Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 344 AM EDT Thu Aug 12 2021 Valid 12Z Thu Aug 12 2021 - 12Z Sat Aug 14 2021 ...Stifling heat wave continues in the Northeast, Mid-South, and Pacific Northwest... ...Daily rounds of strong-to-severe storms from the Mississippi Valley and Great Lakes to the Northeast, monsoon showers and storms could lead to areas of flash flooding in the Southwest... ...Poor air quality due to wildfire smoke continues in the western and central U.S., Tropical Depression Fred to reach the Florida Straits by the start of the weekend... The remainder of the work-week continues to look oppressively hot in the Northeast and the Pacific Northwest. Today features numerous Heat Advisories and some Excessive Heat Warnings from the central Plains to the Northeast. Heat indices in these areas will range between 100-110 degrees with some locations as high as 115 degrees. The Pacific Northwest will also bake as high temperatures soar into the triple digits, leading to the issuance of many Excessive Heat Warnings and Heat Advisories. The Pacific Northwest and Northeast can expect daily record highs to be broken both Thursday and Friday while even more locations have a better chance to observe daily record warm minimum temperatures. A passing cold front ushers in more seasonal conditions to the Midwest on Friday, but the Northeast will have to wait until Saturday for slightly cooler conditions to arrive. The aforementioned cold front will inch its way south and east over the next couple days across the eastern half of the Lower 48. The front's slow movement results in daily episodes of widespread showers and thunderstorms from the central Plains to the Northeast. The best chance for organized severe weather lies just ahead of the front, specifically part of the Midwest and the Northeast today where Slight Risks have been issued by the Storm Prediction Center. Some severe storms could also develop in the Ohio Valley and Mid-Atlantic. By Friday, the severe threat moves into the Mid-South while the Northeast and Mid-Atlantic remain in a favorable environment for severe storms. Excessive rainfall rates are also possible in heavier cells, making it possible for areas of flash flooding to transpire. The Gulf Coast can expect scattered showers and thunderstorms each afternoon and evening with locally heavy rainfall totals. In the West, monsoon showers and thunderstorms will be a daily occurrence in the Desert Southwest, helping to keep temperatures at seasonally cooler levels. That said, some areas of flash flooding are possible due to a pocket of abundant atmospheric moisture centered over the region. In addition, wildfires and their coalesced area of smoke remains a problem for many residents in the West, most notably in the central Rockies and High Plains where Air Quality alerts remain in place. Farther north, the coolest temperatures in the mainland U.S. will be found in the Northern Plains thanks to a pair of passing cold fronts. Last but certainly not least, eyes are turning to the tropics as Tropical Depression Fred is forecast to approach South Florida from Cuba Friday night. Forecast to reach the Florida Keys as a tropical storm, some squalls associated with the outer rainbands of Fred could begin to impact southern Florida on Friday. These squalls out ahead of Fred would likely contain heavy downpours and increasingly gusty winds. Please visit the National Hurricane Center homepage for the latest forecast information on Tropical Depression Fred. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php