Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Louisville Kentucky
629 PM EST Wednesday Nov 25 2015
..updated aviation discussion...
Short term (now through Thursday night)...
issued at 222 PM EST Wed Nov 25 2015
A mild and dry Thanksgiving is in store for southern Indiana and
central Kentucky as the region remains on the western edge of a
surface high pressure while energy associated with the western
trough stays out in the Central Plains to upper Midwest. Warm
breezes this afternoon have allowed readings to jump into low 60s.
Expect a mild night with lows in the low to mid 40s.
For Thanksgiving day, plan on mild temperatures, mostly to partly
sunny skies with a steady south breeze. High temperatures will top
out in the mid to upper 60s, some 10-15 degrees above normal. The
last 60+ degree Thanksgiving in central Kentucky was in 2012, but
the previous two years (2014 and 2013) were unseasonably cold with
highs in the 30s/40s, so outdoor activities will certainly be more
comfortable this year.
South breezes will be in the 15 to 20 mph range, especially during
the late morning and afternoon hours. The mild weather regime
continues Thursday night with temperatures around 50.
Long term (friday through wednesday)...
issued at 245 PM EST Wed Nov 25 2015
An active, unsettled weather pattern will round out November across
the lower Ohio Valley as multiple rounds of rain look to affect the
First, 25.12z guidance has trended slower with the onset and arrival
of the rain for Friday. The surface front and associated shield of
rain is now expected to hold off until Friday late morning (across
southern indiana) to after sunset or closer to midnight (across
southern/southeast kentucky). Consequently, high temperatures were
nudged up several degrees given a little more sunshine (especially
south/east) so plan on highs to once again top in the low to mid 60s.
Precipitation should work southeast out of central Indiana and
Illinois over the course of Friday afternoon/night. An initial wave
of low pressure looks to lift out of Texas Saturday, interacting
with the stalled front across central Kentucky. Latest guidance puts
the front south of the Kentucky parkways during the day Saturday, which
may hold highs north in the upper 40s to low 50s while areas to the
south climb into the upper 50s.
Saturday night into Sunday will likely turn out to be the wettest
time frame of the period as the wave of low pressure slowly lifts
northeast. Pwats will be anomalously high for this time of year,
running around 1.5 inches and forecast soundings show deep
saturation for the area. Bouts of moderate to heavy rainfall,
particularly across southwest Kentucky into portions of central Kentucky will be
No real improvement in forecast model confidence late in the weekend
and into next week as guidance continues to struggle with the
evolution of the western trough and its progression across the
Central Plains. It does appear that we'll see another storm system
develop and eventually a cold front passage, though timing that
feature remains below average. Given we'll be on the warm sector
side with weak/moderate warm air advection in a moist environment,
low chance pops Mon-Tue look good. Beyond that, a model consensus of
lower chances and maybe cooler temperatures seems reasonable.
Total rainfall for the Friday night through Tuesday time frame looks
to be anywhere from 2 to locally 3 inches. The greatest amounts at
this time look to fall across southern Indiana and west central Kentucky.
Aviation (00z taf update)...
updated at 620 PM EST Wed Nov 25 2015
VFR conditions are expected at the terminals throughout the upcoming
forecast period. Surface gusts have died down and are expected to
return from the south at 10-20 knots during the daytime Thursday.
High clouds will continue to stream across the region, with time
height sections indicating perhaps a mid deck as well tonight.