Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
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590 FXUS63 KLMK 060043 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 843 PM EDT Wed Jun 5 2024 ...Updated Aviation Discussion... .KEY MESSAGES... * Scattered showers and storms likely this afternoon and evening. A few strong to severe storms are possible. Gusty winds and torrential rainfall will be the main threats. * Drier weather and cooler temperatures are favored late week into the first half of this coming weekend. && .SHORT TERM /THROUGH THURSDAY/... Issued at 333 PM EDT Wed Jun 5 2024 Afternoon satellite imagery shows partly to mostly cloudy skies across the region. Earlier MCV over southern KY continues to churn eastward helping firing convection over mainly eastern KY. In the wake of the MCV, some partial clearing is trying to take place across portions of central KY (I-65 corridor) ahead of an approaching cold front. Afternoon temperatures were generally in the low-mid 70s in the cloud cover. In areas that had partially cleared, temps had warmed back into the upper 70s to around 80. Some low-mid 80s were located down in the Pennyrile region of western KY. Mesoscale analysis shows instability building across the central part of the region with MLCAPE values in the 800-1200 J/kg range with about 30kts of bulk shear. Low and mid-level lapse rates were still quite meager with rates running around 6 C/km. PWAT values were quite high with widespread 1.7 to 1.8" values, so we have plenty of primo juice to work with. For the remainder of the afternoon, additional forcing for convection remains rather nebulous in the wake of the passing MCV. Frontal forcing remains well to our northwest for now. Some additional insolation may result in an uptick of convection along differential heating boundaries, so will keep isolated/scattered PoP coverage going into the evening hours. Any strong storm will be capable of producing torrential rainfall, gusty winds, and frequent lightning. Localized flash flooding will be a threat, especially in areas that have seen recent rainfall. Moving into the evening hours, surface frontal boundary to our northwest will sink southward into the region. Majority of the 12Z CAMs suggested an uptick in convection along and just ahead of the front and we`re already seeing the start of that across central/southern IL. Early evening coverage looks to be most concentrated across southern IN back into southwest KY. This activity should then drop southward into north-central/east-central KY this evening while weakening as we loose heating/instability. The storms this evening could be on the strong side with torrential rainfall, gusty winds, and frequent lightning being the main threats. We`ll have to be on guard for some localized flash flooding given that these storms should be efficient rain producers. The risk of flooding will be highest where storms tend to train over the same locations. Overnight, the front will continue to push south/southeastward with rain chances ending from NW to SE. Overnight lows will cool into the lower 60s over southern IN and in the mid-upper 60s over much of central/eastern KY. For Thursday, overnight cold front will continue to push southeast during the morning hours. We`ll have some lingering low-level moisture that will be in place during the morning hours. A secondary frontal boundary will drop into the region during the afternoon and may spark an isolated shower or two, mainly across our far eastern counties. Highs for Thursday will be near normal with lower-middle 80s expected. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... Issued at 333 PM EDT Wed Jun 5 2024 Thursday Night through Friday Night... A sfc cold front will be well southeast of the area by Thursday night, with northwesterly flow at all levels. Cooler, drier air filters into the region Thursday night with temperatures falling into the mid/upper 50s. Dry NW flow continues through Friday with high pressure centered over the southern Plains and Lower MS Valley. Expect sunny skies and lower humidity (sfc dewpoints in the lower 50s). Afternoon highs will reach the 75-80 degree range. It will be a bit breezy with NW winds of 10-15 mph, gusting to 20-30 mph. Friday night temperatures will be on the cool side of normal with lows in the 50s. This Weekend into Early Next Week... The upper level pattern deamplifies a bit Saturday with ridging aloft now centered over the western Gulf Coast. An upper level shortwave trough is forecast to rotate southeast over the Upper Midwest and Great Lakes. Weak low pressure spinning up over the southern Plains will also help lead to strengthening SW return flow from the southern Plains east across the Mid-MS and Lower OH Valleys. This will result in modest moisture advection into the OH Valley, but the atmosphere looks to remain rather stable. We could see some weakening convection attempt to push into central or southern KY by evening, but a largely dry day appears likely at this time. Afternoon highs will be in the mid/upper 70s in most areas. The upper level trough over the Great Lakes deepens as it drops south late in the weekend, and a weak sfc cold front is forecast to drop south through southern IN and central KY. Rainfall chances tick upward late Saturday night into Sunday, especially across southern KY. However, rainfall totals are forecast to be relatively light (generally a quarter-inch or less). Some areas across southern IN and north-central KY may not see much rain at all during this time frame. Another push of cool, dry air advection from the north will likely yield fair weather heading into early next week. Highs in the mid/upper 70s look likely for Monday, perhaps with a couple spots near 80 F. Most areas will approach 80 degrees by Tuesday. && .AVIATION /00Z TAFS THROUGH 06Z FRIDAY/... Issued at 843 PM EDT Wed Jun 5 2024 Area of showers and a few isolated thunderstorms are located mainly north or along the Ohio River with just a few showers/storms forming to the south. Winds have not been that gusty and the environment is not great for a lot of convection but enough for a few isolated storms. The best chance for this will towards LEX later this evening and overnight as a cold front currently working across central pushes into the area later this evening and overnight. This will push the showers through. Again some of these showers could have heavy rain with brief period of IFR conditions but so far haven`t seem much of that this afternoon or evening. Generally left it out of the TAFs. Once the front moves through we could see some MVFR and a brief period of IFR conditions for BWG-LEX-RGA in the earl morning hours. Once the front clears for SDF/HNB likely going to see clearing then a wind shift more out of the west. Expect clearing near or shortly after sunrise for BWG-LEX-RGA with improvement to VFR. Winds will also pick up behind the front with gust during the day tomorrow out of the west around 20-25 Kts. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...MJ LONG TERM...EBW AVIATION...BTN