Area Forecast Discussion
Issued by NWS Nashville, TN
Issued by NWS Nashville, TN
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893 FXUS64 KOHX 182239 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 539 PM CDT Thu Apr 18 2024 ...New AVIATION... .SHORT TERM... (Rest of today through Friday) Issued at 1157 AM CDT Thu Apr 18 2024 We started off cloudy this morning, but the clouds have been breaking up and we expect temps to take off into the low to mid 80s this afternoon. As temps warm, the atmosphere will destabilize with capes rising to 1000-2000 J/kg by late afternoon. This will set the stage for development of showers and thunderstorms. The first storms will form late this afternoon and evening as an impulse moves northeast from the Southern Ms Valley. This impulse will bring a first round of scattered thunderstorms starting as early as 3 PM in our western counties, with storms peaking in coverage and intensity from 7 PM to 10 PM. Later this evening, another batch of thunderstorms in the form of a weakening QLCS will come from the west ahead of a cold front. Each of these rounds of storms has the potential to produce severe wx, although latest models are not very impressive bringing shear and instability together. Generally, the greatest thunderstorm coverage and severe potential will exist west of I-65. It looks like the first batch will arrive with fairly strong cape but weak to marginal deep layer shear. A handful of warnings may bee issued for localized wind gusts over 60 mph and severe hail over 1 inch in diameter. Later in the evening, the instability wanes, but shear values will become higher as the QLCS approaches. Damaging wind gusts of 60 mph appear to be the main concern for late evening and overnight, but a tornado cannot be ruled out for our far northwest counties. The incoming band of storms may fall apart pretty quickly while encountering mediocre lapse rates and more stable surface air, possibly already worked over by early evening storms. Otherwise, a few spots may have some brief street flooding with any heavy downpours this evening. We don`t expect widespread flooding problems. Showers and few leftover storms will move out Friday morning. We will be left with mostly cloudy and cooler conditions as a north breeze drops temps back to normal or a little cooler than normal. && .LONG TERM... (Friday Night through next Thursday) Issued at 1157 AM CDT Thu Apr 18 2024 Through the weekend, surface winds will continue to come from the north as the center of cool high pressure slides southward across the plains. Zonal flow aloft will bring a series of weak disturbances, resulting in a good deal of cloud cover through the weekend and perhaps a few light showers, mainly over our southern counties. Weekend temps will be a little cooler than normal. Temperatures will rebound Monday and Tuesday ahead of the next front and chance for showers late Tuesday into Wednesday. && .AVIATION... (00Z TAFS) Issued at 527 PM CDT Thu Apr 18 2024 There are 2 main areas of convection upstream that will provide an impact to the taf fcst through 12Z. The first area extends n-s, just east of the MS river. This is in response to a midlevel axis, with some weak pva to the east into western middle TN currently. The 2nd area resides along the primary frontal boundary which is moving through St Louis and southern MO. For the upcoming taf fcst, thunderstorm activity will reach into northwestern areas early on, Instabilities however are expected to weaken with time. Central and eastern taf sites will likely experience the convection mainly toward 06Z, in association with the primary boundary. The aforementioned mid level wave will lose some of its negatively tilted orientation and become more n-s with time. All in all, TS inclusion is of course warranted this evening, mainly west. Wind gusts with the stronger storms could approach 30-35 kts. Cigs will lower to aob 3kft by the 09Z-12Z time frame. Fropa expected within the 10Z-15Z period. Post frontal upper dynamics are zonally flat and therefore, isolated to scattered light showers should wind down in the morning. Low clouds will hang on through the remainder of the period. && .PRELIMINARY POINT TEMPS/POPS... Nashville 61 72 51 68 / 90 30 10 10 Clarksville 56 69 47 66 / 90 10 10 10 Crossville 60 70 47 64 / 80 60 10 10 Columbia 61 72 49 66 / 80 20 10 20 Cookeville 61 69 49 63 / 90 50 10 10 Jamestown 60 70 46 63 / 90 60 10 10 Lawrenceburg 62 72 51 66 / 90 30 10 20 Murfreesboro 61 72 49 67 / 90 30 10 10 Waverly 56 68 48 65 / 80 10 10 20 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...13 LONG TERM....13 AVIATION.....21