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Area forecast discussion 
National Weather Service Louisville Kentucky
1248 am EDT sun Apr 26 2015

..updated aviation discussion...

..Forecast update...
updated 926 PM EDT Sat Apr 25 2015

Last of the strong to severe storms have pushed out of the forecast
area and air mass has stabilized due to previous storms and loss of
daytime heating. Severe threat has ended for the night and the
remaining portions of the Severe Thunderstorm Watch have been
cancelled.

Short term (now through Sunday night)...
issued at 310 PM EDT Sat Apr 25 2015

..severe weather likely this afternoon and evening...

The warm front continues to creep northward this afternoon and now
lies just to the north of a Richmond, Kentucky to Shepherdsville, Kentucky to
Tell City, in line. South of this line clouds have scattered out and
temperatures have quickly risen into the lower to mid 70s. The area
will quickly become unstable as temperatures continue to rise. Along
the warm front bulk shear values and storm relative helicity values
continue to rise.

Though the radar is relatively quiet right now, storms are expected
to quickly begin to develop in the 4-5 PM EDT time range. Think
there will be two different potential rounds of severe weather this
afternoon and evening. The first will be along and just to the north
of the warm front beginning in the 4-5 PM time frame. Any storms
that form to the north of the front could potentially have large
hail thanks to steep mid level lapse rates. Storms that form more
along and just to the south of the front could be supercells capable
of producing very large hail bigger than Golf balls and possibly a
few tornadoes.

As the surface low associated with this system moves into central Kentucky
a second area of storms will form near the triple point and along
the trailing frontal boundary. These storms look to move into south
central Kentucky around 23-00z. A few of these storms could be supercells,
but some bowing segments will be possible as well. Thus, there is
more of a threat of wind damage across south central Kentucky. As this
area moves eastward through the evening it could lose some of its
punch as instability will be waning at that time. However, the severe
threat could persist into eastern Kentucky.

Most of the strong storms should move out of the forecast area by
02-03z with some light showers lingering into the overnight hours.
Temperatures tonight will be cooler than last night, falling into
the lower 40s to lower 50s. Sunday and Sunday night will be dry.
Highs will be in the 60s with lows in the lower 40s.

Long term (monday through saturday)...
issued at 300 PM EDT Sat Apr 25 2015

Benign weather pattern is expected for much of the extended forecast
period. Overall flow aloft will be somewhat blocky and amplified
with troughs over the northeastern and western U.S. And ridging in
the central U.S. However, a mid-level low will meander east over the
Southern Plains to the south of the ridge. Models suggest this
system will move east into the Gulf Coast states by mid next week,
when GFS and European model (ecmwf) begin to differ in phasing potential with a
shortwave digging southeastward in the northern stream. GFS keeps
the systems separate while European model (ecmwf) tries to phase things leading to a
chance of showers over eastern parts of south-central Kentucky. At this
time, favor a GFS non-phased solution, but will keep a chance of
showers over our far southeast counties in central Kentucky mid week.
Otherwise, looks like dry weather should prevail through the period.

Early next week, temperatures will be below normal with highs in the
lower to mid 60s Monday and Tuesday afternoons, and mid-upper 60s
Wednesday. Expect lows in the upper 30s to mid 40s Tuesday morning
and in the 40s Wednesday and Thursday mornings.

For late next week into next weekend, the ridge aloft should slide
east resulting in continued dry weather and a moderating trend, with
afternoon highs in at least the lower 70s Friday and throughout the
70s on Saturday.

&&

Aviation (06z taf update)...
updated at 1245 am EDT sun Apr 26 2015

IFR conditions are expected throughout much of the overnight before
conditions improve with daytime mixing tomorrow. The surface low
has pushed southeast into eastern Kentucky and TN, bringing northerly
winds and low clouds in its wake. This northerly wind shift and the
lower cigs have not quite made it into kbwg yet, but should before
06z.

Otherwise, conditions will improve through the day today as the
latest guidance suggests we should mix out the low clouds by the
late morning/early afternoon. Could see them lift into a cu deck in
the afternoon, but bases should be VFR. Winds will continue out of
the north around 10 knots.

&&

Lmk watches/warnings/advisories...
Kentucky...none.
In...none.
&&

$$

Update.........Zt
short term.....Eer
long term......twf
aviation.......kjd

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