Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 210544
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
144 AM EDT Tue Oct 21 2014
...Updated Aviation Discussion...
Issued at 840 PM EDT Mon Oct 20 2014
Isolated showers have developed along a weak frontal boundary moving
south along the Ohio River. The most concentrated area of rain is
actually right over Louisville, soon to move into Shelby and Spencer
counties. Currently, only some light sprinkles are apparent over the
Bluegrass and west central Kentucky. Showers will move southeast of
Louisville well before nine thirty this evening. For the rest of
this evening, southern Indiana will stay dry with isolated showers
continuing across central Kentucky and eventually, the southern
Bluegrass if these showers currently exiting Louisville hold
.SHORT TERM (Now through Tuesday Night)...
Issued at 256 PM EDT Mon Oct 20 2014
An upper level trough will deepen across the northeastern CONUS
through the long term, eventually becoming a cutoff low. A cold
front associated with this system will move through the area
tonight. In addition, a couple of PV anomalies rotating around the
base of the trough will bring slight chances for light showers.
The first chance for showers will be late this afternoon into this
evening. Mesoscale models, which have been doing well the past
couple of days, suggest a broken line of showers will develop along
or near the river this evening and shift off to the southeast,
moving out of the forecast area by around 03-04Z. Showers should be
light and measurable precipitation low, so will keep only 20%
chances in the grids. The next disturbance tomorrow morning will
affect mainly southern IN and north central KY. Again, will keep
only a 20% chance in the forecast. Dry conditions are expected from
tomorrow afternoon through tomorrow night.
Temperatures tonight will drop into the mid 40s to lower 50s. Cold
air advection will keep temperatures on the cooler side tomorrow
with highs in the upper 50s to lower 60s expected. Tuesday morning
will see cooler temps with lows in the lower 40s.
.LONG TERM (Wednesday through Monday)...
Issued at 305 PM EDT Mon Oct 20 2014
A departing upper low and sfc high pressure will keep us cool and
dry for the middle of this week. Expect high temps in the upper 50s
and lower 60s Wed/Thurs. Thurs morning looks to be the coolest with
sfc ridging and a light NE flow pulling in cooler air from the
departing low. Lows look to range from the mid 30s to around 40
with frost possible. Friday lows will be a tad warmer ranging from
the mid/upper 30s east of I-65 to lower 40s west of I-65. Expect
increased cloudiness as an upper trough passes through the region
Ridging aloft will move in from the Plains this weekend with another
area of sfc high pressure. This will keep conditions dry with a
warm up in temps through the beginning of next week. With h85 temps
rebounding back into the 10-14 degree C range, sfc highs should be
in mid 60s to low 70s Fri/Sat and then solidly into the lower 70s
for Sun/Mon. Night time lows will jump back into the mid 40s to
.AVIATION (06Z TAF Update)...
Updated at 140 AM EDT Tue Oct 21 2014
Weak cold front is slow to progress past the Ohio River, but will
gradually push south across Kentucky overnight. Light SW winds will
veer to NW or even N by daybreak. Main source of uncertainty is how
far south the strato-cu deck over Indiana and Ohio can build. At
this point expect it to build into SDF and LEX, but BWG will remain
mostly clear. Kept the ceilings VFR, but just barely so at LEX. Even
if LEX does go MVFR expect it to stay above fuel-alternate
High pressure builds from the north during the daytime on Tuesday,
but without a strong push will keep wind speeds just under 10 kt.
VFR strato-cu ceiling will persist at SDF and LEX, but could scatter
out later in the afternoon. Light north winds and clearing skies
expected in the evening.