Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 091911
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
311 PM EDT Sun Mar 9 2014
.SHORT TERM (Now through Monday Night)...
Issued at 230 PM EDT Sun Mar 9 2014
A rather quiet short term period is in store as surface high
pressure continues its influence across the Ohio Valley for the next
36 hours or so. For tonight, skies will continue to remain mostly
clear. As the surface high shifts south and an area of low pressure
passes to the north, the pressure gradient will tighten across the
Ohio Valley tonight. Therefore, temperatures will likely drop
quickly this evening with the loss of sunshine, before leveling out
overnight as southwesterly winds begin to increase. Overnight lows
will be in the mid to upper 30s.
Monday will be a very pleasant March day. With the expected full
sunshine, breezy southwesterly winds aiding in turbulent mixing, and
a continued dry low-level airmass (aided by the potential for some
drier air mixing down during peak heating tomorrow afternoon), think
temperatures may overachieve a bit. Therefore, have gone above most
guidance which puts highs in the mid to upper 60s tomorrow afternoon.
High clouds will begin to increase Monday night into early Tuesday
morning out ahead of the next system. With surface winds continuing
to remain in the 4-7 knot range, overnight lows will be rather mild,
with readings expected in the mid to upper 40s.
.LONG TERM (Tuesday through Sunday)...
Issued at 305 PM EDT Sun Mar 9 2014
A low pressure system still looks to cross the Ohio Valley Tues
Night bringing rain and perhaps a chance of a t-storm. Did expand
the area of t-storm probability up to around the Ohio River near
Louisville as models are keying in on the sfc low tracking along
this route. Any t-storms would be elevated in nature. Rain will
continue for Wed on the back side of this system but it will lighten
in intensity and decrease in coverage, ending by Wed evening.
Expect a total of up to around a half inch of QPF with the most
rainfall expected along and north of the low pressure across
southern Indiana/northern KY. Strong southerly winds ahead of this
low pressure system will push high temps into the upper 60s and
lower 70s for Tuesday! Tues night lows will have quite the range
(37-54 degrees) with colder air beginning to filter in near the end
of the period. We`ll see temps fall into the upper 30s and lower
40s through the day Wed with gusty NW winds.
We`ll then see a dry period with moderating temps Thurs-Sat. Thurs
highs will be in the upper 30s to lower 40s and a chilly start in
the upper teens and lower 20s. Some models have a colder signal for
Thurs morning lows and afternoon highs so will need to monitor that
and see if that holds. Lowered our forecast temps some for Thursday
but think models may be a bit too aggressive with the strength of
the cold air.
Friday may be a bit breezy as southerly winds pull in warmer
air...highs should be in the mid 50s to around 60 Fri/Sat with lows
in the upper 30s and lower 40s both nights.
For Sunday, models indicate another potent upper level trough could
impact our area with significant precip and perhaps another shot of
.AVIATION (18Z TAF Update)...
Updated at 109 PM EDT Sun Mar 9 2014
Low-level clouds continue to quickly clear out early this afternoon
as mixing quickly erodes them. Expect all sites to be mainly clear
by the start of the TAF period. The main forecast issue will be
winds tonight into tomorrow. WSW winds will increase late
today into tonight as an area of low pressure passing to the north
strengthens the surface pressure gradient. There appears to be a
marginal LLWS threat tonight at KLEX and KSDF, especially if winds
at the surface remain light. Will leave this out for now given the
surface winds expected to remain up a bit, but will pass along to
the evening shift for potential further inclusion.
Otherwise, Monday will be mostly clear. WSW winds will be on the
increase, with speeds expected in the 12-16 knot range, with gusts
of 19-23 knots possible.