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

Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
187 FXUS64 KMRX 052341 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 741 PM EDT Sun May 5 2024 ...New AVIATION... .SHORT TERM... (This evening through Monday) Issued at 245 PM EDT Sun May 5 2024 Key Messages: 1. Scattered showers/storms this afternoon will diminish this evening. 2. Increasing chances of showers and thunderstorms later tonight into Monday. Discussion: Weak upper level ridging over us to start will exit east this evening, and an upper level shortwave and associated longwave troughing will move over the region later tonight into Monday. An area of modest upper divergence associated with a right entrance region of the jet will move across our area later tonight into the first half of Monday as well. After the more diurnally driven late afternoon convection diminishes this evening, we will see an area of showers with some embedded thunder moving from southwest to northeast across our area later tonight into Monday. There will likely be a bit of lull behind this main band, but as the atmosphere recharges with some heating (afternoon MLCAPES will likely approach 1000 J/kg at least in the across the south/central) and the axis of the upper trough continues to move east over our area, we will see additional showers and thunderstorms around during the afternoon hours. && .LONG TERM... (Monday night through next Sunday) Issued at 245 PM EDT Sun May 5 2024 Key Messages: 1. Showers and thunderstorms are likely most days through much of the week. 2. Most organized and possibly strongest storms could come Tuesday into Thursday. 3. With several days of rainfall flooding threat will increase next week. Discussion: Monday night will see another day of showers and thunderstorms as the slow moving shortwave slides through the area helping to spark off storms. We will continue the trend of moderate to low CAPE and weak shear leading to similar storm structures as we`ve seen in the past few days. Tuesday will see a chance for a bit more organization when it comes to storms as a strengthening jet moves towards the Ohio Valley, and a LLJ begins to nose into the region. Several rounds of storms are possible with strong winds and flooding looking to be the primary concerns with storms at this time. By Wednesday, the jet will remain across the same area with a southern jet strengthening to in excess of 100 knots. A frontal boundary should be located across the Plains and making it`s way eastward. This should provide a larger divergent pattern aloft and 850mb flow possibly reaching 40 kts by the evening and into Thursday while the frontal boundary approaches from the northwest. Convection during this timeframe would likely be even more organized than on Tuesday. As with the convection on Monday/Tuesday strong winds and heavy downpours leading to flooding still looks to be the primary concern through the middle of the week. By Thursday the front will move into the area allowing for a focus for yet even more focused shower and thunderstorm activity. And forecast confidence continues to be low several days out and with lots of atmospheric changeover between now and Thursday. Almost all models point to a drier and cooler weekend once the front passes through with temperatures barely eking into the 70s for many locations Friday through the end of the weekend. And while there are some low end precipitation chances still possible, expect most locations will finally get a chance to dry out over the weekend. && .AVIATION...
-- Changed Discussion --
(00Z TAFS) Issued at 737 PM EDT Sun May 5 2024 Scattered SHRA and TSRA possible at times through the next 24 hours. Winds will be light outside of any storms at the terminals. A line of convection moving across Alabama will likely reach CHA by 02-03z, bringing gusty winds and temporary VIS restrictions. Tomorrow morning a brief period of MVFR CIGs is expected before a return to VFR. Tried to time out most likely times of convection. Additional TSRA will likely be in the region by the afternoon to the end of the period, even if not at the terminals.
-- End Changed Discussion --
&& .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 66 83 66 86 / 60 60 30 50 Knoxville McGhee Tyson Airport, TN 63 79 63 83 / 40 70 50 60 Oak Ridge, TN 63 79 63 82 / 40 70 50 60 Tri Cities Airport, TN 60 78 60 81 / 30 70 40 70 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... AVIATION...Wellington