273 FXUS63 KLMK 151145 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 645 AM EST Sat Feb 15 2020 ...Updated Aviation Discussion... .Short Term...(Today and tonight) Issued at 330 AM EST Sat Feb 15 2020 Conditions are clear and cold this morning with steady temps in the teens. An upper trough continues to move east over the northern Plains while a downstream ridge builds east across the eastern United States. At the surface, high pressure drifts east over the Mid-Atlantic. Temps have stabilized due to warmer air advecting in aloft via SW return flow. Southerly low-level flow will continue to increase during the day with a tightening pressure gradient between a Plains/Upper Midwest cold front and the East Coast high. The northern system, actually centered over Hudson Bay, will keep deep moisture well north of the region. A mainly clear start will allow temperatures to jump pretty quickly after sunrise. An increase in cirrus is expected this afternoon and evening. Afternoon highs are expected to range from the mid 40s north of I-64 to the lower 50s in southern KY. Mid-level clouds will thicken over southern IN and northern KY tonight. The clouds and south wind will result in a much warmer night with lows generally in the mid 30s. .Long Term...(Sunday through Friday) Issued at 325 AM EST Sat Feb 15 2020 By Sunday morning, a Canadian Low will continue advancing ENE across Hudson Bay with troughing extending southward across the central US. Most of the dynamics of this system will remain far to our north, but broad, weak lifting across the Ohio Valley, coincident with a moist SW flow below 850mb, may be enough to produce some light rain/sprinkles. Otherwise, expect a mostly cloudy end to the weekend with highs reaching into the upper 40s to lower 50s. A quick dose of dry air in the mid levels will shut off any rainfall late Sunday night before rain chances return Monday morning. Broad isentropic lift will see PoPs gradually increase from W to E across the CWA as increased moist air advects in from the Gulf of Mexico. A respectable 50KT LLJ will develop ahead of an approaching cold front overnight Monday into Tuesday morning that will likely see gusty SW winds in the 20-30mph range until FROPA occurs midday Tuesday. Zonal flow will allow for a rather progressive system that will keep QPF limited to under a half inch for most. Model soundings are showing convective potential for our southern counties, which may result in some slightly higher accumulations. Will keep an eye on this feature as new data becomes available. Modified cP air will move into the region behind the aforementioned front, which could result in some light snow as the mid and low level moisture departs the region. Little if any impacts are expected as the prior day's (Tuesday) max temperatures will have reached into the 50s. Wednesday afternoon through Saturday appear to be dry as upper level ridging and surface high pressure dominate the region. Morning lows will start off on the cool side from Thursday through Saturday with temps ranging in the 20s. Highs will rebound quickly though with Thursday in the 30s, Friday in the 40s, and Saturday trying to reach into the 50s. && .Aviation...(12Z TAF Issuance) Issued at 645 AM EST Sat Feb 15 2020 VFR conditions to continue through this TAF period. SCT cirrus will be the primary cloud cover today, though a 6 kft deck will slide east over areas near and north of the Ohio River this morning. A light southeast wind will increase to 10-15 kts by late morning and veer southerly in the process. Gusts to around 20 kts are expected this afternoon through 23z or so. Marginal LLWS conditions will then be in place once sfc winds diminish this evening. After 23z, a 35-40 kt LLJ from the southwest will contribute to LLWS. Mid-level clouds will thicken with lowering ceilings late tonight in southern IN and northern KY. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Short Term...EBW Long Term...CG Aviation...EBW