Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 272228
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
628 PM EDT Wed May 27 2015
Updated 615 PM EDT Wed May 27 2015
Complex of storms that formed this afternoon, and produced isolated
strong to severe winds, has pushed south and east. Trailing
stratiform rain still lingers across the Bluegrass. Models had
advertised convection developing along the cold front but between
the front hanging farther north than expected, and the atmosphere
being worked over, that has not happened. Updating the forecast to
cut back on POPs for tonight. Believe most of the night will be dry,
but with the juicy air mass still in place it`s hard to rule out a
stray shower. Will also include patchy fog after midnight, mainly
east of I-65, given wet ground and small T/Td spreads.
.SHORT TERM (Now through Thursday Night)...
Issued at 245 PM EDT Wed May 27 2015
Have line of storms along the I-65 corridor this hour. The northern
part of the line has been the strongest at this point, with the
southern more widespread and less organized. Thinking at this point,
after collaboration with SPC, is that most of the storms the rest of
the afternoon will be below severe limits, so holding off on issuing
a watch at this time. DCAPE`s are not as impressive over the eastern
part of the area.
The next round of storms for the day will depend on how quickly we
recover from this first round. Areas along and north of the I-64
corridor will have the best chance to fire again before sunset, but
looking upstream there is a dearth of low clouds over southern
Illinois. Will limit late afternoon chances to under 40% for now.
Should these late storms fire up, we could additionally see some fog
form overnight, thanks to lighter winds and the extra influx of
For Thursday, there will be a little less moisture in place across
the region, but more importantly there should be less of a trigger.
Thus storms that develop should not become organized, though an
isolated wind/hail threat isn`t out of the question. Have gone with
40% or less coverage mainly across south central KY, in the area
with best moisture and isolated coverage in the north. Highs
Thursday should be a touch warmer than today, given the less
coverage of storms. For lows, went pretty much with persistence.
.LONG TERM (Friday through Wednesday)...
Issued at 248 PM EDT Wed May 27 2015
An unsettled pattern will continue through the long term period with
rounds of showers and storms expected through the forecast period.
Friday will be quite warm with highs in the mid 80s. The region
should become unstable by afternoon with scattered storms
developing. These should continue into the overnight period.
A stronger shortwave will approach from the west on Saturday. In
addition, a cold front will begin to move in from the northwest by
late in the day. With better forcing aloft and moisture pooling
ahead of the front, storm coverage will increase with a 60-70%
chance for most of the region.
The front will move through most of the region by Sunday night, but
then looks to stall out near the KY/TN border. It will then move
back north as a warm front early next week. Given daytime heating
and multiple boundaries in the vicinity, storm chances will continue
into the first half of the work week. These look to be scattered in
nature with potential lulls in the activity during the overnight
periods. There will be a slight cool down in the wake of the front
with highs reaching into the mid 70s to around 80 on Sunday and
Monday. Temps will warm a bit back into the low 80s by Tuesday.
.AVIATION (00Z TAF Update)...
Updated 130 PM EDT Wed May 27 2015
Have a line of storms approaching SDF and later LEX, then obs
upstream are clear. Have tried to have a window in the forecast with
no VCTS before they return later this afternoon. BWG a little more
unstable with various rounds of storms possible next several hours.
Should the second set of storms hit the terminals around sunset, fog
likely will develop overnight, given expected lighter winds and that
influx of moisture. Thus may have to go more pessimistic with later
forecasts for daybreak Thursday.