Area Forecast Discussion
Issued by NWS Jackson, KY
Issued by NWS Jackson, KY
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994 FXUS63 KJKL 151740 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 140 PM EDT Thu Aug 15 2024 .KEY MESSAGES... - Temperatures will be quite warm this afternoon, climbing to near 90 degrees, before cooling back down closer to normal levels Friday. - Humidity, along with the possibility of showers and thunderstorms, will increase Friday and last into Saturday night. - Below normal temperatures are expected Sunday through Wednesday behind a cold front passage late Saturday night. - Showers and thunderstorms will remain possible Sunday and Monday, especially in the afternoon and early evening, with a drying trend for Tuesday into Wednesday. && .UPDATE... Issued at 1236 PM EDT THU AUG 15 2024 Another forecast update was just issued to increase hourly and maximum temperatures for today. Also removed any remaining outdated afternoon wording from the zone forecast text product. The rest of the hourly forecast elements were freshened up with the most recent obs from around the area. UPDATE Issued at 1025 AM EDT THU AUG 15 2024 Just sent out a quick forecast update to remove mention of fog from the zone forecast text product. The latest obs were used to freshen up the hourly forecast elements such as temperatures and dewpoints to establish new trends. There some noticeable differences between the hourly temperature obs the forecast values so far this morning. Will continue monitoring these trends over the next couple of hours, and might need to issue another update that deals with todays high temperatures. Will also update later to remove any outdated wording from the forecast for today. UPDATE Issued at 719 AM EDT THU AUG 15 2024 The only update needed is to increase Sky cover across the southwestern third of the forecast area with an observed increase in high clouds transported from the next disturbance approaching the area later today. Models suggest after a few hours of increased cloud cover there will be a lull in such cloud cover toward the afternoon. The grids were updated using the latest observations for initialization. && .SHORT TERM...(Today through Friday) Issued at 315 AM EDT THU AUG 15 2024 Upper ridge axis just upstream will cross eastern Kentucky today, with an upper disturbance quickly on its heels pushing a warm front northeast across the forecast area by this evening. The longwave trough begins to move into the Mississippi River Valley and Lower Ohio River Valley late tonight into Friday, with additional disturbances ramping up the low-level warm, moist advection into the region, especially after midnight, with PWs rising from near 1.5" this evening to near 2" Friday morning. Will thus have gradually increasing PoPs and QPF moving in from the west beginning around or shortly after midnight tonight and increasing through the pre-dawn and morning hours. Instability looks rather limited until Friday afternoon, so thinking the initial push of precipitation will mostly be in the form of showers, some producing intense yet brief downpours. For this reason, the Probability of Thunder grids were lowered at least one category through the 18z Friday, with additional lesser reductions in the afternoon. Models suggest an initial round of showers and a few storms moving across the area during the Friday morning period, though there are significant inconsistencies as to whether this activity arrives before dawn or after. After this initial morning round, partial clearing in the afternoon combined with a humid and weakly unstable environment should promote another round of showers and thunderstorms from the afternoon into the early evening hours. As for the temperature forecast, expect the warmest readings of the week as weak warm advection occurs under light southwest winds, with highs in the upper 80s to lower 90s. Warm conditions are expected tonight as warm moist advection increases significantly through the night, with lows in the upper 60s to around 70 degrees. Friday`s highs will be somewhat dependent on timing of disturbances and associated disturbances and cloud cover, but mid-80s seem like the most likely outcome, but with increased humidity resulting in heat indices in the mid-90s for many locations. .LONG TERM...(Friday night through Wednesday) Issued at 305 AM EDT THU AUG 15 2024 It will be a wet start to the period, as KY finds itself with a surface cold front bearing down and traversing the state. This will stem from a strong low pressure system across the Upper Great Lakes, connected to an upper level system also moving through the region. A trough will also be in place across the Ohio Valley as a result of this system, and should remain in place well into Monday. The cold front is still forecast to move through and then exit eastern KY during the day Saturday. Once the front exits, cooler NW will take hold due to the strong upper level flow. However, our presence in the apex of a trough will still promote instability and lift, especially during the afternoon hours, so despite being post frontal, nearly every model keeps pops in through Monday, especially during the afternoon hours. This system will finally begin to exit eastward by Monday night. It won`t move far, however, becoming parked along the Atlantic coastline through mid-week. This will keep NW flow across the region through the remainder of the extended. Models were in very bad agreement the last few nights from Tuesday onwards, but it does look like they are finally starting to trend towards the ECMWF, with a more prominent troughing pattern. If this agreement continues, we should see generally high pressure at the surface (and dry weather), and a cooler/less humid airmass thanks to the NW flow. Saturday will be the warmest day, just ahead of the passing cold front, when highs should top out in the mid and upper 80s. After the front moves through, the rest of the week should be in the low 80s for highs. Lows Sunday and Monday mornings will be in the upper 50s and low 60s with the upper level trough still in play, but as drier air advects in once the front shifts eastward, expect lows to drop into the 50s for the rest of the extended period. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 140 PM EDT THU AUG 15 2024 VFR conditions expected to prevail through out the TAF period. SCT cumulus clouds have sprouted over the area this afternoon, and will remain in place through sunset. Overnight, we will see cloud cover gradually increasing to SCT to BKN by late tonight, as an area of low pressure moves in from the west. Scattered rain showers will begin to affect SYM, LOZ, and SME between 11 and 13Z Friday and JKL and SJS between 12 and 14Z. A few thunderstorms will also begin firing toward the end of the TAF period. Winds should remain light and variable the rest of today and tonight, but will shift to the south or southwest early Friday with values of around 7kts. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AR SHORT TERM...CMC LONG TERM...JMW AVIATION...AR