974 FXUS63 KJKL 101817 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 217 PM EDT Wed Oct 10 2018 .UPDATE... Issued at 201 PM EDT WED OCT 10 2018 Rain has now exited north of the CWA, with much of the region now dry. With scattered clouds across the region and decent moisture, still not confident enough to completely pull pops, so will keep with isolated mention until the next round moves towards the region late this afternoon/evening. Loaded in the latest observations for temps, dew points, and winds to make sure the near term forecast was on track with the latest conditions. With clouds scattering out, temperatures are starting to push upwards, so we may be able to reach our max highs for today. Will continue to monitor this. UPDATE Issued at 1125 AM EDT WED OCT 10 2018 Several updates have been made to the pops/weather based on latest radar trends and hi-res models. The first update around 9am was to increase pops across the northern CWA given the faster trend with the precip on radar moving across the CWA. As this trend continued throughout the morning hours, ended up speeding up pops a bit, with drying now encompassing much of the southern CWA. Based on latest hi-res models, expect that much of the CWA will be dry by 16/17Z and will remain so through much of the afternoon before the next wave of rainfall moves in this evening closer to the actual frontal boundary. That being said, we are very moist outside and there is some limited instability, so did not feel comfortable going completely dry between these two swaths of rain. Kept in isolated mention across the CWA instead. All updates have been published and sent to NDFD/web. A new forecast package was also sent out to reflect these changes. Will continue to monitor the temperature trend over the coming hours as well, and make changes as needed, since it might be more difficult with the ongoing cloud cover and rainfall to reach our forecasted high temperatures for today. UPDATE Issued at 753 AM EDT WED OCT 10 2018 Issued an update to the grids to input the latest observations and trend them into the mid morning hours. Showers have developed and moved into eastern Kentucky this morning and will persist into the afternoon with a few thunderstorms developing as well. The forecast continues to have a good handle on this so will let the current zfp roll. && .SHORT TERM...(Today through Thursday) Issued at 415 AM EDT WED OCT 10 2018 By dawn, showers will begin to develop into the region with enough instability in place for thunderstorms to develop in the afternoon and evening. Locations that see any thunderstorms development will at least see some MVFR conditions set in and this has been shown at some of the sites with the increase in pops. Expect strong south winds through the day with 10 knot winds and a few gusts to 15 knots possible. The shower and thunderstorms will taper off a bit after 00Z. Current conditions across the area feature cloud cover streaming northward as a warm front will begin to develop and shift north. Ahead of the front and even present on radar this hour, showers have developed south of the TN border and are now beginning to shift north ahead of the front. Heading into the day today, showers will become more numerous as southerly flow increases. With the assist of the front and additional instability, will expect thunderstorms to develop by the mid morning to noon hours with instability around 1000 J/KG by the afternoon. As well, southerly winds will be a bit gusty at times with some 20 mph wind gusts possible. The steering winds for this event are quite strong and thus, with the precip being more progressive, the heavy rainfall threat will be minimal. As well, the southerly component of the winds to begin this event are more unfavorable due to the downslope winds. With the current setup, precip amounts from the entire event will be around an inch at most. As east Kentucky will eventually be in the warm sector, high temperatures across the area may crack 80 for one final time this season. The cold front will begin to approach the region tonight as some additional moisture ahead of the front will be drawn northward from Tropical Storm Micheal as it begins to shift to the east. With the weakening of the front as it approaches the Appalachian Range, the lack of instability will be apparent and will trend down the chance of thunder by Thursday morning. However, along the front, expect moderate rainfall through tonight and into the day on Thursday. With the front passing through during the day on Thursday, high temperatures may be realized midday across the area. Highs will struggle to reach 70 as the cooler air filters in behind the front. Precip will finally begin to exit the area by Thursday evening. The model trends suggest this may even be sooner for the end of the precip across eastern Kentucky. Overall, while a moist air mass will be in place today and into Thursday morning, the progressive nature and the breif period of downslope to begin the event will lead to a low flood threat. .LONG TERM...(Thursday night through Tuesday) Issued at 515 AM EDT WED OCT 10 2018 The models are only in fair agreement aloft through the extended portion of the forecast. While they all depict the scale and extent of the significant pattern change occurring over the next few days for the region, they disagree on many of the smaller features that will be key to the weather over the state through the weekend and into the middle of next week. Hurricane Michael's trek to our southeast on Thursday will drive a stake through the heart of the southeast ridge that has extended summer heat and humidity well into this current season. Meanwhile, heights will decrease over the Ohio Valley in response to a large trough centered across the border in central Canada Thursday night. This will establish fast southwest flow in the mid levels for our area with several shortwaves set to move through during the extended period. The first of these will come through Friday night as a sharpening trough - stronger and slower in the ECMWF than the GFS. Will favor the better continuity of the GFS and look to dampen this feature for the grids themselves. The pattern then flattens out to close out the weekend while fast flow continues ahead of the next decent wave inbound by Monday evening - again stronger and slightly slower in the ECMWF than the GFS. For this feature a blend was preferred. The model spread widens further on Tuesday with the ECMWF displaying more troughing for our area than the GFS as the latter looks to start rebuilding the southeast ridge. Have favored the blended solution with the main changes to dampen the lead wave of the larger trough on Friday night. Sensible weather will feature the true start of fall conditions for eastern Kentucky as temperatures struggle to reach 60 degrees for highs Friday after morning readings in the low to mid 40s. This chill continues Friday night through Sunday with some valley upper 30s possible each night and highs only in the upper 50s to low 60s for most - though upper 60s will be possible in the south on Sunday. High pressure moving through should keep the weather dry during this time, though perhaps a few sprinkles or a stray shower will be possible north from a mid level band of clouds passing through with that short wave Friday night. The sfc high will move east on Sunday allowing more moisture to seep into the area by evening ahead of an approaching cold front. This will likely bring showers to the area on Monday along with a reinforcing shot of cold air in its wake. This cold air and the high pressure that moves in Monday night and Tuesday will also probably send temperatures into the upper 30s for Monday morning with patchy valley frost a possibility. Did make some minor changes to the temperatures of the SuperBlend starting point mainly at night for some terrain differences. As for PoPs did also lower them for our northern fringes Friday night into Saturday - negating the ECMWF's outlier solution. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 216 PM EDT WED OCT 10 2018 Rain has moved north of the region, with most sites now experiencing dry conditions and VFR skies. Can't rule out an isolated shower popping up this afternoon, but expect TAF sites to generally remain dry until this evening when rain and thunder chance are expected to increase again just ahead of the incoming frontal boundary. MVFR conditions are likely overnight with the incoming rain, though conditions could deteriorate briefly with any heavier showers. Thunder chances should taper off overnight, with rain expected to continue through much of the duration of the TAF period tomorrow. S to SSW winds under 10 knots are expected through the remainder of the day and overnight, before becoming more NWrly behind the cold frontal passage Thursday morning. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...SHALLENBERGER LONG TERM...GREIF AVIATION...JMW