FXUS64 KMRX 201724 AAA AFDMRX Area Forecast Discussion...UPDATED National Weather Service Morristown TN 124 PM EDT Sat Jun 20 2026 ...New AVIATION... .KEY MESSAGES... Updated at 123 PM EDT Sat Jun 20 2026 - Dry and sunny weather continues today, with a chance of showers returning tomorrow afternoon. - Showers and storms are likely Monday in multiple rounds. Organized severe storms are possible, mainly Monday evening. - Rain chances decrease but continue for the rest of the period with temperatures near or below normal. && .DISCUSSION... Issued at 232 AM EDT Sat Jun 20 2026 High pressure expected to continue to dominate today and into early tomorrow, as the area is sandwiched between a southern and northern stream system. Temperatures a bit warmer today with somewhat lower humidity compared to yesterday. Flow turning out of the southwest on the other side of the high tomorrow, will send in warmer temperatures, as well as increased atmospheric moisture. An approaching shortwave trough from the central Rockies tomorrow, will increase chances of showers and storms later in the day. The strongest instability of a couple hundred J/Kg, will be over the general area of the plateau and southern valley. A second and potentially stronger wave within the flow, will impact the region Monday. This system will eventually bring a cold front across the area. Shear will be more supportive for storms, as well as CAPE, with much of the region forecast to be above 1000 J/Kg. PW values will be returning to near 2 inches, so flash flooding possibility may be heightened. WPC highlights the region with either a MRGL or SLGT chance of flash flooding. Factors possibly working against the severity of Monday afternoon and evening will be, how worked over we may become from late Sunday into early Monday activity, and if any recovery can occur from that. A sliver of a MRGL risk from SPC currently covers the very northern plateau for Day 3 at the time of this discussion. Following Monday, periods of isolated to scattered showers and storms will persist until the end of the forecast period next week under troughiness aloft. Temperatures, as a result, will hold steady near or just below normal. Dew points could possibly remain sub 70s Wednesday through Friday. && .AVIATION... (18Z TAFS) Issued at 123 PM EDT Sat Jun 20 2026 VFR conditions will continue through the rest of this TAF period, with light winds. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 68 88 73 85 / 0 30 70 90 Knoxville McGhee Tyson Airport, TN 64 90 72 84 / 0 20 70 100 Oak Ridge, TN 63 89 72 84 / 0 30 80 100 Tri Cities Airport, TN 59 89 68 83 / 0 0 30 100 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...KS AVIATION...DGS