Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 334 AM EDT Wed Aug 11 2021 Valid 12Z Wed Aug 11 2021 - 12Z Fri Aug 13 2021 ...Stifling summer heat to stretch from coast-to-coast; searing heat takes shape across the Pacific Northwest while sultry conditions persist across the Northeast/Mid-Atlantic and the mid-section of the country... ...Daily rounds of strong-to-severe storms across the Great Lakes and northern Mid-Atlantic... ...Poor air quality due to wildfire smoke continues in the western and central U.S., monsoon showers and storms to drench parts of the Southwest, watching Tropical Storm Fred late week... "The Heat Is On" for much of the U.S. mainland as sweltering temperatures span from sea to shining sea today and Thursday. Heat Advisories and some Excessive Heat Warnings have been issued across much of the nation's mid-section and into parts of the the Northeast and Mid-Atlantic. Some parts of the I-95 corridor could reach 100 degrees Thursday afternoon with oppressive heat indices ranging between 105-110 degrees. Across the Pacific Northwest, daytime highs are forecast to soar above the century mark with high temperature departures anywhere from 15 to 25 degrees above normal. Temperatures on Thursday will even challenge some daily record highs in the Northeast and the Pacific Northwest. Speaking of records, numerous record warm lows are expected to be broken along the West Coast and east of the Mississippi River both Wednesday and Thursday mornings. Looking further ahead, this heat wave looks to stick around into Friday before gradually loosening its grip over these regions this weekend. The Great Lakes are most at risk for severe storms later today as hot and humid conditions ahead of an approaching cold front sets the stage for another round of scattered thunderstorms. An Enhanced Risk for severe weather is in place over western Michigan while a Slight Risk envelops Michigan and portions of the Midwest. Damaging winds, large hail, and tornadoes could accompany any severe thunderstorms. Meanwhile, scattered thunderstorms can be expected from the Midwest to the interior sections of the East Coast including the Northeast, as well as along the Gulf Coast and into Florida for the next couple of days. Most shower and thunderstorm activity will develop in the afternoon and linger into the evening hours each day. Some of these thunderstorms may contain heavy downpours that could result in localized flash flooding. Elsewhere, wildfire smoke continues to plague parts of the West Coast, the Intermountain West, and High Plains with poor air quality through Wednesday. Also, monsoon showers and thunderstorms will be a daily occurrence in the Desert Southwest, helping to keep the heat at bay. That said, some areas of flash flooding are possible as well. Farther north, temperatures in the northern Plains will remain below normal with multiple passages of dry cold fronts over the next couple days. Lastly, eyes are turning to the tropics as Tropical Storm Fred begins to approach the U.S. from the Greater Antilles by the end of the week. Please visit the National Hurricane Center homepage for the latest forecast information on Tropical Storm Fred. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php