Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 230436
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1236 AM EDT Sat May 23 2015
...Updated Aviation Discussion...
Updated 815 PM EDT Fri May 22 2015
Forecast on track for lows tonight in the 50s areawide. Cloud cover
streaming in should keep us from getting as cold as we did this
morning. Also temp/dewpoint spreads as well as guidance would seem
to indicate little chance for fog overnight. Last night`s guidance
did not do well with the fog this morning, but with the high/mid
clouds over us would lean more toward keeping fog out of the
.SHORT TERM (Now through Saturday Night)...
Issued at 328 PM EDT Fri May 22 2015
Mostly sunny skies were noted across the forecast area this
afternoon. Afternoon temperatures have warmed into the upper 60s
and lower 70s. Expect a few high clouds to drift in this evening
with temperatures falling back into the 60s.
A weak surface trough will swing southward toward the region this
evening. This feature will wash out and will not have any effects
on sensible weather, other than some passing high level cloudiness.
Lows tonight will likely drop back into the lower-middle 50s for
most areas, but some of our cooler Bluegrass areas may drop back
into the mid-upper 40s once again.
High pressure will build back into the region resulting mostly sunny
skies for Saturday and mostly clear skies for Saturday night. An
increasing southerly flow will allow slightly warmer temperatures
with highs in the upper 70s to the lower 80s for Saturday. Lows
Saturday night are expected to drop back into the mid-upper 50s.
.LONG TERM (Sunday through Friday)...
Issued at 245 AM EDT Sat May 23 2015
Long Term is characterized by above normal temperatures and a active
period of weather.
Sunday Night through Monday Mid Morning...
Well...the potent upper ridge axis over SC/GA/FL will move east of
the CWA by Monday morning in response to an ejecting shortwave over
the southern Plains. This will shift the deep southerly flow more
over the Ohio River Valley, bringing an increase in temperatures,
moisture, and rounds of scattered storm chances. Will continue to
keep Sunday night basically dry save for a isolated TSRA/SHRA
00-03z. Look for lows in the mid to upper 60s.
Monday - Friday...
An active period of weather takes shape through the remainder of the
week as we contend with the deep SW flow and disturbances it brings
through our area. Like the idea of mainly keeping scattered coverage
of showers/storms going until details of individual perturbations
work themselves out. Remembering the overall pattern last week,
coverage ended up being on the lower end of what was anticipated and
could see that scenario playing out again.
Overall pattern certainly calls for at or above normal highs
(dependent on daily convection) and above normal lows given the
steady southerly flow/higher dew points. Have kept the idea going of
suggesting milder nights than what guidance is calling for. This
worked well last week when we were in the same pattern, so in
general look for upper 60s to around 70 each night through at least
mid week. Highs will mostly be in the lower 80s, with mid 80s
possible under less convection, and upper 70s possible under the
better coverage days.
Right now, the best coverage days look to be later Monday through
Wednesday, drying out toward the end of the week. As mentioned in
the previous discussion, severe weather threat looks relatively low.
However, it does appear that 25-35 knots of 0-6 km shear (marginal)
may couple with weakly moderate instability at times to allow for a
few stronger storms. This would be completely conditional and most
likely focused west of I-65 if it were to occur.
.AVIATION (06Z TAF Update)...
Updated at 1236 AM EDT Sat May 23 2015
High pressure crossing the northeast United States will keep our
weather quiet through this TAF period. The high to our east will
give us light southeast breezes during the daylight hours, and
elevated moisture will produce clouds above 10k ft.