Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
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272 FXUS63 KLMK 291050 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 650 AM EDT Wed May 29 2024 .KEY MESSAGES... * Mainly dry weather and below normal temperatures expected through Friday. * Rain and storm chances return for the weekend and continue into next week. Temperatures and dewpoints will also be on a steady increase into next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 308 AM EDT Wed May 29 2024 An upper level shortwave trough and very weak sfc reflection will continue to rotate southeast from the Lower Great Lakes across the Ohio Valley today. Right on the heels of this wave, high pressure will expand from the Plains to the Upper Midwest. Northwesterly winds are fairly light this morning, but expect breezy conditions to develop by mid to late morning. Gusts to 20-25 mph are likely for the afternoon hours. The core of the mid/upper level shortwave trough and associated deeper moisture will pass to our northeast across OH. However, northerly low-level flow will advect some moisture SSE over southern IN and central KY. Look for an increase in cloud cover beginning late morning, with SCT-BKN low clouds lingering throughout the afternoon hours. Cloud cover will be thicker across the northern half of the forecast area, with more sun in southern KY. The brief uptick in moisture and wave streaming overhead could kick off a few isolated showers from southern/SE Indiana across the Bluegrass Region this afternoon and evening. Cannot completely rule out a rogue lightning strike northeast of Lexington, but the chances are slim due to very limited, shallow CAPE. Most will enjoy a dry day with a steady NW breeze. Highs will range from the upper 60s/low 70s in SE IN and the Bluegrass to the mid 70s in south-central KY. Cloud cover diminishes this evening and overnight as high pressure noses in from the northwest. Winds will also diminish quite a bit after sunset, which should set the stage for a cool night with some fog. Patchy dense fog seems possible early Thursday given elevated soil moisture and temperatures dropping into the lower 50s in many areas. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 308 AM EDT Wed May 29 2024 Dry and quiet weather will continue Thursday and Friday as an upper level ridge shifts from the central U.S. into the eastern CONUS. The proximity of the ridge and surface high pressure will promote subsidence aloft and keep rain chances near 0% for this timeframe. It`s not until Saturday that we begin to see some changes to the dry and quiet pattern we`ve grown accustomed to. Southerly return flow on the western side of the surface high pressure and upper ridging will help to advect in a more moist/slightly humid airmass ahead of an approaching shortwave trough and surface low pressure. Models are in fairly good agreement of showers and storms developing ahead of the trough/low, but vary some on the timing and arrival of said feature. Latest data seems to suggest higher chances for precipitation later in the day Saturday, and it could continue into Sunday as the low travels eastward at a fairly slow pace. Model soundings reveal very poor lapse rates and near moist-adiabatic profiles with the arrival of precipitation, so instability will be very minimal. Some marginal shear (25-30kts 0-6km shear) will be present, though, so if we are able to destabilize some, can`t rule out isolated strong storms during the afternoon and evening hours Saturday. Upper level flow/pattern going into early next week looks quite disorganized and weak as the main jet energy remains well off to our north. Within the weaker westerly flow aloft, though, models prog subtle shortwaves and/or vort max`s to wobble into the Ohio and Tennessee Valleys and `spark` off rounds of showers and storms. Timing these individual features this far out is a bit difficult, so PoPs during this timeframe will remain elevated and broad-brushed to account for precip potential. && .AVIATION /12Z TAFS THROUGH 18Z THURSDAY/... Issued at 649 AM EDT Wed May 29 2024 VFR conditions appear likely for much of this TAF period. A shortwave trough will rotate southeast across the Ohio Valley today. Northerly low-level flow will advect lower level clouds between 3-5 kft over southern IN and north-central KY by late morning. Expect SCT-BKN ceilings to linger through much of the afternoon, with less cloud cover across southern KY. NW winds will gradually increase this morning. Gusts to 15-20 kts are likely late morning into the afternoon hours. Winds will diminish once again with sunset. Cannot rule out fog late tonight into early Thursday morning, but confidence is low at this time on IFR/LIFR conditions. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...EBW LONG TERM...DM AVIATION...EBW