Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 250726
Area Forecast Discussion
National Weather Service Louisville KY
326 AM EDT WED MAY 25 2016
.SHORT TERM (Now through Thursday)...
Issued at 315 AM EDT Wed May 25 2016
Mild conditions have held on through the night, with light south
breezes and slowly increasing dewpoints. Aside from a few radar
returns that suggest isolated light rain showers over south central
Kentucky, we are almost entirely precip-free as new convection
advertised by most of the models has failed to materialize over the
lower Ohio and Wabash Valleys, and an earlier MCS has almost
completely fizzled over western Tennessee.
Short-term forecast confidence is sorely limited due to this poor
model initialization. Expect an increasingly muggy low-level air
mass to evolve today, with isolated to scattered shower and
thunderstorm chances. Ongoing MCSs over Kansas and Oklahoma will
likely gust out before reaching the Mississippi, but these will bear
watch for any MCV development that could serve as a trigger here
later tonight. Again will limit POPs to slight or low chance, with
the best chances over southern Indiana as the upper flow pattern
would seem to favor disturbances tracking ENE across there.
Expect more of the same on Thursday as it is becoming increasingly
difficult to pin down the upper impulses that may trigger convection
over the Ohio Valley. Precip chances will remain limited to chance,
and temps will continue to run several degrees above normal by day,
and trend warmer each night.
.LONG TERM (Thursday night through Tuesday)...
Issued at 310 AM EDT Wed May 25 2016
Upper ridging over the southeast CONUS will be the main player
through the weekend into early next week, resulting in warm and
muggy conditions. Upper trofiness will hold over the Plains, and
impulses will round this trof and head into the Great Lakes, with
scattered showers and storms possible if any of these disturbances
track close enough to the Ohio Valley.
For now will largely broadbrush POPs in the 20-30% range, but at
this point would not brand any day a washout. As disturbances become
more clear, will likely see some POPs bumped up while others could
be removed. Temps will be modulated primarily by clouds and any
convection that pops in the afternoons, with the main theme being
above normal. The real unknown, especially late in the weekend, will
hinge on the fate of a subtropical system that most of the models
show off the Carolina coast. If this system is strong and/or close
enough, we could get into the subsidence region on its western
flank. That would cut into precip chances and give temps a better
chance of cracking 90 on Monday and/or Tuesday.
.AVIATION (06Z TAF Update)...
Issued at 1258 AM EDT Wed May 25 2016
Mainly VFR conditions will be carried in the TAFs for this forecast
period. The challenge, however, is the potential for showers and
storms. The storms over west central TN have been weakening.
However, most short term guidance shows showers developing north of
this area early this morning and pushing east across central
Kentucky. The models do seem to be overdoing the ongoing
precipitation somewhat, however, so confidence on coverage is low.
Therefore, will include VCSH this morning into the afternoon hours
based on a consensus of the guidance. Thunderstorms are not out of
the question today, but given the uncertainty in coverage, will hold
off on mentioning TS in the TAFs at this time.
Ceiling are expected to remain mainly VFR unless a thunderstorms
moves over the terminals. Winds will be out of the south to
southeast and could be a bit gusty this afternoon at SDF and BWG.