Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 190713
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
313 AM EDT Sun Apr 19 2015
.SHORT TERM (Now through Monday)...
Issued at 251 AM Sun April 19 2015
The weather will remain quite unsettled through the short term
period as multiple rounds of showers and storms will be possible.
The first round will bring the most widespread rain this morning
through early afternoon. A surface low currently over Arkansas will
move northeast through the day passing just to the northwest of the
forecast area. Scattered light showers are showing up on radar this
morning associated with isentropic lift ahead of the warm front that
will move north this morning. Showers are expected to increase in
intensity and coverage through the next few hours with widespread
rain showers and scattered thunderstorms continuing through the
morning as the warm front crosses the region.
There should be a bit of a break in the showers and storms early
this afternoon. Winds will increase in the warm sector this
afternoon both at the surface and aloft. Soundings continue to
indicate instability will develop later in the afternoon,
particularly if any breaks in the clouds are able to form. Scattered
showers and storms are expected to develop from mid afternoon and
continue until early evening. A few of the storms could become
strong to marginally severe this afternoon with isolated damaging
winds and hail. Outside of any thunderstorms, winds will be breezy
this afternoon with gusts to around 30 mph.
There will likely be another break in precipitation this evening
before another shortwave and its attendant surface low approach from
the west. This low will finally swing a cold front through the
region during the day on Monday. Scattered to numerous showers and
scattered thunderstorms will continue to be possible through the day
Monday. Temperatures on Monday will be tricky with the front moving
through. At this time they look to hold steady of fall a few degrees
through the afternoon hours.
Storm total rainfall will be in the one to one and a half inch range
with amounts up to two inches possible. The bulk of the rain will be
this morning through mid afternoon. Though widespread flooding
issues are not anticipated, some rises can be expected on smaller
streams, as well as ponding of water in low lying areas.
.LONG TERM (Monday Night through Saturday)...
Issued at 250 AM EDT Sun Apr 19 2015
We should be drying out Monday night as high pressure moves into the
Deep South and as the broad low pressure area beginning to affect us
now heads off to the northeast. We will head into a period of
temperatures a little below normal for the rest of the long term, as
troughing aloft looks to persist.
As for the next chance for rain, the latest NAM and GFS both hint at
some precip along the Ohio River Tuesday afternoon, whereas our
ongoing forecast is dry. This precip looks to be in response to
moisture returning on the back side of the departing high pressure,
as it heads to the southeast U.S. coast. The Euro and GEM both hold
off on this precip until Tuesday night or Wednesday, instead having
a cool front approaching the region be responsible for forcing the
showers. Will lean the latter direction, and keep rain chances to
After that precip, the next solid chance for rains looked like it
would come Friday with the 00Z models yesterday, but now that threat
has shifted to Friday night/Saturday, once again as the models think
another system is getting organized over the Central Plains. Will
keep pops in the chance range given this uncertainty.
.AVIATION (06Z TAF Update)...
Updated at 1258 AM EDT Sun Apr 19 2015
All terminals are currently VFR, but conditions will deteriorate at
all sites this morning as a low pressure system approaches the
region. Showers have already begun to spread north into the BWG area
ahead of this system. The more widespread showers will hold off
until 08-10Z. However, they will quickly spread northward through
this time frame. Ceilings will initially fall to MVFR by around
sunrise. All of the guidance is showing a period of IFR ceilings
from mid morning through mid afternoon, so have added that in to the
forecast for all sites. Scattered thunderstorms embedded in the more
widespread rain showers will be possible through mid day, so will
continue to carry VCTS. There will likely be a dry period through
mid to late afternoon. However, scattered storms are expected to
again develop this afternoon. With only scattered coverage, have
decided to carry a PROB30 group for the storms this afternoon.
Winds today will shift to southerly by this afternoon and
south-southwesterly this evening. Winds will increase to 10-15 knots
sustained this afternoon with gusts up to 25 knots possible outside
of thunderstorms. Any thunderstorms that do affect the terminals
this afternoon could have some strong gusts associated with them.