Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 281043

Area Forecast Discussion
National Weather Service Louisville KY
643 AM EDT SAT MAY 28 2016

...Updated Aviation Discussion...

...Forecast Update...
Issued at 615 AM EDT Sat May 28 2016

Still having a difficult time generating precip in this juicy air
mass, so shower and T-storm chances may be slightly delayed compared
to the previous forecast. Precip over the lower Mississippi Valley
has failed to materialize, with radars not tapping much more than a
mid-level deck lifting into the Missouri Bootheel and western
Tennessee. Patchy light rain is also noted in a few spots on an axis
of higher precipitable water that is oriented north-south through
Alabama and Middle Tennessee into central Kentucky.

Still believe chance POPs are on track, but not looking for much
QPF out of it. Grids updated to show slower timing and less morning
thunder potential, but zones remain unchanged.

.SHORT TERM (Now through Sunday)...
Issued at 255 AM EDT Sat May 28 2016

Amplified upper pattern continues to maintain a weak, but quite warm
and humid southerly flow into the Ohio Valley. However, coverage of
any showers and storms has been limited due to the lack of lifting
mechanisms both at the surface and aloft. We have seen a fairly
narrow plume of showers since late evening in central Kentucky but
that is fading. Upstream convective activity is still limited, but
we are starting to see a smattering of showers in the Lower
Mississippi Valley, with an upper impulse being thrown out of a
convective complex along the western Gulf Coast.

Based on hi-res and legacy model data, would look for these showers
to blossom as they lift NE toward the Ohio Valley today, bringing a
solid chance for showers and T-storms to the area mainly during the
afternoon hours. Confidence is still limited as it still doesn`t
look like a well-organized rain shield, but it`s more than just
popcorn storms, so will ramp POPs to 50% at most. Not expecting any
organized severe storms as the flow remains quite weak, but it`s
juicy enough for the odd pulse storm to produce gusty winds, and
brief locally heavy rain could result in short-fuse flood concerns.
Temps continue above normal but clouds and precip will limit
diurnal ranges.

This impulse kicks through this evening, and the upper pattern
starts to flatten out as the deep trof over the Plains lifts into
the western Great Lakes. One more impulse will swing through on
Sunday as the trof gets picked up in the westerlies, so will
continue a 20-30 POP through Sunday, with temps just a couple
degrees warmer than today thanks to more sunshine.

.LONG TERM (Sunday night through Friday)...
Issued at 255 AM EDT Sat May 28 2016

Weak and zonal flow aloft will set up by Memorial Day, with faster
westerlies across the Great Lakes and shortwave ridging over the
Ohio Valley. Low-level air mass remains warm and humid, but
precipitable water decreases to around 1 inch for Monday and
Tuesday, so will stick with the theme of a couple of dry days.
Should still get a decent amount of cu, so will limit max temps to
the upper 80s.

Upper pattern starts to amplify again from midweek onward, but we`ll
again be relying more on the available moisture than the strength of
any dynamics for our precip chances. As such, confidence in the
timing of anything remains limited, so will roll with a model
consensus of scattered coverage for most of the latter half of the
week. Temps remain above normal through the period, especially at
night as cooling will be limited by clouds and abundant low-level


.AVIATION (12Z TAF Update)...
Issued at 643 AM EDT Sat May 28 2016

Generally VFR through the TAF period. Primarily a SCT/BKN mid deck
and southerly winds staying up around 5-10 knots today.

Showers will be possible just about any time in this very humid
atmosphere. Will continue with VCSH in the TAFs. Thunder isn`t out
of the chances would be diurnally driven this


.LMK Watches/Warnings/Advisories...


Short Term.....RAS
Long Term......RAS
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