Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 101705
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
105 PM EDT Thu Jul 10 2014
...Updated Aviation Discussion...
Issued at 1255 PM EDT Thu Jul 10 2014
Surface frontal boundary fairly evident in visible satellite
imagery this afternoon. This boundary stretches from near KBWG
northeastward to near KLEX. Some isolated showers and storms have
popped up along this boundary. Expect isolated coverage to
continue this afternoon...with the best chances...mainly east of
US 27/127 and south of I-64. Otherwise, rest of forecast elements
look in good shape for the afternoon hours. Afternoon highs in the
84-89 degree range still look very attainable.
.SHORT TERM (Now through Friday)...
Issued at 252 AM EDT Thu Jul 10 2014
Pre 1st Period...
Well...Low over the eastern Buckeye state with secondary front
producing very isol showers from OWB to Breckinridge County.
Coverage is basically 5-10% with isolated showers. OWB is carrying
bkn095, so likely most of this is aloft and not striking the ground.
However, weak convergence feature been persistent enough to justify
including isol shra moving southward thru 15z across wrn and srn CWA
to the TN state line. This lines up well with PAH fcst.
Well...1020 mb sfc High pressure over Lake Michigan and moving
towards lake Huron and Lake Erie will provide us OH Valley with very
pleasant and drier airmass with no precip at all. Temps yesterday
across STL and Central IL were in the upper 70s to lower 80s. Temps
should be in the lower to mid 80s, but have added a fudge factor of
1-2 degrees for drying brown grasses with little rainfall as of
late. With dew points mixing out into the mid to upper 50s, added
just a tad to make mid 80s today. Expect some afternoon Cu and some
sct high CI up top.
Tonight will be mostly clear with light and variable winds with
temps in the lower 60s, except LOU metro. Friday is a repeat of
Thursday with temps 2-3 degrees with warmer with slightly higher
.LONG TERM (Friday Night through Wednesday)...
Issued at 300 PM EDT Thu Jul 10 2014
The main weather story during the extended period will be the highly
anomalous upper low/trough that models prog will rotate southeast
out of Canada and into the Great Lakes early next week. Active
convective weather is likely across the Ohio Valley ahead of this
system over the weekend and early next week, with much cooler
weather and below normal temperatures behind the system by mid next
At the start of the period on Saturday, a corridor of instability
and embedded thunderstorms should exist from about Nebraska to the
western Ohio Valley, on the north and east perhiphery of a large
upper ridge over the southern Plains states. Models for the last few
runs have shown that clouds from this activity should move into our
northern forecast area on Saturday, and a couple showers are
possible early on from a mid-level cloud deck. Otherwise, any
showers the first half of the day should end as the air mass remains
relatively stable (compared to our north and west where scattered
convection is expected). With some sun in the afternoon, high
temperatures should reach the upper 80s in southern IN and around
90/lower 90s in central KY.
For Saturday night, there appears to be no definable forcing
mechanism and with noctural cooling, conditions should be dry. Only
exception could be parts of southern IN by Sunday morning for any
convection upstream that propagates southeastward toward/into the
area. For now, will only carry isolated convection in this area.
On Sunday, the transition to a more active weather pattern begins.
Air mass destabilization will begin as low-level moisture becomes
more prevalent over our area. However, with some capping in place,
most of the activity may again remain north and west of our area,
but scattered storms are possible Sunday afternoon and evening over
the northern half of the forecast area. Afternoon temperatures will
again reach 90 or lower 90s over much of the region.
.AVIATION (18Z TAF Update)...
Issued at 104 PM EDT Thu Jul 10 2014
Weak frontal boundary is pushing through the region this afternoon.
The front extends from near Lexington, KY down toward Bowling Green,
KY. This feature should continue to push southeast through the
afternoon. Some scattered showers will be possible over the next
few hours near the KLEX terminal...with KBWG and KSDF remaining
dry. A diurnal cumulus field around 5-6kft AGL will continue
through the afternoon. Winds behind the front will mainly be out of
the north to northeast at 5-7kts. VFR conditions are very likely
for the evening and overnight hours with a light northeasterly
surface wind flow.