Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 131706
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
106 PM EDT Thu Mar 13 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Friday)...
Issued at 300 AM EDT Thu Mar 13 2014
Currently, the axis of a deep 500mb trough responsible for New
England`s heavy snow is moving east of the Appalachians. More of a
zonal flow will replace this feature over the Lower Ohio Valley for
the rest of today and into Friday.
Forecast soundings and satellite confirm drier air moving south into
the area, and any lingering light snow flurries across our southern
counties will end prior to dawn. Scattered to broken strato-cu will
also diminish by mid morning. For the rest of today, expect skies
will become mostly sunny. Northwest winds will continue to diminish
and then become light westerly towards early afternoon as a surface
ridge axis moves east across Tennessee. Temperatures will stay
chilly, although with lighter winds and sun this afternoon, our
apparent temperatures will not seem so bad. Expect a bit of a range
in highs this afternoon with upper 30s likely across the northern
Bluegrass and upper 40s southwest of Bowling Green.
A substantial warming trend will arrive by Friday. Low pressure
moving across the western Great Lakes will combine with high
pressure across Georgia to bring a tightening pressure gradient over
the Commonwealth. Temperatures won`t fall too much by Friday
morning, and may even stay steady after midnight Thursday evening.
Winds will become southerly at 5 to 10 mph by dawn.
Under mostly sunny skies, breezy winds will develop from the
southwest by noon Friday. Gusts may exceed 30 mph by early
afternoon. Highs will exceed 60 almost everywhere and may rise into
the mid 60s across our southwestern forecast area near Bowling
.LONG TERM (Friday Night through Wednesday)...
Issued at 250 AM EDT Thu Mar 13 2014
A variety of model solutions exists for much of the long term period
as we sit in a tough split flow pattern. The first weather system
of interest will be primarily Sun as an upper trough and sfc low
move mainly across locations to our south. Timing/track of this
system remains a challenge so will side with the more consistent
ECMWF and ensemble means. That being said, some isld to sct rain
shower activity may be possible Fri night/Sat ahead of this weather
system. Then the main push of moisture will arrive Sat night/Sun,
moving out by Sun night. Overall this system looks to be on the
rainy side with QPF amounts of up to a half inch possible by Sun
night mainly across south central KY. However, it will be possible
to see a brief rain/snow mix on the back side Sun night before
precip ends. Saturday we`ll be mild in the mid to upper 50s for
highs before cooling off into the 40s for high Mon/Tues.
The next weather system of interest will be a cold front progged to
move through the area sometime Tues night-Wed night. Models are
very far apart on fropa timing at this point, thus will keep POPs
low. Precipitation type looks to be primarily in the form of rain.
Temps should be seasonal for mid March for mid and latter portions
of next week.
.AVIATION (18Z TAF Update)...
Updated at 105 PM EDT Thu Mar 13 2014
VFR conditions will prevail through the period, although LLWS will
be a concern tonight. Surface high pressure continues to push to
the east across all terminals early this afternoon. After a period
of light and variable winds, winds will slightly increase to around
5-9 knots out of the SSW later this afternoon. Mainly clear skies
will prevail, although a SCT to BKN deck of mid-level clouds could
affect KSDF and KLEX a bit later this afternoon/evening.
A low-level jet will ramp up tonight just above the surface, setting
the stage for a period of LLWS at all sites. This jet could be on
the order of 40-45+ knots late tonight into Friday morning, with the
highest values expected at KLEX and KSDF. Otherwise, skies should
be mainly clear, although some high clouds will increase towards
The main story during the day on Friday will be surface winds.
Southwesterly winds will increase to 20 to 25 knots, with gusts of
30 to 35 knots possible. Mid and high clouds will slowly increase
through the day.