NWS Area Weather Forecast Discussion
Louisville, KY
LMK
LMK
000 FXUS63 KLMK 160712 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 312 AM EDT Sun May 16 2021 .Short Term...(Today and tonight) Issued at 300 AM EDT Sun May 16 2021 Latest WPC analysis places a quasi-stationary sfc front from southern Kansas across the Ozarks and well into Tennessee, but it`s fairly difficult to pick up in the obs this far east. Deep convection is occurring north of the front in Kansas, but none of the models exactly have a good handle on any of the very widely scattered light rain showers east of the Mississippi. Most precip over the Ohio Valley is being lost to evaporation, but a few sprinkles have been hitting the ground. Main challenge in the next 24 hrs is precip potential and timing, and confidence is somewhat limited. Mid-level clouds have us off to our mildest start in nearly two weeks, but will also severely limit diurnal warming especially as they thicken along the northward moving warm front. Think there is an opportunity for precip, mainly as light rain, from mid-morning into early afternoon. Rain chances today will be mainly focused south of the Western Kentucky and Bluegrass Parkways, with about a 50/50 chance of measurable precip. With next to no instability and weak dynamics, there`s a low probability for embedded thunder and no expectation of severe wx. Better rain chances will be after midnight tonight, as the shortwave ridging aloft progresses far enough east to let the sfc warm front get a stronger northward push. We`ll ramp POPs up to likely roughly along and north of the I-64 corridor. Will also include a chance for embedded thunder, but again not expecting any organization or intensity. QPF is still modest, around a quarter inch where the best rain chances will be. && .Long Term...(Monday through Saturday) Issued at 255 AM EDT Sun May 16 2021 The long term period continues to look unsettled for Monday and Tuesday as an oscillating quasi-stationary sfc boundary extends from the central Plains and cuts across the Ohio Valley. After a stretch of unseasonably cool temperatures last week, we look to transition to a warmer pattern later in the upcoming week as the amplified flow aloft develops a broad ridge across the eastern third of the US. For Monday, the sfc boundary should be located just to our north. A southerly low level jet core will be off to our west, but enough Gulf moisture advection overrunning the boundary will pose an increased precip prob for areas along and north of I-64. Forecast sounding profiles reveal a lack of shear, but do carry sufficient instability in the neighborhood of 1200 J/kg of SBCAPE. This will pose more of a brief heavy rain type of convection. Favorable environmental parameters for flash flooding concerns are not quite met, with the warm cloud layer expected to be around 8k ft (greater than 10k ft is favorable), and PW of 1.2" will be slightly lower than the 75th percentile from BNA sounding climo, but we will be near 80% RH in the low/mid levels. Southerly winds will not only bring additional moisture to the region, but will also bring seasonal temps back to the forecast, with mid-upper 70s expected. On Tuesday, the upper level pattern will begin to amplify as a stacked low sits over the Mountain West and upper ridging takes place over the eastern third of the CONUS. However, at the sfc, expect to see continued PoPs as waves eject out of the central Plains and ride along the wavy frontal boundary. The sfc boundary will eventually shift northward by Tuesday night, bringing drier wx to the region. QPF for Monday to Tuesday is focused primarily along our southern IN counties, which could see up to 0.5-0.75". For areas along the I-64 corridor, around a quarter of an inch is possible for Mon-Tue. For Wednesday and beyond, strong meridional flow sets up across the US. The stacked low once over the west will track northward along the southern stream ridge and eventually open. Upper level ridging looks to anchor itself across the eastern US, placing sfc high pressure over the East Coast and deep southerly flow along the Mississippi/Ohio River valleys for mid to late week. With possibly the warmest days of the year thus far, we could see temps reach the mid-upper 80s for Wed-Sun. && .Aviation...(06Z TAF Issuance) Issued at 115 AM EDT Sun May 16 2021 IMPACTS: VFR conditions overnight. MVFR in light rain roughly daybreak through early afternoon. DISCUSSION: Light winds and mid-level ceilings will prevail overnight, perhaps building down to FL060 by daybreak. Light rain will break out around daybreak, and even if some terminals remain dry expect MVFR ceilings. Will recover to VFR late afternoon, with SDF and HNB deteriorating late evening as another round of rain arrives. Either could eventually build down to IFR but expect that will be beyond the valid time of these TAFs. CONFIDENCE: Medium confidence on all forecast elements. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Short Term...RAS Long Term...CJP Aviation...RAS
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Forecast Discussion from: NOAA-NWS |
Script developed by: El Dorado Weather Adapted by FrankfortWeather.us |
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