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

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893 FXUS64 KMRX 050542 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 142 AM EDT Wed Jun 5 2024 ...New AVIATION... .UPDATE... With increased cloud cover and lingering convection, temperatures have remained higher than expected this evening. As such, temperatures were raised for the evening with a slighter increase in overnight lows. Also, PoPs were increased in central portions of the area to encompass the line of showers and storms moving through the area. Otherwise, fairly limited changes were made. && .SHORT TERM... (This evening through Wednesday) Issued at 203 PM EDT Tue Jun 4 2024 Key Messages: 1. Showers and thunderstorms will be more isolated overnight and into the early morning hours. 2. Scattered to numerous showers and storms are expected Wednesday afternoon and evening. Cannot rule out a few strong storms with locally gusty winds or heavy downpours but overall, general thunderstorm activity will be predominant. Discussion: Shower and thunderstorm activity has increased the past couple of hours. With low shear and low to moderate CAPE expected this afternoon, a few strong storms will be possible but severe potential will be low. In the upper levels, a shortwave moving out of IL/MO into the Ohio Valley is bringing enhanced activity to the region this afternoon and evening. Activity will be more isolated in the overnight and early morning hours. Tomorrow, a trough stretches from the Ohio Valley to Arkansas/West Tennessee. This will bring another round of showers and storms to the region starting in the morning for the Cumberland Plateau and Southern Tennessee Valley and spreading areawide in the afternoon hours. With low deep layer shear and moderate CAPE tomorrow afternoon, some strong storms are likely and a few severe storms will be possible but widespread severe weather is not expected. Some patchy fog is possible in the early morning hours but lingering cloud cover overnight will limit fog potential. Southwesterly winds will increase slightly tomorrow ahead of a cold front that will stay to our west through this forecast period. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 203 PM EDT Tue Jun 4 2024 Key Message: 1) Drier and cooler Friday into Sunday behind the front. 2) Poor agreement in models from Sunday onward, with a boundary over the southeastern US. Discussion: By Wednesday night we`ll likely see another round of storms move through as the frontal boundary finally pushes through the southern Appalachian region heading into the overnight hours. Some storms could last into sunrise on Thursday, but many people should be fairly dry for Thursday as the drier air from the northwest begins to move in. Cooler and drier conditions will likely persist for most people Friday and Saturday with daytime highs staying just below seasonal normals and dew point values only in the 50`s meaning it should be a generally pleasant weekend. Shower and thunderstorm chances will make a return to the region by late Sunday as a weak shortwave dives through the Tennessee Valley. Somewhat uncertain on where the best dynamics with this quick moving system will be, but it looks likely it will be somewhere in the Tennessee/Ohio Valley Sunday into Monday. Once we move into next week things become much more unclear as stationary boundary looks to strengthen convergence somewhere in the southeastern United States. Most models are keeping the focus of enhanced thunderstorm activity with this system somewhere between the Tennessee Valley and the Gulf Coast. Will keep moderate precipitation chances in the forecast, but hopefully long range models come into better agreement to increase confidence on where this boundary sets up. && .AVIATION...
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(06Z TAFS) Issued at 133 AM EDT Wed Jun 5 2024 Included some morning shra with mvfr cigs at CHA based on recent radar and sfc ob trends over northern Alabama, as well as shra at TRI. Cannot rule out brief mvfr cigs or br development due to low level moisture from recent rains but opted to not include as uncertainty is high. Additional showers and storm development is expected late this morning into the afternoon hours, with a drier trend for the evening. Southwest winds will approach 10kts at all sites but gusts close to 20 are possible at TYS ahead of an approaching front this afternoon.
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&& .PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN 87 69 88 65 / 60 70 30 10 Knoxville McGhee Tyson Airport, TN 83 68 85 62 / 80 70 40 10 Oak Ridge, TN 82 68 86 60 / 80 70 30 10 Tri Cities Airport, TN 82 66 82 58 / 80 80 60 10
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&& .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...McD AVIATION...KRS