FXUS63 KLMK 210511

Area Forecast Discussion
National Weather Service Louisville KY
111 AM EDT Tue May 21 2019

...Updated Aviation Discussion...

.Forecast Update...
Issued at 940 PM EDT Mon May 20 2019

Very pleasant weather this evening with comfortable temps, low
humidity, and a light north wind. High-level cirrus clouds are
beginning to stream into our forecast area from the west ahead of
the large MCS from the southern Plains to mid MS Valley. This will
continue overnight, with high clouds becoming more dense with time,
especially over our northern and western counties. Overnight lows
may be affected a bit but still expecting lows from near 50 in our
northern and eastern counties to the mid and upper 50s in south-
central KY. No changes to the forecast on Tue at this time.


.Short Term...(This evening through Tuesday)
Issued at 305 PM EDT Mon May 20 2019

Dry and pleasant weather will continue tonight as high pressure over
Gitche Gumee noses all the way south into the Ohio Valley. However,
as the sfc high makes its way east toward Whitefish Bay on Tuesday,
sfc winds will clock around to the east and southerly mid-level flow
will bring increasing clouds into our westernmost counties as early
as daybreak.

Warm advection showers could break out from the Pennyrile up through
the Wabash Valley, but should stay far enough west that we can stick
with a dry forecast through the day in spite of plenty of cloud
cover. Warm front will start to pull muggy tropical air into south-
central Kentucky in the afternoon, resulting in a fairly wide range
in max temps. Look for a range from the lower 70s in the northern
Bluegrass region to mid 80s along the Tennessee border.

.Long Term...(Tuesday night through Monday)
Issued at 255 PM EDT Mon May 20 2019

Tuesday Night - Wednesday...

A weakening convective line will be moving out of MO Tuesday night
as an upper low slides back to the northern Plains. The line will
weaken as it moves east as it encounters drier air and loses low
level jet influx. This will bring slight chances for showers and
storms Wednesday morning, mainly west of I-65. Redevelopment will be
possible Wednesday afternoon along any leftover outflow boundaries,
keeping isolated showers/storms possible during the day.

Thursday - Monday...

The upper-level ridge looks to build back in over the Southeast US
by Thursday and stay in place through the remainder of the forecast
period. This will bring hot and mainly dry conditions across the
area. Temperatures look to reach into the mid/upper 80s to lower 90s
each day. With >593m heights over GA/FL with ridge axis over
CWA...Low 90s looks feasible especially Thursday and Friday. Heat
indices will not be as bad you might think due to dew points only in
the mid 60s.

The GFS and CMC hint at a couple of weak shortwaves moving over the
top edge of the ridge during this time period, so will carry slight
chance of POPs Thursday and Friday, mainly in southern IN and
northern KY.


.Aviation...(06Z TAF Issuance)
Updated at 110 AM EDT Tue May 21 2019

It still looks like a dry warm front will lift north at least into
southern KY this afternoon, with winds switching from variable to
southerly at BWG. Winds should stay become more easterly at the
northern sites, though a turn to southeasterly will occur later this
evening at HNB/SDF, along with some directional shear aloft that's
enough to mention with a llws group.




Short Term...RAS
Long Term....JDG/JML
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