Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 240657
Area Forecast Discussion
National Weather Service Louisville KY
257 AM EDT SAT SEP 24 2016
.SHORT TERM (Now through Sunday)...
Issued at 245 AM EDT Sat Sep 24 2016
Through Sunday, continue to plan on dry conditions and very warm to
hot temperatures for mid to late September. Expect mostly clear
skies and light winds with patchy morning fog in the typical river
valleys and sheltered locations. Highs today will top out in the
upper 80s to low 90s, and generally the same on Sunday. It will feel
a bit more muggy outside compared to the past few days, but overall
humidity levels won`t be too oppressive. Morning lows will range
from the lower to mid 60s in the coolest valleys to near 70 in the
Louisville metro center.
.LONG TERM (Sunday night through Friday)...
Issued at 246 AM EDT Sat Sep 24 2016
The main highlights in the long term are precipitation chances
Monday and the arrival of fall-like temperatures next week.
A deep upper level closed low currently over the Rockies will
advance toward the Upper Midwest and Great Lakes by Sunday night and
Monday. This feature will bring a surface cold front into the region
Monday. Forecast guidance has trended faster with the frontal
passage, bringing it through the I-65 corridor by mid-morning Monday
and east of the I-75 corridor by mid to late afternoon.
Moisture return and transport ahead of the front is weak as PWATs
are only forecast to rise to the 1.3 to maybe 1.5 inch range.
Additionally, if the front clears through most of the area during
the morning to early afternoon, it won`t have maximum daytime
heating to help fuel more storms. The better dynamics are expected
to stay northeast into portions of Ohio, so overall coverage of
showers and storms may be quite limited. Will still advertise 30-40
percent chances, highest north of the I-64 corridor. Rainfall
amounts will be generally light as well with most areas likely to
pick up less 0.10 of an inch.
However, the front is still on tap to bring a major pattern change
for the area with upper level troughing hanging on across the Great
Lakes and mid-Atlantic through next week. Expect a sharp temperature
drop Monday night and most folks Tuesday morning will wake up to
temperatures in the low 50s with some upper 40s likely across
Tuesday through Thursday will be quite nice with very comfortable
fall-like weather. Highs are forecast to stay in the 70s region-wide
with cool morning lows in the upper 40s to lower 50s.
There will be some breezy afternoons on Tuesday and Wednesday
with northwest winds 15-20 mph, but overall conditions will be
very pleasant. The core of the upper trough will be off to the
northeast where cold-top instability showers may be possible. At
this point, that looks to stay out of the area though if the
24.00z deterministic ECMWF solution verifies, some showers may be
possible mid-week across southeast Indiana and the northern
Friday and beyond the forecast guidance differs considerably with
the evolution of the upper trough. For now a model consensus
approach continues to feature dry weather and moderating
temperatures back to around normal or slightly above normal.
.AVIATION (06Z TAF Update)...
Issued at 1237 AM EDT Sat Sep 24 2016
Nearly calm conditions both at and just above the surface will lead
to the potential for fog tonight, especially at BWG. The ridging
providing us with those calm conditions will keep the weather quiet
on Saturday with scattered high-based cu and a light NNE breeze.