KLMK issues Area Forecast Discussion (AFD) valid 2019-12-02T05:32:00Z 566 FXUS63 KLMK 020532 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 1232 AM EST Mon Dec 2 2019 ...Updated Aviation Discussion... .Forecast Update... Updated at 850 PM EST Sun Dec 1 2019 GOES IR cloud top temperatures show deep enough moisture over us now to have some ice crystals aloft, but they are...in general...melting to all rain before hitting the surface. Have seen a couple of rain/snow mix reports from mPing and a report just now out of Lexington. As we continue to cool through the evening, I would expect to see a few more mix reports. That same satellite imagery is showing some gaps in the deeper cloud cover about to rotate into the region, which could allow for more of a period of drizzle rather than snow. A deeper plume of clouds is over central Illinois right now, and expect that to rotate around to our southwest forecast area later overnight. The good news is that all of this precipitation is falling on very warm road temperatures...and those are forecast to stay warm enough through the night to mean little in the way of impacts. We may have a few swaths of snow bands able to produce up to around a half inch of snow, but as soon as the heavier rates stop, the roads should melts fairly quick. After crunching the numbers with the latest hi- res guidance, we still have most areas totaling under an inch. The area currently covered by the Winter Weather Advisory still has the best chances to reach that half inch to inch range, mainly in the 2 AM-10 AM EST time frame...so will not make any changes. Current special weather statement looks good as well...highlighting the possibility for a few half-inch totals. && .Short Term...(This evening through Monday) Issued at 319 PM EST Sun Dec 1 2019 ...Light Snow Accumulations Possible Tonight Into Monday... A closed low will wobble from the southern Great Lakes into the central Appalachians tomorrow, then off the mid Atlantic Coast by tomorrow night. A notable 1000-700mb moisture pool wrapped into the system will slide across our region, coincident with falling temps tonight, and pretty steady temps into Monday. Overall, surface temperatures are expected to largely remain at or above freezing through the event, although lower to mid 30s should be common by Monday morning. Forecast soundings show pretty steep low level lapse rates with saturation up into at least the bottom half of the DGZ, with pockets of deeper saturation at times and depending on location. All of this translates to what will likely be a light rain transitioning to more prominent periods of light snow the deeper into the night we get. However, some pockets of moderate snowfall rates are possible with the best showers overnight and into Monday morning. So, the question becomes can it snow hard enough to overcome the marginal surface temps and road temps that are expected to remain above freezing? Think we'll mostly see a half an inch of snow or less mainly on grassy and elevated surfaces, however a few localized higher amounts are possible given the showery nature of this event. Hi-res models seem to support sporadic and showery snow totals giving confidence to what we are seeing on forecast soundings and typical showery NW flow (near surface) events. Do think we could see some light and brief accums on roadways where it does snow harder, but given the showery nature, can't really pinpoint any one area. Overall, have been consistently coming up with slightly higher totals in our far easter CWA, in part due to what could be a fairly prolonged upslope enhancement. 1000-850 mb streamline trajectories do show a long fetch off of Lake Michigan well into Monday that could provide prolonged moisture for the upslope component, and you can see this on some model solutions. So, decided to issue a Winter Weather Advisory for amounts up to 1 inch in that area in coordination with surrounding offices, and it goes for quite a while until 21z Monday. Elsewhere, will handle things with a continued Special Weather Statement. Again, expecting a half an inch or less mainly on grassy and elevated surfaces. Although don't completely rule out a few slick spots toward dawn where any moderate rates may occur. Confidence isn't overly high in this event given the limiting surface factors and variable degrees of saturation into the DGZ, so some changes to the current products may be needed as the event unfolds. Stay tuned. Otherwise, surface temps will stay in the 30s on Monday with lingering precipitation ending mainly as flurries or drizzle. Expect widespread cloud cover .Long Term...(Monday night through Sunday) Issued at 233 PM EST Sun Dec 1 2019 Scattered flurries or sprinkles may linger through the evening hours Monday before tapering off as drier air advects in from the northwest. Going forward the rest of the week, flow aloft will generally remain out of the northwest and result in a dry forecast for several days. The next shot of precipitation will come Friday when a fast moving shortwave ejects into the southern Plains and dives into the Tennessee Valley. Temperatures at this time look to support rain with this event, with the highest chances down toward the Tennessee border. Dry and mild conditions look to follow into the weekend. && .Aviation...(06Z TAF Issuance) Issued at 1225 AM EST Mon Dec 2 2019 Cold rain and mainly fuel-alternate MVFR ceilings in the terminals initially, but colder air just upstream is still on track to change over to snow at times. Confidence is fairly high that we'll see enough IFR ceilings to justify TEMPO groups at all but BWG, while visibility remains more uncertain. Brief IFR vis possible in pockets of heavier snow, but shouldn't persist enough to mention anything below 3SM. Precip will taper just before daybreak, but fuel-alternate ceilings will persist for most of the day. W-NW winds with gusts near 20 kt should also continue, with winds diminishing and ceilings lifting to high-end MVFR after dark. && .Hydrology... Issued at 315 PM EST Sun Dec 1 2019 ...Minor River Flooding Ongoing... Area rivers are on the rise after widespread rainfall amounts of 1.5- 4 inches over the past 24 hours. Several river flood warnings are in effect for locations that are either already experiencing minor flooding or are forecast to rise to minor flood stage. Minor flooding is currently occurring along the Green River above Woodbury, Rough River near Dundee, Stoner Creek at Paris, and Elkhorn Creek at Peaks Mill. Additional minor flooding will likely occur early this week at other locations along the Green and Rolling Fork rivers. The Kentucky River will likely exceed Action stage and approach Flood Stage in a few locations, but confidence is slightly lower in Minor Flooding. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon for KYZ055>057-066-067-078-082. && $$ Update...RJS Short Term...BJS Long Term...DM Aviation...RAS Hydrology...BJS