983
FXUS63 KLMK 130716
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
216 AM EST Mon Jan 13 2025

.KEY MESSAGES...

*  Very cold air works in across the area today with temperatures 10
   to 15 degrees colder than Sunday.

*  Very cold temperatures Tuesday and Wednesday with morning lows in
   the single digits and teens. Wednesday morning could feature
   temperatures near zero in some locations.

*  There is a chance for minor snow accumulations on Tuesday. Snow
   amounts are expected to be less than 1 inch.

*  Milder temperatures Friday, with widespread rain Friday night
   into Saturday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 215 AM EST Mon Jan 13 2025

Strong yet moisture starved cold front is currently stretching from
Toledo, OH to Indianapolis, IN to St. Louis, MO. This also evident
in observations where temperatures from KIND to KHUF and south are
at or above 30 while everything north has fallen into the 20s. Along
and ahead of the front have been some mid-level stratus that appears
to be filling in over southern IN. Clouds will be around through the
morning as the cold front continues to push southward into southern
IN by around 09-10z and then into northern and central KY by 12z. By
daybreak, the arctic front will likely be bisecting the CWA from the
NE to the SW (from Cynthiana to Russellville) with temperatures
north and west in the 20s and areas to the south and east still in
the 30s. Cold air will continue to advect in from the northwest
during the day but with diurnal heating, temperatures will remain
mostly steady with a strong NW to SE temperature gradient across the
area. The aforementioned line from Harrison county to Logan and
Butler counties will be roughly where the 30 degree isotherm will be
for most of the day. Mid to upper 20s to the north in KY with low
20s across southern IN. South of that line temperatures will be near
30 to just above freezing across the Lake Cumberland region.

Strong Canadian high pressure builds over the Ark-La-Tex region and
Lower MS Valley during the day allowing drier air to work in along
with the cold. While we will have cyclonic flow aloft, clouds will
scatter out after midday and into the afternoon with partly to
mostly sunny skies. Winds will turn more westerly and be steady
around 10 mph this afternoon. Where temperatures fall into the 20s,
wind chill values will be in the mid/upper teens.

Dry, very cold air will continue to work into the region overnight
with mainly clear skies. 850mb temperatures will range from -8 to -
13 degrees C overnight. This will help lows fall mainly into low
teens to around 10 above with just a few locations around 15, mainly
along the southern most tier counties. Wind chill values by daybreak
Tuesday will feel like they are in the single digits.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 215 AM EST Mon Jan 13 2025

Tuesday - Wednesday Night...

Another reinforcing cold front dropping through the Ohio Valley on
Tuesday will bring a chance for snow and another brief shot of very
cold air. A fairly sharp but very positively tilted upper shortwave
trof will provide just enough dynamics to take advantage of very
limited moisture, though we are still marginal for being able to
generate even measurable precip. Will carry a 20-30% POP for what
could be a dusting of fluffy snow across southern Indiana and mainly
north central Kentucky. Snow accums will be less than 1 inch, and
while air and sfc temps could support minor impacts, the very low
water content will further limit the potential.

Tuesday night and Wednesday look quite cold as dry high pressure
settles directly overhead. Widespread lows in the single digits are
likely Wed morning with the exception of south-central Kentucky,
where lows will be in the teens. Highs on Wed afternoon will
struggle into the 20s, and there`s a window for a quick drop on Wed
evening before return flow develops and temps flatline in the teens.

Thursday - Sunday...

Warm advection pattern sets up for Thu-Fri, allowing temps to
recover to near normal on Thursday and a few degrees above on
Friday. Split flow pattern aloft limits confidence in timing, but
there`s just enough phasing to draw a moist SW flow into the Ohio
Valley by Friday night. Best chances for a widespread moderate rain
are Friday night into Saturday morning. High confidence in plain
rain (albeit a chilly rain with temps in the 40s) through the day
Saturday.

New model runs are hanging up the upper trof, increasing the precip
chances on the cold side of the system Sat night into Sunday. This
would result in a period of snow before it`s all said and done, but
confidence is too low in any accumulation potential. Higher
confidence in the cold surge, which heralds a return to lows in the
20s and highs struggling to crack the freezing mark.

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 100 AM EST Mon Jan 13 2025

There are two distinct mid-level cloud areas over the Ohio Valley
per the 0530z nighttime microphysics satellite imagery. The first is
over northern KY and southern IN. CIGs have been generally been
between 3000-5000ft with a few exceptions where CIGs dropped to MVFR
for a very brief period. The second area of clouds is associated
with the cold front that is currently setup along the I-70 corridor
from Indianapolis IN towards St. Louis MO. These two areas are
expected to fill in the gap currently between them with mainly
BKN/OVC through the rest of the overnight and into the start of the
day. Cold will will push through from the northwest to the southeast
after 0900z. Winds will shift from the southwest to more west-
northwest and stay there through the period. Could have winds around
10kts during the forecast period. Clouds will scatter out with
increasing CIGS. Overall, confidence continues to grow for VFR
flight categories through the forecast period.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...RAS
AVIATION...BTN