Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 242307
Area Forecast Discussion
National Weather Service Louisville KY
707 PM EDT TUE MAY 24 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Wednesday Night)...
Issued at 248 PM EDT Tue May 24 2016
As of mid afternoon, a surface analysis showed high pressure
centered across the mid-Atlantic coast, while latest visible
satellite had mostly clear skies minus a few cumulus west of I-65.
The upper levels are characterized by an anomalous cut off low off
the New England coast while weak ridging to southwesterly flow was
across the central Plains. Temperatures locally were in the upper
70s to low 80s with a rather dry air mass in place. Dewpoints have
mixed out into the upper 30s to mid/upper 40s.
For this evening and tonight, look for a gradual increase in
moisture as the upper disturbance to our west begins to slowly drift
toward the area. Overall it will be a dry evening as the instability
axis remains to our west, however late this evening and overnight,
we`ll see increasing 850 mb moisture transport. This may fuel some
elevated showers or storms, mainly north of the KY parkways into
southern Indiana. However, coverage isn`t expected to be high so
POPs were confined to the 20 to 30 percent range. Plan on lows in
the low 60s.
For Wednesday, look for a slightly more humid/muggy day as dewpoints
creep up into the low 60s, especially west of I-65. This increased
moisture, combined with a passing upper level shortwave, will help
spark a bit more coverage of showers/storms in the afternoon. The
highest chances, still capped at about 30 percent, will be across
southern Indiana and portions of west-central Kentucky. Plan on
highs in the low/mid 80s. A muggy evening/night will then be on tap
with lows staying up in the 60s.
.LONG TERM (Thursday through Tuesday)...
Issued at 253 PM EDT Tue May 24 2016
The long term period will be characterized by an upper level ridge
anchored off the southeast US while passing shortwave troughs will
work to dig through the central Plains into the lower Great Lakes.
Our area will be on the periphery of this ridge, at least Thursday
into the weekend.
This upper level ridging will work to limit precipitation chances to
mainly diurnal showers/storms with more organized convection likely
staying to our west/northwest. We`ll have to watch to see if the
ridge breaks down any further and allow these systems to pass more
closely, but for the most part, look for a more summer-like pattern
with above normal temperatures in the mid/upper 80s and mild/muggy
overnights in the mid/upper 60s. The model consensus precipitation
chances were capped in the 20-30 percent range for most periods in
the forecast, and it`s possible as the forecast becomes clearer,
POPs during a few of these periods may be able to be completely
.AVIATION (00Z TAF Update)...
Issued at 706 PM EDT Tue May 24 2016
VFR conditions are expected to prevail through the valid TAF period.
A loosely-organized MCS continues to push southeast through southern
MO/northern AR this evening. Guidance is not handling this system
well at all, thus there is some uncertainty in the forecast for
tonight. Will include VCSH in BWG where some of the light
stratiform rain may fall, but will continue to go dry at KSDF/KLEX.
May see a few showers or even an isolated storm developing at
SDF/LEX after 06Z tonight, but uncertainty is too high at this time
given the ongoing convection to the southwest to include a mention.
A few isolated to widely scattered storms will be possible at
all sites on Wednesday, with WSW winds around 10 knots.