Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 291045
Area Forecast Discussion
National Weather Service Louisville KY
645 AM EDT THU SEP 29 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Friday)...
Issued at 320 AM EDT Thu Sep 29 2016
Anomalously deep upper level low will hang right over Kentucky for
much of the short term period. The short term multi-model consensus
is excellent agreement with this scenario. While there is excellent
model agreement in the upper level low progression and tracks, there
remains a bit of uncertainty about precipitation coverage and
temperatures during the period.
In terms of sensible weather, cloudy conditions are expected today
through Friday as the upper low remains overhead. Diurnally driven
showers and a few thunderstorms are likely as we see a bit of
surface heating combined with the cold core of air aloft. This
results in steep lapse rates during the afternoon sufficient for
convective development. Based on model proximity soundings, the
depth of the cold air looks lower today than yesterday, so we could
see storms producing small hail. Wind fields look rather chaotic
and disorganized, so we do not think winds will be a weather hazard
through the period. As for temps, we could see some breaks in the
clouds in some areas which could result in a more chaotic looking
temperature map this afternoon. Current thinking is that we`ll see
most locations in the lower to middle 60s for highs. Our far NE
could be a touch colder with upper 50s to around 60...while some of
our far western areas could reach the upper 60s for a short time.
For tonight, mostly cloudy skies with additional scattered showers
will be around...given that the upper low is overhead. Lows will
range from the upper 40s to the lower 50s.
More of the same is expected for Friday with cloudy skies and
scattered to numerous showers and a few thunderstorms around. The
multi-model consensus suggests higher PoPs across the west/northwest
sections with perhaps drier conditions down across our SE sections.
Highs will remain in the lower-mid 60s in many locations, though our
southern sections could see some upper 60s in spots.
.LONG TERM (Friday Night through Wednesday)...
Issued at 328 AM EDT Thu Sep 29 2016
Friday Night through Saturday Night...
The latest forecasts suggest that the upper level low will remain in
the vicinity of the Ohio Valley Friday night and then start to lift
out during the day on Saturday. Overall model run to run
consistency is getting better in this time frame...so forecast
confidence continues to increase. In terms of sensible weather, we
expect more cloud cover and scattered to numerous rain showers with a
few thunderstorms here and there. Greatest coverage looks to be
Friday night and into the day on Saturday with a drying trend
starting Saturday night. Lows Friday night should cool into the
lower 50s with highs on Saturday warming into the middle to upper
60s. Lows Saturday night look to cool into the lower 50s once again.
Sunday through Wednesday...
By Sunday, the closed low will start to lift out to the north and
then northeast as a stronger trough axis develops across the western
US. As this trough axis deepens, we`ll see heights rise across the
eastern US resulting in a dry period of weather for our region.
Highs Sunday/Monday/Tuesday will warm into the middle to upper 70s.
Some lower 80s look to return to our region by Wednesday. Overnight
lows through the period will remain in the lower-middle 50s.
.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Thu Sep 29 2016
Flight conditions have not dropped quite as low as previously
forecast this morning. BWG/SDF remain VFR and LEX is currently MVFR
as of 630am. Expect VFR/MVFR conditions to continue through the
Rain chances will increase this afternoon courtesy of the upper low
over the region. There is a chance for t-storms as well but feel
those chances are too slim for a TAF mention attm. By the end of
the TAF period, flight conditions will likely go high end MVFR or
VFR. Will be optimistic with this TAF issuance and go with VFR.
Winds will remain light between W-NW-N through the TAF period.