Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 121845

Area Forecast Discussion
National Weather Service Louisville KY
245 PM EDT Sat Aug 12 2017

.Short Term...(This evening through Sunday night)
Issued at 200 PM EDT Sat Aug 12 2017

High pressure and dry weather building into the region from the
north and northwest at this time, though still have some residual
moisture across southern KY likely to spark showers/storms for
another hour or two.

With the proximity of the high to us, expect a weak north to
northeast wind tonight. Visibility guidance is coming up with a
couple of areas for light fog across south KY, where
dewpoints will be slowest to drop, and another across southern IN,
where winds will be lightest and temperatures have the best chance
to drop. The best chance for some kind of impactful visibility will
be the northern group, so will put in some fog wording for now.

Otherwise, the forecast looks great for the short term. Temperatures
should be a few degrees below normal for highs and lows.


.Long Term...(Monday through Saturday)
Issued at 230 PM EDT Sat Aug 12 2017

The surface high should keep us dry through at least Monday as it
ridges across the IN/OH region. An inverted surface trough tries to
build in again across southern KY, but models last week over did
this troughing, so not as convinced in rain chances this go around.
Our Tuesday may end up dry as well, as the timing of a shortwave
ridge coming in from the west could keep us dry. The 12Z NAM is the
fastest with this ridging keeping it over us all day, and the SREF
QPF has a relative min across our part of KY/IN. The GFS was a
little slower, so it does have more QPF from afternoon activity.
Have gone with slight chances for rains across the south.

The forecast for Wed could have us warmer and continued dry, as that
ridging builds over the Deep South. 00Z GEFS shows some model
agreement with this scenario, though the Euro keeps our flow more
zonal and consequently wet. Will consider the Euro an outlier
here and lean on the dry side here and go a little warmer as well.

By Thursday, this ridge flattens out as a weak cool front moves
across the Midwest. Thursday and Thursday night look to have our
best rain chances, in association with this front. The forecast for
Saturday will depend on how far south this front gets...with the
GEFS keeping in some rain chances for KY. The SuperBlend also keeps
in chances roughly south of the Bluegrass Parkway in Kentucky and
see no good reason to change it.

With that ridging aloft, we have our best chance for SDF to get back
into the 90s Tuesday to Thursday (it`s been since 8/3). So most of
the long range will be near normal for highs, but with higher
dewpoints, our overnight lows likely will be at or above normal.


.Aviation...(18Z TAF Issuance)
Issued at 142 PM EDT Sat Aug 12 2017

Currently, a layer of broken low level clouds blanket central
Kentucky. This layer of clouds is drifting southeast and will mostly
clear out as the day continues. BWG, SDF, and LEX are in VFR. This
is expected to continue through the forecast period for SDF and LEX.
BWG has a chance to drop to MVFR tomorrow morning with light fog
possibly forming. Wind will remain from the north at 5-10 knots.




Short Term...RJS
Long Term...RJS
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