Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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095 FXUS64 KMRX 281753 AAC AFDMRX Area Forecast Discussion...UPDATED National Weather Service Morristown TN 153 PM EDT Sun Apr 28 2024 ...New AVIATION... .UPDATE... Issued at 1003 AM EDT Sun Apr 28 2024 Visible satellite imagery shows an area of clouds covering portions of the southern plateau and southern Tennessee valley this morning. This is appears to be associated with moisture advection and weak ascent along the 295K theta surface. As daytime heating continues and the mixed layer deepens, these clouds should scatter out rather quickly by midday, leaving partly cloudy skies at worst in those areas. Made some adjustments to sky cover to come in line with observations. Don`t see a need to adjust temperatures yet as these clouds should dissipate soon, and none of the high res or rapid update guidance show any substantial difference in forecast highs in those areas vs the current forecast. Wouldn`t be surprised if the forecast winds up being a degree or two high though. Otherwise, no changes for the morning update. && .SHORT TERM... (Today and tonight) Issued at 349 AM EDT Sun Apr 28 2024 Key Messages: 1. The Wind Advisory will be allowed to expire at 4 AM. 2. Warm temperatures today under mostly sunny skies. Discussion: Current wind gust speeds have dropped under 40 mph at Cove Mountain and Camp Creek, and are expected to continue to trend downward, so the Wind Advisory will be allowed to expire at 4 AM. A large high pressure ridge through the lower and mid levels will continue to be located east of the area today and tonight, just of the NC/SC coastline. With the southerly low level flow and scattered to no cloud cover, highs today will be warm, in the lower 80s in most Valley locations. Tonight will be mostly clear, and perhaps a little breezy in the mountains and foothills once again as the nocturnal southerly jet picks up, but likely under Advisory criteria. Lows will be mainly in the mid 50s to lower 60s. && .LONG TERM... (Monday through Saturday) Issued at 349 AM EDT Sun Apr 28 2024 Key Messages: 1. Continued above normal temperatures through the upcoming week. 2. Active weather pattern to bring chances for showers and storms Tuesday, Thursday night through Saturday. Discussion: Starting Monday the upper trough to the west begins to shift east toward the Ohio Valley and Great Lakes. The main surface low will be far to the northwest over WI and MN. The cold front will move from the upper Mississippi Valley and approach the lower Mississippi Valley and Ohio and Tennessee Valleys Monday evening. Showers and thunderstorms will develop Monday night and continue Tuesday across the Tennessee and Ohio Valleys. Expect rain showers and possible thunderstorms to move onto the plateau during the day Tuesday. Some may be strong. There also could be some locally heavy rainfall but flooding right now looks to not be significant. The cold front will be slowly crossing east Tennessee Monday night and Tuesday. The convection will be through by late Tuesday evening with ridging aloft moving in for the rest of the night. Wednesday should start out dry with higher pressure settling in. Also dry Wednesday night although some shortwave energy may produce a few showers across eastern KY and southwest VA. Higher pressure will build back in Wednesday for a mostly sunny day but a new system with cold front will approach the western sections Thursday into Friday. Thursday ahead of the front will likely be the warmest day of the week just ahead of the front. Highs mid to upper 80s Thursday. Rain may hold off until Thursday night as the front is moving slow. Friday all areas get some more showers and possible storms. The precipitation should move out Saturday afternoon with clearing by evening. A more significant rainfall is expected with this later system with the slow movement. Possibly 0.5 to one inch of rainfall. && .AVIATION... (18Z TAFS) Issued at 143 PM EDT Sun Apr 28 2024 The 18z TAFs will be a persistence forecast since there`s little change expected in the weather pattern. Continued southerly moist flow should produce a temporary SCT-BKN025 deck at KCHA between roughly 10z and 13z or so. Otherwise, VFR Conditions are expected at all terminals. Only other forecast item of note will be the occurrence of gusty winds again tomorrow at KCHA, with gusts of 18-20kt expected. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 83 61 83 64 / 0 0 0 70 Knoxville McGhee Tyson Airport, TN 83 59 83 62 / 0 0 0 40 Oak Ridge, TN 83 59 83 62 / 0 0 0 50 Tri Cities Airport, TN 81 55 82 57 / 0 0 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...CD LONG TERM....TD AVIATION...CD