012 FXUS64 KMRX 071841 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 241 PM EDT Fri Oct 7 2022 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Saturday) Issued at 142 PM EDT Fri Oct 7 2022 Key Messages: 1. Cold front passage occurs later today, but will be moisture starved so no rainfall expected. 2. Front will knock highs down into the 60s for Saturday. Discussion: Compact shortwave will swing through midwest and into the Ohio valley this afternoon and evening, pushing a cold front southeast through the forecast area. Visible satellite tells the tale, which is that the front is moisture starved. As such, don't expect much more than some increased low clouds as the front moves in later this afternoon. Some guidance does try to spit out a hundredth or two of QPF in some of the higher terrain of southwest Virginia and the east TN mountains, but this seems optimistic to say the least. Have continued with a dry forecast as a result. Speaking of moisture levels, did undercut NBM guidance for dewpoints this afternoon and overnight. Believe winds may stay elevated enough to prevent temperatures from dropping too far but with dewpoints expected to drop into at least the mid, if not low, 30s tonight in the north a few patches of frost could occur. Certainly don't expect this to be the rule, so will hold off on any frost/freeze products for the short term period. Saturday will be cool, with highs in the 60s and dry continental air continuing to filter in from the north. && .LONG TERM... (Saturday night through next Friday) Issued at 142 PM EDT Fri Oct 7 2022 Key Messages: 1. Dry and cooler through the weekend, with frost potential Saturday night, followed by a warming trend. 2. The next chance of rain will be with a cold frontal passage on Thursday. Discussion: Towards the latter half of the weekend and into early next week, low amplitude zonal flow will reside across the eastern two-thirds of the CONUS. High pressure at the surface will remain anchored across the Tennessee Valley and into the Appalachians. Dry and below normal temperatures can be expected Sunday through Tuesday with a slight warming trend. Good radiational cooling conditions Saturday night will lead to areas of frost across southwest Virginia, and northeast Tennessee. Amplification in the upper levels begins on Tuesday as a lead shortwave digs into the intermountain west, increasing downstream heights across the Tennessee Valley. Southerly flow increasing as the surface high moves off shore the eastern coast will transport higher theta-e air poleward. Temperatures increase Tuesday onward with highs approaching the mid to upper 70's, back to near normal. Forecast confidence begins to decrease slightly the middle to latter half of next week as the aforementioned shortwave moves off the Rockies. A cold front will approach from the west providing for an increase in showers and thunderstorms especially on Thursday into Thursday night. Generally followed the NBM with PoPs, advertising chance PoPs for this period. Much drier and cooler weather follows the frontal passage with temperatures back to near or below normal. && .AVIATION... (18Z TAFS) Issued at 134 PM EDT Fri Oct 7 2022 VFR conditions are expected to prevail through the period. Incoming front later this afternoon may bring FEW-SCT bases between 4-6k AGL to all terminals but that should be about it. Some guidance does bring in MVFR CIGS to KTRI later today, but front is moisture starved so I believe that is too pessimistic. Otherwise, winds will be light at KTYS and KTRI but could see +12kt winds at KCHA tomorrow morning onward. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 51 70 42 71 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 47 65 41 69 / 0 0 0 0 Oak Ridge, TN 46 65 39 68 / 0 0 0 0 Tri Cities Airport, TN 43 60 35 65 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...CD LONG TERM....Diegan AVIATION...CD