Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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816 FXUS64 KMRX 190507 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 107 AM EDT Wed Jun 19 2024 ...New AVIATION... .UPDATE... Issued at 1018 PM EDT Tue Jun 18 2024 Not much to update, most of the region is plus or minus a few degrees of the temperature forecast this evening, so just blended observations into the forecast. Radar is quiet, and satellite shows high clouds streaming on by. Temperatures are a pleasant warmth outside, one of the bonuses of a hot summer. && .SHORT TERM... (This evening through Wednesday) Issued at 258 PM EDT Tue Jun 18 2024 Key Message: 1. Hot and dry conditions prevail. Upper level high centered near Virginia/West Virginia/southeastern Pennsylvania will gradually drift northwest over the next 24 hours. There has been some scattered thunderstorm activity develop along the western edge of the ridge this afternoon. Expect that the majority of activity will generally stay north and west of the forecast area through the remainder of the afternoon. There may be a few isolated showers that do develop in our forecast area but they should be short lived. The surface high will build west and provide a more stable atmosphere overnight and into Wednesday. As such, no convective activity is expected. Sadly, hot temperatures will persist and will only be a degree or two cooler. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 258 PM EDT Tue Jun 18 2024 Key Messages: 1. Above average temperatures continue Thursday through the extended. 2. Diurnal convection possible this as early as Saturday afternoon but higher chances Sunday and early next week as a frontal boundary approaches the area late Sunday into Monday. Discussion: Strong ridging will continue across the Eastern states through the weekend with 594 to 598 dam 500mb heights across the Appalachians through Saturday. A continued subsidence pattern under the ridge will keep the threat for showers and storms away. The easterly to northeasterly flow will continue with downslope conditions and dewpoints will be lower in the lower to mid 60s. Instability will be limited and temperatures will be up in the lower to mid 90s. On Saturday a shortwave trough across the upper Mississippi Valley will slowly move southeast toward the Ohio Valley. There should be an increase in moisture from the south as the surface high shifts a little further east. A few terrain showers and storms are expected to form in the eastern TN mountains and possibly southwest Virginia. Sunday the front is expected to get a little closer with a better chance of afternoon and evening showers and storms as the upper ridge flattens out. A weak surface cold front will also approach the area Sunday night and Monday. Increasing southerly boundary layer flow and increasing low-level moisture and decreasing upper-level heights will also raise instability. There should be an increase in the chance of diurnal showers and thunderstorms Monday across the region. Models then want to keep the front over the forecast area Tuesday. Highest chances Tuesday look to be over the southern part of the area based on where the cold front ends up. This will likely change with the slow movement of the front. && .AVIATION...
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(06Z TAFS) Issued at 1253 AM EDT Wed Jun 19 2024 VFR conditions at all TAF sites throughout the forecast. Winds will be light easterly due to surface ridging just north of the area.
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&& .PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN 91 69 93 71 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 91 67 91 70 / 0 0 0 0 Oak Ridge, TN 90 67 91 70 / 0 0 0 0 Tri Cities Airport, TN 89 63 90 65 / 0 0 0 0
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&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...Wellington AVIATION...DH