013 FXUS63 KJKL 280141 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 941 PM EDT Sat Apr 27 2024 .KEY MESSAGES... - Mostly cloudy with light showers and sprinkles passing through this afternoon. - Becoming very warm tomorrow and lasting at least through the middle of the week. - Showers and thunderstorms at times next week, primarily Monday night and Tuesday. && .UPDATE... Issued at 941 PM EDT SAT APR 27 2024 Minor downward adjustments were made to the minimum temperatures overnight in valleys as observations show temperatures already in the lower 60s. Anticipate overnight temperatures dipping into the middle 50s in many of the valleys, except lower 50s in the coolest hollows. Outside of the valleys, look for lows generally in the upper 50s to lower 60s. The remainder of the forecast is on track. UPDATE Issued at 640 PM EDT SAT APR 27 2024 Just did a quick update to the forecast to account for the latest trends. Isolated light rain showers and patches of sprinkles that moved through the area late this afternoon have now dissipated. Used the latest obs to freshen up the forecast grids and to establish new trends in temperatures, humidity, and winds. No updates to those forecast elements were deemed necessary at this time. The updated grids have been saved, published, and sent to NDFD. && .SHORT TERM...(This evening through Sunday night) Issued at 355 PM EDT SAT APR 27 2024 19Z sfc analysis shows eastern Kentucky between two strong weather systems - a deep low over the Plains and strong high pressure off to the northeast. This is keeping a sustained southerly flow of air into the region - generally at 10 to 15 mph with still some gusts of up to 25 mph. Under partly to mostly cloudy skies, a couple of areas of light showers are moving through eastern Kentucky within the large warm sector that encompasses the region. Currently, temperatures are fairly uniform in the mid to upper 70s while dewpoints are generally in the mid to upper 50s. The models, and their individual ensemble suites, are in good agreement aloft through the short term portion of the forecast. They all depict Kentucky on the northwest fringe of a large Southeast ridge. A weak impulse is passing through Kentucky this afternoon and that is knocking down the 5h heights a tad as it passes through the northern parts of the JKL CWA. Through the weekend, a deep, but opening, closed low rolls northeast from the Central Plains to the Upper Midwest into Monday morning. Locally, this will mainly serve to tighten up the mid level southwest flow during the short term portion of the forecast, but aside from the perturbation affecting the area this afternoon there is not appear to be much energy that will impact this part of the state until later Monday. Given the small model spread, the NBM was used as the starting point for the short term grids with any adjustments mostly related to terrain distinctions at night. Sensible weather features a warm and dry couple of days, aside from the showers and sprinkles passing through this afternoon. Will not deviate too much from the high end NBM output of temperatures for Sunday under that 5h ridge and with less clouds anticipated than today. For tonight and Sunday night, mostly clear skies will allow for good radiational cooling both nights and set up decent ridge to valley temperature splits. Have adjusted the NBM guidance for temperatures to account for the terrain distinction. Did also include a touch of river valley fog during the late night hours each night. The main adjustments to the NBM starting point were centered around adding in terrain details to the hourly temperatures and lows tonight and again Sunday night. Minimal PoPs after 00Z Sunday in the NBM and they were left that way. .LONG TERM...(Monday through Saturday) Issued at 341 PM EDT SAT APR 27 2024 The latest model data still showing a consistent set up across the country for the beginning of next week. An area of low pressure is forecast to be pushing northeastward into the western Great Lakes out of the central Plains Monday and Monday night. As this system moves toward southeastern Canada, it will drag a weak cold front through the Ohio and Tennessee Valley. The front will make only gradual eastward progress, however, as a strong subtropical ridge will be dug in just of the southeastern CONUS coast and will not be easily displaced. As the upper trough continues its northeastward push, the ridge will finally begin to erode and moves further offshore, allowing the front to finally move through our area from late Monday through Tuesday. With ample low level moisture and instability in place, showers and thunderstorms will fire along and ahead of the approaching boundary. Our highest precipitation chances will occur Monday night into Tuesday, as the front moves through. The rain should gradually taper off during the day on Tuesday, with the last showers and storms finally exiting the area sometime late Tuesday evening. We should see a brief lull in the precipitation, as a weak surface ridge temporarily settles over the area Tuesday night through Wednesday night. However, based on the latest model runs, enough lift associated with a weak impulse aloft that will be rotating around the northern edge of the ridge, could allow a few showers and storms to form north of the Mountain Parkway in our area. After that, another system is forecast to move our way out of the northern Plains on Thursday. This system looks like it will not be super strong, but will provide plenty of lift, instability, and moisture to our area to allow showers and scattered thunderstorms to form all across eastern Kentucky to end the week. Another batch of rain should begin moving into our southwest counties Thursday morning, with showers and storms gradually overspreading the area through out the day, as another cold front slowly approaches from the west and southwest. The front should make its main push through the region Friday into Friday evening, before moving off to our east late Friday night into early Saturday. With moisture wrapping around the backside of the fronts surface heading into the weekend, isolated to scattered storms could persist across the area on Saturday, but should slowly taper off toward the end of the day, as the upper low moves further to our east. Temperatures should be well above normal through out the extended, as persistent, vigorous southerly or southwesterly flow sets up across the region. Highs in the upper 70s to mid 80s should not be uncommon. Winds will increase and become brisk and gusty during the passage of each weather system, especially the end of week system, as it looks like it might have a slightly strong pressure gradient than the early week one. Modest ridge valley temperature differences may also occur Tuesday night and Wednesday night, between systems. No significant weather concerns at this time. That being said, always remember that any thunderstorm can produce locally heavy rainfall, gusty winds, and frequent cloud to ground lighting. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 700 PM EDT SAT APR 27 2024 Still expecting VFR SCT low and BKN high clouds across the forecast area this evening, with bases at 6k and 25k based on the latest obs. These clouds will continue to steadily scatter out during the evening, and should give way to mostly clear skies by 5z tonight. Southerly winds should diminish to less than 10kts this evening as well. Any fog that forms in the valleys late tonight will not affect the TAF airports. The latest model guidance continues to suggest the possibility of LLWS of up to 40kts from the south, primarily at KSME and KLOZ late tonight, and possibly to a lesser extent at KSYM and KJKL for a time. The final six hours of the TAF period look to be quite pleasant, with mostly clear skies, VFR conditions, and southerly winds of 6 to 10kts. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AR/GEERTSON SHORT TERM...GREIF LONG TERM...AR AVIATION...AR