Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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213 FXUS64 KMRX 131120 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 720 AM EDT Sat Jul 13 2024 ...New AVIATION... .SHORT TERM... (Today and tonight) Issued at 228 AM EDT Sat Jul 13 2024 Key Messages: 1. A few degrees warmer today. Temps in the low to upper 90s. 2. A few isolated showers and storms possible across the east TN mountains. Discussion: Overall, another hot and mostly dry forecast. A very weak disturbance will move across central KY today. This slightly raises the probabilities for a few isolated showers and storms developing across the area. However, even though the HRRR shows a few spotty showers across the valley this afternoon, NAM soundings show a fairly strong mid-level cap in place. Also, NBM doesn`t have any POPs in for the valley so will go with a dry forecast. The best chances for any precip are across the east TN mountains, but still only slight chance POPs. High temps will be a few degrees warmer today, around 5 to 8 degrees above normal with temps in the lower to upper 90s. Went well below NBM guidance for today`s dewpoints based on yesterday`s observations. Went a few degrees lower than NBM10. && .LONG TERM... (Sunday through Friday) Issued at 228 AM EDT Sat Jul 13 2024 Key Messages: 1. Warming trend continues this weekend into early next week, with the potential for record breaking daily high temperatures for the start of the work week. 2. Outside of an isolated high elevation shower/storm, mostly dry conditions are expected through the middle of next week. 3. Chances of precipitation begin to increase by late next week as a weakness in the ridge develops. Discussion: Ridging will remain in control Sunday and into the first half of the new work week, with mostly dry and anomalously hot conditions. By Monday and Tuesday, H85 temperatures near 23 to 25 degrees C will translate to potentially record breaking daily maximum temperatures across the region. Relative to our previous heat wave, Td will remain in the mid to upper 60s holding heat indices fairly close in proximity to the actual temperature - upper 90s to low 100s. While conditions look borderline at the moment, the area to keep an eye on for potential heat headlines(such as a heat advisory) would be central and southern valley. During this time frame subsidence aloft will restrict isolated diurnal convection to higher elevations. An upper trough swings into the Great Lakes region mid-week and flattens out ridging atop the southeast CONUS. A slow moving surface boundary draping through the Ohio Valley will bring widespread precipitation chances Wednesday into Thursday alongside a cooling trend. Better forcing remains displaced well to our north, so while we may not find ourselves with as much rain as we would like, mean ensemble guidance suggest that the probability of one-half inch of QPF through Thursday night is around 70-90%. Furthermore, signals suggest precipitation chances may linger to some extent Friday into the weekend as the boundary stalls to our south and upper troughing becomes stagnant. Daily Record High Maximum Temperatures Date Chattanooga Knoxville Tri-Cities Oak Ridge 07-13 105(1980) 100(1936) 96(1993) 100(1980) 07-14 103(1954) 101(1954) 98(1954) 101(1954) 07-15 103(1977) 98(1995) 96(1995) 100(1980) 07-16 105(1980) 100(1980) 100(1988) 103(1980) 07-17 103(1980) 101(1980) 94(1980) 103(1980) && .AVIATION... (12Z TAFS) Issued at 719 AM EDT Sat Jul 13 2024 VFR conditions through the period with light northerly winds at CHA and TYS and west at TRI. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 98 74 99 75 / 10 0 0 0 Knoxville McGhee Tyson Airport, TN 96 71 97 73 / 10 0 10 10 Oak Ridge, TN 96 70 96 72 / 10 0 10 10 Tri Cities Airport, TN 92 67 93 68 / 10 10 10 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... LONG TERM....KRS AVIATION...