Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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293 FXUS64 KMRX 280534 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 134 AM EDT Fri Jun 28 2024 ...New AVIATION... .UPDATE... Issued at 958 PM EDT Thu Jun 27 2024 No changes are needed to the forecast. Showers in SW NC have been dissipating with boundary layer stabilization. CAMS show some showers persisting across northern GA and upstate SC, but these should remain outside our forecast area, and PoPs ending after midnight in that area appears on track. Some patchy fog may be possible in some areas as dewpoints remain in the upper 60s to lower 70s, with calm winds and clear skies. && .SHORT TERM... (This evening through Friday) Issued at 227 PM EDT Thu Jun 27 2024 Key Messages: 1. A few isolated showers and storms persist through early evening, mainly along and south of I-40. 2. Drier overnight with areas of patchy fog. 3. Back to slightly above normal temps tomorrow, along with a few, diurnally driven, isolated showers and storms. Discussion: Our upper shortwave can currently be seen via satellite spinning down across MS/AL. The bulk of the precip associated with this feature is to our south, but we remain on the northern periphery of this system. This means isolated to scattered showers and storms will continue into this evening, but mainly along and south of I-40. No severe weather is expected. We dry out overnight as this system drops further south, along the Gulf Coast. Areas of patchy fog are likely, especially for any areas that received rainfall over the past 24 hours. Tomorrow, we get a southerly return flow as high pressure begins to develop just off the east coast. This moisture return will allow for some diurnally driven showers and storms during the afternoon hours. Coverage should be isolated to scattered at best. No severe weather is expected. && .LONG TERM... (Friday night through next Thursday) Issued at 227 PM EDT Thu Jun 27 2024 Key Messages: 1. Scattered showers and thunderstorms through the weekend with a diurnal increase in coverage. 2. Drier next week with ridge building across the region. Signals for hot weather returning. Discussion: Ridging continues across the Lower Mississippi Valley on Friday night. A strong shortwave across the northern Mississippi Valley into the Great Lakes will flatten the ridge across the Tennessee and Ohio Valleys and bring an associated cold front our direction. Ahead of this front, diurnal convection will be possible on Friday, and more likely, on Saturday and Sunday. The highest chances each day will be across the higher elevations. The NAM shows MLCAPE of around 2000 to 2500 each afternoon with a very moist atmospheric profile. Because of this, DCAPE will be limited to less than 800 J/Kg. This means that the severe risk is low, but a few damaging wind gusts could still occur. PW values are expected to be 2.1 to 2.4 inches ahead of this frontal boundary. Model QPF is not especially high, but this atmospheric profile will support very heavy rain rates with stronger convection. This could result in some localized higher rainfall totals and flash flooding, especially with any training convection. Behind this front, somewhat cooler and drier air is expected early next week. However, ridging builds back in mid-week with a warming temperature trend on Tuesday through Thursday resulting in above normal temperatures once again. By late week, southerly flow returns with increasing moisture and low diurnal thunderstorm chances. && .AVIATION... (06Z TAFS) Issued at 127 AM EDT Fri Jun 28 2024 Will see scattered to sometimes broken clouds around for much of the period, but any cigs will generally be at VFR levels. The best chance for MVFR cigs looks to be at CHA late tonight into the first part of the morning, and will include a tempo group there for a few hours with those MVFR cigs. There will be some mainly isolated convection around mainly during the day, but the probability looks too low to include at the terminals for now. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 92 76 91 76 / 20 20 60 30 Knoxville McGhee Tyson Airport, TN 92 74 91 75 / 20 10 70 50 Oak Ridge, TN 92 74 90 74 / 20 10 70 50 Tri Cities Airport, TN 90 71 90 72 / 20 10 70 50 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...DGS LONG TERM....JB AVIATION...