Area Forecast Discussion
Issued by NWS Jackson, KY

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000 FXUS63 KJKL 261959 AFDJKL Area Forecast Discussion National Weather Service Jackson KY 359 PM EDT THU MAY 26 2016 .SHORT TERM...
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(This evening through Friday night) Issued at 359 PM EDT THU MAY 26 2016 Strong troughing across the southwest conus and ridging for the southeast conus has led to SW to NE flow aloft across the mississippi and Ohio River Valley. Several short waves continue to eject ne along this flow and into the Ohio River Valley, including the one that spawned a strong line of showers and thunderstorms this morning over western KY and Illinois. This line has sustained itself throughout the day and is now traversing central KY. Decent instability present, along with good mid level drying, have led to several of these storms going severe. Most of the hi res models have had a fairly good handle on this system through the afternoon, with preference for the HRRR which has been initializing well since this morning. They also all have this line weakening as it moves into our western CWA, then quickly dissipating as it moves east late this afternoon/evening. Forecast soundings show good CAPE, LI`s -6 to -8, and steep lapse rates. However our shear is lacking, and strong storms will likely not be able to sustain themselves. As such, agree with models to a certain degree. We could still see some isolated embedded cells that could pop up to severe limits, or produce small hail at the least. But do agree that there will be a diminishing trend as we head into the evening. By overnight, this line of showers and thunderstorms will move eastward out of the region. High pressure will take hold, generally to our southeast, leaving southerly flow across the region. The continued moisture influx, in addition to the lingering moisture and a night time inversion taking hold, could lead to fog development across the CWA, especially in the valley locations. High pressure will remain in control tomorrow. However southerly flow will continue, allowing temps to easily climb into the mid and even upper 80s by the afternoon. With that southerly flow will also come moisture, so diurnal CU development will be likely. Afternoon instability will also be in place, so scattered showers and thunderstorms may develop for the afternoon. .LONG TERM...(Saturday through Thursday) Issued at 330 PM EDT THU MAY 26 2016 We begin the period more influenced by the upper level ridge extending west out of the Mid Atlantic Coast, while upper level closed low resides in the Central Plains states. Overall better PVA will remain east of the region, but enough influence to include some higher chance pops mainly toward the northern and western portion of the CWA on Saturday and Sunday. Now moving into the first part of the work week more uncertainty exists with regard to waves and any residual down stream storm complexes that hold together. Also another complication exists in the tropics with potential for a developing tropical system near the Carolina Coast line. Right now the GFS has been the most volatile with little continuity run to run, while the ECMWF seems to be more consistent. The influence from this overall should reside latter portion of the long term period, therefore for now will stick with model blend approach for now. This especially as shear will be nil through the long period leading to little if any organization of storms. Toward the very end of the period ridging breaks down more allowing for more height falls. This will lead to higher chance pops by Thursday given this looks to be the overall best synoptic feature we have seen. Given the ridging a more summer time feel will remain in place through the long term period.
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&& .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 207 PM EDT THU MAY 26 2016 While a few lingering showers are ongoing across eastern KY a the time of TAF issuance, attention turns to a strong line of showers and thunderstorms currently moving across western and central KY. Convection is now also occurring ahead of the main line. Timing this out, expect the western most TAF sites (KSME/KLOZ) to be affected first, likely between 22 and 23z. The line is then expected to lose overall intensity as it continues eastward toward the other TAF sites through around 3z. At present time, it is hard to know exact impacts on each TAF site, so will likely need to update TAFs as we see storms are nearing the airports. Ongoing threats to our west include hail, torrential rains, frequent lightning, and gusts between 30 and 40kts. After the line moves through later tonight, high pressure and some possible clearing will take hold. This may lead to some fog development at the TAF sites, though confidence on exact VIS restrictions is lows, especially considering it will be very much correlated with when and how much rain occurs this evening. Any fog should clear out by morning, with (VFR) diurnal CU developing as we head into the early afternoon. && .JKL Watches/Warnings/Advisories... None. && $$ SHORT TERM...JMW LONG TERM...DJ AVIATION...JMW is the U.S. government's official web portal to all federal, state and local government web resources and services.