897 FXUS63 KJKL 110855 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 455 AM EDT Thu Oct 11 2018 .SHORT TERM...(Today through Friday) Issued at 402 AM EDT THU OCT 11 2018 Current conditions across eastern Kentucky feature a swath of rainfall streaming northward through the region. This tropical moisture continues to push north into the area ahead of the now land fallen and weakening Tropical Storm Micheal. At this time as well, the cold front is pushing across central Kentucky and will begin to push this swath of rainfall eastward bringing an end to the precip from west to east through the day today. In the meantime, in the predawn hours, this precip is quite slow to exit and some training of more moderate showers may persist through dawn before the front finally pushes the rainfall east. Any instability has been tapped and thus will only be dealing with moderate showers through the first part of the day. A few issues will be possible with minor flooding in the predawn hours until the front finally pushes through and shunts the rainfall eastward. Heading into the midday hours, models still support the cold front pushing through Kentucky and the rest of the precip by 00Z. Expect temperatures to fall through the morning hours and with skies beginning to clear up through the day, temps may warm up a few more degrees despite the CAA behind the front. Daytime highs will likely be reached by 18z. Decent gradient with the front will lead to strong wind gusts behind the front. Some northwest winds with gusts to 20 and 25 mph will be likely this afternoon. By tonight, clear skies will allow temperatures to drop in the 40s for lows and even some upper 30s. This will indeed be the first short of Fall temperatures. Winds remaining up a bit over night will likely be a bit too strong for frost development at this time. As well, the dry airmass moving in may keep fog from developing as the current pattern is quite a quick chance in airmass. Thus will keep fog and frost out of the forecast tonight. Heading into the day on Friday, with the northwest flow in place, will expect cooler temperatures in place. While skies will remain clear for much of the day, cloud cover will finally push into eastern Kentucky late day associated with a fast moving front. This will make for temperatures to struggle to get out of the 50s for highs. In addition, the fast moving front will bring another round of showers to the area by late day Friday. .LONG TERM...(Friday night through Wednesday) Issued at 455 AM EDT THU OCT 11 2018 The models remain in, at best, fair agreement aloft through the extended portion of the forecast. They all agree that a more active and decidedly colder pattern has arrived, though. Initially a lead trough will further lower heights across the Ohio Valley with energy surging in from the Midwest Friday night into Saturday morning. This sharpening of the longwave trough will pass through Kentucky with fairly good timing among the models, but still sharper in the ECMWF. This near agreement has raised confidence in the consensus model output for this time period. Heights rebound slightly in the wake of this shortwave for Saturday and Saturday night yielding relatively fast southwest flow through the state by the latter part of the weekend. Several small shortwaves will be embedded in this flow lasting into Monday morning. The southeast ridge does also strengthen during this time and further lock in the deep layer southwest flow. Later the next bout of troughing will ease into the area Monday night into Tuesday with additional energy, though the main feature will be dampening. Here the models further diverge with the weaker, quicker, and seemingly out of phase ECMWF dissipating its energy more than the GFS as it sinks into Kentucky. The model differences extend through Wednesday making for low confidence in any model specific details after Monday. Given these concerns did not make many changes to the overall theme of the model blend, except to be a bit more pessimistic with respect to drying and clearing for early to mid week - more in line with the National Blend (NBM). Sensible weather will be changeable through the period and definitely on the cool side, though seemingly more so given the warmth so far this autumn. In fact, the clipper bringing a shot of light pcpn to the area Friday night into Saturday morning will try to get its snow flakes to the sfc but be thwarted by a too warm for that boundary layer - so cold rain showers it is. Chilly high pressure follows with highs only in the low to mid 50s most places for Saturday - though dry. Return flow in the high's wake will bring moderating conditions but more moisture into the area starting Saturday night and likely holding off any valley frost threat. This moisture congeals over the area on Sunday with showers possible by evening and continuing into Monday due to a stalling frontal boundary and the active mid levels. The clearing of this front is in question with the ECMWF more progressive than the GFS through mid week. Am not that confident that this will be the case so have held in rain chances and also modified the frost potential given the probability of more clouds around each night next week. Did make some temperature adjustments most nights from the blend for terrain differences through the period. Also raised PoPs for Tuesday and Wednesday due to the model uncertainty and some support from the NBM. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) ISSUED AT 155 AM EDT THU OCT 11 2018 As showers and a few thunderstorms continue to push east through the area overnight, ceilings and vis will be on the decline with deteriorating conditions through the dawn hours. These low cigs and vis will persist through midday. As the cold front pushes east through the region the low cigs and vis will slowly begin to improve in the afternoon as skies will even begin to clear out by the evening. The cold frontal passage through the region today will cause a wind shift to west and northwest. Expect some wind gusts up to 15 and 18 mph in the afternoon. Skies will begin to clear out across the entire area by the end of the TAF period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM...GREIF AVIATION...SHALLENBERGER