Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 211951
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
351 PM EDT Sun Sep 21 2014
.SHORT TERM (Now through Monday Night)...
Issued at 300 PM EDT Sun Sep 21 2014
A cold front will move southeast of the Lake Cumberland region by
late afternoon. A few showers and perhaps even a thunderstorm have
developed over the southern Bluegrass and Lake Cumberland region
within a thin axis of instability right along this boundary. Any
storms will move southeast of our CWA by around 6 pm. In its wake,
significantly cooler air will arrive after midnight, as a sharp
500mb trough axis swings east of the Commonwealth by Monday
In the short term, skies will clear for a few hours across central
Kentucky by late afternoon. Despite brisk northwest winds this
afternoon, colder air will lag behind the actual front itself, so
early evening will stay relatively mild. Cloudiness will actually
increase by mid to late evening as steepening lapse rates may
promote some scattered to occasionally broken strato-cu diving south
Robust surface high pressure will sag south and lie over Missouri
Monday morning. Skies will clear at least by dawn Monday and will
stay clear for the next several days. Lows by dawn will fall into
the lower 50s, and recover only to the mid 60s to around 70 Monday
With very light winds and ideal radiational cooling conditions,
temperatures early Tuesday will be the chilliest of this young fall
season. Lows early Tuesday may approach 40 across our nominally
cooler rural locations, while averaging in the upper 40s elsewhere.
.LONG TERM (Tuesday through Sunday)...
Issued at 255 PM EDT Sun Sep 21 2014
Surface high will ridge into the Ohio Valley from the northeast for
much of the work week, maintaining dry weather and mild temps,
albeit with a gradual warming trend as the week progresses.
Coolest day will be Tuesday, with temps limited by a chilly start,
and shallow mixing in the NE flow. Might only mix to 900mb, which
would barely allow highs to crack 70. Have gone generally with lower
70s, in line with the NAM MOS guidance but undercutting GFS MOS by
Temperatures will begin a slow recovery on Tuesday night, as the
thermal trof will be solidly to our east. Latter part of the week
should see temps near climo as the building ridge evolves into a Rex
block with a closed upper high over the Great Lakes. The developing
upper low over the Deep South could start to turn the pattern more
unsettled next weekend. However, confidence remains limited this far
out, so will include no more than slight chance POPs for next
.AVIATION (18Z TAF Update)...
Issued at 115 PM EDT Sun Sep 21 2014
A cold front will move south of the Commonwealth by mid-afternoon.
Winds have already become northwest at SDF and LEX, and will veer to
the northwest at BWG by 19z. For the rest of this afternoon,
northwest winds will continue around 11 to 12kt, with gusts up to
18kt. Winds will become more northerly and diminish to under 10kt by
late evening. Northeasterly winds of 5 to 10 mph expected for
The threat of any showers for BWG has essentially ended. MVFR
ceilings at BWG will lift to VFR and scatter out by 19 to 20z this
afternoon. Ceilings have will have lifted to VFR at SDF and LEX by
TAF issuance time, and will tend to clear by 20z.
Aside from scattered VFR level clouds passing through around the
late evening through the early morning hours, mostly clear skies are
expected. Monday will stay clear.