Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 071058
Area Forecast Discussion
National Weather Service Louisville KY
558 AM EST SUN FEB 7 2016
...Updated Aviation Discussion...
.SHORT TERM (Now through Monday)...
Issued at 245 AM EST Sun Feb 7 2016
...Winter Returns Tonight...
We`ll enjoy one more unseasonably warm and partly cloudy day before
the well advertised return of winter. High temps should top out a
degree or two warmer than yesterday reaching the low to mid 50s by
this afternoon. After a mostly sunny to partly cloudy morning,
clouds will increase from NW to SE this afternoon.
Short range models continue to vary on the amount of moisture
pooling along the initial cold front progged to cross the region
tonight. With initially dry conditions this evening, will keep POPs
low (mainly 20-40%) before midnight as the atmosphere may take a
little time to moisten up. After 6Z, most short range models have a
good signal for a band of light precip crossing central KY so have
kept 60% POPs during that passage. A relative lull in precip
activity may occur closer to 12Z before a showery regime sets up for
the rest of the day Monday. Precipitation amounts should remain
light tonight and Monday with a total of up to 0.25 inches of liquid
P-type will be a bit challenging as we enter the colder pattern.
Soundings indicate that the boundary layer will be warm enough for
all rain tonight before midnight. After midnight, temps will fall
into the lower 30s and the boundary layer will likely become cold
enough for a mix of rain/snow or a period of all light snow
especially closer to sunrise. The latest model guidance suggests a
slight warm up into the upper 30s by early afternoon and then temps
crashing through the 30s during the afternoon hours Monday as the
colder air rushes in. This will result in a mix of rain/snow Monday
transitioning to all snow by late afternoon/early evening. Some of
the high-res models and forecast soundings indicate a good shot at
convective snow showers for locations cold enough late Mon
afternoon/evening which may result in bursts of moderate to at times
heavy snow. A light accumulation of snow (under 1 inch) is possible
in many locations by Mon evening.
.LONG TERM (Monday Night through Saturday)...
Issued at 305 AM EST Sun Feb 7 2016
Monday Night - Wednesday...
An anomalous upper low will settle over the Midwest for the
beginning of the work week resulting in on and off snow showers for
Mon night and Tues for the entire area. By Tues night/Wed the upper
trough will slowly push east out of the Ohio Valley resulting in
snow shower chances mainly along and east of I-65 Tues night and
then off to the Bluegrass region for Wed.
Light accumulating snow will be possible Mon night-Wed with many
locations seeing between 1-3 inches of snow. The highest amounts
should end up in southeast Indiana and the Bluegrass of KY which
will be under the influence of the upper trough for a longer period
and terrain may enhance snow showers. Model soundings continue to
indicate periods of low level instability stretching into the
favored dendritic growth zone which would result in moderate to at
times heavy snow reducing vsbys and potentially creating travel
Temperatures will be on the decline through Wed as the cold air
blasts into the Ohio Valley. While highs on Tues will be in the
upper 20s to around 30, highs on Wed will only reach the lower 20s.
Low temps will be coldest on Wed night with lower 10s and single
digits expected. Will need to fine tune these temps as snow cover
is established early this week. WNW winds will gust up to around
25mph especially during the daylight hours as well adding to the
raw, wintry conditions.
Thursday - Saturday...
By Thurs, the upper trough will be making decent progress eastward
shutting off snow shower activity and allowing temps to moderate
into the 30s for highs by the end of the week. The 0Z models have
come into agreement on a northern stream shortwave possibly merging
with a wave traversing the southern U.S. on Fri night which could
result in additional light snow. Went ahead and added a 20% POP Fri
night for this system.
.AVIATION (12Z TAF Update)...
Updated at 558 AM EST Sun Feb 7 2016
VFR conditions will persist through the day as high pressure shifts
off to the east. Mid/high clouds will thicken through the daylight
hours, but any cigs will remain VFR. Winds will become gusty around
20 knots this afternoon out of the SSW.
A cold front will approach the region tonight, bringing showers and
a wind shift to more westerly. Have higher confidence in shower
coverage around KLEX, so will go with some prevailing -SHRA there
and MVFR cigs/vsbys. Otherwise, MVFR cigs look likely to plague all
sites by the end of the period and into the SDF planning period.