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Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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139 FXUS64 KMRX 122320 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 720 PM EDT Mon Aug 12 2024 ...New AVIATION... .SHORT TERM... (This evening through Tuesday) Issued at 229 PM EDT Mon Aug 12 2024 Key Messages: 1. Mostly areas stay dry stay dry through the short term. 2. Slight chance POP northeast TN and southwest VA tomorrow morning. Slight Chance POP east TN mountains tomorrow afternoon. Our northwest flow pattern remains in place due to a broad trough to our northeast and ridging to our west. Expect dry conditions overnight with below normal temperatures around 5 degrees below normal. A weak and moister starved shortwave will move through the Ohio River Valley tomorrow morning. As a result, NBM gives a slight chance POP and increased cloud cover for northeast TN and southwest VA. Most other areas expected to be dry through the day. However, slight chance POPs in place across the east TN mountains during afternoon peak heating. High temps will be near normal. && .LONG TERM... (Tuesday night through next Monday) Issued at 229 PM EDT Mon Aug 12 2024 Key Messages: 1. Near normal temperatures continue. 2. Mostly dry conditions through mid-week before increasing chances of showers and storms late week into the weekend. Discussion: Not a whole lot to speak on for the first few days of the extended period. Surface high pressure and associated subsidence will keep the area mostly dry, though an occasional diurnal pop-up shower cannot be ruled out in the higher elevations. Temperatures will remain seasonal and are likely to do so through the majority of the long term. An upper level shortwave will influence the deepening of surface low pressure in the upper mid-west by the late week. As this surface low progresses across the western Great Lakes and into Michigan we can expect enhanced frontogenetical forcing locally. This will lead to heightened chances of showers and thunderstorms by Friday and into Saturday. Model derived soundings suggest periods with Bulk Effective Shear approaching 25-30kts and a low-end southwesterly LLJ near 30kts. We will need to keep an eye on potential strong/severe chances over the coming days but aforementioned soundings also suggest a limiting factor may be available energy, with CAPE values generally 1500 J/kg or lower Friday. Even less so by Saturday due to a worked over environment & potential lingering cloud cover. For Sunday and into early next week, troughing looks to remain anchored over the Ohio Valley and into the mid-south. Persistent deep northwesterly flow will allow for lingering PoP chances during this time, however, PWAT falling to near 1 inch and a thermodynamic profile trending more stable all suggest that any signals for notable impacts will be well diminished. && .AVIATION... (00Z TAFS) Issued at 718 PM EDT Mon Aug 12 2024 VFR conditions expected for the next 24 hours. Light winds and mostly clear skies will continue, with a chance of a brief shower this evening across southwest Virginia being the only weather of note. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 90 67 91 69 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 87 63 88 64 / 0 0 0 0 Oak Ridge, TN 86 63 88 65 / 0 0 0 0 Tri Cities Airport, TN 84 58 84 61 / 0 20 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... LONG TERM....KRS AVIATION...