Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
867 FXUS64 KMRX 081851 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 251 PM EDT Tue Sep 8 2026 ...New DISCUSSION... .KEY MESSAGES... Updated at 243 PM EDT Tue Sep 8 2026 - Mostly dry conditions through Wednesday. Scattered to numerous showers and storms possible at times Thursday evening through Saturday. - Above normal temperatures expected through the forecast period. && .DISCUSSION... Issued at 243 PM EDT Tue Sep 8 2026 An anomalous upper level ridge continues to build into the region this afternoon. H5 heights near 595 dam will translate to above normal temperatures - about 5 degrees above normal per early September standards. Surface high pressure will keep the area mostly dry, though a few isolated showers cannot be ruled out in the high terrain. This pattern will continue into Wednesday. By Thursday an upper level trough and associated jet is expected to dip into the Great Lakes region. An accompanying cold front will provide an axis of forcing leading to a return of shower and storm chances by Thursday evening and night. Chances for precip will generally be greatest north of I-40 during this time. While the aforementioned jet will depart east, additional impulses and associated vorticity maxima will swing through the southern Appalachians Friday and Saturday, all while the frontal boundary lingers across the region. This will maintain daily chances for showers and storms. Per latest RRFS and NAM12, may have to keep an eye on Friday for a low potential of isolated strong storms. Latest soundings from these models suggest MLCAPE near 1500 J/kg, effective shear near 20kts, and mid-level lapse rates near 6. A transition to quasi-zonal flow is expected Sunday. While not totally dry, a lesser coverage of precip chances is expected. This will continue to be the case into the new work week as additional shortwave ridging builds atop the southern Appalachians. && .AVIATION... (18Z TAFS) Issued at 141 PM EDT Tue Sep 8 2026 VFR conditions with light winds and SCT/BKN mid to high level clouds this afternoon. Patchy fog is expected across the valley tonight, but confidence in any impacts to a terminal are too low to include at this time. Conditions will remain VFR tomorrow afternoon with light winds from the S/SW. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 69 93 69 95 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 67 91 67 91 / 0 0 0 0 Oak Ridge, TN 67 90 66 91 / 0 0 0 0 Tri Cities Airport, TN 62 86 63 86 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...KRS AVIATION...KRS