Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
756 FXUS64 KMRX 241105 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 705 AM EDT Sun Aug 24 2025 ...New AVIATION... .DISCUSSION... Issued at 132 AM EDT Sun Aug 24 2025 Key Messages: 1. A few showers and storms are possible until the afternoon with the best coverage in eastern areas along the mountains. 2. Dry and much cooler conditions are expected Monday through Wednesday with lows nearing records on Wednesday morning. Slightly warmer and mostly dry conditions are expected late in the week. Discussion: Currently, deepening upper troughing extends from Ontario down through the Great Lakes and Midwest. A frontal boundary is moving through the Ohio River Valley. Embedded shortwaves and abundant moisture allowed for persistent showers and storms yesterday afternoon and overnight. The front is expected to move through the region late this afternoon into the early evening. Additional showers and storms are possible ahead of the front. However, CAMs indicate coverage to be limited, likely due to limited instability from activity yesterday into this morning. Far eastern portions of the area may destabilize close to 1,000 J/kg MLCAPE before the front arrives. However, this will limit potential coverage and intensity for most. Late tonight into Monday morning, the front will have moved far past the region with broad troughing deepening across the eastern U.S. High pressure, currently centered in southern Canada, will gradually move into the region by Tuesday and Wednesday. This will provide drier and notably cooler conditions, especially overnight due to radiational cooling. 850mb temperatures now look likely to drop below 10 Celsius, which is nearing record low values for this time of year. With the most ideal radiational cooling likely to be Wednesday morning, lows will likely drop well into the 50s with upper 40s looking probable. Here are the record lows for the day, which may be approached: Date Chattanooga Knoxville Tri-Cities Oak Ridge 08-27 53(1942) 50(1879) 46(1945) 54(1966) High pressure is likely to remain in place across the eastern U.S. with upper troughing shifting to our east into the weekend. Ridging and better moisture will likely remain to our west, keeping mostly dry and slightly warmer conditions in the region. && .AVIATION... (12Z TAFS) Issued at 635 AM EDT Sun Aug 24 2025 There will be showers and possibly an isolated thunderstorm around early in the period. MVFR conditions can be expected as well early especially TRI, with lower conditions possible with some of the showers. Conditions will trend to VFR by early afternoon, and VFR conditions will likely continue through the remainder of the period all sites. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 85 61 81 61 / 40 0 0 0 Knoxville McGhee Tyson Airport, TN 84 61 80 58 / 40 0 0 0 Oak Ridge, TN 85 58 79 57 / 30 0 0 0 Tri Cities Airport, TN 81 59 76 54 / 40 10 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...BW AVIATION...