942 FXUS64 KOHX 061113 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 513 AM CST Sat Feb 6 2021 .UPDATE... FOR 12Z AVIATION DISCUSSION. && .DISCUSSION... Trends continue upward for accumulating snow potential on the Plateau this evening and overnight, with next week still showing some differences between the models. Still low confidence on next week's potential for any mixed precip/snow, but models have nudged upward on surface temps so forecast leaned a little more towards rain in the southeast, but still looks to be cold enough for snow in the northwest. More on that below. First half of today will be dry as the Plains trough approaches from the Ozarks. 850 mb temps look to hold below freezing for most before some WAA moves into southern zones. High temps today will get to the mid 40s to around 50, but look to fall quickly after sunset to the mid 30s. This will be another event where a few degrees up or down will be a huge difference not only on what type of precip gets to the surface, but if snow will stick. The Plateau looks to get to snow from a rain snow mix before midnight, especially at higher elevations, so accumulating snow potential will begin this evening. Models really ramp up the snow potential around midnight on the Plateau, showing high omega values, decent q vector convergence, and deep moisture. The GFS again shows very high snow totals, but most models via cross sections show the deep moisture and strong lift, so current snow forecast lines up with model average including CAMs. Consensus has around 2 tenths of an inch of QPF for the Plateau, and even at a simple 10:1 snow ratio that would put down 2 inches. Towards the end of the event as temps cool a bit further, snow ratios could climb a bit, and based on forcing/moisture some areas could get up to around 3 inches on the Plateau. Again, a few degrees higher or lower will drastically change the forecast. If temps hold in the mid 30s longer, and rain/snow mix persists past midnight, less snow. If snow starts earlier, chances for getting higher snow totals will increase. Snow forecasts in the south can never be a slam dunk! Areas east of I-65 could see a dusting to around a half inch, with a few areas closer to the Plateau getting around an inch if the transition to all snow occurs around midnight. For the rest of the mid state, a dusting to a few tenths will be possible. Went with a winter weather advisory for the upper Cumberland and areas nearby, but the advisory may need to be expanded southward if models continue to trend upward for amounts at higher elevations outside of the current advisory. Sunday and Monday will be dry before a Midwest trough tries to bring a cold front southward. Previous runs had this trough diving southeastward, but current solutions keep it up north, which should keep most of the area with rain chances if precip develops Tuesday. By Wednesday, another trough develops in the Plains, and begins to move eastward. The GFS remains a little colder than the ECMWF/Canadian, but has trended warmer. This should keep most of the daytime precip as rain, but as temps cool in the evening, chances for snow will spread southeastward Wednesday evening. By Thursday, a stronger trough from the northern Plains looks to phase with the weaker trough to the south which intensifies moisture advection into the mid state. The ECMWF and GFS even try to sneak a little CAPE into southern zones, but left out mention of thunder for now as uncertainty on precip type and temps is high next week. Models do not agree on the strength of this northern Plains trough, but they do show hints of a cold front moving through Thursday night, and that is currently the best shot at some accumulating snow for the mid state. Precip chances move out Friday morning and cold air looks to move in. The GFS has the coldest air, while the ECMWF is quite a bit warmer. Did not change the extended temps much but the spread is very high...if the GFS is correct, we will be in the low teens Saturday morning, if the ECMWF is correct, we will be in the upper 20s. Still hoping for some consistency between the model solutions for next week! && .AVIATION... 12Z TAF DISCUSSION. BNA/MQY/CKV/CSV...VFR conditions this morning with some mid and high clouds. Rain will works its way from south to north across middle TN this afternoon. By 00Z-02Z MVFR CIGs expected followed shortly there after by VIS. Rain will change to a rain/snow mix or all snow and when this happens CIGs will drop to IFR and even LIFR at CSV. Precipitation will clear from west to east starting at CKV after 09Z and won/t be to CSV until after 07/12Z. && .OHX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 6 PM this evening to 6 AM CST Sunday for Cumberland-Fentress-Overton-Pickett-Putnam-White. && $$ DISCUSSION......Barnwell AVIATION........12