Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 231037
Area Forecast Discussion
National Weather Service Louisville KY
637 AM EDT MON MAY 23 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Tuesday)...
Issued at 245 AM EDT Mon May 23 2016
Our region is on the west side of a slowly weakening upper level low
pressure system, which is centered along the central NC/VA border
this hour. A narrow meridional ridge is just to our west, and that
system will nose in here, keeping us dry and warmer to start the
work week. Forecast thinking in house has been that it will be hard
to get up to the 90s under this warm regime given the very green
vegetation out there. That said though, south central KY is still
below normal for the year, so they have a better chance to reach at
some point this week.
First off though, we should have a day of temperatures similar to
Sunday, with a continued northerly component to the wind. Tonight
should be a degree or two warmer as we start to come around to more
of a southerly flow. Then Tuesday, highs should start jumping up, 3-
5 degrees above their values today...reaching the mid 80s for SDF
.LONG TERM (Tuesday Night through Sunday)...
Issued at 300 AM EDT Mon May 23 2016
The ridge axis will start getting east of us Tuesday night, with
models forecasting a weakness in the ridge possibly allowing some
rains into the region overnight. By 06Z Wed, higher precipitable
water air will be restricted to west of the I-65 corridor, but by
daybreak more of the region should see that moisture come in. The
best forcing for showers would be to our north however, along a warm
frontal boundary. That said, have reduced the rain chances for
That same focus for convection may end up keeping us more scattered
with storms during the day Wednesday. A few models show some weak
disturbances moving through the flattening ridge allowing for more
storm coverage. Will lean toward a little drier solution for now,
based mainly off models with better reliability at the mid-range,
the MEX, European statistical guidance, and consensus of all models.
That same set of guidance calls for a better chance for storms
Wednesday night, possibly as an MCS developing over the Upper
Midwest drops into the Ohio Valley, as per latest ECMWF solution.
That type of system is difficult to pin down this far out, but given
a fairly soupy airmass in place (sounding climatology would indicate
in roughly the 90th percentile), any impulses in the vicinity would
have a chance to spark off some storms.
By the end of the work week, a more defined trough is forecast to
move across the Central Plains, restrengthening the ridge to our
east. In this pattern, a plume of moisture out of the Gulf will
develop. The question mark is how close this plume gets to us.
Should it stay just to our west, we could end up with limited
coverage of afternoon storms, but if nearby we would have plenty.
The model blend keeps the pops in the chance range each period and
will not stray too far from those values.
Temperatures this period will depend somewhat on timing of precip,
but in general we look to be above normal each day.
.AVIATION (12Z TAF Update)...
Issued at 630 AM EDT Mon May 23 2016
VFR conditions are expected through this TAF period as high pressure
builds into the region. Skies will be mostly clear today and
tonight. Light and variable winds this morning will become easterly
around 5-7 knots by mid day. They will become light and variable to
calm again tonight.