area forecast discussion
National Weather Service Louisville Kentucky
1255 am EDT sun may 26 2013
..updated aviation discussion...
Forecast update...
issued at 803 PM EDT Sat may 25 2013
A quick update to account for showers coming in from the northwest,
which are remaining a bit more robust than was earlier thought they
would. Chance pops north for this activity, given regional radar
loops and hrrr/rap support.
&&
Short term (now - Sunday night)...
issued at 300 PM EDT Sat may 25 2013
Currently, a scattered to broken mid deck of clouds stretches from
Louisville to London, KY, with clear skies south and west of this
line. Skies will become mostly cloudy everywhere through the late
afternoon and early evening as deeper moisture associated with a
remnant mesoscale convective system overspreads the area. Current radar imagery shows a
narrow batch of light returns extending southeastward into southern
Indiana. This appears to be associated with a convergent zone in the
northwest flow aloft beneath the right entrance region of an upper
level jet. Although T/TD depressions are running around 20-25
degrees, some returns appear strong enough that some light rainfall
could hit the ground. Have included mention of sprinkles and a
slight chance of measurable rain from French Lick, in to
Shelbyville, Kentucky to Richmond, Kentucky late this afternoon and evening.
This will include the northeastern portions of Louisville. Most
locations will remain dry until after midnight. Otherwise, nice
temperature gradient has set up between mostly clear skies to the
southwest and mostly cloudy skies in the northeast. Highs in the mid
70s SW and upper 60s NE still look reasonable.
As we move past midnight, chances for measurable rain will increase
as deeper moisture begins to saturate the lower atmosphere and an
isentropic lift component overspreads northwestern portions of the
County Warning Area. This enhanced moisture/lift will then gradually fill in across
the entire County Warning Area toward dawn on Sunday. Despite the increase moisture,
still can't go above scattered rain shower chances as column does
not look to completely saturate and general surges in deeper
moisture are somewhat unorganized. Tonight's lows will certainly be
milder than last night's. Look for the Mercury to bottom out in the
upper 40s to mid 50s.
Sunday will bring continued isolated to scattered rain shower
chances, along with a small chance for a thunderstorm. This will
occur as isentropic lift continues to occur over a weak warm front
near the region. The exact placement of this feature is still in
question but the best consensus leaves northeastern portions of the
County Warning Area under the best chances for rain. A decent temperature gradient
will likely set up from southwest to northeast much like today. Look
for upper 70s SW to lower 70s NE.
Sunday night will see slowly retreating precipitation chances
confined to northern portions of the County Warning Area as the frontal boundary
lifts north. Still expect no more than isolated to scattered. Lows
will be generally in the mid and upper 50s.
Long term (monday - saturday)...
issued at 245 PM EDT Sat may 25 2013
This period will feature mostly warmer than normal temperatures and
mostly dry conditions as a ridge builds in aloft and at the surface.
The best chance for rain looks to be at the beginning and perhaps
again at the end of this period. For the first chance, a warm
front will be somewhere near our northeast forecast area Monday
morning, which will serve as a focus for activity during the day.
That front should lift north of the region Tuesday. The subsidence
aloft building in should put a damper on rain chances through the
work week, and allow temperatures to rise at least into the
mid/upper 80s by Wednesday, possibly the 90s. Then Saturday a closed
low moving over the plains may push the ridge over the southeast
U.S. Far enough east to allow for some scattered storms to develop,
mainly across our northwest forecast area.
&&
Aviation (06z taf issuance)...
issued at 1255 am EDT sun may 26 2013
The light rain currently streaming southeast across sdf and Lex will
continue off an on through the night. It should decrease by sunrise.
Models continue to indicate some showers may develop in this same
area this afternoon. However, coverage does not look to be high
enough to include in the tafs at this time. Winds will be mainly
light and variable tonight. They will be out of the east through the
day today. Skies will remain mostly cloudy, with the lower cloud
deck at sdf and Lex around 6-7 kft.
&&
Lmk watches/warnings/advisories...
in...none.
Kentucky...none.
$$
Update...........13
short term.......bjs
long term........rjs
aviation.........Eer
