Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 191935

335 PM EDT Tue Aug 19 2014

.SHORT TERM (Now through Wednesday Night)...
Issued at 334 PM EDT Tue Aug 19 2014

Somewhat of a complicated and low confidence forecast in the near
term.  Currently, partly to mostly sunny skies were noted across the
forecast area.  Temperatures ranged from the lower to middle 80s in
the Bluegrass and central locations to the upper 80s over the far
southwestern areas near Bowling Green.  Insolation is near its
maximum and highs for the day will likely occur very shortly.

Satellite and regional radar composites show a band of convection
working in from the west.  This is ahead of a mid-level wave
rotating around a large closed 500 hPa center well to our north. A
remnant MCV can be seen in the satellite imagery out near St. Louis
and will work eastward into Indiana this afternoon.  As the
afternoon wears on, expect convective inhibition to decrease out
ahead of the approaching MCV.  This should result in a marked uptick
in convective activity to our west which will spread eastward.  The
activity will likely decrease in intensity somewhat as it outruns
the instability axis to the west and also starts to feel the
influence of the loss of daytime heating.

With this said, feel that high PoPs are justified out west of
Interstate 65 later this afternoon and evening.  This afternoon`s
convection is likely to be strong to severe with damaging winds and
large hail being the primary severe weather threats.  However,
expect wind damage to become the primary threat as the line moves on
off to the east this evening/tonight.  Will carry PoPs into the
east, but slightly later than in previous forecasts.  Generally
expect convection to be largely diminished after midnight.
Temperatures this evening will cool back into the upper 70s to the
lower 80s...with overnight lows cooling back into the lower 70s.
We`ll also be on close watch for the reformation of fog tonight.
Overall, current indications suggest it will not be as widespread as
this morning...but it could be locally dense in some locations.

For Wednesday/Wednesday night, expect another day of diurnally
driven convection with an enhancement during the late
afternoon/evening hours as another mid-level wave approaches the
region.  Convection on Wednesday still looks to be generally
scattered in nature, so plan on continuing scattered coverage at
this time.  Instability will be on the increase during the afternoon
hours, so some strong to severe convection can not be ruled out once
again.  Mid-level shear is only forecast to be around 30-35kts, so
organized convection looks likely with multicelluar clusters moving
through the region posing a threat of wind damage.  Still plan on
cutting temperatures a bit as most model guidance is still
exhibiting a warm bias.  Highs on Wednesday will warm into the
middle 80s in the NE with middle-upper 80s in the central sections
and around 90 across the south/southwestern sections.

.LONG TERM (Thursday through Tuesday)...
Issued at 311 PM EDT Tue Aug 19 2014

...Hot weather expected through early next week...

A warm front will be pushing north across the region at the
beginning of the long term. Aloft a strong ridge will build in from
the south and remain in place through Sunday morning. It will then
begin to break down a bit Monday into Tuesday as a weak front
approaches from the northwest.

Thursday into Thursday night we will see another round of storms as
the front continues its push northward. Most of the area could see
storms but the best chance will be across southern Indiana and
north/east central KY. Some of the storms could be strong to
marginally severe across this area. There is some uncertainty still
in how strong the storms will be given previous multiple rounds of
storms and uncertainty in the position of the warm front. If they do
develop, gusty winds and hail would be the main concerns.

As the ridge builds in through this weekend the areas with the
storms chances will continue to push northeast leaving areas in the
southwest dry. By the end of the weekend into early next week, rain
chances decrease, so will keep the forecast dry Sunday night into

The bigger story for the end of the week into early next week will
be the heat. As the ridge builds in temperatures will be on the
rise. From Friday through Monday high temperatures will range from
the lower to mid 90s, with the potential for upper 90s if the dry
conditions can persist over the southwest. Combined with dewpoints
in the upper 60s to lower 70s, heat index values will rise into the
upper 90s to lower 100s each afternoon.


.AVIATION (18Z TAF Update)...
Issued at 125 PM EDT Tue Aug 19 2014

VFR conditions are expected at the terminals through the afternoon
and evening hours.  Main forecast challenge remains centered on
convective chances late this afternoon and evening.  The high
resolution models suggest that storms will develop along the
southern flank of a eastward moving mid-level wave swinging through
the Ohio Valley.  This flank of storms looks to develop out over
southern IL this afternoon and then push east-southeast through
southern Indiana and west-central KY.  Initially capping will limit
convection this afternoon but as it weakens, instability will be
quite high across the region.  Overall forecast confidence on the
convective evolution is fairly low.  Based on the high resolution
forecasts, it would appear that KBWG would see the highest chances
of storms late this afternoon/eve.  Thus, have enough confidence to
go with at least VCTS in the BWG TAF for now...but will hold off at
KSDF and KLEX.  Any storms will quickly die off tonight with the
loss of heating.  Light winds and mostly clear skies will likely
lead to patchy dense fog developing once again...especially at KLEX
and KBWG.




Short Term........MJ
Long Term.........EER
Aviation..........MJ is the U.S. government's official web portal to all federal, state and local government web resources and services.