Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 222333
Area Forecast Discussion
National Weather Service Louisville KY
733 PM EDT SUN MAY 22 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Tuesday)...
Issued at 250 PM EDT Sun May 22 2016
...Very nice spring weather for the short term...
Very pleasant weather is in progress this afternoon across central
KY and south-central IN. Current ASOS and KY Mesonet temperatures
range from the lower to upper 70s and should top out a couple/few
degrees higher late this afternoon. As expected, clouds have
developed and moved south across parts of the Bluegrass at this
time. The east half of our forecast area will be partly cloudy into
early evening, and mostly sunny west.
Clouds east will move out and dissipate tonight, leaving a clear sky
overnight with lows in the upper 40s over parts of east-central KY
to 50-55 elsewhere. Fog is not expected to be a problem Monday
morning like it was this morning over south-central KY. However,
there could be some brief low-level/river valley patchy fog around
daybreak across southern and eastern areas of central KY.
Monday will be another great weather day with a sunny sky, light
wind, low humidity, and highs in the mid-upper 70s west, and upper
70s/around 80 west. This weather continues on Tuesday with a mostly
sunny sky (although some clouds will begin to increase in the
afternoon west) and warmer temperatures in the lower to mid 80s.
.LONG TERM (Tuesday Night through Sunday)...
Issued at 315 PM EDT Sun May 22 2016
...More summerlike with scattered storms through the long term...
The extended forecast for mid week through next weekend will feature
warm to potentially very warm afternoon temperatures, higher
humidity (surface dewpoints through the 60s, with upper 60s at
times), and periodic thunderstorm activity across the OH Valley. The
atmosphere will become more moist in general with precipitable water
values generally from 1.0-1.5 inches, with periods of roughly 1.5-
Afternoon high temperatures will generally be in the lower and mid
80s each day Wednesday through next weekend, with some upper 80s
possible late this week. However, this is all predicated on where
thunderstorms and resultant cloud debris occur which will have
substantial effects on the daily thermal profile. With dewpoints in
the 60s, it will feel more summerlike during the period.
The models overall appear to be in reasonable agreement, with less
agreement by next weekend with the ECMWF maintaining a pattern a bit
more conducive to storms than the GFS. Overall, from Wednesday
through next weekend, there will be a daily chance of storms, which
could occur at night as well. The atmosphere will be moderately to
potentially strongly unstable at times, and any forcing could set
off scattered to numerous thunderstorms across the lower OH Valley.
Trying to be more specific for our area, models suggest that
scattered showers and storms could approach the area late Tuesday
night and Wednesday morning with modest elevated instability. Models
then show better surface-based instability and another potential
round of convection associated with a shortwave in the west-to-
southwest mid-level flow moving into our area late Wednesday or
Wednesday night. Mesoscale boundaries put down by any convection and
debris clouds will affect convective evolution and temperatures.
Scattered storms are possible again Thursday with ample instability
and models hinting at subtle forcing in southwest flow aloft into
the lower OH Valley. Some storms Wednesday and Thursday could be
strong at times, with isolated pulse severe type storms possible,
although organized severe does not look that likely due to only
modest wind fields.
On Friday/Saturday, models show significant shortwave moving east
out of the western U.S. This could set the stage for episodes of
severe weather across the nation`s midsection and into the mid MS
Valley. Scattered to numerous storms could affect our area as well,
but too early to determine potential storm strength.
Locally heavy rainfall will occur from time to time from mid week
through next weekend, so we will have to monitor any hydro/flood
concerns if enough convection materializes and propagates over
similar areas during the period. On the other hand, it certainly
will not rain all the time, and some periods of sunshine are
expected as well.
.AVIATION (00Z TAF Update)...
Issued at 733 PM EDT Sun May 22 2016
Benign weather is expected over the upcoming TAF period. We`ll see
a bit of mid-high level clouds pass over the region this evening,
but it will not have any effect on aviation at the terminals.
Surface wind will remain light out of the northwest.
For the overnight period, VFR conditions are expected at KSDF and
KLEX. However some ground fog looks possible at fog-prone KBWG.
Winds will go calm there overnight and it appears that the 23/08-12Z
would be the best time to see conditions drop down to MVFR.
For the remainder of the TAF period, VFR conditions are expected
with clear skies and light northeasterly winds.