Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 051409
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
909 AM EST Thu Mar 5 2015
Issued at 909 AM EST Thu Mar 5 2015
Measurable snow is expected to taper to flurries between 15Z and 18Z
as dry air continues to invade from the northwest. Will cancel the
WSW over southern IN and Trimble County at this time, where just
flurries are falling.
Issued at 620 AM EST Thu Mar 5 2015
Best frontogenetic forcing is shifting east now, enhanced EPV values
just behind that forcing is helping to spur on one more band from
west of Louisville down to Beaver Dam, where they need no more snow.
The stronger band now runs from Lexington southwest to Bowling
Green. Both bands have a steady eastward progression on radar,
following the moisture plume and forcing aloft as they shift east.
Latest high report is 19" at Falls of Rough in Breckinridge County.
Have updated products for this latest thinking.
.SHORT TERM (Now through Friday)...
Issued at 245 AM EST Thu Mar 5 2015
...Snow Continues Early This Morning...
...Bitter Cold Friday Morning...
Had an impressive couple of bands moving slowly over the region
overnight. So far the highest total is 16" in Radcliff, in Hardin
county, with several foot+ reports. Would not be surprised to have
many more reports as people wake up this morning. Snow will start to
taper off over the morning hours as the plume of moisture shifts
slowly east. Will keep the Winter Storm Warning up at least through
daybreak. Day shift may be able to transition it over to a
Traveler`s Advisory for slick and snow-covered roads.
Skies will clear tonight with winds going light and variable as well
as high pressure moves into the Ohio Valley. With the snowpack in
place temperatures still look on track for near record lows. Have
gone well below guidance and may not be low enough with this
Winds will become more southerly by Friday afternoon, and under a
good March sunshine, we should get close to the freezing mark, but
given the snow pack in place kept the forecast under for most
.LONG TERM (Friday Night through Wednesday)...
Issued at 255 AM EST Thu Mar 5 2015...
...Spring is coming...Snowmelt in earnest...
Friday Night - Saturday...
Well...the major winter storm has long passed and wide area of
surface high pressure will dominate with dry conditions. The
challenge of the long term is forecasting temperatures over the
snowpack. Some places have 12-20 inches in the mesoscale bands.
Lowered Temperatures even though we will have return flow with light
southerly winds. This could set up a eerie fog scenario with
advection fog set up on cold thickness snowpack with high liquid
Expect low temps Sat to range between 10-13 degrees, but adjusted
low lying snowpack areas. Highs on Sat afternoon to rise above
freezing into the mid and upper 30s.
Sunday - Thursday...
Agree with the previous forecaster that the GFS tries to bring a
very small amount of precip into our area from a disturbance passing
to our north on Sunday, but moisture profiles seem too shallow for
precipitation. Thus, will continue with increased clouds and no
The bigger story for next week is a big warm up for the Ohio Valley
taking temperatures back to around normal. The upper level pattern
will flatten over the CONUS early next week helping temps to
moderate over our region as thicknesses steadily rise. In addition
a more active southern stream should help push warm air into the
Ohio Valley starting Tues. Some rain chances look to occur in the
Tues-Thurs time frame next week although models are in disagreement
as to when and how much rain we will receive mid week next week.
Therefore will continue 20-30% POPs in that time frame. One thing
that long range models are in agreement with is high temperatures
reaching the 50s and perhaps low 60s Tues-Thurs next week! Snowmelt
will occur in earnest! Spring will soon be upon us.
.AVIATION (12Z TAF Update)...
Issued at 615 AM EST Thu Mar 5 2015
A major winter storm is winding down at the TAF sites, although BWG
and LEX still have a few more hours of light to moderate snow to
deal with. SDF will be finishing the snow shortly after this
forecast goes valid. Expect visibilities to continue to be 1/2 to 1
SM in snow, with visibilities likely hanging around 1-2 SM in BR
after snow ends well into the day. Ceilings are expected to be in
the IFR or low MVFR range in snow, improving to mostly above fuel
alternate later today. SDF has already gone into the high MVFR range
and is expected to stay there before going back to VFR later this
Otherwise, expect light northerly winds to persist through the day
with any lingering stratocu scattering out this evening as Arctic
high pressure builds into the area.
KY...WINTER STORM WARNING until 1 PM EST /Noon CST/ this afternoon