Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 190442
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1242 AM EDT Sat Apr 19 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Saturday Night)...
Issued at 255 PM EDT Fri Apr 18 2014
Storm system across the southeast U.S. will help to keep our weather
quiet this period. We will see a steady north to northeasterly wind
at the surface, in the flow around this system. There is a cloud
gradient from northwest to southeast today, with cirrus streaming
north from this low, but these clouds should shift east tonight.
Despite the sunshine tomorrow, lower thicknesses, kept low by that
closed low to our southeast, will mean temperatures stay within 5
degrees of normal this period.
.LONG TERM (Sunday through Friday)...
Issued at 310 PM EDT Fri Apr 18 2014
Sunday - Friday...
An amplified upper level ridge will be in place over the Ohio Valley
on Sunday, upstream of a closed upper low off the SE CONUS. This
will result in a warm and dry day with temperatures nearly 10
degrees above normal for this time of year. Most highs should stay
in the upper 70s although a few spots may touch 80 degrees. Sunday
night will be continued dry with mild overnight lows in the low and
mid 50s. Expect to see a light southerly wind to develop toward
dawn, along with increasing upper level sky cover.
By Monday, the upper level ridge axis will move off to the east.
Meanwhile, a shortwave will dive across the northern Plains heading
into the Great Lakes. An associated surface low will strengthen
ahead of this feature with some weak isentropic ascent possible over
the Ohio Valley. Forecast models continue to depict QPF over our
area on Monday, however agree with previous forecast reasoning in
keeping low chances across our western CWA further removed from the
upper level ridge. The main chances for scattered showers and a few
thunderstorms will arrive Monday night into early Tuesday as the
aforementioned surface low slides across the Great Lakes, dragging a
cold front through our region as it does so. There continues to be
some question as to how much moisture this system will have to work
with as return flow from the Gulf looks to be limited by the upper
level ridge in place the day before.
Highs Monday will be a bit cooler in the mid 70s under increased sky
cover. Monday night will be even milder than Sunday night under a
steady southerly flow ahead of the approaching cold front. Tuesday
will see highs in the lower 70s despite being post frontal as we`ll
see some peaks at the sun in the afternoon and cooler air lags
behind a bit.
We`ll see a dry period of weather Tuesday night through Thursday as
progressive upper level ridging builds back over the region, and
high pressure at the surface also holds. Temperatures Wednesday will
be the coolest of the period and should top out right around 70
degrees. Thursday will be back in the mid 70s. Overnight lows during
mid week will generally be near the normal mark.
Confidence decreases by the end of next week as the progressive
upper level ridge pushes off to the east and the next trough moves
in. There is general agreement in the next wave developing, however
timing is certainly in question. Will go with low chances for
showers and a t-storm during this time.
.AVIATION (06Z TAF Update)...
Issued at 1241 AM EDT Sat Apr 19 2014
VFR conditions will prevail through the valid TAF period. The
broken cirrus deck currently over the region will slowly push east
overnight, allowing sites to go mainly clear by the daylight hours.
After light and variable winds early this morning, winds will
increase to around 10 knots out of the ENE today.