FXUS63 KLMK 261809

AFDLMK



Area Forecast Discussion

National Weather Service Louisville KY

209 PM EDT Thu Jun 26 2025



...Updated Aviation Discussion...



.KEY MESSAGES...



* Heat and oppressive humidity continue, with a Heat Advisory in 

  effect at least through today. 



* Increasing coverage of afternoon thunderstorms Friday through the 

  weekend. 



* Very warm temperatures continue well into next week, but a weak 

  cold front brings lower humidity by Wednesday.



&&



.SHORT TERM /THROUGH FRIDAY/...

Issued at 336 AM EDT Thu Jun 26 2025



Heat and humidity will remain in full force today as the upper ridge 

axis still sits east to west across Kentucky. Forecast is largely 

"rinse and repeat" with isolated diurnal convection and max temps 

perhaps falling a degree or two short of Wednesday's highs. That is 

still enough for the 5th or 6th consecutive day (depending on which 

part of the area) of triple-digit heat index values. Heat Advisory 

looks good through at least the end of today. Still no relief 

tonight outside of late-day storms, with Friday morning lows mainly 

in the lower/mid 70s, while urban Louisville struggles to drop below 

80. 



By Friday the upper low currently between Florida and the Bahamas 

lifts across the Okefenokee Swamp, and a shortwave trof pushes 

across Wisconsin, both of which will serve to pinch off the upper 

ridge. We'll still be quite hot and humid Friday, but with the ridge 

starting to break down we'll see increased coverage and earlier 

development of diurnal convection. This limits confidence in 

maintaining triple-digit heat index values for enough of the day to 

warrant extending the advisory at this time. That being said, later 

shifts may need to carry the advisory into Friday for at least part 

of the area.



&&



.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...

Issued at 336 AM EDT Thu Jun 26 2025



The weekend will feature what is best described as a weakness in the 

upper ridging, which will allow for scattered, mainly diurnally-

driven convection each day. While it won't be as oppressively hot as 

most of the week has been, highs could still top 90 any place that 

manages to avoid convection through the peak heating of the day. 



Tuesday, model agreement continues to look fairly good as the 

global models begin to form a ridge over the Rockies and a trough 

over the East Coast. Northwest flow over the Lower Ohio Valley will 

push a cold front through the CWA, bringing a line of showers and 

thunderstorms with it. Shear continues to be weak, but stronger wind 

gusts become more likely during the afternoon and evening hours. By 

Wednesday a broad upper trof over the eastern CONUS and a sfc high 

building SE from the Upper Midwest will bring temperaturss near 

normal, but more importantly manageable dewpoints in the mid 60s.



&&



.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...

Issued at 209 PM EDT Thu Jun 26 2025



Mostly VFR conditions will continue as upper ridging and surface 

high pressure remain over the Lower Ohio Valley. The exception could 

be if one of the isolated to scattered storms directly hit an 

airfield this afternoon/evening. Coverage remains limited, but we 

continue to see these storms develop over urban heat and propagate 

along outflow boundaries. Winds are generally out of the southwest 

and are expected to back towards the south tonight.



&&



.LMK WATCHES/WARNINGS/ADVISORIES...

KY...Heat Advisory until 8 PM EDT /7 PM CDT/ Friday for KYZ023>043-

     045>049-053>057-061>067-070>078-081-082.

IN...Heat Advisory until 8 PM EDT /7 PM CDT/ Friday for INZ076>079-

     083-084-089>092.



&&



$$



SHORT TERM...RAS

LONG TERM...RAS

AVIATION...KDW

