Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 231847
Area Forecast Discussion
National Weather Service Louisville KY
247 PM EDT TUE AUG 23 2016
.SHORT TERM (Now through Wednesday Night)...
Issued at 203 PM EDT Tue Aug 23 2016
A weak disturbance sparking showers and a few thunderstorms from
Missouri to west Tennessee this afternoon will drift eastward and
may bring a stray shower or storm to southern Indiana and central
Kentucky tonight on the nose of a low level jet. Will account for
that in the forecast but will keep PoPs low.
Keeping PoPs low but non-zero is pretty much the theme for the 7-day
forecast. On Wednesday, and into Wednesday night, moisture will
increase significantly as a pool of 2"+ PWATs flows into the region.
Combined with warmth and instability, widely scattered thunderstorms
may pop up, especially in the afternoon and evening. An upper ridge
established over the southeast U.S. will force the best chances for
convection over southern Indiana.
Dew points will return to the 70s on Wednesday with afternoon heat
index well into the 90s. August is back.
.LONG TERM (Thursday through Tuesday)...
Issued at 217 PM EDT Tue Aug 23 2016
Quasi-stationary upper ridging will remain over the southeast U.S.
into early next week, along with surface high pressure stretching
from the mid-Atlantic to the Gulf coast.
A cold front over the central Plains mid-week will advance eastward,
stretching from the Great Lakes to the Texas Panhandle by Thursday
morning. The front will weaken significantly as it approaches the
Ohio Valley Thursday, and will have lost much of its identity by the
time it drifts into Kentucky Thursday night and runs into the
southeast U.S. ridging. 7H temperatures Thursday will be very warm,
around 11C. Sounding progs show weak mid-level lapse rates and both
mid- and low-level capping. Lots of dry air showing up in the
soundings too as PWATs actually decrease ahead of the approaching
front thanks to a patch of dry air from Texas and northern Mexico
making into the Ohio Valley. So, while thunderstorms can`t be ruled
out in the warm unstable air ahead of the front, will need to keep
PoPs low. The best chances will be in southern Indiana Thursday
afternoon closest to the front and under stronger winds aloft.
High PWATs return for Friday and through the weekend. It`s difficult
to pin down any significant fropas, as is often the case at this
time of year, but the atmosphere will be warm, moist, and unstable
enough such that scattered storms, primarily diurnal, aren`t out of
the question each day. Better chances north and west, lower chances
south and east with ring of fire convection around the southeast
U.S. upper ridge.
.AVIATION (18Z TAF Update)...
Issued at 1245 PM EDT Tue Aug 23 2016
Generally VFR conditions are expected through this TAF period, with
the exception of some light fog possible Wednesday morning at BWG.
Through the rest of this afternoon winds will be out of the south at
6-9 knots. Winds will become light and variable tonight, then
strengthen out of the south again tomorrow. Scattered cu is expected
this afternoon. Mid and high cloud cover will then increase into
tomorrow as a disturbance moves into the region. Some showers and
storms will be possible tomorrow, but coverage looks fairly
isolated, so will keep precipitation out of the forecast for now.