Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 182310
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
710 PM EDT Thu Sep 18 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Friday Night)...
Issued at 245 PM EDT Thu Sep 18 2014
A tranquil and mild weather pattern will continue to finish out the
work week. Easterly low-level gradient has become more pronounced
today with high pressure over northern Michigan, and will keep the
boundary layer just mixy enough the next couple of nights that fog
will not be a concern. That leaves us with a temp forecast, and we
expect to see a gradual moderating trend as the surface high
retreats into New England, and the upper pattern becomes more zonal.
Given recent trends where much of the guidance has been too warm and
the NAM MOS has performed fairly well, will again lean on the low
end of the guidance envelope. Should see a decent spread in temps
tonight between the Louisville heat island and the cooler valleys,
but developing return flow Friday night should be just enough to
keep temps a bit more uniform.
.LONG TERM (Saturday through Thursday)...
Issued at 300 PM EDT Thu Sep 18 2014
Saturday - Sunday Night...
The long term will begin with southerly flow and warmer temperatures
as high pressure over New England slowly shifts to the east.
Temperatures on Saturday morning will start out in the upper 50s to
lower 60s and rise into the lower to mid 80s by the afternoon. This
will be the warmest day of the long term.
An upper level trough and surface low will move across the
northeastern CONUS through the second half of the weekend and into
the early work week. This will drag a cold front through on Sunday
into Sunday night. Scattered showers and thunderstorms will
accompany the front as it moves through. There may be a few storms
pre-dawn Sunday in southern Indiana. Rain chances will increase
through the morning as the front moves through. The best chance
looks to be in the afternoon as temps warm and the region becomes
somewhat unstable. Rain should end by Monday morning with clouds
clearing out by mid day. Temperatures will fall through this period.
Highs on Sunday will be in the upper 70s to lower 80s while Monday`s
highs are expected to reach only in the lower to mid 70s. Lows will
fall from the 60s to the 50s.
Monday - Thursday...
High pressure will build in at the surface behind the front. Aloft
an upper level trough will be replaced by ridging by midweek.
Tuesday will remain cool with highs in the lower 70s (possibly 60s)
and lows in the upper 40s to lower 50s. We will then see a gradual
warming trend the next couple of days.
.AVIATION (00Z TAF Update)...
Issued at 705 PM EDT Thu Sep 18 2014
VFR conditions are forecast for this TAF period with sfc high
pressure controlling the region. The latest model guidance
indicates a weak LLJ around BWG around sunrise which should provide
enough mixiness to prevent fog formation. NE winds have stayed up
this evening as well causing a light dry air advection. NE winds
will decrease to 3-5 kts overnight, then become more easterly for