NWS Forecast Discussion - Louisville, KY

FXUS63 KLMK 231443

Area Forecast Discussion
National Weather Service Louisville KY
943 AM EST Fri Feb 23 2018

.Forecast Update...
Issued at 940 AM EST Fri Feb 23 2018

Have a second wave of moderate rain falling just south of the Ohio
river this hour. Kentucky Mesonet 3-hour rainfall totals with this
band are in the half to three quarter inch range, and the line is
starting to progress eastward, though lighter rains remain behind
it. KLVX and KVWX shows the low-level jet is weakening this hour and
expect the coverage in showers to diminish over the next couple of
hours as well. Expect we still could see scattered showers in the
afternoon, as any little bit of heating could refire additional
rains. At this point, the best focus looks to be over southern
Indiana. Expect coverage to pick up again late tonight as the low-
level jet ramps up again after midnight.

Have sent out a zone/grid update with this thinking in mind.


.Short Term...(Today through Saturday Night)
Issued at 400 AM EST Fri Feb 23 2018



Early this morning moderate steady rains with embedded isld t-storms
were occurring over much of southern Indiana and portions of north
central KY.  The heaviest axis of rain extended from northern Ohio
County, KY through Harrison County, IN as of 330am EST.  Areal and
Flash Flood Warnings are in effect along this axis as 1-2 inches of
rain has fallen on already well saturated grounds. Expect the
heaviest rains to continue along this axis close to the Ohio River
through the morning hours.  The 0Z WRF-ARW seems to have the best
handle on the heaviest precip axis with most other models too far
NW.  Leaning on the ARW as the best guidance for this forecast, the
heavier band of showers/embedded t-storms does look to shift
slightly SE into the Louisville Metro before sunrise and then into
the far northern Bluegrass close to sunrise.  1-2" of rain can be
expected with locally higher amounts possible along this axis. Look
for flood warnings to continue to be issued along this heavy precip
axis through the morning hours.

As the LLJ decreases after sunrise, expect precip intensity to
gradually decline toward mid morning. The precipitation should also
shift farther southeast toward mid morning to include more of
central KY.  Will need to keep an eye on locations in central KY
from Hart County northeast through the Bluegrass that had many flood
problems yesterday as additional rains will likely be problematic

As we head into the afternoon hours, expect a break in rain or just
isld to scattered light rain showers.  High temps should range from
the low 60s-low 70s.


Tonight another round of showers will likely move into the region
after sunset with the best coverage of precipitation expected after
midnight as a warm front draws close to the area.  Identifying
potential problem areas for flooding is difficult at this point as
model solutions vary on where the heaviest rains will fall.  Once
again though, most of the area is well saturated so flooding issues
may arrive especially after midnight.  Low temps will range through
the 50s.

Saturday/Saturday Night

A warm front will lift north through the region Fri night into Sat
morning bringing rounds of moderate to at times heavy rainfall Sat
morning.  Sat morning flooding issues are possible.

We should see a break or isld/light showers from mid morning through
early afternoon.  A strong warm sector looks to establish itself
over our area bringing in sufficient instability for strong to
severe storms Sat evening into Sat night.  Strong dynamics
associated with the approaching cold front will result in perhaps
some initial cellular structures mainly to our west transitioning to
a line of storms by Sat evening and pushing through our region Sat
night.  The main threats with storms will be damaging winds and
flash flooding with the greatest risk area along and west of I-65 in
KY. While the wind risk may diminish some as the line heads into
east central KY, the flash flood threat will remain high through the
overnight hours Sat night.  With much of the area already well
saturated, widespread flash flooding will be possible Sat night into
Sunday morning. Stay abreast of the latest forecasts for Saturday.

.Long Term...(Saturday night through Thursday)
Issued at 430 AM EST Fri Feb 23 2018

Dry weather looks to finally return Sunday and early next week.
However, the Ohio River and other rivers will continue to rise. Keep
a close eye on the river forecasts in coming days.

The next chance for rain looks to arrive Wednesday and Thursday as a
boundary sets up to our south and a low pressure system moves
through to our north on Thu.  Additional rainfall amounts of up to
1.5" can be expected from this mid week weather system.  Temps look
to remain relative mild with highs in the upper 50s and 60s for much
of the week with lows in the 30s/40s.


.Aviation...(12Z TAF Issuance)
Issued at 640 AM EST Fri Feb 23 2018

IFR to MVFR cigs/vis continue across the area along with light to
moderate rains.  While improving conditions are expected to high end
MVFR or even a period of VFR, have kept the TAF a little on the
pessimistic side.  Rains are expected to gradually diminish through
the morning hours although model guidance hasn`t been doing
particularly well with overnight rains.  Still think a period with
only some isld showers or even a dry period should occur this
afternoon/early evening.  After 0Z tonight, expect declining flight
conditions and additional rain showers to develop increasing in
coverage late tonight after midnight.


Updated at 445 AM EST Fri Feb 23 2018

Copious amounts of rainfall have lead to excessive runoff and river
flooding in many locations over southern Indiana and central
Kentucky.  The latest synoptic models indicate an additional 2-4"
inches of rain is likely through Sunday morning.  This additional
rainfall will result in continued rises on area rivers, creeks and
streams.  Continued river flooding is expected and will likely
worsen in coming days.  Many river points may reach moderate flood
levels over southern Indiana and central Kentucky with some even
approaching major flood levels.  For a complete list with forecast
hydrographs, please visit our website at:

In addition to river flooding, typical low-land and flood prone
areas are likely to experience flooding at times through the coming
days.  Widespread showers and storms forecast to move through the
area Saturday evening and Saturday night will pose an elevated flash
flood risk to much of the area.  A Flood Watch is in effect through
Sunday morning.  Stay alert to current flood warnings at


IN...Flood Watch through Sunday morning for INZ076>079-083-084-

KY...Flood Watch through Sunday morning for KYZ023>043-045>049-



Short Term...AMS
Long Term...AMS

NWS LMK Office Area Forecast Discussion