Area Forecast Discussion
Issued by NWS Jackson, KY

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000 FXUS63 KJKL 282340 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 740 PM EDT Sat Mar 28 2020 .SHORT TERM...(This evening through Sunday night) Issued at 335 PM EDT SAT MAR 28 2020 Current conditions across the region features eastern Kentucky continuing to be in the warm sector of a developing storm system. The warm front has lifted north and is now along northern OH and IN. Partly to mostly cloudy conditions have been in place over eastern Kentucky over the past 24 hours as some daytime cumulus and some cirrus ahead of the main low to the west. This, with strong southwesterly flow has allowed high temps this afternoon to jump into the mid 80s. The lack of good cloud cover may lead to some ridge to valley temperature differences overnight but nothing compared to last night. Model trends have continued to trend slower with the approach of the developing squall line over central Kentucky and the approach of the main front. Concerning instability with the approach, now being slower and more towards dawn, even moist bias models are showing only 1000 to 1200 J/KG. Most high res models are keeping instability about 1000 J/KG at most. CAMs at this point, are showing much of the convection weakening by the time it reaches I-75 with the northern half of the line dissipating with a bit stronger convection developing along a broken line in the south. This too, given the strong cap and dry conditions in place, will weaken. The southwest along and west of the I-75 corridor may be the most likely area to see a wind threat from the dying line of convection. This line, given strong progressive flow will quickly push east through east kentucky with clearing likely by Sunday afternoon. Die to the lack of colder air behind this front, a spot or 2 may warm to 70 degrees for a high by tomorrow afternoon. The only other concern behind this front with winds mixing to the surface from 800MB. While a 30 mph gust to the surface will be likely, at this point, wind Advisory criteria is not expected. Will mention a 30 to 35 mph wind possible in the HWO though. With clear skies setting up Sunday night and winds slowly decreasing, temps will drop into the 40s for lows. There may be some ridge to valley differences. Otherwise, the main concern will be for the Saturday morning and into Saturday afternoon range. .LONG TERM...(Monday through Saturday) Issued at 405 PM EDT SAT MAR 28 2020 The period is expected to begin with the axis of a a mid and upper level ridge extending from the Gulf of Mexico and Bahamas region into the mid MS Valley region. An upper level low and associated trough will be moving across the St Lawrence Valley and Northeast Conus. Further west, an upper level trough is expected to moving across the southern Rockies and Four Corners region while an upper level low is expected to be nearing the pacific northwest. A ridge of sfc high pressure is expected to be building across the area to start the period. Sfc and upper level ridging will gradually move across the area on Monday and Monday night. However, with the axis of the upper level ridge moving east of the area by dawn on Tuesday while the shortwave initially over the Four Corners will have moved across the Plains and reach the mid MS Valley by dawn on Tuesday. Moisture and clouds will increase on isentropic lift ahead of the approaching shortwave on Monday night and showers could occur late, particularly in the Lake Cumberland region. The shortwave trough is expected to move into the OH and TN Valley on Tuesday as the sfc low track across the southeast with an inverted trough/sfc reflection of the upper trough/low extending into East KY. This shortwave trough will depart to the northeast late Tuesday night and Wednesday while a sfc low tracks off the Carolina coast. This system will likely lead to showers showers across the area Tuesday and Tuesday night. The cooling aloft may also steepen lapse rates for a few thunderstorms Tuesday evening into early on Tuesday night. Another soaking rain should fall from this system, especially across the southern half to two thirds of the area. At this time QPF is expected to average a quarter to two thirds of an inch across the area. A brief period of height rises should follow Wednesday into the day on Thursday as an upper level ridge moves across the southeast and OH Valley. Sfc high pressure will also build into the area during this time. Shower chances should be minimal during this period and the model blend NBM pops may be overdone Wed afternoon and Wed night. There remains uncertainty in timing of the next shortwave trough moving across the Plains into the eastern Conus Thursday to Saturday and associated sfc system and cold front. The recent model trends have been generally toward the cold front approaching the area on Friday and moving east of the area Friday night. This period appears to be unsettled with chances for showers, especially along and near the front. Additional weaker shortwaves moving through the flow should lead to a fair amount of cloud cover and isolated to scattered showers at times from late Thu into Thu night at at the end of the period as well. Temperatures after Monday night will average below normal, especially for highs as the first low pressure system and shortwave trough moves across the area followed by westerly upper level flow. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 740 PM EDT SAT MAR 28 2020 VFR skies will roll on for much of the night before storms arrives late tonight into early Sunday morning. These storms will lower CIGs possibly into the MVFR range or lower as the thunderstorms roll through in the pre-dawn to early morning hours Sunday. This will be quite temporary as CIGs return to VFR through the remainder of the morning and remain that way through the period. There will be a strengthening low jet tonight and this will lead to a period of LLWS once again through the night. The winds will be out of the southwest through the period and will start in the 5-10 knot range through the night. Then deep mixing will lead to gusty winds through the morning and afternoon Sunday in the 20 to 27 knot range. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM...JP AVIATION...DJ is the U.S. government's official web portal to all federal, state and local government web resources and services.