Scientific Forecaster Discussion
fxus63 klmk 220720
Area forecast discussion
National Weather Service Louisville Kentucky
320 am EDT sun Sep 22 2019
Short term...(today and tonight)
updated at 305 am EDT sun Sep 22 2019
Progressive upper shortwave trof over the upper Midwest will push
eastward into the Great Lakes by tonight, and drive a cold front
into the Ohio Valley. We'll be hot and dry today, with Max temps
near 90 one more time. Low humidity and increasingly breezy
conditions could create some grass/brush fire concerns, and we are
currently on the fence as far as a Special Weather Statement to
highlight the increased fire danger.
Cold front and associated precip shield will move into southern
Indiana late tonight, and it will be touch and go for a possible
27th consecutive day without measurable precip at sdf while day 26
is a better bet at Lex. Best precip chances will be after midnight,
but could still be hit and miss especially across Kentucky. Storm Prediction Center has
general thunder outlooked across southern Indiana and north central
Kentucky, but given a lack of cape isolated thunder wording is about
all we expect.
Precip shield will really break up on Monday as the front is left
behind by the upper support. Will still support chance pops Monday
morning but no mention of thunder with instability still absent.
Plenty of cloud cover and cooler northwest flow behind the front will limit
the temp recovery Monday afternoon, but we will still be above
Long term...(monday through saturday)
updated at 245 am EDT sun Sep 22 2019
Monday night - Wednesday morning...
Sfc high pressure system is expected to gradually slide overhead the
region Monday night in the wake of the exiting cold front. This
system coupled with zonal flow aloft will allow for dry conditions
to persist through Wednesday. Afternoon temps should also feel quite
pleasant during this stretch, with highs expected to only reach the
upper 70s to low 80s.
Wednesday afternoon - Thursday...
By Wednesday afternoon, a cold front extending from Michigan to Arkansas will
begin edging toward our region, causing chances of precipitation to
return. This system is expected to be short lived though, and some
models even have it eroding as it enters the region. Will continue
to carry chance pops over southern in and north central KY, as those
locations seem to have the best support and chance of seeing
precipitation at this time. Otherwise, look for lows in the lower
60s on Wednesday night ahead of the front, with highs Thursday in
the low 80s.
Friday - Sunday...
By Friday, the southeast Continental U.S. Ridge looks to build once again and is
expected to remain throughout the weekend. Unfortunately, this will
cause afternoon highs to rise back into the upper 80s to low 90s, so
don't put your Summer clothes away quite yet!
Aviation...(06z taf issuance)
updated at 115 am EDT sun Sep 22 2019
Light winds overnight will pick up out of the S-SW by mid-morning as
the gradient tightens ahead of a cold front. Expect gusts around 20
kt for much of the afternoon, with only a few-sct diurnal cu as the
moisture supply remains limited. Will lose some of the gusts after
sunset but wind speeds stay up at 10 kt or a bit higher, with
thickening and lowering clouds at hnb and sdf. Precip chances should
hold off until the sdf planning period, where we will carry a prob30
for MVFR vis in thunderstorms toward Mon morning.