Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 232207
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
607 PM EDT Wed Jul 23 2014
Issued at 606 PM EDT Wed Jul 23 2014
Scattered to numerous storms have re-fired ahead of the cool frontal
boundary currently along a BWG/LEX line, with the aid of
differential heating from upper level clouds. These storms are
moving slowly off to the east, and have been able to produce very
heavy rainfall, a localized damaging wind gust and hail. The threat
for stronger storms will diminish over the next two hours as storms
move east of the area, and we lose daytime heating. Did update the
forecast to increase rainfall totals and increase coverage of
t-storms this evening.
.SHORT TERM (Now through Thursday Night)...
Issued at 320 PM EDT Wed Jul 23 2014
The cold front was very near the Ohio River as of 3pm. Most storms
have exited the region with thinning of clouds noted. With many
daylight hours left, some instability may rebuild and forcing from
the front could cause a few more storms/showers to redevelop late
this afternoon and evening. However, the strongest forcing along
the front will remain SW of our region and earlier showers/storms
have created a more stable moist environment. Post frontal
convection near IND is dissipating as well. Thus, think that more
showers/storms are possible but will limit POPs to 20-30% for this
evening. Also, any convection that does form is expected to remain
below severe limits due to limited forcing and instability. In
fact, it will probably be hard to even get a strong storm going with
gusty winds in this environment.
Any convective activity should cease after midnight with only some
patchy light drizzle/low clouds and maybe even some light fog late
tonight into tomorrow morning. A cooler airmass will enter the area
resulting in low temps in the 60s tonight.
With sfc high pressure and upper level troughing over the region
Thurs/Thurs night, we`ll experience unseasonably cool conditions.
Highs Thurs afternoon will drop back into the upper 70s and lower
80s with skies becoming mostly sunny during the afternoon hours.
Thurs night lows will bottom out in the upper 50s and lower 60s
under mostly clear skies.
.LONG TERM (Friday through Wednesday)...
Issued at 320 PM EDT Wed Jul 23 2014
Friday should be one more quiet day, with lower dewpoints and
temperatures still a few degrees below normal. A disturbance flowing
down within the northwest flow aloft will run into the dry air over
us, which should keep us from getting rain. This first system could
set the stage for another system to have a little more moisture to
work with late Friday night as it gets into southern Indiana. Cloud
cover with this system, similar to today, will pose a large question
mark on temperatures and rain chances in the day Saturday. MEX
guidance is calling for highs in the 90s Saturday, with the chance
for storms waiting until the evening as yet another disturbance
rolls through and takes advantage of that heating/instability. Will
not go as high as the guidance for temperatures, but still be around
90 for many locations.
The rain chances will continue Sunday and Sunday night as we get a
cool front to move from the Midwest into the Ohio Valley. That front
will bring another round of unseasonably cool temperatures to the
region for at least the first half of the work week. Once again,
records are possible with this round of cooling.
.AVIATION (18Z TAF Update)...
Issued at 200 PM EDT Wed Jul 23 2014
A cold front to our NW combined with an upper level trough will
continue to provide convection chances through tonight. While
BWG/SDF sit in a lull currently with only a few showers around,
storms should redevelop late this afternoon and evening along the
cold front and move toward the terminals. LEX currently has a
t-storm at the TAF site, but should see a lull in convective
activity by around 1830Z. LEX will also get in on the redevelopment
of storms later today according to the latest model data.
Redevelopment of convection later today is dependent on clouds
clearing/thinning along the front which currently they are thinning
in this area fairly quickly. Also some convection has redeveloped
over central Indiana. T-storm chances should cease after the fropa
between 1-4Z. After the fropa we`ll see low clouds build in with
cigs dropping into the low end MVFR or IFR late tonight into
tomorrow morning. Vsbys should drop to MVFR as well. Lingering
showers and drizzle will prevail through the overnight hours.
Conditions will improve to solid MVFR by mid to late morning
Winds will remain WNW this afternoon and evening ahead of the fropa
and then turn NNE behind the fropa between 5-10 kts. Higher winds
may occur in any t-storms.