284
FXUS63 KLMK 101116
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
616 AM EST Fri Jan 10 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

*  A significant winter storm will affect the region today and
   tonight.  Widespread snowfall accumulations of 3-6 inches with
   locally higher amounts are expected down along the KY/TN border.

*  A Winter Storm Warning remains in effect for all of central
   Kentucky and southern Indiana.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 313 AM EST Fri Jan 10 2025

Quiet weather was in progress across southern Indiana and central
Kentucky this morning. Satellite imagery showed mostly cloudy skies
across the region as mid-high level clouds continue to stream in
ahead of our approaching winter storm.  Clear skies earlier this
evening allowed temperatures to tank across the Bluegrass region of
central KY where readings were in the upper single digits to the
lower teens.  Out toward the I-65 corridor temps were slowly rising
into the upper teens and lower 20s.  Down in the karst region
(Bowling Green area), temps were mainly in the mid-upper 20s.  Area
radars showed some light returns across far southwest KY.  However,
none of this was reaching the ground due to dry air in place in the
lower levels.  The closest precipitation making it to the ground was
along a line from Jonesboro AR southeast to Memphis, TN.

In the near term, cold and dry weather is expected for the next few
hours.  Model soundings from across the CWA show abundant low-level
dry air in place from about 700 mb down to the surface.  As upper
forcing arrives later this morning and moisture continues to advect
northward, we`ll see at least some snow flurries develop in our far
western/SW areas toward sunrise, but accumulating snow is not
expected to develop in our region until after sunrise.

Moving into the daylight hours, continued low-level moisture
advection courtesy of a nice low-level flow off the Gulf will allow
the atmospheric column to saturate during the morning hours.  Light
snows will move into southwestern KY after sunrise and rapidly
expand east and northeast.  Light snows are likely to develop within
the I-65 corridor by mid-late morning and then into the Bluegrass
region by the early-mid part of the afternoon.  The strongest
forcing looks to arrive in the afternoon with our heaviest snowfall
occurring from mid-afternoon through the late evening hours.

Forcing for this event continues to look strong, although the 00Z
model trends continue to show slightly lesser amounts of QPF.  Model
proximity soundings continue to show plentiful moisture and lift
within the DGZ and enhanced synoptic scale forcing will be here as
we`ll be in the left exit region of the approaching 300 mb jet.
Model time-height cross sections from N to S continue show the best
frontogenetical forcing in the I-40 corridor and this could still
get into southern KY this afternoon/evening.  Elsewhere, still
seeing some potential for some heavier banded precipitation across
the CWA.  The HRRR has been suggesting a quick moving heavier band
of precip moving up the WK/BG Parkway corridor.  For most locations,
snowfall rates will likely be under an inch per hour. However,
within these mesoscale bands, 1-1.5"/hr rates could be attained. By
late evening, the best forcing will be passing off to our east and a
rapid decrease in snowfall will occur from west to east.  Much of
this snowfall will likely exit the LMK CWA in the 11/03-09Z time
frame.

As for accumulations, as mentioned above, QPF for this amount has
continued to trend downward slightly.  Overall, a broad area of 3-6
inch snows are expected for the CWA with perhaps a stripe of 4-6
across the southern third of Kentucky.  For most folks,
accumulations will likely average right around 4 inches.  Some will
see less, others will see more, especially if an area gets under one
of these mesoscale bands.  No changes are required for the ongoing
headlines.  Travel is expected to become problematic this afternoon
and evening due to the snow and temperatures remaining below
freezing.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 313 AM EST Fri Jan 10 2025

Sfc high pressure will build in over the Tennessee and Ohio Valleys
for the weekend behind the departing system. Expect a cold day
thanks to a fresh snowpack, overcast skies and a steady WNW wind.
Highs will top out near 30 Saturday afternoon, but with the breeze,
will feel like the low/mid 20s. Clouds will start to partially clear
Saturday night into Sunday. Lows are expected to be in the mid/upper
teens but will be dependent on quickly clouds can clear out
overnight.

By Sunday, the sfc high will have pushed eastward and over the
southeastern US. Winds will become more south-southwesterly allowing
for increased WAA. Along with the sfc high, upper ridging will
develop over the area as well helping to boost temperatures into the
mid/upper 30s in afternoon. This will help to melt the ice and
snowpack currently over the area. Expect a mix of sunshine and
clouds during the day Sunday.

Clouds will increase ahead of the next approaching system which
features a shortwave trough dropping southward out of the Upper
Midwest and moisture deprived cold front associated with it. The
front is expected to push through the Ohio Valley sometime Monday
morning, even with the lack of moisture, there may be enough to
squeeze out a couple of light snow showers or flurries Monday
morning. Little to no accumulation is expected with this system. It
will be cloudy to start the week and temperatures will start in the
low/mid 20s then warm into the low/mid 30s for the afternoon. each
night bottoming out Reinforcing shot of cold air arrive Tuesday into
Wednesday as a strong Canadian high builds in out of Saskatchewan
for the middle of the week. No snow but it will be cold with partly
to mostly clear conditions. Highs both days will only top out in the
low/mid 20s with lows Wed morning/Thu morning in the single digits
to around 10 degrees.

Pattern looks to flatten out some for the end of the week with
temperatures slightly moderating upward into the 30s for Thursday and
Friday. At this time the forecast for the end of the week looks to
remain dry.

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 615 AM EST Fri Jan 10 2025

VFR conditions will be seen at the beginning of the TAF period.
Conditions will deteriorate later this morning at KBWG first as a
winter storm moves into the region.  The snow should start up at
KHNB/KSDF by mid-late morning and then at KLEX in the early
afternoon.  Cigs/vsbys will fall into the MVFR range and then
solidly into the IFR range.  Moderate to heavy snow will be seen at
the terminals roughly from 10/17Z through about 11/04Z.  Current
thinking is that vsbys will probably drop to about 1/2SM in the
snow, but some tempo drops to 1/4SM can`t be ruled out at times. The
snow will taper off from west to east after 11/04Z.  However, low
cigs will remain in place through the end of the period.  Surface
winds will be light during the entire period.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
     KYZ023>043-045>049-053>057-061>067-070>078-081-082.
IN...Winter Storm Warning until 7 AM EST /6 AM CST/ Saturday for
     INZ076>079-083-084-089>092.

&&

$$

SHORT TERM...MJ
LONG TERM....BTN
AVIATION.....MJ