Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 PM EDT Wed Sep 16 2020 Valid 00Z Thu Sep 17 2020 - 00Z Sat Sep 19 2020 ...Widespread life threatening flooding likely from the northeastern Gulf coast, across portions of the Southeast and Southern Appalachians as Sally moves slowly northeastward... ...Frosts and freezes likely across the Upper Mississippi Valley and Upper Great Lakes Thursday and Friday mornings, while below average temperatures spread across areas to the east of the Mississippi River by late week and the weekend. Above average temperatures to continue from the Great Basin/Rockies into the High Plains... ...Poor air quality will continue across the Pacific Northwest, Northern Rockies and portions of Central California... ..Cooler air moving into the Pacific Northwest and Northern to Central California over the next two days along with much needed rains over western portions of Washington State and Oregon late Thursday into Friday... Sally will be moving very slowly northeast tonight into early Thursday across southeast Alabama, through north central Georgia during the day Thursday and into central South Carolina by early Friday. While the wind speeds associated with Sally are expected to continue to diminish as it pushes inland, the slow movement of Sally will continue the threat widespread life threatening flooding from the northeast Gulf Coast, across portions of the Southeast and the Southern Appalachians. For areas from far southern Alabama into the Florida Panhandle, storm total rainfall amounts of 12 to 24 inches are likely with isolated maximum totals over 30 inches possible. These rainfall totals will produce historic flooding for these regions. Farther inland, rainfall totals of 4 to 8 inches with isolated maximum of 12 inches are possible across portions of the Southeast and Southern Appalachians, with widespread life threatening flooding likely. In addition, severe weather is possible on the southeast of the storm from North Florida and across the eastern portions of Georgia, South Carolina and North Carolina where tornadoes and high winds are possible. The last rains associated with Sally will be pushed off the Southeast coast Friday night into early Saturday by a strong cold front. This cold front will bring below average temperatures to areas east of the Mississippi river Friday into this weekend. Frosts and freezes are likely both Thursday and Friday morning over the Upper Mississippi Valley and Upper Great Lakes and from northern New York State into northern New England on Friday. Cooler weather is also on tap for the Pacific Northwest into Northern and Central California over the next two days. While temperatures drop, hazardous air quality from on going fires will continue. There is potential, however, for some much needed rains to move into western portions of Washington State and western Oregon late Thursday into Friday. In between the cooler temperatures along the west coast and over the East, above average temperatures expected to continue through the Rockies, Great Basin and across the Northern to Central High Plains over the next two days. Oravec Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php