Shelbyville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

143
FXUS63 KLMK 301146
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
646 AM EST Thu Jan 30 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

*  Widespread soaking rains arrive this afternoon and continue into
   Friday. Rainfall amounts up to 2 inches expected, with locally
   heavier amounts possible.  A few thunderstorms are possible late
   Friday afternoon into early Friday evening.

*  Widespread flash or river flooding is not expected with just
   minor, localized concerns in low-lying or poorly-drained areas.

*  Dry and mild conditions for this weekend into early next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 319 AM EST Thu Jan 30 2025

===== Soaking Rain Arrives Later Today =====

Sfc high pressure directly over the area early this morning will be
departing to the east today, which will support warm return flow
with south-southeasterly sfc winds. The clear and dry weather will
be ending as a large vertically stacked upper low spins across the
central Plains today. Dry weather will continue after sunrise this
morning, though cloud cover ahead of the system will be increasing
overhead. Rain chances will first enter the forecast area from the
south and west by mid to late morning as isentropic lift gets
established, though any precip will likely remain light as the
better moisture transport will still be to our south.

Light to moderate rain will spread across the entire area by the
afternoon hours, though Thursday evening through Friday morning is
still expected to be the primary window for widespread moderate to
locally heavy rainfall. We`ll remain in a WAA regime ahead of the
cold front, which will help our sfc temperatures rise into the 50s
for most this afternoon.

For tonight, widespread soaking rain will be a sure bet, driven by a
strengthening LLJ with winds in the 850mb layer approaching 60 kts.
This will support a maximized moisture transport axis, with PW
values expected to exceed 1.25". From the BNA sounding climatology,
this would be near, if not exceeding, the max for the Jan 31
database. HREF and LREF agree on PW probabilities, and both have a
+90% chance of exceeding 1.25" values for central Kentucky.
Additionally, both highlight a 50% chance of exceeding 1.50" across
south-central Kentucky.

With the sfc low expected be occlude as it tracks across the mid-
Mississippi River Valley, the triple point appears to pass through
the region somewhere overnight. This will provide additional low
level moisture convergence, and support an axis of potentially
heavier rainfall in a southwest to northeast oriented corridor.
Yesterday the data appeared to track along the Ohio River, but as of
this morning that axis appears to be shifted slightly to the south
and more in line with the Parkways.


===== Rainfall Amounts and Probabilities =====

Storm total QPF with this event will be roughly 1-2+ inches, with
some locally higher amounts possible. This rainfall is expected to
fall over 18-24 hours, though the bulk of rain is expected Thursday
night into Friday morning. High confidence remains for all areas to
pick up at least an inch of rain, but confidence is low-medium for
high-end precip amounts due to uncertainty where heavier precip
bands may exactly set up. Regardless, widespread flash or river
flooding is not expected, though localized minor issues will be
possible, especially in low-lying or poorly-drained areas.


.LOW END, EXPECTED, AND HIGH END AMOUNTS...

Location           Low End      Expected        High End
------------------------------------------------------------------
Louisville:         0.8"           1.9"           2.5"

Bowling Green:      0.9"           1.9"           2.5"

Lexington:          1.0"           1.9"           2.5"

Frankfort:          0.7"           1.9"           2.5"

Elizabethtown:      1.2"           2.2"           2.7"

Beaver Dam:         1.0"           2.2"           2.9"

Jasper IN:          0.8"           1.5"           1.9"

Madison IN:         0.7"           1.2"           1.7"


==================================================================


.PROBABILITY OF EXCEEDANCE...

Location        At Least 1"     At Least 2"     At Least 3"
------------------------------------------------------------------
Louisville:         84%              29%             --

Bowling Green:      88%              36%             --

Lexington:          90%              38%             --

Frankfort:          83%              35%             --

Elizabethtown:      95%              45%             --

Beaver Dam:         91%              51%             8%

Jasper IN:          81%               7%             --

Madison IN:         71%               3%             --

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 319 AM EST Thu Jan 30 2025

Friday through Saturday Night...

At the start of the period, widespread rainfall is likely to be
confined to areas east of the I-65 corridor.  This activity will
quickly move off to the east with a large dry slot moving into the
region during the morning and afternoon hours. So we should see a
break in the precipitation for a time with generally breezy
conditions across the region.  Highs in the afternoon will likely
warm into the upper 50s to the lower 60s.

Friday afternoon and into the early part of Friday evening look
interesting as the upper level through axis pushes into the region
from the west.  Model proximity soundings show steepening lapse
rates above a near-surface inversion.  Shear profiles are marginal
here with less than 25 kts of bulk shear.  The strong forcing ahead
of the upper trough is likely enough to fire off some low-topped
showers and thunderstorms, given those steep lapse rates.  This
convection would not likely last all that long because we`ll loose
heating and instability quickly after dark.  However, the period
between say 21Z Friday through about 01Z Saturday would be the best
chance at seeing some storms.  Drier conditions are expected Friday
night with lows dipping into the upper 30s to around 40.

For Saturday, dry conditions are expected with partly cloudy skies.
Temperatures will be a bit cooler here with highs in the upper 40s
to around 50 across southern Indiana and the northern half of
Kentucky.  Lower 50s for highs are expected across southern KY. Lows
Saturday night will drop back into the upper 30s to around 40.

Sunday through Wednesday...

Moving into the late weekend, the upper level pattern will deamplify
with a more zonal flow pattern taking shape.  This will result in
dry weather for Sunday and Monday.  Highs Sunday will be mild with
readings in the lower 60s across southern Indiana and northern
Kentucky.  Across southern KY, highs in the 62 to 67 degree range
are expected.  Lows Sunday night will dip back into the low-mid 40s.
Highs on Monday will be similar to Sunday with readings in the lower
60s over the north and in the mid-upper 60s across southern KY. Lows
will dip into the upper 30s/lower 40s.  A weak perturbation will
come through the region on Tuesday and will bring some increase in
cloudiness and perhaps a few isolated showers and cooler temps.
Highs Tuesday will range from the upper 40s/lower 50s in the north
to the mid-upper 50s in the south.  Additional showers are likely
Wednesday as a frontal boundary stalls out across the region.

&&

.AVIATION /12Z TAFS THROUGH 18Z FRIDAY/...
Issued at 645 AM EST Thu Jan 30 2025

Terminals will remain VFR for the next several hours, but clouds
will continue to gradually increase ahead of our next weather
system. Rain will spread across the area by early afternoon, first
at BWG, then HNB/SDF, and last at LEX/RGA. Ceilings are expected to
drop quickly with the initial onset of precip, first to MVFR this
afternoon, then to IFR by this evening and into the overnight.
Heavier rain rates will be possible, which will result in reduced
vis at all terminals as well. Restricted flight categories will
prevail through the end of the period. Winds will primarily be from
the S-SE.

&&

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

&&

$$

SHORT TERM...CJP
LONG TERM...MJ
AVIATION...CJP