Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 191329
Area Forecast Discussion
National Weather Service Louisville KY
929 AM EDT Wed Oct 19 2016
Issued at 926 PM EDT Wed Oct 19 2016
Isolated to scattered showers continue this morning across southern
IN and portions of central KY. Have not seen any lightning with this
activity so far. The forecast was updated to account for the latest
radar trends, including spreading the slight chance pops a bit
further south and lowering them across portions of southern IN. The
latest mesoscale guidance shifts the area of showers/storms mostly
into southern IN by this afternoon. Think the activity will remain
fairly scattered in nature, so pops were decreased just a bit. There
is still a chance for a strong storms or two this afternoon.
.SHORT TERM (Now through Thursday)...
Issued at 228 AM EDT Wed Oct 19 2016
Early this morning a cold front was parallel to and north of the
Ohio River from central Ohio to southern Illinois. This front will
sag slowly south to the river today and will be a focal point for
shower and thunderstorm activity. Chances of scattered showers and
storms will increase as the day goes on, especially this afternoon
with some diurnal destabilization.
A wave moving up the front will spark showers and thunderstorms this
afternoon over the Ozarks. Southern Missouri and northwest Arkansas
stand the best chance of severe storms with this feature. Farther
east, in southern Indiana and north central Kentucky surface
instability and mid-level lapse rates will be weaker. Wet bulb zero
heights will be on the high side for any significant hail. Still,
there will be enough bulk shear to support storms, especially over
southern Indiana, and soundings show some dry air aloft suggesting a
few strong wind gusts possible with the stronger cells.
High temperatures today will be very tricky given clouds and showers
in the north, and more sun possible in the south. Some guidance is
suggesting no temperature rise at all along and north of the Ohio
River. Looking at current obs and available guidance, will go with
highs in the upper 70s to around 80 along and north of the river,
and lower to middle 80s across most of central Kentucky.
Tonight the wave that will have sparked convection over Missouri and
Arkansas will head northeast and bring more widespread showers, with
embedded thunderstorms, to southern Indiana and north central
Kentucky. Temperatures will drop back into the 60s.
On Thursday the wave will head off to the northeast and drag the
cold front through the region ahead of the approaching upper trof.
Again, surface instability and mid-level lapse rates will be weak.
WBZ`s will be high. However, there looks to still be a gusty wind
threat with a continued layer of dry air aloft and stronger winds
aloft as the trof approaches. The best shot at strong storms will be
in the afternoon east of Interstate 65.
Temperatures will be tricky once again on Thursday with the passage
of the cold front. Southern Indiana should peak in the mid 60s while
the Lake Cumberland region enjoys one more unusually warm October
day with the mercury peaking around 77.
We could use some rain, and pretty much everybody should get
something out of this system. Ahead of the front dew points will be
in the mid 60s and precipitable water amounts will be around 1.5-1.6
inches which is well above normal for this time of year. Right now
it looks like an inch or more of rain will be possible, especially
over southern Indiana. Locally heavier amounts where training occurs.
.LONG TERM (Thursday night through Tuesday)...
Issued at 234 AM EDT Wed Oct 19 2016
The sharp upper trof will pass overhead pre-dawn Friday, pushing
showers and thunderstorms out of the region ahead of it. Surface
high pressure will then move in for a cool, dry weekend. Some folks
could see lows in the upper 30s Saturday morning.
A weak surface front may pass through here Sunday night/Monday.
However, the Gulf will be cut off and any Pacific moisture should
remain well off to the north, so the front would come through dry.
High pressure will then move back in to continue the dry weather
through the end of the 7-day forecast.
.AVIATION (12Z TAF Update)...
Issued at 625 AM EDT Wed Oct 19 2016
A cold front lies right along the Ohio River just north of SDF with
isolated to scattered showers moving west to east nearby. Moisture
pooling along it has resulted in lower ceilings near SDF and it`s
expected that MVFR conditions will start the 12z TAF period.
With the front stalled along/near the Ohio River most of today,
scattered showers and some thunderstorms will periodically move
across SDF and LEX. The best chance for thunder will come with
maximum daytime heating in the afternoon.
As an area of low pressure organizes to the west and moves toward
the area this evening, the front may move back to the north just
enough to keep most of central Kentucky dry, and provide an
opportunity for ceilings to lift back into VFR range at SDF/LEX.
By the end of the TAF period, the center of the low pressure will be
between SDF and CVG, and lower ceilings will begin to advance
southeastward as it passes. Looking ahead into the SDF planning
period, low ceilings are likely beyond 12z Thursday with abundant
moisture and rain showers around.