Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 348 AM EDT Sat Jul 28 2018 Valid 12Z Sat Jul 28 2018 - 12Z Mon Jul 30 2018 ...Severe thunderstorms and flash flooding possible across portions of the central Plains... ...Dangerous heat to continue across the Southwest and California through Saturday, moving into the Pacific Northwest by Sunday... A series of upper level disturbances rounding the top of a stubborn ridge across the Southwest will interact with a frontal boundary draped from the central High Plains to the lower Mississippi Valley. This will result in numerous showers and thunderstorms from the Rockies to the central Plains and into the middle/lower Mississippi Valley this weekend. A moist and unstable airmass in place will allow for an environment favorable for both severe weather and heavy to excessive rainfall/flash flooding, with the greatest chance along the frontal boundary in the High Plains and also near a surface low developing over Oklahoma. The Storm Prediction Center has highlighted a region from southeast Wyoming to central Kansas within a slight risk for severe thunderstorms on Saturday, and along the Colorado front range on Sunday. WPC also has slight risks on their excessive rainfall outlooks for the weekend across parts of the central Plains. Please refer to the outlooks by these centers for additional information. The relentless heat across the Southwest and parts of California should finally begin to return to near normal values by Sunday, but there are still numerous excessive heat warnings and advisories in effect through Saturday. The upper ridge responsible for the dangerous, multi-day, heat wave will also begin building up the west coast through the weekend. Afternoon high temperatures by the end of the weekend across the Pacific Northwest could be anywhere from 5 to 15 degrees above normal, and excessive heat watches are in effect for some locations as afternoon highs are forecast to soar into the mid to upper 90s. Due to continued hot and dry conditions, fire weather and poor air quality also will remain a concern across much of the Western states. Meanwhile, a lingering front across the Southeast keeps showers and storms in the forecast for the weekend from the Carolinas to the Gulf Coast and Florida. Much of the activity should be relatively light and scattered in nature, but the best chance for heavy rainfall will be along the stalled boundary in the eastern Carolinas. The northern portion of this front will move slowly eastward and off the Northeast coast by Sunday, but additional rain and thunderstorms are possible for New England on Saturday. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php