Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 020714
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
314 AM EDT Thu Jul 2 2015
.SHORT TERM (Now through Friday)...
Issued at 314 AM EDT Thu Jul 2 2015
...Heavy Rainfall Across Central and Southern Kentucky thru
A nearly stationary frontal boundary is currently sitting WNW-ESE
across our CWA with deep moisture pooling south and west of it. It
is not expected to move a whole lot through the day, meanwhile a
higher precipitable water airmass (> 2") will continue to move in. A
complex of showers and storms has organized over MO and southern IL
over the past few hours ahdead of an upper disturbance embedded in
the NW flow. This complex will steadily push east toward our CWA,
arriving in our west around 5 AM EDT. Expect widespread rainfall,
with pockets of very heavy rainfall, to push east through the
morning across our southern CWA. Be careful through the morning
In collaboration with surrounding offices, decided to keep
the ongoing Flash Flood Watch as is across southern KY where
heaviest rainfall is expected to fall (1-2", locally higher).
Rainfall amounts should taper further north as you near the I-64
corridor. Had been concerned about our far NW given the amount of
rain that fell earlier this evening, however think this area will
only see scattered shower activity through today being north of the
The main batch of showers and thunderstorms exits our east by 11
AM/Noon EDT, with a relative lull in coverage through early and mid
afternoon. Scattered showers will then have the potential to
redevelop mid to late afternoon, mainly across KY. Given the lack of
insolation, this may be overdone by current model solutions so will
rely more on hi-res output, which puts less coverage this evening
Another disturbance will dive through the NW flow aloft later
tonight and into tomorrow, which will drag an associated surface low
south of our CWA. The end result will help to pull the stalled
synoptic boundary still sitting over our CWA through as a cool front
through the day on Friday. As a result, only expect scattered
coverage of showers and a few storms mainly across our south from
later tonight through Friday.
High temperatures will struggle today under rainfall and cloudy
skies. Will go with max readings in the 74-79 range. Lows will
mostly range in the 65-70 range tonight. Highs Friday will be
similar to today, in the mid and upper 70s.
.LONG TERM (Friday Night through Wednesday)...
Issued at 305 AM EDT Thu Jul 2 2015
Pattern remains fairly unsettled for most of the next week. No
single day appears to be a washout, but there is also no
identifiable dry period either.
Best precip chances Fri night through Monday will be across south
central Kentucky, as shortwave upper ridging takes hold over the
Great Lakes, and a bubble of surface high pressure tries to nose
into the Ohio Valley from the north.
Better coverage and organization of storms is expected by Tuesday or
Wednesday with the cold front trailing off a fairly vigorous upper
trof passing through the Great Lakes. Better instability and better
dynamics could support some stronger storms, but that remains a
low-confidence forecast at this time.
Temps through the period will run near or slightly below climo by
day, and near or above climo by night, as abundant clouds and
moisture will limit diurnal ranges.
.AVIATION (06Z TAF Update)...
Issued at 104 AM EDT Thu Jul 2 2015
A very unsettled period of weather looks to affect all TAF sites as
a nearly stationary frontal boundary sits near SDF/LEX, and several
upper disturbances pass through NW flow aloft.
SDF will start out in MVFR SHRA with occasional dips into IFR
visibility and TSRA possible. A brief improvement is expected
between 3 and 5 AM, before another round of showers and storms
through late morning. After another midday lull, showers and storms
could then fire in the late afternoon and evening. Frontal boundary
should find its way north of the terminal with a steady south wind
outside of any t-storm outflow boundaries.
BWG should see activity pick up toward dawn with periods of SHRA and
TSRA throughout the remainder of the TAF cycle. Brief instances of
IFR visibility are certainly possible along with t-storm wind gusts.
Otherwise, expect VFR with steady south winds.
LEX will also see activity pick up over the next few hours as the
frontal boundary slowly works toward the area. Several periods off
and on shower and t-storm activity are expected through the day with
temporary IFR visibilities and t-storm wind gusts possible. Once the
frontal boundary passes, south winds should prevail outside of any
KY...FLASH FLOOD WATCH through Friday morning FOR KYZ026-027-061>067-