National Weather Service Raw Text Product

897 
FXUS63 KLMK 130227
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1027 PM EDT Sat Oct 12 2024

.KEY MESSAGES...

*  Warmer temperatures and dry weather continues into tonight. 

*  Breezy and very isolated showers along and east of US-127 on 
   Sunday.

*  Turning much cooler next week with widespread frost likely 
   Tuesday and Wednesday nights.

&&

.UPDATE...
Issued at 1027 PM EDT Sat Oct 12 2024

Evening satellite imagery shows mostly clear skies across the 
region.  Temperatures were in the lower to middle 60s across the LMK 
forecast area.  We do have some of our cooler valley locations 
coming in a bit cooler with lower-middle 50s.  Current forecast 
remains on track for the overnight hours.  Products have been 
refreshed with new observational data and blended into the ongoing 
forecast.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 314 PM EDT Sat Oct 12 2024

An upper level trough over central Canada this afternoon is forecast 
to amplify as it drops southeast over Ontario, the Upper Midwest, 
and Great Lakes tonight and Sunday. A 1012 mb sfc low currently over 
southern Iowa is forecast to move east along an existing quasi-
stationary boundary through northern portions of IL/IN/OH. This wave 
of low pressure will gradually deepen tonight through Sunday with 
the arrival of stronger divergence aloft downstream of the upper 
trough. 

Central KY and southern IN will be positioned south of the sfc low 
and trailing cold front through Sunday morning. Low-level SW flow 
will continue to increase this evening and overnight in the warm 
sector. Despite the arrival of a potent 40+ kt SW low-level jet 
early Sunday, dry weather remains likely. Low-level moisture return 
is relatively meager, and a strong low-level inversion will be in 
place. In fact, this inversion will remain in place through much of 
Sunday. 

As for sensible weather, tonight will be dry with mostly clear to 
partly cloudy skies. It will be notably milder than previous nights 
due to increasing southerly winds. Sunday morning lows will be in 
the mid 50s to lower 60s. 

Sunday morning will start off dry and breezy with partly sunny 
skies. The sfc cold front pushes southeast through the forecast area 
during the afternoon and evening hours. Forecast soundings show some 
weak CIN lingering even into the late afternoon. Sfc dewpoints creep 
up to near 60 F in a narrow pool of moisture along the front. We 
could realize 1000+ J/kg of CAPE above the weakening inversion 
across south-central KY and the Bluegrass Region. Our far eastern 
and southeastern CWA will have the best chance at seeing a brief 
shower/storm late in the day. However, low-level forcing isn't all 
that strong and moisture availability is decent at best. Most areas 
will stay mainly dry with fropa, with only a 10-15% chance for rain 
late in the day southeast of a BWG to LEX line. Sunday will be the 
last warm day, with highs topping out in the upper 70s to lower 80s 
prior to fropa.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 314 PM EDT Sat Oct 12 2024

Sunday Night - Thursday Night...

An anomalous trough envelops the eastern CONUS through the early 
week timeframe. This will result in below normal temperatures 
through mid week, and mostly dry conditions. One exception to the 
dry conditions will be Tuesday, where a shortwave embedded in the 
parent trough rotates through the area. This will drag a secondary 
cold front through to reinforce the cold air, and could trigger some 
light shower activity as well. Will be introducing a 20% chance of 
light rain showers across our NE CWA to account for this as models 
have been fairly consistent with this chance the past few runs. 
Outside of that, the main focus will be on the cool days and cold 
nights, and their respective frost/freeze potential through mid week.

Still looks like the coldest nights of the forecast period, and of 
the season so far, will be Tuesday and Wednesday nights. Strong 1028-
1030mb Canadian high pressure builds into the area by then with good 
radiational cooling prospects both nights. The surface high looks to 
be settled a little more directly overhead on Wednesday 
night/Thursday morning, so have been trending that night a bit 
cooler as pattern recognition would suggest this should yield some 
cooler spots than Tuesday night. Regardless, either night should 
have a high likelihood of frost potential. Although the chance for 
freezing temperatures is a bit lower, LREF probabilities suggest a 
20-30% chance in the eastern CWA either night. The bottom line is 
that Frost headlines are likely, while Freeze headlines remain 
possible both of these nights.

Daytime highs will also be notably cooler early to mid week. Steady 
cold advection and some lingering stratocu across our NE CWA will 
only allow for upper 50s and low 60s. Farther SW outside of the 
stratocu deck, look for a better chance at mid 60s across the SW 
CWA. Highs on Monday will be around 20 degrees cooler than Sunday! 
Even cooler highs follow on Tuesday and Wednesday as more of the 
area will be confined to the mid and upper 50s. Only areas down 
around Bowling Green are expected to still reach into the lower 60s.

The upper pattern begins to transition on Thursday as a ridge axis 
begins to build in from the SW. Meanwhile, the surface high will be 
shifting east, and heights/thicknesses will slowly begin to rise. As 
a result, highs on Thursday recover back into the mid and upper 60s 
after a cold start Thursday morning. Thursday night, some 
patchy frost may still be a possibility in the coolest spots. 

Friday - Saturday...

Milder and dry conditions continue late week into the first part of 
the weekend as the upper ridge becomes established over our area, 
and a slight warm advection component kicks in on the western edge 
of the retreating surface high. Highs back in the low to mid 70s 
seem reasonable by this time.

&&

.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 717 PM EDT Sat Oct 12 2024

VFR conditions are expected for the upcoming TAF period.  For the 
overnight period, the main issue will be low-level wind shear.  With 
a cold front approaching from the northwest late tonight, model 
soundings show the flow in the lower part of the atmosphere ramping 
up.  It appears that we'll see LLWS in the 13/06-13/12Z time frame. 
After sunrise, we'll see good mixing which will allow that higher 
momentum air to reach the surface.  Surface gusts of 20-25kts are 
expected during the day on Sunday after 13/14Z and will continue 
into the evening before slacking off.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

UPDATE.......MJ
SHORT TERM...EBW
LONG TERM....BJS
AVIATION.....MJ