Area Forecast Discussion
Issued by NWS Jackson, KY
Issued by NWS Jackson, KY
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032 FXUS63 KJKL 040851 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 451 AM EDT Tue Jun 4 2024 .KEY MESSAGES... - The threat of showers and thunderstorms will increase through mid-week. - Relatively cooler and drier weather will arrive behind a cold front which will pass through eastern Kentucky on Thursday. && .SHORT TERM...(Today through Wednesday) Issued at 450 AM EDT TUE JUN 4 2024 Mid/upper level ridging is slowly shifting eastward away from our area early this morning. This will open us up to the influence of a deepening and growing mid/upper level low migrating slowly east southeast over south central Canada, and shortwave impulses circulating around it. One of these waves will move northeast over the region today and interact with moist low level flow out of the south to produce scattered to numerous showers and thunderstorms. Activity should peak late in the day and decrease tonight as the initial wave aloft departs and we cool/stabilize. A second wave circulating around the large scale low will approach from the west on Wednesday. It will again take advantage of a flow of moist air into the area from the south southwest and lead to shower and thunderstorm development, with activity again peaking late in the day. There is not model agreement on the QPF and coverage on Wednesday, and a blended solution was used with POPs of around 70%. .LONG TERM...(Wednesday night through Monday) Issued at 450 AM EDT TUE JUN 4 2024 General agreement continues with respect to the mid/upper level patterns aloft. An elongated low and associated trough will have spun its way into the Great Lakes region at the start of the extended. The low...or mean low sets up residence over the Great Lakes for the remainder of the period, sending additional short wave impulses around the southern periphery of the mean low, into the Ohio Valley. At the surface, a relatively strong surface cold front will move through eastern Kentucky late Thursday or Thursday night. A stacked low over the Great Lakes, will keep our area under the influence of northwest flow. Subtle short wave disturbances passing across the region combined with wrap around moisture and diurnal heating will keep a general 20-30 PoP going through the period, with a noticeable diurnal flavor to activity. Sensible weather features generally dry weather for many, though isolated to widely scattered showers, commonly referred to as hit or miss showers and thunderstorms could impact anyone on any given day and at any given time. However, the most likely window of time for rain would be in the afternoon and early evening time frames. Other than Wednesday night at the start of the period, Sunday is the next most likely day of more widespread rain as PoPs increasing to around 40% as another cold frontal system passes through the Ohio Valley. After Thursday`s low to mid 80s for max temps, daily highs will average around 5 degrees below normal, or mid 70s through the period. Our coolest day through the extended will be Friday, with Saturday being slightly warmer by a degree or two. With lower surface dew points in the low 50s and a gradient wind around 10 mph, Friday will feel the coolest. Overnight lows will run in the 50s, though we may be flirting with upper 40s in some of our coolest valley locations by Saturday morning. Not seeing any solid signals with respect to hazards through the period. Instability will be relatively low, with MLCAPES only climbing to between 750 and 1250 J/kg Wednesday. Instability looks even weaker for Sunday. At this time effective shear is not even reaching marginal levels. Thus any organized convection will likely be limited to features such as frontal boundaries. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 204 AM EDT TUE JUN 4 2024 Valley fog can be seen developing on satellite imagery late tonight. It will continue to expand overnight, and could affect many TAF sites at times, but confidence in the extent is low. At this time have only used a TEMPO group for MVFR conditions. Fog will dissipate in the morning, leaving VFR conditions everywhere. Scattered showers and thunderstorms are forecast to develop in the afternoon, resulting in localized sub-VFR conditions before most of the activity subsides in the evening. Confidence is too low for anything more than VCTS to be mentioned in TAFs. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JMW LONG TERM...RAY AVIATION...HAL