Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 010148
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
948 PM EDT Sun Aug 31 2014
Issued at 948 PM EDT Sun Aug 31 2014
Scattered showers and storms continue to weaken across the forecast
area. We still have one small batch of showers just east of
Bardstown up toward Frankfort. This activity will continue to
weaken and move east over the next few hours. Thus, will continue
some low chance PoPs across the Bluegrass region for the next few
For the overnight period, skies will initially clear out. However,
with the very moist low-level environment and light winds, expect
low stratus to build back down with skies going back to mostly
cloudy. Patchy fog looks like a good bet across the region.
However, the surface winds may remain elevated enough to keep the
lower atmosphere mixed to prevent widespread dense fog. On the
other hand, if we decouple completely and do not have the low-level
stratus build down, we could see a bit more fog than what is
currently forecast. For now have gone with mostly cloudy skies
overnight with patchy fog. Overnight temperatures will remain in
the upper 60s to the lower 70s. Will highlight the fog potential in
the HWO product and continue to monitor conditions closely this
evening and into the overnight.
.SHORT TERM (Now through Monday Night)...
Issued at 300 PM EDT Sun Aug 31 2014
Lift associated with the right rear entrance of an exiting jet and
tropical moisture will slowly move east this evening. Areas of light
rain showers will diminish later this afternoon or evening.
Shallow moisture will remain behind though and clouds will have a
hard time clearing this evening and overnight. With south winds
around 5 mph expected overnight, our lows early Labor Day will range
from 70 to the lower 70s.
A strong jet now entering the central plains will spawn low pressure
across Minnesota late this evening. This cyclone will deepen later
Monday as it moves well north of the Great Lakes. It will provide a
cold front that will move southeast into central Missouri and
Illinois by early Tuesday.
Moist air and surface convergence ahead of this boundary will lead
to widespread convection to our northwest late Monday. Some of these
storms, which may be in a weakening phase, may move into southern
Indiana towards the Ohio River during the morning hours.
So...expect partial clearing Monday with quite warm and humid
conditions during the afternoon hours. An isolated thunderstorm or
two may develop during the afternoon, but coverage will be minimal.
Dewpoints will stay around 70 with temperatures peaking into the mid
to upper 80s. Southwest winds will actually increase to 10 to 15 mph
tomorrow afternoon as this surface trough nears. By Tuesday morning,
will go with a 50% chance of showers and storms arriving across
southern Indiana by the pre-dawn hours.
.LONG TERM (Tuesday through Sunday)...
Issued at 251 PM EDT Sun Aug 31 2014
A very weak cold front will cross from northwest to southeast
through the LMK CWA Tuesday-Tuesday night, just about washing out as
it does so. Showers and thunderstorms will accompany this feature,
especially during the day on Tuesday. The main threat from any
stronger storms will be locally gusty winds, along with heavy
downpours with precipitable waters near two inches.
Went on the cool side of guidance for highs on Tuesday. There
should be a fair amount of clouds around, and convection will be
possible in the morning as well as the afternoon. For now will go
with lower to middle 80s.
The southeast U.S. upper ridge will then build into the Tennessee
and Ohio Valleys Wednesday through Friday, bringing a return to very
warm, sticky weather. High temperatures Wednesday should be in the
middle and upper 80s, and around 90 Thursday and Friday. Scattered
diurnal storms will be possible during this period so will hold on
to small PoPs.
Next weekend the upper ride will get flattened by an upper trof
cruising along the Canadian border. Also, a surface cold front will
approach us from the northwest and move through southern Indiana and
central Kentucky sometime Friday night into Saturday morning. This
front will be a little stronger than the Tuesday front, and will
bring another round of showers and thunderstorms. Depending on the
timing of the front, a few strong storms with gusty winds could
occur, especially Friday afternoon and evening.
High pressure will then build back in at the surface for Saturday
and Sunday. However, we`ll be close to the favored upper disturbance
track along the north edge of an upper ridge strung out along the
southern third of the U.S., so will have to keep a small PoP in the
.AVIATION (00Z TAF Update)...
Issued at 704 PM EDT Sun Aug 31 2014
Scattered showers will continue to move across east-central Kentucky
this evening. Back edge of the showers and clouds is currently
along the I-65 corridor. Expect showers to diminish rapidly over
the next hour or two with the loss of insolation. Wind will
generally remain light out of the south this evening.
For the overnight period, a moist low-level environment will be in
place across much of the region. Recent satellite imagery shows
clearing skies out across western KY. However, much of the model
guidance suggests that low-level stratus build down will occur
overnight. Surface winds may remain elevated enough to keep
widespread fog from forming. For now, plan on going with lowering
ceilings this evening and into the overnight. Plan on keeping KBWG
and KSDF in the MVFR range, though some temp IFR visibilities can
not be ruled out at KBWG between 01/09-13Z. Over at KLEX, expect
MVFR cigs to redevelop around 01/02-03Z and then drop down to near
IFR levels from 01/06-14Z.
Ceilings and visibilities will recover to VFR conditions by 01/14Z.
Surface winds will pick up on Monday with sustained southwest winds
of 10-14kts with gusts of up to 18-20kts being possible. Some
isolated convection may develop during the afternoon, but overall
coverage looks too sparse to include in the upcoming TAF forecast.