Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 290709
Area Forecast Discussion
National Weather Service Louisville KY
309 AM EDT FRI JUL 29 2016
.SHORT TERM (Now through Saturday)...
Issued at 305 AM EDT Fri Jul 29 2016
Broad trough axis over the region now with a few smaller vortmaxes
embedded within its flow. One such vortmax now is entering western
Iowa and northwest Missouri. As it heads eastward, the NAM responds
by developing a line of storms along the lower Ohio and Wabash later
this afternoon. Given amount of moisture in place and boundaries
from precip yesterday would not be surprised to see other scattered
storms developing ahead of this, more like the representation of the
WRF`s. As such will broad brush a 40 pop across the region this
afternoon. Timing of precip will have an effect on high temperatures
today, but in general should see readings in the mid 80s. Coverage
of storms and speed of motion should limit chances for flooding
today. Cannot rule out localized flooding, but expect coverage to be
isolated enough to preclude going with a flash flood watch.
As that PV anomaly gets east of our region tonight, some drier air
will try and filter in from the north. Statistical guidance responds
by bring us less rain chances Saturday. Previous forecast had higher
pops, and do not want to rule out chances altogether, given the
troughing over the region. Will trend pops down for now.
Temperatures should be similar today for highs, in the mid 80s.
.LONG TERM (Saturday Night through Thursday)...
Issued at 300 AM EDT Fri Jul 29 2016
Little changes with the pattern Sunday, but by Monday, the main
trough axis will have shifts into the eastern Great Lakes region.
This shift will bring us back into a favorite forecasting pattern,
northwest flow aloft in the long range. This pattern looks to remain
in place through midweek, with the GFS/Euro/GEM all showing various
timing for disturbances dropping down in this flow. By Wednesday,
the ridge will start bringing the heat and by Thursday the ridge
axis looks to be along the Ohio Valley, according to the GEFS
ensembles. Spreads are low for the scenario, so there is some
confidence in its solution. That ridge should limit us to isolated
to widely scattered airmass thunderstorms in the afternoon and early
.AVIATION (06Z TAF Update)...
Issued at 125 AM EDT Fri Jul 29 2016
Main TAF challenge will be convective trends near BWG, followed by
the potential for low stratus/fog tonight. A weakening line of
thunderstorms has just moved through BWG, and will likely be out of
the region by TAF issuance time. While a few showers may be
possible through the overnight hours, think this initial surge will
shunt the activity more off the ESE.
Then the focus will turn to fog/stratus potential tonight into the
early morning hours mainly at LEX. Think the clouds/showers around
BWG should keep fog formation to a minimum. LEX will stand the best
chance to see IFR stratus and/or fog early this morning given the
rainfall today. Have favored more stratus than fog with this cycle
as it appears winds may stay up just enough to keep the low-levels
mixed. Some light fog or low stratus will be possible at SDF as
well, but will leave just a TEMPO group for MVFR vsbys for now.
Any fog/stratus will burn off through the morning hours, leaving
partly cloudy skies. Convection will once again be possible during
the afternoon hours at any site, but coverage is expected to be much
lower than today so will leave any mention out for now. Winds will
be out of the WSW at 5-10 knots.