Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 341 AM EDT Mon May 28 2018 Valid 12Z Mon May 28 2018 - 12Z Wed May 30 2018 ...Subtropical Storm Alberto to bring heavy rainfall and possible flash flooding from the eastern Gulf Coast northward... ...Severe thunderstorms to break out along the dry line stretching over the southern/central High Plains... ...More record heat expected from the Great Lakes and Middle Mississippi Valley down toward the Ozarks and Southern Plains... Based on the latest National Hurricane Center forecast, Subtropical Storm Alberto is forecast to make landfall over the western Florida panhandle by midday with intensity dropping off thereafter given land interactions to the circulation. As this occurs, expect gusty winds and rough surf to accompany the heavy rainfall threat. Additionally, a small threat for tornadoes will exist over the southeastern U.S., particularly where appreciable heating occurs which would bolster instability in the atmosphere. However, the most prominent threat will likely be the drenching tropical rains with several inches possible from the western/central Florida panhandle northward over much of Alabama. An additional maxima is possible over the interior Carolinas given local upslope effects. These mentioned locations can expect the best threat for flash flooding as shown by the latest Excessive Rainfall Outlook. Otherwise, while general rainfall amounts should be modest in comparison to the eastern Gulf Coast, it will likely remain quite wet over the mid-South up toward the lower Ohio Valley as well as the coastal Carolinas. In advance of an expansive upper low across southwestern U.S., a north-south oriented dry line over the southern/central High Plains will be a focus for active convection. Multiple impulses within the mentioned upper low will be foci for thunderstorm development, particularly as the surface warms with daytime heating. Much of the thunderstorm initiation should take place on the dry line where numerous severe storms are possible as noted in the Storm Prediction Center convective outlook. At the onset of storm development, the primary hazards will be large hail and perhaps a few tornadoes before evolving into more of a damaging wind threat into the evening and overnight hours for locations downstream. By Tuesday, the threat area will have adjusted to the east with a primary focus from central Oklahoma up into southern Nebraska. A wavy west-east oriented boundary will generally set up from South Dakota eastward into the Upper Midwest and Great Lakes region. South of this frontal zone, abundant heat will remain the norm with daily record temperatures likely. Departures from climatology are in the 15 to 20 degree range which supports highs in the 90s as far north as southern Minnesota/Wisconsin. Expected highs on Memorial Day will be in the upper 90s across Minneapolis/St. Paul with some slight cooling likely by the following day. Eventually the record heat will shift into the Southern Plains for Tuesday with a particular focus across the Lone Star state. Widespread mid/upper 90s are possible over central portions of the state with triple digits along the Rio Grande River. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php