Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 260711
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
311 AM EDT THU MAY 26 2016

.SHORT TERM (Now through Friday)...
Issued at 300 AM EDT Thu May 26 2016

Summertime air mass is now established over the Ohio Valley with
dewpoints into the 60s and precipitable water pushing 1.5 inches.
Upper trof has settled in over the High Plains, with an amplifying
ridge along the East Coast.

This pattern figures to remain fairly stagnant for the next couple
of days, resulting in a continuation of the warm and fairly muggy
conditions that took hold on Wednesday. Even with abundant low-level
moisture, the greatest instability and the favored track for most of
the synoptic-scale upper disturbances will be to our north and west.
Convective potential will be driven largely by whatever
destabilization can occur diurnally, and low-level boundaries that
manage to push in with decaying MCSs from the Plains. Will carry a
20-30 POP with a slight diurnal signal through tonight.

Confidence in model guidance is fairly low, but signs do point to a
dry day on Friday as deep southerly flow may better focus storms
over the Mississippi Valley, leaving us in a relative minimum for
moisture and instability. Will go with a dry forecast for now, but
proceed cautiously. With the dry forecast, would expect Friday to be
the warmer day in the short-term, with upper 80s quite likely
anywhere that sees enough insolation.

.LONG TERM (Friday Night through Wednesday)...
Issued at 300 AM EDT Thu May 26 2016

Unsettled pattern will continue through the Memorial Day weekend,
with warm and muggy conditions and isolated to scattered showers/
storms almost on a daily basis.

Will start out Saturday with the most amplified pattern, but the
upper trof over the Plains tries to lift out, with a fair bit of
bagginess in the flow translating NNE through the Ohio Valley. This
will likely be the most unsettled day of the period, and we`ll carry
the highest POPs but still limit to a 50 percent chance given low
confidence in the timing of any impulses.

As we head into Memorial Day and early next week, the pattern
flattens out a bit. The wild card is the warm core system that is
progged to develop off the Carolina coast. If it gets close and/or
strong enough, subsidence could keep a lid on convection here,
allowing us a dry day but pushing temps close to 90. Otherwise will
see a continuation of the summer pattern, resulting in isolated/
scattered POPs, with the best chances in the afternoon, and temps
running several degrees above normal, especially by night.

&&

.AVIATION (06Z TAF Update)...
Issued at 120 AM EDT Thu May 26 2016

Remnant mid and high clouds from Indiana through central Kentucky to
middle Tennessee will move east overnight. Most showers with this
moisture dissipated last evening, although there are several renewed
showers mainly in Tennessee. While additional scattered showers and
possible overnight, they should stay south of the 3 TAF sites.

Main concern overnight is fog development at BWG. Already, their
surface temp/dewpoint spread is low, and the site received over an
inch of rain Wednesday. Once mid clouds clear later this morning,
local vsbys should become MVFR and could go briefly IFR at times
before dawn. Caveat to this is model depiction of cloud development
around 5-6 kft later this morning which could help limit fog.

During the day Thursday, conditions will be VFR. At this time, it
appears any convective development should remain isolated/widely
scattered, with a slightly better chance at SDF where VCTS is
included in TAF during mid/late afternoon. However, any residual low-
level boundaries and any effect of current upstream convection as it
moves eastward could affect convective evolution over lower OH
Valley later today.

&&

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

$$

Short Term........RAS
Long Term.........RAS
Aviation..........TWF



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