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000
FXUS63 KLMK 301951
AFDLMK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
251 PM EST Sat Nov 30 2013

.SHORT TERM (Now through Sunday Night)...
Issued at  PM EST Sat Nov 30 2013

Upper level disturbance that brought us some high clouds this
morning has made its way east of the area, and mostly sunny skies
will persist for the remainder of the late afternoon and evening.
Temperatures have overachieved today under full sun and a steady
warm advective component. Most locations are solidly in the mid 50s.
Expect winds to slacken a bit and temperatures to quickly drop after
sunset with the large T/Td spread (currently 25-30 degrees). Some of
the cool eastern valley locations will probably drop into the upper
20s, with most other spots in the 30-35 degree range for lows. Many
lows will likely occur well before dawn as some low to mid level
clouds (4-7 k feet) begin to move into the area ahead of the next
weak system. Northern temps will likely rise a bit toward dawn as a
result.

As we move into the day on Sunday, low and mid level clouds will
continue to be on the increase from NW to SE across the area. These
clouds are trending faster so will continue the downward trend for
the forecast high temperatures. Looking for mid to upper 40s across
southern Indiana, with low 50s across south central Kentucky as the
clouds get in pretty quick. Will continue to leave the forecast dry,
however there is some indication that enough low level moisture may
be present for some drizzle. Either way, measurable precipitation
does not look likely.

Will continue with slight chances for a light rain shower on Sunday
night, especially across south central Kentucky as deeper moisture
pools ahead of a southern stream system scooting across the Ozarks.
Overall, moisture will still be quite limited although slightly more
impressive. May end up with a high coverage drizzle/low coverage
measurable rain shower scenario. The extensive cloud cover will keep
temperatures milder with lows only bottoming out in the upper 30s
and low 40s.

.LONG TERM (Monday through Saturday)...
Issued at 230 PM EST Sat Nov 30 2013

Troughing will be over the region at the start of the period, and
forecast soundings show plenty of low-level moisture. Numerical
guidance has low ceilings/visibilities for Monday morning. The
moisture is shallow enough that it will be difficult to squeeze out
measurable precip, but drizzle will keep Monday raw. Those clouds
may stick around well into Monday night and would be a portent of a
dreary week to come.

That said, Tuesday may be the best day of the week. We will see a
brief zonal flow aloft, and highs look to get up to normal. Then
comes a front that will stall out as that flow aloft becomes
parallel to the surface flow. Models are in pretty good agreement on
this scenario, and these models paint a wet picture across our
region Wednesday through at least Friday. Multiple disturbances
riding northeast with that flow aloft will mean some heavier rain
periods than others, but the GFS and ECMWF differ on timing these
disturbances. The GEFS has precipitable waters going up to 2
standard deviations above normal Thursday, so this system will bear
watching for flood potential. Have put in a slight chance for
thunder across the south given the warm airmass in place ahead of
the presumed location of the front.

The temperature forecast will depend greatly on where the front
stalls as well as timing of rains, so confidence is lower here.
There is even a chance we could see some wintry precip later in the
day Friday, depending on how quickly the last surge of cold air gets
in here. For now Saturday looks like it should be dry but cold as
high pressure behind this slow-moving front finally moves into the
mid-Mississippi river valley.

&&

.AVIATION (18Z TAF Update)...
Updated at 1159 AM EST Sat Nov 30 2013

VFR conditions will prevail through the forecast period with a
steady SSW wind up around 10 mph this afternoon. Expect occasional
gusts up between 15 and 20 mph as well. Skies will remain mostly
clear through the rest of the day as only a weak upper level
disturbance passes overhead.

Gradient winds will slacken to around 5 mph or less out of the south
around sunset. Overnight, expect a scattered to broken low to mid
level deck of clouds to stream in ahead of the next weak frontal
boundary. By mid to late morning on Sunday, expect a ceiling around
4 K feet, especially at SDF/LEX.

&&

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

$$

Short Term........BJS
Long Term.........RJS
Aviation..........BJS