Marine Weather and Tide Forecast for Louisville, TN

DISCUSSION
Issued at 235 AM EDT Thu May 21 2026

Scattered showers and a few storms will remain across the area through the night and into the late morning hours. The risk of severe weather is little to none due to the decrease in instability across the area. The main impacts overnight with any thunderstorm will be locally heavy rain and brief gusty winds.

Scattered showers and storms then continue from morning through the afternoon and evening as a weak shortwave moves across the area.
No severe weather is expected today due to poor lapse rates, and only modest instability due to an increase in cloud cover, along with weak shear. Locally heavy rainfall is possible though as PW values remain elevated at 1.6 to 1.8 inches. Any area that sees repeated rounds of heavy showers could see some minor flooding issue.

Frontal boundary lifts back north on Friday and provides focus for more showers and storms through the day. Shear will be a little better across the area, and if we can get some breaks in the clouds, then instability will be as well. SPC only has us outlooked in general thunder as of now but if the ingredients come together we could see a few strong to severe storms, but chances are low as of now.

Showers and storm chances remain in place through the weekend and into early next week as A deep SW flow persists across the region. This will set the stage for several disturbances to move across our region within this SW flow pattern. No notable signs of any severe threat at the moment but we will continue to monitor as we approach the weekend timeframe. As we have been advertising, QPF through the next 7 days will vary widely across our area, depending on which areas see repeated showers and storms over numerous days. Generally speaking, 1-3" of rain is forecast through the period.

AVIATION
(12Z TAFS)
Issued at 749 AM EDT Thu May 21 2026

Morning rain overspreading the valley from the south likely to continue to around noon before weakening or dissipating. MVFR to at times IFR conditions during heavier bouts of rain within the overall stratiform coverage. This afternoon into early evening another bout of scattered TS with associated VIS reductions likely, though not confident in direct terminal impacts.
Confidence decreases through the period, with low confidence in any rain overnight. MVFR CIGs should be developing by the end of the period at KCHA or just west of the terminal.

PRELIMINARY POINT TEMPS/POPS
Chattanooga Airport, TN 80 65 81 66 / 90 80 90 100 Knoxville McGhee Tyson Airport, TN 79 65 82 65 / 100 60 90 100 Oak Ridge, TN 78 63 80 63 / 100 70 100 100 Tri Cities Airport, TN 78 61 79 61 / 90 50 90 90

MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.