Area Forecast Discussion National Weather Service Morristown TN 326 PM EST Sat Nov 26 2016 .SHORT TERM (This Afternoon through Sunday)... Skies have cleared out quickly over the last couple of hours with mostly sunny skies now into NE TN and SW VA. However, temperatures this afternoon are generally in the 40s/50s with northerly winds. Current water vapor imagery and RAP upper air analysis indicates an upper level trough along the Eastern Seaboard with a ridge across the Great Plains. At the surface, high pressure is centered just to the west and forecast to move through the area tonight. PW values tonight are forecast to be in the 0.1-0.2 inch range. These values are near the minimum observed for late November. The combination of the dry airmass and surface high pressure overhead will set the stage for ideal radiational cooling conditions tonight. Lows tonight across the area will generally be in the mid to upper 20s but expect low 20s in the cooler locations. Temperatures will warm quickly tomorrow with the dry airmass remaining in place. Unfortunately, this will lead to elevated fire danger across the area with RH values dropping down to 20-25 percent tomorrow afternoon. The good news is that winds will be light from the southwest at around 5-10 mph at the most. With upper level heights rising and mostly sunny skies on Sunday, high temperatures will range from mid 50s to low 60s for most valley locations. .LONG TERM (Sunday night through Saturday)... The main focus will continue to be on the big rain-maker during the first half of the long term as well as high winds during the initial trough approach. On Sunday night...ridging still in place but slowly pushing east due to incoming system. Southerly flow will allow for low temps to be a few degrees above normal, mid to upper 30s north and lower 40s south. Amplifying trough to the west pushes in through the day on Monday. Strengthening southerly flow will allow highs to climb into the upper 50s to low 60s, 3 to 5 degrees above normal. Start bringing in precip chances by Monday afternoon but the bulk of the precip will hold off until Monday night. The main focus for Monday will be increasing winds due to strengthening 850mb jet. By late afternoon, sustained winds across the lower elevations will range from 10 to 15 mph with gusts from 15 to 20 mph. Winds in the higher elevations will be sustained from 15 to 20 mph with gusts up to 35 mph. Our highest peaks along the TN/NC line could gust up to 45 mph by late afternoon. Monday night: Lows will be around 15 degrees above normal due to strong southerly flow and cloud cover. Best chances for precip look to occur between midnight and 7 am Tuesday. QPF amounts will generally range from half an inch to one inch. Only expecting half an inch up across NETN where downsloping winds will initially limit precip. PW values are near max values for this date during the overnight hours. The NAM and GFS both show a 60 to 70kt 850mb jet moving across Monday night. It still looks like a high wind warning will eventually be needed for our higher terrain along with an advisory across the foothills for Monday night into Tuesday morning. Across the high terrain, winds could gust over 60 mph which could bring down quite a few trees. Will continue to watch this situation closely. Still not sold on a mountain wave event. Wind direction is not ideal and the inversion is lacking. Tuesday: High winds diminish in the morning as the jet moves east. There are big differences between the NAM and GFS regarding precip. The nam wants to hang the front up across the mountains and allow it to rain for most of the day, generally east of I-40. The GFS and ECMWF are more aggressive with the front and push it east of us by late Tuesday morning. Will split the difference with pops until there is better model agreement. If the NAM verifies, precip through the day Tuesday should generally be light to moderate. Highs will be in the mid to upper 60s, around 10 degrees above normal. At some point, we will see a break in the precip before the next wave moves in. General consensus is that the next wave will move in late Tuesday night into Wednesday morning. Another 1 to 3 inches of rainfall is possible with this wave as it moves through as PW values are again maxed out for this time of year. 850 mb jet isn't nearly as strong but the high terrain could still see gusts up to 30 mph. Enough instability remains present to allow for thunder in grids Tuesday night. Lows will remain mild and be in the low to mid 50s. Precip pushes east by Wednesday afternoon before a third and final wave moves in for Wednesday night into Thursday, where another inch of rain is possible. Precip ends on Thursday as a more zonal flow returns. Event total precip from Monday night through Thursday will range from 2 to 4 inches for most areas, with locally higher amounts possible. Extreme NETN and SWVA will see slightly lower amounts due to downsloping early in the event. Quiet weather and more seasonable temps return for the rest of the long term. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 30 63 43 62 / 0 0 0 20 Knoxville McGhee Tyson Airport, TN 28 60 38 62 / 0 0 0 20 Oak Ridge, TN 28 60 38 62 / 0 0 0 20 Tri Cities Airport, TN 25 58 31 58 / 0 0 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$