Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 104 AM EDT Sat Oct 03 2020 Valid 12Z Sat Oct 03 2020 - 12Z Mon Oct 05 2020 ...The flash flood threat due to heavy rain over parts of Florida continues through the weekend... ...Heat continues in the West while cooler than normal temperatures persist in the eastern half of the country... Tropical Storm Gamma is forecast to cause heavy rain across portions of Southeast Mexico, Central America, and western Cuba as it crosses near or over the Yucatan Peninsula into the Bay of Campeche over the next few days. While this cyclone looks to stay away from the U.S., some of its tropical moisture is spreading into the Florida peninsula, focused in the vicinity of frontal zones. Additional heavy rainfall is possible over portions of Florida through the weekend before possibly fading on Monday. Some heavy rain could spread to the coastlines of Georgia and the Carolinas and Southern New England along a coastal front in advance of the development of a surface low off the Eastern Seaboard Sunday night/Monday morning, but the heaviest rain looks to remain offshore. In terms of the upper-level pattern over the rest of the U.S., ridging will be slow to weaken/flatten over the West causing dry and very warm conditions, while the eastern half of the country sits underneath an upper-level trough and will enjoy fall-like temperatures. Under the Western ridge, record highs are possible across parts of the West Coast and Great Basin this weekend, and across the southern Rockies into the southern Plains by Monday. Fire danger is a threat given the pattern. Air Quality Alerts are also in effect for portions of the West due to the combination of smoke from area fires and the high pressure ridge trapping pollutants near ground level. Meanwhile, cooler than normal temperatures are likely from portions of the Plains eastward. Highs of 10 to 20 degrees below normal are expected across the Midwest for the weekend. Morning lows could approach or drop below freezing in parts of the Great Lakes region to Ohio Valley and Appalachians. Showers are possible causing generally light precipitation over portions of the Plains to the Mississippi and Ohio Valleys toward the Great Lakes. Some snow could mix in with these showers in parts of the Upper Mississippi Valley. Roth/Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php