Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 221533
Area Forecast Discussion
National Weather Service Louisville KY
1133 AM EDT SUN MAY 22 2016
Issued at 1125 AM EDT Sun May 22 2016
All low clouds and fog have dissipated over south-central KY late
this morning, with a sunny sky across our entire area. Morning
temperatures have risen rapidly with current ASOS and Kentucky
Mesonet observations showing mid 60s to lower 70s. 12z NAM soundings
for this afternoon show dry adiabatic lapse rates from the surface
to roughly 750 mb, so warming should continue in earnest. With this
in mind, have raised temperatures a bit areawide this afternoon with
mid and upper 70s expected, and SDF could hit 80. With the dry
adiabatic lapse rates, winds could be a bit gusty at times this
afternoon (prevailing winds up to 10 mph with some gusts 10-20 mph).
Meanwhile, an area of sct/broken clouds over OH is moving south and
will affect eastern KY this afternoon. Models show some steep lapse
rates aloft with this, and sct showers are possible over far eastern
KY. However, showers will not affect our Bluegrass region, although
some increase in clouds (partly sunny) is expected in this area this
afternoon. Otherwise, a very nice weather day is in store across the
region this afternoon.
Issued at 915 AM EDT Sun May 22 2016
The Dense Fog Advisory expired at 900 am EDT. There are still some
low clouds and fog over parts of south-central KY, although morning
visible satellite imagery shows these clouds dissipating as the
sun starts to warm the boundary later. Also, BWG which had been at
1/4 mile visibility is now up to 3 miles and improving quickly.
Thus, there will be some low clouds and local fog for another hour
or so in parts of the south, but this will be followed by mostly
sunny conditions by late morning.
Still expecting some increase in clouds over eastern parts of
forecast area by early afternoon from the north, but this is covered
well in current grids. Will update grids again late this morning for
expected afternoon trends.
.SHORT TERM (Now through Monday)...
Issued at 251 AM EDT Sun May 22 2016
The concern for the forecast area over the next few hours will be
the dense fog that has formed. Mostly clear skies and calm winds
will continue overnight. However, direr air trying to filter in from
the north should keep the fog from developing too much further to
the north. Therefore, will not expand the Dense Fog Advisory any
further to the north at this point, and some locations on the
northern edge of the Advisory could see some improvement over the
next few hours.
Conditions should begin to improve shortly after sunrise. For the
remainder of the day, the upper level trough that moved through
yesterday will continue to slowly shift eastward. A disturbance
rotating around the back side of this trough may bring some
increased cloudiness to the Bluegrass region this afternoon. The
rain, however, should stay east of the area. Despite northwesterly
winds, temperatures should rise nicely today under mostly sunny
skies, with highs topping out in the mid to upper 70s.
High pressure at the surface and ridging aloft will slowly build in
from the west tonight through Monday. Dry weather will continue with
temperatures near normal for this time of year.
.LONG TERM (Monday Night through Saturday)...
Issued at 305 AM EDT Sun May 22 2016
The long term period will start out dry with ridging aloft and high
pressure at the surface. Southerly winds will usher in warmer air.
Temperatures on Tuesday look to top out a bit above normal in the
Beyond Tuesday the pattern becomes more unsettled as the upper level
ridging flattens out somewhat. Moisture will be on the increase as
southerly winds usher in more humid air from the Gulf of Mexico. By
Thursday dewpoints look to be solidly into the mid to upper 60s.
Temperatures will top out in the lower to mid 80s each afternoon.
Multiple disturbances moving through the flow aloft look to bring
rounds of showers and thunderstorms from Tuesday night through the
end of the week. Some diurnal convection may form as well. The
period will not be a washout by any means, but trying to time the
periods of thunderstorms is difficult. Some strong storms are not
out of the question, though the best chance for severe weather will
likely be west of the forecast area. It will be much more muggy than
what we have seen over the last couple of weeks, however.
.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Sun May 22 2016
Latest GOES-R fog probs as well as current area obs continues to
indicate poor flying conditions south of a SDF/LEX line. Kept in a
couple more hours of IFR at BWG before all sites become VFR. They
should stay this way through the evening, but then overnight BWG
likely will return at least to low-end MVFR visibility. Winds will
be from the northwest today before becoming variable again this