Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 221311

Area Forecast Discussion
National Weather Service Louisville KY
911 AM EDT Tue Aug 22 2017

.Forecast Update...
Issued at 910 AM EDT Tue Aug 22 2017

Forecast pretty much on track for today. Seeing a weakening line of
showers/storms about to move into Dubois county. Expect boundaries
out ahead of the main cold front to initiate new storms as we heat
up. Soundings show decent enough shear that a few of the stronger
cells could produce wind gusts to 60 mph, some small hail, and
briefly heavy rain. No need for a zone update at this time.


.Short Term...(Today through Wednesday)
Issued at 245 AM EDT Tue Aug 22 2017

A strong cold front will bring a line or a few broken lines of
showers and storms to the region today.  Convection could start as
early as mid morning mainly over southern IN or west central KY.
Convection will grow upscale this afternoon and continue into the
evening hours as it pushes SE through the region.  Most CAMs
indicate enough instability (2500-3000 j/kg) along with 25-35 kts of
0-6 km bulk shear should precede convection this afternoon/evening
to provide a strong to severe storm threat.  The main severe threat
will be damaging winds with storms this afternoon & evening.  If
convection starts early in the day over southern IN/northern KY and
provides enough of a cloud shield, forecast instability may not be
realized during the afternoon/evening hours causing storms to be
weaker in nature.  Convection will exit to the SE late tonight into
Wed morning.

Temperatures today should reach the mid to upper 80s in most
locations with 90 degrees possible over south central KY.  Lows
tonight will range through the 60s to around 70.

A cool, dry pattern will start Wed in the upper troughing behind the
front.  High temps Wed will fall back into the upper 70s/lower 80s.

.Long Term...(Wednesday night through Monday)
Issued at 300 AM EDT Tue Aug 22 2017

Wednesday Night - Saturday...

Cool, dry weather will persist through the end of the week as a
broad upper level trough sticks in the area.  Expect high temps to
remain in the upper 70s/lower 80s which is slightly below normal for
this time of year.  Low temps will range through the 50s.

Sunday - Monday...

For the beginning of next week, the remnants of a tropical cyclone
look to move NE into the region.  While the op GFS is faster than
the ECMWF, both carry the same idea.  Therefore kept low POPs going
the beginning of next week.  The ECMWF is much slower than the GFS
however so either Sun/Mon could be dry but will go with the
consensus for now.

Temperatures may take a slight rebound with highs in the lower 80s


.Aviation...(12Z TAF Issuance)
Issued at 626 AM EDT Tue Aug 22 2017

A cold front will move through the region today. Ahead of this front
showers and storms will move through. The main line of storms will
be just ahead of the front this afternoon and evening. The guidance
is a bit split on whether showers and storms will pop up ahead of
the main line late this morning into the early afternoon hours. To
account for this uncertainty, have added in VCSH in the morning with
VCTS and TEMPO TS groups during the most likely window for storms
this afternoon. These should quickly clear out as the front moves
through this evening.

Winds today ahead of the front will be out of the southwest and
gusty at times. Winds will switch to westerly right behind the front
and northerly by daybreak tomorrow. Ceilings are expected to remain
VFR today, but a stratus deck could develop tonight before the drier
air works in behind the front. The MVFR stratus deck looks to mainly
affect LEX and BWG.




Short Term...AMS
Long Term...AMS
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