Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 292212
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
612 PM EDT FRI JUL 29 2016

...Forecast Update...
Issued at 612 PM EDT Fri Jul 29 2016

Did a quick update to increase pops across our NW CWA where moisture
convergence has increased along a boundary that is roughly along the
Ohio River. Meanwhile, a broken line segment with a bit of a cold
pool push is moving into our western CWA where some 40 mph gusts are
possible. Latest mesoanalysis shows a moderately unstable airmass
coincident with around 30 knots of effective bulk shear. Reasonable
to think that a brief severe storm is possible, but more concerned
about training storms along the boundary, as rainfall rates have
been periodically impressive. Overall, best storm coverage is an an
area that can handle a bit more precipitation, but will be
monitoring the potential for localized Flash Flooding and marginal
severe potential over the next several hours. Do expect storms to
diminish in coverage and intensity later this evening. At this
point, don`t expect a widespread Flash Flood threat so don`t
anticipate any headlines for now.

.SHORT TERM (Now through Saturday Night)...
Issued at 335 PM EDT Fri Jul 29 2016

Isolated/scattered convection is ongoing in central Kentucky, with
the greatest coverage and intensity along the Tennessee border.
Looking upstream, an upper impulse swinging through the Wabash
Valley has generated a broken line or T-storms that will head toward
southern Indiana and north central Kentucky by early evening.
Therefore we will see the focus shift from our southern zones to our
northwest zones in the next couple hours, but given recent rains,
and the humid air mass, any storms could produce localized flooding
through this evening. Also seeing just enough instability to combine
with the forcing aloft, so a few strong storms could produce gusty
winds, especially along and north of Interstate 64.

Look for POPs to diminish this evening given the loss of heating,
and mid-level drying behind the upper disturbance. However with this
much low-level moisture, cannot rule out a slight chance, so will
hang on to that POP through the overnight.

Rinse and repeat for Saturday as we remain under a broad upper trof,
and the air mass remains juicy. Expect convective coverage to be
slightly less given the slight decrease in deep moisture, as well as
the lack of dynamics to focus convection. Still look for scattered T-
storms, with the main threat still localized heavy rainfall and
flooding. Given the low convective temps in this air mass, expect
max temps to run near or just below climo, but with limited cooling
at night.

.LONG TERM (Sunday through Friday)...
Issued at 335 PM EDT FRI JUL 29 2016

Broad upper trofiness overhead on Sunday will start to shift
eastward on Monday, but will not fully give way to the upper ridge
centered over the Southern Plains. This will leave the NW flow door
open for episodic MCS activity through at least the middle of the
week. Therefore will maintain at least a 20-30 POP for much of the
week, and while it will continue to show a diurnal focus, confidence
in the timing of POPs is still on the low side. By Wed-Thu expect
enough influence from the ridging to push temps back into the lower
90s in quite a few places. Air mass will remain quite humid, keeping
mins solidly above normal throughout.

&&

.AVIATION (18Z TAF Update)...
Issued at 100 PM EDT Fri Jul 29 2016

Main challenge this afternoon is the evolution of convection and its
impact on the terminals. Main focus for storms currently is across
south central Kentucky, and BWG has had TS in the area for a couple
hours. Will initialize VCTS/CB, but not confident enough in any of
these storms actually causing restrictions to cig/vis at the
airport.

By mid/late afternoon, an upper impulse currently moving through the
Wabash Valley will trigger convection along a stationary front
draped near the Ohio River. Will introduce VCTS at SDF and LEX at
that time, but again not including any restrictions at either
terminal.

Convection will diminish around sunset as it is again diurnally
driven. BWG and LEX could have some concerns with fog/stratus toward
morning, and based on both model guidance and what we saw this
morning, will carry that as mainly stratus. LEX will go down to fuel-
alternate MVFR, but BWG is more likely to sock in with LIFR. Expect
this deck to lift mid to late morning on Sat as mixing starts to
improve.

&&

.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&

$$

Update.........BJS
Short Term.....RAS
Long Term......RAS
Aviation.......RAS



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