Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 050506
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
106 AM EDT Tue May 5 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Tuesday Night)...
Issued at 245 PM EDT Mon May 4 2015
The synoptic pattern early this afternoon features a trough across
the southwestern CONUS, with downstream ridging across the Ohio
Valley. This ridging will amplify over the region through the
short-term period, bringing continued dry and mild conditions.
Convection from last night into this morning across IL/IN laid out
an outflow boundary which has now pushed into western Ohio and
southern IN, but it has become very diffuse as it has largely mixed
out. The enhanced cu that had been found along this boundary have
since dissipated, likely due to a thicker cirrus shield pushing into
southern Indiana from the west. Latest mesoanalysis depicts
500-1000+ J/kg of uncapped MLCAPE across southern IN and
west-central KY, so a rogue storm developing still cannot be ruled
out. However, the lack of surface convergence will limit
shower/storm potential and coverage, thus will go with a dry
forecast through the remainder of the afternoon and evening.
For tonight, clouds should once again largely dissipate leading to a
mostly clear night. Overnight lows will be very similar to last
night, perhaps a little warmer given the warmer high temperatures
and slightly higher dewpoints we`ve experienced today. This puts
temperatures in the 50s and lower 60s.
More of the same can be expected tomorrow as ridging amplifies over
the region. This should push today`s convection associated with a
weak surface front over IN/IL/MI well north by tomorrow afternoon.
Southwesterly winds and sunshine will once again combine to push
temperatures into the low and mid 80s.
The broken record of pleasant weather continues into tomorrow night,
as mainly clear skies and dry weather prevail. Overnight lows will
be very similar to values the past few nights, with readings
expected in the 50s and lower 60s.
.LONG TERM (Wednesday through Monday)...
Issued at 315 PM EDT Mon May 4 2015
Continue to see a ridge over the region for the midweek. This will
keep us above normal for temps with dry conditions. The GFS
continues to be the wet model for diurnal convection Thursday
afternoon, but this time the NAM and SREF also hint at something
going on in our east. Decided to go ahead an put in slight chance
pops east of I-65, as forecast soundings do indicate some potential
for isolated coverage given convective temperatures around 80.
Limiting factor here will be lack of focusing mechanism as well
moisture, with precipitable waters in the low one inch range.
Kept Friday dry, though GFS again tries to bring in some QPF. System
off the southeast U.S. coast should be able to provide us some
subsidence to limit rain chances. Then for Saturday we tap into some
better moisture coming in from the west, as well as a weakening
system over the southeast U.S. Thus have chance pops, mainly in my
Indiana counties. This chance will spread to the rest of the region
Sunday and Monday, with the better focus looking to be on Monday as
a cold front approaches the region.
We should stay in a warm pattern through this period, given no real
airmass changes. Thus have highs each day solidly in the 80s, with
perhaps a spot or two touching 90 on Friday or Saturday. These
readings would be 10-15 degrees above normal for this time of year.
.AVIATION (06Z TAF Update)...
Updated at 105 AM EDT Tue May 5 2015
VFR conditions are expected as upper level ridging slowly builds
over the region. Winds are expected to be calm or light southerly
early this morning with some light fog possible at BWG towards dawn.
Winds during the daylight hours today will be out of the SSW around
8-10 knots. Scattered cu is expected to develop by mid day with some
upper level clouds possible as well. Winds will decrease in
strength again this evening.