498
FXUS63 KLMK 120529
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
129 AM EDT Wed Jun 12 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Below normal temps and humidity today followed by a warming
    trend with hot and dry conditions for the remainder of the week.

*   Heat illnesses possible Sunday and Monday, especially for those
    with heat sensitivities and those without adequate cooling /
    hydration.

&&

.UPDATE...
Issued at 953 PM EDT Tue Jun 11 2024

Current forecast remains on track with only minor changes to account
for latest observations. Another quiet and relatively cool night as
surface high pressure and dry airmass favors radiational cooling.
Finally, best chances of patchy fog will be across the Bluegrass and
south central Kentucky where dewpoints will be higher.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 243 PM EDT Tue Jun 11 2024

Clear skies and temperatures across the region during the early
afternoon between the upper 60s to low 70s, which is slightly warmer
than temperatures yesterday at this time.  Highs today are still
slated for the mid to upper 70s, which is between 5 and 10 degrees
below normal for mid June.

For tonight, high pressure continues to dominate our local weather
with mostly clear skies and lows dipping back into the low-mid 50s.
A few of the valley locations will likely drop back into the upper
40s once again for some chances of patchy fog.

High pressure continues Wednesday with clear skies and warming
temperatures returning closer to normal into the low to mid 80s
(between 5 and 7 degrees warmer than today/Tuesday). Light and
variable winds will slowly be returning to the south for light warm
air advection. Dew points will be increasing by about 10 degrees
from today/Tuesday, so a slightly more "humid" feel for Wednesday.
An air quality alert is in effect for unhealthy and sensitive groups
for Wednesday for southern Indiana and the Louisville Metro counties
in Kentucky.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 243 PM EDT Tue Jun 11 2024

Large scale patterns over our neck of the woods look fairly
consistent in deterministic and ensemble model runs. Cluster
analysis over the mid- and long-range forecast over the Ohio Valley
show basically no differences between the clusters, indicating
higher confidence in the placement of large-scale features across
the region. Wednesday night to Thursday weak troughing aloft over
the Deep South will head east as a large ridge of high pressure
drifts from the Desert SW into the central and southern Plains
Friday and then over our area Sunday/Monday.

What that means for us is a steady increase in temperatures through
the work week and Saturday. Then as that ridge gets right over us
Sunday/Monday, low-level thicknesses increase quickly and southerly
winds will allow for more moisture to come in as well. That
combination will help to bring up Heat Indices as well as, our first
heat wave of the season so far. Given the shock from the recent
below normal temperatures, went ahead with some messaging to
partners about this sudden change, which could cause issues to heat-
sensitive groups.

Only other sensible weather to deal with is a slight chance for
measurable rain as a weakening cold front approaches the area Friday
morning. Grand Ensemble models show 30/100 models with some
measurable precip over our southern IN and northern KY counties, but
NBM has come in with 5-10 pops. Again, this is not a lot of rain, as
the line should be weakening, but worth a mention in the public
forecast.

Next chance for precip could come with some pulse storms developing
in the warm/humid airmass Monday afternoon. Some capping likely will
be in place, but cannot rule out an isolated storm developing in
what looks to be an airmass with precipitable waters getting at
least to the 75th percentile.

&&

.AVIATION /06Z TAFS THROUGH 12Z THURSDAY/...
Issued at 123 AM EDT Wed Jun 12 2024

Thanks to a large area of sfc high we remain locked into nice,
mainly clear weather with VFR flight categories through the forecast
period. There are a few high clouds associated with a disturbance
over TX but other than that it will remain quiet with light and
generally light winds. May see more of a southerly flow around BWG
but generally light and variable to calm through the remainder of
the overnight.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Air Quality Alert until midnight EDT tonight for KYZ029>031.
IN...Air Quality Alert until midnight EDT /11 PM CDT/ tonight for
     INZ076>079-083-084-089>092.

&&

$$

UPDATE...ALL
SHORT TERM...MCK
LONG TERM...RJS
AVIATION...BTN