KLMK issues Area Forecast Discussion (AFD) valid 2019-12-01T20:21:00Z 536 FXUS63 KLMK 012021 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 321 PM EST Sun Dec 1 2019 .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...(18Z TAF Issuance) Issued at 1244 PM EST Sun Dec 1 2019 A cold front has pushed through the area and we will see sustained winds between 15 and 25 mph, gusting up around 30-35 mph for the remainder of the afternoon and evening. Stratocu associated with the comma head of a large storm system to our north has wrapped back into the area, and we'll see deteriorating ceilings from W to E later this afternoon into the evening. MVFR and into the fuel- alternate range will be the most prevailing ceiling through the end of this cycle, however there is a chance of IFR ceilings at HNB/SDF/LEX after sunset and at time through the pre-dawn hours. LEX will hold onto IFR ceilings into Monday morning. The other issue is with light rain showers changing to some rain/snow mix or even brief light to moderate snow showers overnight. Confidence in changeover timing is low due to sporadic rate changes driving p-type, but overall only brief vis reductions and minor accumulations (<1") mainly on grassy and elevated surfaces are expected. && .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 from 10 PM EST /9 PM CST/ this evening to 4 PM EST /3 PM CST/ Monday for KYZ055>057-066-067-078- 082. && $$ Short Term...BJS Long Term...DM Aviation...BJS Hydrology...BJS