textproduct: Louisville

KEY MESSAGES

* Cloudy and cool conditions are expected today, with patches of drizzle possible this morning.

* Active weather pattern will bring additional rainfall to the area Thursday through Saturday, though flooding and severe weather are not expected at this time.

* The late weekend and into early next week will see drier conditions, before another chance for rain arrives by the middle of next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 347 AM EST Wed Nov 19 2025

Early this morning, the last of the rain showers are clearing into southern and southeastern KY as radars are quiet across most of the CWA. What's left of the sfc low pressure/cold front which contributed to the development of showers and storms over the past 24 hours is meandering southward across southern KY this morning. The mid-level disturbance which was supporting the sfc low is crossing the Appalachians at this hour, and this setup will result in further sfc cyclolysis later today.

Behind the remnant sfc front, an expansive area of low stratus stretches across much of the Midwest and Ohio Valley. In the immediate vicinity of the sfc front, lower visibilities due to patchy fog have been noted so far this morning; however, these have generally improved once N/NE flow kicks up in the wake of the low. As a result, we may be able to avoid dense fog headlines this morning; however, obs trends will continue to be monitored through the morning.

Today, sfc high pressure will move across the Great Lakes with the remnants of the sfc front extending from the mid-Atlantic back into the TN valley. The large area of low stratus overhead will have difficulty eroding, with overcast skies likely remaining in place through the day. Model soundings depict the layer of llvl saturation at only about 2-4 kft deep; however, this could be just thick enough for some patchy drizzle, especially this morning. With low clouds in place and weak cold advection from N/NE flow expected, think temperatures will struggle to warm much if at all through the day. There should still be a north-to-south gradient in temperatures today, though it shouldn't be quite as stark as on Tuesday. The current forecast has highs in the low-to-mid 50s across southern IN and north central KY, but it remains a distinct possibility that many locations will stay in the upper 40s. Across southern KY, temperatures will likely be fairly stagnant in the upper 50s and low 60s.

Low clouds are likely to continue tonight into Thursday morning, although some scattering will be possible across southern KY. If low clouds scatter, dense fog would be possible, and there may be patchy fog Thursday morning even in areas which don't see clearing as a result of weak winds near the surface. Because of low confidence, we'll keep fog out of the forecast tonight for now, but it is certainly a possibility. Temperatures will fall very gradually tonight as a result of the ample moisture; lows Thursday morning should bottom out in the mid 40s to around 50.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 347 AM EST Wed Nov 19 2025

Thursday through Saturday Night...

Medium-range guidance has remained fairly consistent in showing an unsettled pattern for the end of the week as multiple disturbances are expected to move across the Ohio Valley between Thursday and Saturday. The synoptic pattern will feature broad upper troughing along the west coast, with a combination of northern stream troughing and southern stream ridging leading to a zonal, highly baroclinic flow pattern across the eastern CONUS. Within this zonal pattern, several embedded pieces of upper-level energy will be shedded off of the main trough out west before a final shortwave slides across the region Friday night into Saturday morning. Continued low-to-mid level S/SW flow will advect rich moisture into the region, conditioning the environment for multiple rounds of rainfall.

While the day on Thursday is expected to begin dry, the first chance of rain is expected to move across the area Thursday afternoon into Thursday night. As this disturbance swings through the region, it will help to lift the remnant frontal boundary over the TN Valley back to the north. Exactly how far north the front lifts Thursday night into Friday will play a role in how much rain falls Friday into Friday night, as it will serve as a focusing axis for subsequent rounds of rain. The GFS continues to be on the drier side as it lifts the front into Indiana on Friday, limiting precipitation until the last wave/cold front swings through Friday night. In contrast, the wetter Euro solutions keep the front suppressed to the south over the Ohio Valley on Friday, resulting in greater support from isentropic lift ahead of the main system passage. This would also play an important role in temperatures, as the wetter/south solutions are also cooler on Friday. At this time, the blended guidance takes both solutions into account, resulting in widespread rainfall amounts of 1-1.5". If subsequent runs trend toward the Euro, amounts may need to be increased, though this should still be below totals which would cause any considerable flooding issues.

Saturday morning, the final disturbance should clear the region, resulting in drier weather for the second half of the weekend. At this time, there is a chance for showers on Saturday, though there is increasing likelihood that much of the afternoon will be dry, especially along and west of I-65. Temperatures should remain near or above normal into the weekend.

Sunday through Tuesday Night...

Upper ridging should build over the southern Plains and into the Mississippi Valley on Sunday as a closed upper low continues to spin over the western CONUS. This should allow drier air and high pressure to be in control on Sunday, which looks like one of the better days for outdoor activities over the next 7 days.

Early next week, there is fairly good agreement in the large scale features as the upper low out west is expected to be forced eastward by a northern stream wave. However, there are small-scale differences between guidance which result in different sensible weather impacts next Monday into Tuesday. The ECMWF has stronger ridging ahead of the upper low, resulting in a slower propagation eastward and delaying the next chance of rain across the area until next Tuesday. In contrast, the GFS features weaker ridging and a slightly faster system early next week, bringing rain chances in during the day on Monday. While blended guidance does feature low- end rain chances on Monday, there is a reasonable likelihood that we remain dry until next Tuesday, when another chance for showers (and possibly storms) moves through the region.

Extended Forecast Discussion...

An interesting period of weather looks possible as we head toward the Thanksgiving holidays. A decent mid-latitude cyclone looks to pass to our west/northwest in the late Tuesday night and Wednesday time frame. Models show plentiful moisture and shear for widespread showers and perhaps some thunderstorms. However, the usual uncertainties on instability remain and will not be resolvable until early next week. The GFS/GEM are the quickest bringing this system through, while the Euro is slightly slower, by 12-18 hours. This system will then likely usher in a much colder airmass as we head into Thanksgiving Day.

Since our last extended discussion, several iterations of signal analysis has been completed. While earlier signal analysis had a weak signal centered around 11/28, the latest iterations have a much stronger signal for the same period. Taking into account the possibility of the upper pattern becoming a bit more amplified, this signal may pass through the region in the 11/28-11/30th time frame. All three dynamical models (GEM/Euro/GFS) are hinting at the emergence of a southern stream system in this time frame which could bring wintry weather to the region late Thursday and into Friday.

AVIATION /12Z TAFS THROUGH 18Z THURSDAY/

Issued at 641 AM EST Wed Nov 19 2025

Pervasive low stratus with pockets of lower visibilities from patchy fog and drizzle will continue this morning, with the lowest flight categories expected between now and 15-16Z. Later today, a slow improvement to IFR categories is expected, with low MVFR ceilings possible this afternoon and evening. Winds should be light out of the northeast today (generally less than 8 kt), with winds expected to back to the N/NW at HNB and BWG this afternoon. Later in the forecast period tonight, it is possible that the low stratus could begin to scatter out, particularly at BWG, but confidence in this outcome is low right now. With weak winds expected tonight into Thursday morning, it is likely that moisture will settle, resulting in lower visibilities. At this time, it doesn't look like the low clouds will scatter out completely until the day on Thursday.

LMK WATCHES/WARNINGS/ADVISORIES

KY...None. IN...None.