NWS Area Weather Forecast Discussion
Louisville, KY
LMK
LMK
000 FXUS63 KLMK 192320 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 720 PM EDT Fri Oct 19 2018 .Short Term...(This evening through Saturday) Issued at 243 PM EDT Fri Oct 19 2018 ...Gusty Winds With Cold Frontal Passage Tomorrow Afternoon And Evening... Regional radars reveal a band of showers stretching from TX into the Great Lakes region ahead of a pre-frontal trough. Obs across western KY and southern Indiana are already reporting rain, and expect that rain to move quickly into western parts of the region over the next couple of hours before covering the entire area tonight. The rain showers with the pre-frontal trough look to be mostly out of the region by sunrise Saturday morning, with the exception of locations across eastern KY and near the TN border where showers could linger into the late morning hours. Models indicate clouds slowly clearing in areas along and west of I-65, though forecast soundings show some moisture potentially trapped near the top of the boundary layer, so confidence in this clearing remains low. The bigger story tomorrow will be the winds. A strong cold front will swing through late in the afternoon, and model soundings indicate very deep mixing and gusty (40-50kt) winds near the top of the boundary layer with the fropa due to a strong post-frontal surface high tightening the pressure gradient. With fropa occurring so late in the day, there will be a small window for 40+ mph surface wind gusts before the boundary layer stabilizes enough in the evening hours to keep gusts under 40mph. The best chance for these strong winds will generally be across southern Indiana and northern Kentucky. After collaborating with surrounding offices, will hold off on the issuance of a wind advisory for the moment, but if conditions continue to look favorable for strong wind gusts, then a wind advisory may be needed in subsequent forecast updates. .Long Term...(Saturday night through Friday) Issued at 255 PM EDT Fri Oct 19 2018 We start off this period with a secondary cold front crossing into Eastern Kentucky. The pressure gradient associated with this frontal passage is fairly tight, and the response will be gusty west to northwest winds through the evening hours. The high pressure building in behind this front looks to become centered over the Commonwealth by Sunday afternoon and then into the Appalachians by Monday morning. Still think the proximity of the high center will make for light and variable winds through the night and subsequent good conditions for frost development. Lows should be similar to Sunday morning, but the calmer winds should make for more widespread frost development. Taking a quick look at any potential cloud layers that could affect temperatures, the GFS does show increased RH values in the 300-500 mb layer come in from a system to our west Monday morning. Will have to watch this system to see if any adjustments are needed to Monday morning lows. Tuesday we are still on tap for a brief warmup, though a reinforcing dry cold front should clip through here in the afternoon/evening hours. That front should keep our temperatures below normal for Wednesday. After that models diverge a bit on whether a southern stream system affects us. The 00Z Euro had some rain chances both Thursday and Friday, whereas the GFS keeps us dry. The 12Z Euro came in drier for Thursday but still has some rain Friday. Looking at the 12Z GEFS, there is a hint of a wave coming through the Mid MS Valley but the QPF stays to our south. The European statistical guidance has been doing well of late, with fairly reliable percentages, and the 00Z version called for 40-60 pops between the days. SuperBlend gives a value roughly between the GFS stat guidance and the Euro so decided not to stray too far from what it came up with. . && .Aviation...(00Z TAF Issuance) Issued at 720 PM EDT Fri Oct 19 2018 An upper trough swinging through the region will bring a variety of weather to the TAF sites during this forecast package time frame. Corridor of showers at press time will slowly push off to the east this evening, but low ceilings will move in and lower to IFR. That moisture will get trapped and persist into Saturday morning before lifting and breaking in the afternoon. Of potentially greater concern tomorrow will be strong and gusty winds coming in from the WNW as we sit in a tight pressure gradient between low pressure to our northeast and Canadian high pressure to our northwest and strong winds aloft come sweeping in from the northwest. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Short Term...DM Long Term...RJS Aviation...13
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Forecast Discussion from: NOAA-NWS |
Script developed by: El Dorado Weather Adapted by FrankfortWeather.us |
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