FXUS63 KLMK 111453

Area Forecast Discussion
National Weather Service Louisville KY
953 AM EST Mon Dec 11 2023

Key Messages:

- Below normal temperatures today

- Predominantly dry weather and seasonable temperatures


.Forecast Update...
Issued at 951 AM EST Mon Dec 11 2023

GOES satellite imagery shows stratus layer scattering out across the
area as the 850-mb thermal trough slowly lifts and daytime heating
increases. Satellite also shows a mid-level cloud deck moving in
from the west associated with a small vorticity impulse, but given
subsidence in the AVA of the departing trough, most of these clouds
may dissipate before progressing through central Kentucky. As a
result, went ahead with HREF 11/0Z sky cover that reflects a quicker
clearing trend this afternoon. Otherwise, no major changes are
anticipated with this update as surface high pressure remains in


.Short Term...(Today and tonight)
Issued at 307 AM EST Mon Dec 11 2023

GOES low cloud IR imagery shows low stratus continuing across much
of the region this morning.  The western edge of the cloud cover
extends from Dubois county IN southeastward to just east of Bowling
Green.  The cloud cover has resulted in a gradient of temperature
across the region.  Under the clouds, temperatures were in the lower
30s, but out across our far west in the clear skies, temperatures
were in the low-mid 20s.  Based on recent satellite imagery, we're
not expecting the stratus to really make any headway in moving
eastward and most locations will likely keep the stratus deck
through sunrise.  In the near term, no significant weather is
expected.  Overnight lows will be in the lower 30s under the clouds,
with lower-mid 20s out across the far west in the clear skies.

For today, high pressure out to the west will build eastward. Cloud
cover should start to mix out by mid-late morning and then continue
into the afternoon.  Winds will start off out of the northwest this
morning and then gradually back to the southwest in the afternoon
hours.  As for temperatures, highs will range from the lower 40s
over SE Indiana and the Bluegrass region of central KY to the
lower/mid 40s over our far southwestern areas.

For tonight, high pressure will be located to our east and we'll see
a continued light flow out of the south.  Current thinking is we'll
see a ridge/valley split with the decoupled/protected valleys going
into the low-mid 20s with the ridges staying in the upper 20s to
around 30.


.Long Term...(Tuesday through Sunday)
Issued at 250 AM EST Mon Dec 11 2023

On Tuesday, dry weather will be prevalent across much of the
CONUS east of the Rockies. An upper level trough will slide across
Ontario and the Great Lakes region, taking an associated surface
cold front with it as it translates eastward Tuesday night into
Wednesday. We'll be on the southern edge of this cold front, with
forcing and moisture expected to be minimal with this system. As a
result, substantial weather changes are not expected with this
front. Despite a lack of lower troposphere moisture, mid- and
upper-level moisture should help bring in a few extra clouds
Tuesday night into Wednesday. Winds should gradually veer from SW
on Tuesday to N/NE by Wednesday, helping to bring marginally
cooler air into the region.

For the second half of the upcoming week, there should be a gradual
warming trend across the Ohio and Tennessee Valleys as mid- and
upper-level ridging builds across the Mississippi Valley and spreads
eastward by early next weekend. A cutoff upper low across the
southwestern U.S. will meander east-southeastward, with its
associated moisture plume now expected to remain well west of the
region through at least Saturday morning. As such, there is high
confidence in dry weather for late this week into early next

Precipitation chances for the second half of the weekend into early
next week are also decreasing as newer medium range guidance comes
in. With the preponderance of guidance keeping the cutoff low
suppressed southward into the Gulf of Mexico, moisture advection
will struggle to make much if any northward progress, with a fairly
dry air mass remaining in place over the Ohio and TN Valleys. A
northern stream shortwave may bring some moisture with it as it
passes by Sunday, but without support from any enhanced meridional
flow which would come from phasing with the low over the Gulf of
Mexico, any disturbance that passes through the region would
struggle to produce any precipitation. Have continued to delay and
trim back PoPs this weekend, and would expect to continue to trend
toward a dry forecast given recent guidance. Above normal
temperatures are favored this weekend, with highs in the mid 50s and
lows in the upper 20s and low-to-mid 30s.


.Aviation...(12Z TAF Issuance)
Issued at 615 AM EST Mon Dec 11 2023

Morning IR satellite imagery shows that the low stratus has been
attempting to scour out.  So far, it's been a little more successful
over the Bluegrass region, but not over north-central KY.  However,
after sunrise, we should start to see skies scour out with cigs
returning to VFR.  Winds this morning will start off out the
northwest at 2-5kts and then back to the southwest this afternoon.

For tonight, VFR conditions are expected with light winds.  The
outlook for Tuesday calls for VFR conditions as high pressure
becomes the driver of our weather for the next several days.




Short Term...MJ
Long Term...CSG