545 FXUS63 KLMK 081812 AFDLMKArea Forecast Discussion National Weather Service Louisville KY 212 PM EDT Mon Sep 8 2025
...Updated Aviation Discussion...
.KEY MESSAGES...
* Chilly conditions expected this morning with lows in the 40s.
* Dry and pleasant weather expected this week with a gradual warming trend in temperatures.
* Next chance of rain likely not arriving until next Sunday or Monday.
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.UPDATE... Issued at 1148 AM EDT Mon Sep 8 2025
The forecast is on track this morning. No updates needed or planned. We`re well on our way to a dry and comfortable day with highs in the 75 to 80 degree range for most.
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.SHORT TERM /THROUGH TONIGHT/... Issued at 317 AM EDT Mon Sep 8 2025
Skies were clear across the region this morning. GOES night-time fog imagery shows fog in the deeper valleys across eastern KY and down in the Lake Cumberland region. Temperatures across the region were in the mid-upper 40s in the valleys and around 50 on the ridges. Temperatures are running a little warmer this morning mainly due to a light northeasterly wind that is keeping the boundary layer a little more mixed and not allowing a good radiational cooling profile. No significant weather is expected through sunrise. Overnight low temperatures will be in the low-mid 40s in the valleys with upper 40s on the ridges and in the 50s in the urban corridors. In our typical colder spots that have good radiational cooling, a shot at the upper 30s still looks possible.
For today, after a chilly start, we`ll see mostly sunny skies with a diurnal Cu field setting up in the afternoon. Highs will range from the low-mid 70s across southern Indiana and the northern half of Kentucky. Across southern Kentucky, highs of 75-80 are expected.
For tonight, another night of clear skies are expected with some light fog possible in our Lake Cumberland valley locations. Lows will range from the mid-upper 40s in the valleys to around 50 on the ridges and in urban corridors.
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.LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 317 AM EDT Mon Sep 8 2025
For the long term period, still not seeing much change in the current forecast thinking. Model solutions continue to be quite steady in showing a rather blocky pattern across North America with troughs on both coasts and a ridge across the Plains. The ridge across the Plains may grow a little more to the east during the late week period.
In terms of sensible weather, mostly sunny days and mostly clear nights are expected with no real rainfall chances. On a whole, temperatures through the period will average below normal for early September. However, as the aforementioned ridge axis moves eastward, we`ll see temperatures warm through the upcoming work week. Highs on Tuesday will be in the upper 70s to the lower-mid 80s with overnight lows in the upper 50s. Highs on Wednesday will warm into the low-mid 80s across southern Indiana and northern Kentucky, with southern Kentucky seeing temps warm into the upper 80s. For Thursday through Sunday, highs in the afternoon will warm into the 85-90 degree range with overnight lows in the upper 50s to the lower 60s.
Looking further ahead, the upper level ridge across the Plains will continue to build toward the end of the extended period. A closed cut off low looks to drop southward out of Ontario and into the Great Lakes by late Sunday and into Monday which may drive a cold front through the region bringing our next chance of measurable precipitation. Uncertainty increases with time here as to what happens with this cut off low. OP Euro solutions keep it parked over the northern Ohio Valley and into the northeast US, while the Euro AI allows the low to open up and move off the east coast. The implications here will mainly affect temperatures, where we would see cooler conditions if the upper low sets up over the Ohio Valley, with potentially hotter conditions if the low moves off to the east with ridging building in. With continued ridging over the Plains, it appears that a core of heat will develop out across the Midwest and into the Mid-MS Valley. This could eventually work its way into our region.
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.AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 211 PM EDT Mon Sep 8 2025
VFR conditions prevail through this forecast cycle with high pressure in control. Look for a few cumulus around 6 K feet this afternoon with a steady ENE to NE surface wind. Winds go light and variable tonight, and then pick up again light out of the SE on Tuesday.
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.LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None.
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UPDATE...BJS SHORT TERM...MJ LONG TERM...MJ AVIATION...BJS
NWS LMK Office Area Forecast Discussion