Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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619 FXUS64 KMRX 231836 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 236 PM EDT Sun Jun 23 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (This evening through Monday) Issued at 149 PM EDT Sun Jun 23 2024 Key Messages: 1. Thunderstorms arrive from the northwest this evening. A few could pose a damaging wind risk mainly over the northern plateau region, but most will be run of the mill storms. 2. Monday will be dry and slightly cooler with dew points in the 60s by afternoon. Discussion: A trough is moving into the region from the Ohio Valley this afternoon. The surface cold front is currently (215 PM EDT) near SE Missouri/NE Arkansas. Hi-res guidance suggests isolated showers and storms developing early this evening. The best chance for strong showers and storms and the most coverage will be mid to late evening as the cold front moves into Middle Tennessee. The threat for severe storms looks marginal with CAPE less than 1000 and the front approaching the region after sunset. A few strong to severe storms cannot be ruled out mainly in the Plateau Counties. Showers and storms will likely be scattered and some locations may not even get any rain. The cold front will move through in the early morning hours. Monday will be dry with slightly cooler temps. Humidity will be lower with dew points dropping to the 60s by tomorrow afternoon with northerly flow and good mixing conditions. && .LONG TERM... (Monday night through next Sunday) Issued at 149 PM EDT Sun Jun 23 2024 Key Messages: 1. Rain chances arrive on Wednesday through Wednesday night with a weak frontal passage. Another front may bring showers and storms next weekend. 2. Above normal temperatures continue through the period, although humidity may be moderated on Tuesday and Thursday behind frontal passages. Discussion: We will be in a deep northerly flow pattern to start the period, with a cold front across central AL/GA and high pressure centered over WV. Dry air near the surface behind the front will provide comfortable low temperatures Tuesday morning, in the upper 50s to mid 60s. Highs will reach the 90s again under full sun, but dewpoints in the low to mid 60s will take the edge off the heat a bit. Low level moisture will increase somewhat on Wednesday as a cold front moves into the OH Valley region. A pre-frontal trough may bring some scattered showers and storms Wednesday afternoon, with greater coverage expected Wednesday night with the frontal zone and upper trough passage. CAPE will be generous with the NAM showing MLCAPE around 2000 J/kg, which should support some strong pulse convection, but the lack of shear will limit any organized threat of severe storms. Low probability wording in the HWO will continue for now. Dry conditions are likely on Thursday, although the NBM holds some chance PoPs in the area behind the front and upper trough. This appears overdone and will be lowered to a slight chance. Temps and dewpoints will drop slightly on Thursday behind the front, with highs in the mid 80s to lower 90s, and dewpoints in the lower to mid 60s. High pressure off the Atlantic coast becomes dominant again on Friday, which will bring rising temperatures and humidity. Models differ on timing of an approaching cold front over the weekend, which will bring some increasing rain chances either Saturday or Sunday. && .AVIATION... (18Z TAFS) Issued at 112 PM EDT Sun Jun 23 2024 VFR conditions are expected outside of thunderstorms. Scattered showers and isolated storms are expected this evening. Thunder potential is low to medium since storms will likely be isolated as a cold front approaches after sunset. Winds will become more northerly but light tomorrow morning. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 74 95 69 94 / 40 10 0 10 Knoxville McGhee Tyson Airport, TN 72 91 65 92 / 50 10 0 10 Oak Ridge, TN 71 90 65 92 / 50 10 0 10 Tri Cities Airport, TN 69 86 60 88 / 60 10 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...McD LONG TERM....DGS AVIATION...McD