Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 151041
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
641 AM EDT Sat Mar 15 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Sunday)...
Issued at 305 AM EDT Sat Mar 15 2014
The cold front moving though tonight has been mostly dry, except for
possibly a few sprinkles in southern Indiana. The remainder of the
night and the daytime hours should be dry as weak ridging building
in from the northwest quickly passes through. Clouds associated with
the front will move off to the east early this morning leading to a
mostly clear day. Temperatures have been warmer than guidance lately
with the higher sun angle. Given the good amount of sun today, have
gone a bit warmer than guidance for high temps. They should range
from the upper 50s to mid 60s.
For tonight and tomorrow a low pressure system will move from Texas
east-northeast across the Gulf coast states. Precipitation
overrunning the warm front associated with this low will spread into
central Kentucky late tonight into early tomorrow morning.
Precipitation will then spread north across the entire forecast area
Temperatures with this system will be tricky as the low passes to
the south of the forecast area. A wide range of high temperatures
can be expected on Sunday from the mid 30s in the north to the upper
40s in the south. Aloft, there is a warm layer, though it is not
nearly as strong as we have seen in past systems, so it does not
look like there will be complete melting in this layer.
South central Kentucky will remain all rain through Saturday night
and Sunday. Further north- mainly north of Interstate 64- there will
be a mix of snow and rain. All snow is looking possible during the
afternoon hours Sunday across portions of southern IN and far north
central KY. However, some sleet may mix in at times as well.
With the warm ground temperatures, any snow will initially likely
have a hard time accumulating. However, by late afternoon some
accumulations will be possible. This would be mainly along a line
from Jasper, IN to Cynthiana, KY and points north. Half an inch to
possibly an inch may be possible in this area, depending on how much
sleet mixes in with the precipitation and where the northern edge of
the precipitation shield sets up.
.LONG TERM (Sunday night through Friday)...
Issued at 325 AM EDT Sat Mar 15 2014
...A Chance of Accumulating Snow Sunday Night...
Sun Night Model Trends
One of the last bursts of winter looks to impact the area Sun night
as a low pressure system moves across the Gulf states and Tennessee
Valley. Our region will be to the north of the low track (cold
side) and thus have the potential for wintry precip. A multitude of
different model solns and temp profiles exists for this storm so
confidence in exact p-type and amounts is low at this time.
However, will highlight the common themes and trends with this
latest suite of 0Z models. WPC seems to prefer the general track
closest to the latest runs of the ECMWF/UKMET/GEM which would bring
the heaviest precip axis through central KY. However, it should be
noted that other model runs of the GFS/NAM/ECMWF have brought the
heaviest precip axis closer to the Ohio River and southern Indiana.
Can`t rule these out but did trend the heaviest precip axis toward
north central KY. Also, it should be noted that the GFS/NAM/ECMWF
have trended faster in moving precip out of the area late Sun
night/early Monday morning with dry air invading the mid levels
Sun Night P-type and Potential Wintry Accums
As far as p-type goes, some models tend to paint a better warm nose
creating the possibility for sleet/freezing rain. However,
generally speaking the preferred ECMWF/UKMET/GEM track and
progression of this system would probably lend more to just
rain/snow mix more than anything. At this point with so many temp
profiles on the table, decided to keep p-type rain to rain/snow to
all snow with a chance of sleet possible in the transition zone.
Think the rain/snow mix Sun evening will start out over central KY
just south of the I-64 corridor and transition south fairly quickly
to the Tennessee border by around midnight. The best QPF should
fall before midnight so the most likely areas of seeing any
accumulating snow would be southern Indiana and areas of central KY
along and north of the parkways. Due to the progressive nature of
this system, think that 1-2 inches of snow could fall...maybe 3
inches at the most. Because antecedent ground temps will be so
warm, that may cut into the snow totals some. Grassy and elevated
sfcs will see the highest snow accums. However, temps do look to
fall into the mid and upper 20s by Monday morning in the above
mentioned area so think that the Monday morning commute may be
South of the parkways, precip will be primarily rain Sun evening and
then transition to snow around or after midnight before ending.
With temps likely hovering in the lower 30s in this area, think that
any accums would be mainly on grassy surfaces and short-lived.
Some models indicate that precip could end late Sun night or early
Mon morning as some light drizzle or freezing drizzle but won`t get
that detailed in the grids just yet.
Also, NNE winds will gust into the 25-35 mph range Sun night.
Monday - Friday
The rest of the long term forecast looks less eventful. A cold
front looks to bring rain to the area some time in the Tues
night-Wed night time frame. Then another cold front looks possible
for next weekend. Both of these systems look to be weak and quick
moving and may contain some isld-sct t-storms but will be primarily
After a chilly Monday with highs in the upper 30s to mid 40s, the
rest of the week looks to be quite seasonal with highs in the
50s/60s and lows in the 30s/40s.
.AVIATION (12Z TAF Update)...
Updated at 640 AM EDT Sat Mar 15 2014
VFR conditions are expected through tonight. Today will be mostly
clear with light and variable winds as high pressure ridges in from
the northwest. Rain showers may start to affect BWG by early
tomorrow morning and spread into SDF by mid morning as a low
pressure system moves south of the area. Winds will shift to
northeasterly tomorrow morning and become gusty.