Area Forecast Discussion National Weather Service Morristown TN 334 PM EST Sun Nov 27 2016 .SHORT TERM (This Afternoon through Monday)... High clouds are already moving in across the forecast area ahead of the approaching system. Current water vapor imagery and RAP upper air analysis indicates a couple of shortwave troughs, one located across the Rocky Mountains and another moving along the Pacific Coast. Upper level ridging extends from the Gulf of Mexico northwards into the Great Lakes. At the surface, high pressure is centered just to the east of the area across the Carolinas with lee cyclogenesis along the front-range of the Rocky Mountains. Dry conditions have continued this afternoon with dewpoints in the upper teen to low 30s has lead to enhanced fire danger across the area this afternoon and issued a statement earlier this morning. Cloud cover will continue to increase overnight as the upper level trough dives quickly into the Southern Plains. The surface high will shift eastward out over the Atlantic with southerly flow returning to the area. This southerly flow will advect moisture into the area ahead of the approaching cold front. Overall, expect the bulk of the moisture will arrive just beyond the end of the short-term period. A few shower will be possible along the highest elevations where a bit of upslope may occur Monday and again across the Plateau as the system starts to move in late in the forecast period. The main impact in the short-term period will be the strong southerly winds that develop ahead of the system. The GFS is the strongest with the low level winds indicating 925 mb winds of 50-60 kts late Monday night. The NAM and ECMWF are a bit more conservative in the 35-45 kt range. Regardless, strong southerly winds are forecast ahead of the system. With this, a high wind watch continues for the higher elevations in SW NC and along the TN/NC line. Wind speeds of up to 60 mph will be possible in the higher elevations. A wind advisory has been issued for the remainder of E TN where winds will gust to around 40-45 mph at times late Monday. .LONG TERM (Monday night through Sunday)... Monday night: Period starts with precip knocking on our door with longwave trough just to the west. Latest guidance continues to suggest best chance of pops will be around midnight and through early Tuesday morning. Initially, have pops increasing from the west but did define an area of much lower pops along the foothills of our eastern mountains to account for strong downward vertical motions. Downsloping winds will keep this area the driest the longest, but it will eventually rain. 60 to 70kt jet moving in overnight has prompted a high wind watch for the higher elevations of our eastern mountains and a wind advisory elsewhere, expect for our Southwest Virginia counties. An advisory for our Virginia counties will likely come during the next forecast issuance. Winds could gust over 60 mph across the highest elevations with gusts up to 40 across lower elevations. Still looking at generally three quarters of an inch to one and half inches of precip Monday night into Tuesday morning south of I-40. Half an inch to three quarters of an inch for Northeast TN and Southwest Virginia. PW values continue to be near max values for this time of year. Lows Monday night will be mild with lows 15 to 18 degrees above normal. Lows will only be a few degrees below our normal highs for this time of year. Tuesday: NAM in a little better agreement today with GFS and ECMWF, but still not great. NAM still wanting to hang up the boundary across the eastern mountains and allow precip to hang in east of I- 40, especially across the foothills and eastward, for much longer Tuesday than other models. Will continue to split the difference in pops. Currently have high wind watch and advisory expiring 12z Tuesday as the stronger jet core move east of the mountains. Tuesday still looks breezy though as there is still a 30 to 40kt 850mb jet in place through the day. Highs on Tuesday in the upper 60s to low 70s due to strong southwest flow and partial clearing later in the day. Last half of Tuesday into first half of Tuesday night looks dry. Tuesday night and Wednesday: Dry conditions will quickly give way to another large batch of precip moving in as another wave of moisture surges in from the southwest. PW values with this wave are at record levels as soundings are completely saturated from the surface all the way up through the upper levels of the atmosphere. Highest pops look like they will occur after midnight and continue through much of Wednesday. During this time we could pick up 1 to 3 inches of rain across much of our area, with 1 to 2 inches across Northeast into Southwest Virginia. It also appears that we could see some strong storms late Tuesday night and into Wednesday morning across the Southern TN Valley. Soundings indicate robust shear in place with low to moderate CAPE values for this time of year. The main threat with any storms at this time appears to be small hail and damaging winds. Lows overnight will be near our normal highs. Highs on Wednesday will be in the low to mid 60s. Event total precip still looks like a general 2 to 4 inches of rain for most of the area with 1 to 3 inches for Northeast TN into Southwest Virginia. Locally higher amounts possible across the Central and Southern TN valley. Wednesday night and beyond: A few light showers could linger overnight and into Thursday morning but the bulk of the precip will have moved off to our east. Lows will be cooler behind the boundary with temps in the upper 30s to low 40s. A more zonal flow returns Thursday and lasts through the remainder of the long term giving us quiet weather. Highs and lows during this time will be more seasonable. Another system looks to move in at the end of the period that could bring us more rain. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 44 67 55 73 / 0 30 100 60 Knoxville McGhee Tyson Airport, TN 39 65 55 72 / 0 10 100 70 Oak Ridge, TN 40 62 53 71 / 0 20 100 60 Tri Cities Airport, TN 31 60 49 69 / 0 10 90 80 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...High Wind Watch from Monday afternoon through Tuesday morning for Cherokee-Clay. TN...High Wind Watch from Monday afternoon through Tuesday morning for Blount Smoky Mountains-Cocke Smoky Mountains-Johnson- Northwest Carter-Sevier Smoky Mountains-Southeast Carter- Southeast Greene-Southeast Monroe-Unicoi. Wind Advisory from 1 PM EST /noon CST/ Monday to 7 AM EST /6 AM CST/ Tuesday for Anderson-Bledsoe-Bradley-Campbell- Claiborne-East Polk-Grainger-Hamblen-Hamilton-Hancock- Hawkins-Jefferson-Knox-Loudon-Marion-McMinn-Meigs-Morgan-NW Blount-North Sevier-Northwest Cocke-Northwest Greene- Northwest Monroe-Rhea-Roane-Scott TN-Sequatchie-Sullivan- Union-Washington TN-West Polk. VA...None. && $$