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fxus63 klmk 181918 

Area forecast discussion
National Weather Service Louisville Kentucky
318 PM EDT Mon Jun 18 2018

Short term...(this evening through tuesday)
issued at 317 PM EDT Mon Jun 18 2018

Afternoon satellite imagery and observations reveal another hot and
humid afternoon across the forecast area. National Weather Service obs and Kentucky mesonet
stations show temperatures in the upper 80s to the lower 90s. The
hottest locations were generally in the urban heat island areas.
Radars show scattered convection out across mainly southern
Kentucky. The most persistent band of convection stretch from near
Bowling Green northeast to near Richmond. The storms are bringing
some cooling relief to a few select areas. Where it has rained,
temps have dropped back into the upper 70s.

For the remainder of the afternoon hours, we expect temperatures in
many areas to Max out in the next hour or so with upper 80s and
lower 90s being the rule. Heat indices will continue to run in the
upper 90s to near 100 in places. Convection will continue to
develop and move generally eastward across mainly south-central Kentucky.
The convection will likely start to diminish as we head toward
sunset with evening temperatures remaining in the 80s. Convection
could be strong at times with torrential rainfall, gusty winds, and
frequent lightning being the main threats. Overnight, we'll see
skies once again clear out. Some patchy fog will be possible in
some areas. Overnight lows will bottom out in the upper 60s to the
lower 70s. The urban corridors may not drop below 74-75 overnight
once again.

For Tuesday, we expect another repeat performance of today. Hot and
humid conditions are forecast once again. Afternoon highs look to
top out in the upper 80s to the lower 90s. With dewpoints in the
low to mid 70s, we'll see heat indices in the upper 90s to near 100
once again. Diurnally driven convection will be seen again with
isolated to scattered coverage.


Long term...(tuesday night through monday)
issued at 200 PM EDT Mon Jun 18 2018

..increasing heavy rainfall threat late this week...

Scattered convection will likely be ongoing across the northern half
of the forecast area Tuesday evening, but will diminish somewhat
with sunset. A weak shortwave aloft is forecast to pivot over the
forecast area Tuesday night. Meanwhile, a nearly stationary surface
front will still be draped across northern Indiana and Ohio. And
lingering showers and storms should become pretty isolated by late
Tuesday night, with the best chance across southern Indiana. Lows in
the low 70s will be common Wednesday morning, with the Louisville
Metro in the mid 70s.

On Wednesday, a low pressure system will strengthen slightly over
the Central Plains. The digging upper trough will continue to erode
the ridge over the Ohio Valley. The east-west surface boundary will
provide increasing low-level convergence for thunderstorm
development in a very humid environment as it sinks south toward the
Ohio River Wednesday evening into Thursday. Scattered thunderstorms
are likely for Wednesday, with numerous showers/storms possible
north of I-64. Highs in the mid to upper 80s will be common, though
drier areas in southern Kentucky could easily hit 90 once again.

The weather will be quite active Thursday through Saturday with a
risk for heavy rainfall and at least some flash flooding. This
fairly potent low pressure system will move over Missouri by
Thursday evening, with the stationary boundary still draped over the
forecast area. Additional rounds of showers and thunderstorms are
likely Thursday through Saturday. The boundary lifts north of the
area Thursday night, and the surface low is forecast to deepen over
Illinois on Friday. With the enhanced wind fields in the low and
upper levels associated with the mid-latitude cyclone, there is some
potential for severe weather in addition to flooding Friday
afternoon and evening. Given a very moist environment with fairly
abundant cloud cover, a linear convective system could evolve to
produce a damaging wind threat. Highs through this period will be
limited to the 80s given increased precip chances.


Aviation...(18z taf issuance)
issued at 120 PM EDT Mon Jun 18 2018

Another hot and humid afternoon is on tap for the area. Diurnal cu
field developing quite nicely with bases in the 3500-4500 ft above ground level
range. Convective temperatures are a little lower today and we're
already seeing some showers trying to fire. Best chances for storms
this afternoon look to be at kbwg and perhaps up at klex. Lesser
coverage looks likely over at khnb and ksdf so plan on keeping those
terminals dry for the afternoon. Winds will remain out of the
west/southwest with speeds of less than 8 knots. Skies will clear
back out tonight with light and variable winds along with VFR

The outlook for Tuesday is much the same, a continued hot and humid
air pattern with diurnal thunderstorm development once again.


Lmk watches/warnings/advisories...


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