Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 220124
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
924 PM EDT Wed Jun 21 2017

.Forecast Update...
Issued at 924 PM EDT Wed Jun 21 2017

The light showers that moved into southern IN have now moved east
and mostly dissipated. The remaining pops were therefore removed
from the forecast. Mostly dry conditions are expected overnight.
Some showers and storms will then start moving into southern KY
around daybreak. Some minor edits were made to the hourly pop grids
tomorrow to slow the progression of precipitation northward.
However, the overall message remains the same with likely showers
and thunderstorms in the afternoon.

&&

.Short Term...(This evening through Thursday night)
Issued at 309 PM EDT Wed Jun 21 2017

Tonight looks mostly dry. The best chance of a shower will be in
southern Indiana closer to a retreating warm front draped from
Illinois to Ohio. Clouds will help to keep temperatures up with lows
in the upper 60s to around 70.

Thursday Tropical Storm Cindy will move up the Sabine River.
Isentropic lift will increase over the Tennessee and Ohio Valleys
beneath upper level divergence. LI and CAPE forecasts show that
instability will be enough for thunder but on the weak side, with a
tall, thin CAPE in the soundings. These factors combined with
precipitable water values climbing to over two inches by afternoon
will support widespread development of showers and storms. K Index
values will reach into the middle 30s with 850 dew points in the mid
teens Celsius and soundings showing a deep warm cloud depth. While a
strong storm or two isn`t out of the question, locally torrential
downpours will be the main threat with Thursday afternoon storms.

We may see a relative lull in activity Thursday evening. Then late
Thursday night, as Cindy`s circulation moves into Arkansas, a cold
front will approach from the northwest. By the end of the short term
the front should stretch from Michigan to Missouri, resulting in
increased rain chances after midnight especially across southern
Indiana and north central Kentucky.

.Long Term...(Friday through Wednesday)
Issued at 318 PM EDT Wed Jun 21 2017

...Heavy Rainfall Forecast Friday and Friday Night...

Today`s NHC Cindy track has trended a bit to the south, from
crossing Kentucky to crossing Tennessee instead. The remnants of
Cindy will proceed from Arkansas Friday morning to the central
Appalachians Friday night. Meanwhile, a cold front will come in from
the northwest, reaching the Ohio Valley by evening. Between the two
systems, showers and storms will be a good bet Friday and Friday
night. The deep moisture put in place in the short term will remain
available to the weak instability present, with heavy rain
continuing to be the main threat from this event. The best chance of
a strong storm looks to be Friday afternoon over southern Indiana
and north central Kentucky in conjunction with the incoming cold
front.

Right now we have storm total rainfall numbers in the 2 to 4 inch
range. Tropical remnants are tricky to forecast, though, and these
numbers will likely undergo adjustments over the next few forecast
cycles.

Rainfall of that magnitude may cause minor flooding on small
streams, but the main issue will be local flash flooding under
torrential downpours.

Rain chances behind Cindy this weekend into early next week will be
low as Canadian high pressure moves slowly across the central and
eastern United States. So, places that get soaked Thursday and
Friday will have a chance to dry out.

&&

.Aviation...(00Z TAF Issuance)
Issued at 721 PM EDT Wed Jun 21 2017

VFR conditions are expected through the rest of the evening and
through the overnight hours. Winds will be fairly light out of the
south to south-southwest. Cirrus will be the main cloud type, though
some lower clouds will move into BWG towards dawn.

Moisture from Tropical Storm Cindy will be streaming into the area
over the next couple of days. This will lead to deteriorating flying
conditions at the airports tomorrow. Ceilings will lower through the
day to MVFR, starting in the morning with BWG. SDF and LEX will
follow suit by mid day to afternoon. An area of showers and
thunderstorms will move north across the region tomorrow as well.
BWG can expect to see rain in the morning, SDF by early afternoon,
and LEX around mid afternoon. There then looks to be a break in the
precipitation for a brief period tomorrow evening.


&&

.Hydrology...
Issued at 325 PM EDT Wed Jun 21 2017

Periods of heavy rain are expected starting Thursday afternoon and
ending by early Saturday morning. This is due to a combination of
the remnants of Tropical Storm Cindy coming up from the south and a
cold front sweeping in from the northwest. The wettest day will be
Friday. At this time between 2 and 4 inches of rain are expected
with the entire system -- Thursday afternoon through Friday night.
It is important to note, though, that within this general area of
rain there may be narrow bands of higher amounts where thunderstorms
train over the same locations.

This will lead to rises on some streams in the area with minor
flooding especially possible in the Green, Barren, and Kentucky
basins.

In addition, thunderstorms will produce locally torrential downpours
which could lead to flash flooding.

If you live in a flood prone area, watch water levels closely over
the next few days.

&&

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

$$

Update...EER
Short Term...13
Long Term...13
Aviation...EER
Hydrology...13


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