061 FXUS63 KLMK 131132 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 632 AM EST Thu Feb 13 2025 ...Updated Aviation Discussion... .KEY MESSAGES... * Widespread rainfall between 2 and 5 inches Friday night through early Sunday will likely lead to widespread areal, river, and isolated flash flooding. Falling temperatures on Sunday could cause light snow to mix in on Sunday. * Rapidly falling temperatures into the teens could cause lingering wet surfaces to freeze. Black ice may be possible for the Monday morning commute. * Another system could bring additional snow showers on Tuesday and Wednesday of next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 307 AM EST Thu Feb 13 2025 Cold air will continue to advect in behind the departing cold front today as strong sfc high pressure continues to build over the central CONUS. Pressure gradient will tighten over the region producing breezy 20-25 mph gusts out of the west-northwest. Low level moisture will remain under a temperature inversion keeping skies cloudy to mostly cloud for most of the day. This will keep it relatively chilly through out the day with temperatures in the low/mid 30s during the afternoon. As drier air continues to work in from the west, skies should start to clear later in the day and we might get a brief period of sunshine in the late afternoon to right before sunset. High pressure will continue to build over the region overnight, clearing skies and diminishing winds. This will result in a cold overnight with lows in the mid/upper teens with right around 20 across out southern tier of counties close to the KY/TN border. For those with concerns regarding the flooding expected this weekend, today and tomorrow will be the last days to bring preparations to completion. (See below) && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 307 AM EST Thu Feb 13 2025 Friday... We'll enjoy a dry day on Friday as surface high pressure centers to our NE. We should see a good amount of sunshine at least through the morning and early afternoon. By mid to late afternoon, we'll see increasing mid and upper sky cover ahead of the next system. Surface winds don't really veer to a southerly component through the daylight hours, so likely won't be able to tap into any warm advective component. We will get a nice diurnal spike from morning lows in the teens and low 20s, but still only expecting upper 30s and 40s across the area. Friday Night - Sunday Night... A strong storm system is expected for the weekend, and will bring flooding impacts to our region. A Flood Watch has been issued for early Saturday morning through early Sunday afternoon. Widespread areal and river flooding along with isolated flash flooding are all possible. A trough will steadily move out of the western CONUS, and into the central CONUS through the weekend. Meanwhile, surface low pressure is expected to develop and strengthen from around the Red River Valley up through the central Appalachians, with a surface low track near or directly over our CWA. We'll see overrunning precipitation with isentropic lift beginning late Friday night/early Saturday morning, before stronger low level jetting and favorable mid and upper level forcing take hold through Saturday as the trough axis arrives. The combination of the strong low level moisture transport and good mid to upper level support will yield widespread rainfall, along with a more concentrated frontogenetical band of precipitation embedded within. The biggest issue is that this band could stay nearly stationary, or waffle slightly before finally being pulled through as the surface low/cold front passes Saturday night. In the meantime, precipitation totals are likely to add up where this band sets up and lingers. Models have been consistent in saying that this will most likely be across our southern and central CWA, and some of the data from earlier today have backed off from a more northern solution. We tend to like the southern solution in this type of setup as the frontal band can self-reinforce and limit northward progression sometimes. See this more often in pure convective situations with reinforcing outflow, but could happen in this scenario too, as suggested by the 12/12z global C-Shield solution. Bottom line is that there is very high confidence in flooding potential across central and southern KY, with less confidence in the extent of precipitation across southern IN and far north central KY. Overall, the QPF forecast hasn't changes much with 2 to 5 inches expected across the Watch area. Heaviest rain still looks to fall in the Green and Cumberland basins, along with the Rolling Fork and Rough River basins. The Kentucky River basin will see a lot of upstream contributions from the eastern KY heavy rain, plus 2 to 3 inches over the basin itself in our area. Much of that water eventually finds its way into the Ohio where flooding will also be likely later into next week. Also want to mention we could see a brief severe threat if the surface low is able to pull up any instability across our SE CWA on Saturday evening/night. Right now, it appears we are lacking instability, but perhaps a brief window could materialize if the track is far enough NW. Something to watch, but seems a fairly low probability at the moment. Cold front passes through late Saturday night, with precipitation ending west to east on Sunday. Could see a brief change over to snow on the back side, but not expecting any issues from that at this time. It is worth noting that temperatures drop well into the teens by Sunday night, so any lingering puddles, wet roadways, etc will have a good chance to freeze. Black ice due to lingering wet roadways could be a secondary concern. Monday - Wednesday... Fairly high confidence in a dry Monday as high pressure briefly builds in. However, lower confidence for Tuesday and Wednesday as a weak wave or two may slide through the area. Looks like a pretty cold stretch with highs mostly in the 30s each day and lows in the teens and low 20s. Any precipitation by mid week has a chance to be snow, and some light accumulations could be possible. && .AVIATION /12Z TAFS THROUGH 18Z FRIDAY/... Issued at 632 AM EST Thu Feb 13 2025 Flight categories will range from IFR for LEX/RGA to MVFR for SDF/HNB/BWG through most of the day as drier, cooler air filters into the region. Low level moisture will remain trapped under an inversion keeping the low stratus around for bulk of the day. High pressure builds in from the west tightening the pressure gradient over the region. Winds will gust to 20-25kts this afternoon. As the high pressure gets closer the skies will start to clear and we will start to see VFR flight categories return as winds diminish later tonight. && .HYDROLOGY... Issued at 632 AM EST Thu Feb 13 2025 Another strong storm system will arrive this weekend, with an additional 2 to 5 inches of rain in the forecast. Central and southern KY are currently expected to see the higher totals out of this wave as well. Overall, total rainfall amounts through next Sunday could range between 2 and 3 inches across southern Indiana and north central KY, and 3-5 inches in southern Kentucky. With already saturated soils, and area rivers and streams continuing to run high, these waves of rain will make areal flood and river flood threats increase as we move through the week. The river basins that stand the biggest threat of widespread minor flooding, and higher impacts, would be the Green, Rough, Rolling Fork, Cumberland, Kentucky, and Licking. The Ohio River will also see notable rises with added rainfall and contributions from tributaries. All of these streams will be subject to minor flooding, and there's about a 30- 50% chance of some spots reaching moderate flooding on the Kentucky River. Lower, but notable, chances for major flood in some locations are also on the table. A moderate risk (level 3 out of 4) of excessive rainfall has been outlooked for much of central and southern KY by the Weather Prediction Center. Stay up to date of the latest forecasts during this active and impactful stretch of weather. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...Flood Watch from late Friday night through Sunday afternoon for KYZ023>031-033>043-045>049-053>057-061>067-070>078- 081-082. IN...Flood Watch from late Friday night through Sunday afternoon for INZ084-089>092. && $$ SHORT TERM...BTN LONG TERM...BJS AVIATION...BTN HYDROLOGY...BJS