wildfires continue to infuse the air with copious amounts of smoke. A steady increase in moisture is expected over the coming days for Mexico and the Desert Southwest as Hurricane John tracks north and west in the Pacific Ocean. Showers and thunderstorms may be possible for the Southwest by the end of the week. On the east coast, strong southerly flow will pump hot and humid air inland. This will result in above normal temperatures and even higher heat index values ahead of the approaching cold front. Heat Advisories and Air Quality alerts for excessive ozone concentrations are in effect across much of the Northeast and the northern extent of the Mid-Atlantic region through this evening. Heat Advisories have also been issued for portions of the Deep South through this evening. Expect conditions to begin improving once the cold front passes through in the coming days. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php