Area Forecast Discussion
Issued by NWS Jackson, KY
Issued by NWS Jackson, KY
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795 FXUS63 KJKL 150630 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 130 AM EST Fri Nov 15 2024 .KEY MESSAGES... - Temperatures will be near normal through Saturday, before trending to around 10 degrees above normal for the first half of next week. - Rain chances return late Monday night into Tuesday. - A cooler pattern is on track to arrive later next week. && .UPDATE... Issued at 130 AM EST FRI NOV 15 2024 No significant changes to the forecast with mainly just the inclusion of the latest obs and trends for the T/Td grids and continuing the drizzle mention. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the SAFs. UPDATE Issued at 1031 PM EST THU NOV 14 2024 Late evening update is out. Expanded 15 PoPs through the overnight compared to the previous update, and also expanded the areal extent of patchy drizzle in the grids and text forecasts. With continued overcast conditions, lows tonight will only be a few degrees below current readings. UPDATE Issued at 600 PM EST THU NOV 14 2024 Early evening update is out to remove any mention of thunder from the Hazardous Weather Outlook, and also to fine-tune PoPs based on latest observed and model trends. && .SHORT TERM...(This evening through Friday night) Issued at 248 PM EST THU NOV 14 2024 We are seeing an upper level low and occluded front continue to work across the Ohio Valley this afternoon. This has sparked off additional showers this afternoon, with some breaks leading to steeper lapse rates. We have not seen much in the way of thunder given the lack of ice, with more signal showing up in areas mainly north of I-64. Given this focused the chances of thunder through the afternoon in these area. The shower activity will subside through the late afternoon and early evening once we loose the daytime heating. The forecast soundings including HREF driven data then transition this to more of a low stratus and drizzle scenario through the night into Friday morning and with little spread. This as low level moisture gets stuck underneath an inversion aloft. Therefore went more pessimistic on cloud cover through the night. Friday, an area of high pressure is well forecast to progress eastward into the Ohio Valley. This should help to dry us out some but some data indicates that we could see the drizzle continuing a little longer. However, we will at least keep the low stratus around through much if not all day, with the inversion strengthening through the day. Given this once again kept the sky a little higher through the day than NBM. In light of this, also lowered afternoon highs just a little, with afternoon highs in the low to mid 50s. Friday night, there remains some concern that we keep this stratus deck into Friday night, with some disagreement showing up in the CAMs. Also, the inversion will continue to strengthen through the evening and overnight and this would further push this stratus downward. Even so, kept some fog in there Friday night because any clearing could result in river valley fog at a minimum, but the overall confidence is low. Also, if we don`t clear expect fairly uniform overnight lows in the upper 30s to lower 40s. .LONG TERM...(Saturday through Thursday) Issued at 336 PM EST Thu Nov 14 2024 While the long term forecast period opens with sunnier skies on Saturday, the amplified nature of the current synoptics aloft means that this reprieve from grey November is only temporary. The leftover stratus deck from Friday should gradually thin/dissipate from southwest to northeast throughout the morning and early afternoon hours on Saturday. By Saturday afternoon, an upper level ridge will be centered over the region, and the flow aloft will shift towards a more westerly orientation. At the surface, a high pressure system will move into the Ohio River Valley on Saturday. These features combine to produce clearer skies, more efficient diurnal mixing, and a subtle warming trend for Saturday. Expect temperatures to approach 60 degrees in locations that clear more quickly, but highs will be in the mid 50s in our cloudier northeastern counties. On Saturday night, the clearer conditions will favor efficient radiational cooling and our forecast area`s conventional ridge-valley temperature splits. While ridges will remain in the 40s, sheltered and shaded valleys may reach the mid 30s overnight. Patchy valley fog appears likely given the overhead positioning of the ridging, although less moisture will be present than there was on Friday night. By Sunday, the aforementioned features will have propagated further east into the northern Appalachians. As a result, flow throughout the atmospheric column will shift to a southwesterly orientation. These winds will advect warmer air and modest amounts of moisture into the area. Sunday`s sensible weather will be marked by noticeably warmer temperatures in the mid to upper 60s, but with a return to at least partly cloudy skies. These advective processes will continue into Monday, with afternoon highs approaching 70 degrees, despite a further increase in cloud coverage. Confidence continues to increase in a drier daytime and evening forecast on Monday, with models now in consensus that a northern stream disturbance will remain displaced from the forecast area. As such, the attention shifts towards the middle of the week, when a serious of vigorous troughs will eject out of the Rockies. On Tuesday, the first of these troughs will eject out of the Ozarks and into the Upper Midwest. The aforementioned ridging will remain parked over the southeastern part of the country and thus block this primary trough from progressing further east into the Ohio River Valley. Around the same time, a second trough will emerge off the Southern Rockies and then phase with the first low to create an anomalously deep closed upper level low. Confidence is fairly high that these features will evolve in this manner, but the various pieces of forecast guidance resolve the timing, strength, and exact positioning of the resultant closed low quite differently. Here in Eastern Kentucky, this set-up correlates to a more active weather pattern. Rain chances will return to the forecast late Monday night into Tuesday and then linger around for much of next week. The exact details regarding the phasing and evolution of this upper level low will play a significant part in determining convective potential and precipitation types through the end of next week. At this temporal range, it is important to not read too much into one single model run when it comes to forecasting these details, so thunder and winter precipitation types have been accordingly left out of the grids for now. Model signals and atmospheric teleconnections do point towards a cooler and more active weather pattern next week, but model spread is too high to provide specifics at the time of this forecast`s issuance. Interested parties are encouraged to stay tuned to future forecasts as higher-resolution model data comes in and the guidance suite comes to a consensus over the next few days. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) ISSUED AT 115 AM EST FRI NOV 15 2024 Conditions to begin the period are generally IFR at the northern and eastern TAF sites and MVFR for LOZ and SME. CIGs could generally lower a bit more into the dawn as an inversion strengthens in the lower levels, with fog a concern at ridgetop sites such as KJKL. Given the inversion, expect only limited improvements to the CIGs into the MVFR category by late in the afternoon as mixing will be limited. Light and variable winds will hold through the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...DJ LONG TERM...MARCUS AVIATION...CMC/GREIF