Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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382 FXUS64 KMRX 032339 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 739 PM EDT Mon Jun 3 2024 ...New AVIATION... .SHORT TERM... (This evening through Tuesday)... Issued at 325 PM EDT Mon Jun 3 2024 Key Messages: 1. Most areas have stayed dry today with only a few isolated showers and thunderstorms around this afternoon. These storms have been across southeast Tennessee, southwest North Carolina and the northern Cumberland Plateau. 2. Tonight there will be some patchy fog, locally dense in places with only a few showers lingering into th evening. 3. Increasing rain chances Tuesday with more widespread coverage, especially during the afternoon hours. Discussion: More sunshine, with warmer afternoon temperatures today. Some isolated showers and storms were moving across the Cumberland Plateau and southeast TN and southwest NC this afternoon. This convection should weaken early this evening. Some patchy fog will form as winds will be light and low level moisture is high. Weak ridging is still over the eastern Tennessee Valley both at the surface and aloft. A shortwave trough moving into the lower MS Valley tonight will set off storms to the west and then they will move into west TN, MS and AL overnight tonight and early Tuesday. Outflows from any thunderstorm complexes will be the focus for more development farther east Tuesday and shift east or northeast through the forecast area Tuesday afternoon. This will usher in another wet pattern the next couple days. Lowered rainfall amounts from what was originally in the grids for tomorrow afternoon. But some heavier showers could produce significant rainfall locally. Per SPC Day 2 outlook afternoon thunderstorms are possible as one or more convectively enhanced vorticity maxima float across the Ozarks into the TN Valley region. A seasonally moist and moderately unstable, but weakly sheared environment is forecast. Some local enhancement to shear is possible near remnant MCVs or outflow boundaries moving through the area. Isolated strong to severe storms capable of strong gusts and marginal hail will be possible through early evening. This area will be mainly west of the forecast area but some strong storms could affect the southern plateau later in the day. && .LONG TERM... (Tuesday night through next Monday)... Issued at 325 PM EDT Mon Jun 3 2024 Key Message: Multiple rounds of showers and storms are expected Tuesday into Thursday. A few strong to marginally severe storms cannot be ruled out Wednesday, with damaging winds the primary threat. Isolated flash flooding is also possible. Discussion: By Tuesday night the shortwave will be lifting out towards the northeastern United States, and helping to act as the focal point of the first round of thunderstorms. We should see a uptick in storm strength and coverage during the afternoon hours on Tuesday coinciding with peak heating. Wednesday looks to be the greatest chance to see the strongest thunderstorms of the week as the jet aloft helps to amplify lift and the LLJ increases in strength as the front approaches the area. Forecast soundings show that there is enough instability to support healthy thunderstorm development, and with the increasing LLJ shear gets an uptick to around 20-30 knots, which would help storms maintain strength. With the drier air aloft the DCAPe values also jump up over 500 J/kg, which suggests collapsing thunderstorms could have enough momentum behind them to cause sporadic wind damage. At this time am not expecting widespread severe thunderstorms, but some of the strongest storms of the day could briefly see severe level winds... In addition the higher PWAT values of around 1.75" will help to produce heavy downpours under the core of these storms, and an isolated flooding risk. Thursday should see some additional shower activity as the front moves through, but QPF and storm coverage should both be lower than Wednesday. We should see a break in activity heading into the weekend as the low continues to swing around the New England region, and drier northwest air flows into the region. Temperatures through the weekend should be fairly mild with most locations topping out around the 80 degree mark. && .AVIATION...
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(00Z TAFS) Issued at 736 PM EDT Mon Jun 3 2024 A few showers and thunderstorms are in the vicinity of CHA this evening, and this activity should decrease after sunset. There`s about a 10 percent chance of isolated showers overnight, mainly at CHA and TYS, but thunder probabilities were too low to carry throughout the overnight hours. With a clear sky and light wind, fog is expected at TRI tonight with MVFR and IFR conditions possible. Showers and thunderstorms increase in coverage on Tuesday afternoon with more widespread coverage than today expected. Have included VCTS at all sites after 18z Tuesday. Prevailing winds remain light generally from the southwest.
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&& .PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN 68 84 69 86 / 40 70 60 80 Knoxville McGhee Tyson Airport, TN 65 84 67 83 / 20 80 60 90 Oak Ridge, TN 64 83 66 82 / 10 70 60 90 Tri Cities Airport, TN 60 84 63 81 / 10 50 40 90
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&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...TD AVIATION...JB