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Area forecast discussion 
National Weather Service Louisville Kentucky
639 PM EDT Friday Jul 31 2015

..updated aviation discussion...

Short term (now through Saturday night)...
issued at 300 PM EDT Friday Jul 31 2015

A surface high pressure ridge extending east to west over Kentucky
this afternoon will linger over the area for the first half of the
weekend. The scattering of fair weather cumulus that developed
during the peak daytime heating hours today will dissipate quickly
this evening, leaving few if any clouds for the first half of the

Daytime highs in the 80s will combine with dew points in the upper
50s and lower 60s to result in some of the nicest weather of the
Summer for the Ohio Valley.

Long term (sunday through friday)...
issued at 315 PM EDT Friday Jul 31 2015

In the medium range, the models continue to agree with a rather dry
start to the period. High pressure at the surface and northwest
flow aloft should result in a dry forecast period for Sunday.
Temperatures should moderate slightly with afternoon highs ranging
from the middle-upper 80s in the Bluegrass to the upper 80s to the
lower 90s in the southwest. A weak disturbance will drop through
the region on Sunday and into Monday which may result in some
isolated storms across the region. Latest model blends continue to
suggest at least isolated pop chances for Monday afternoon...north
of the bg/weak parkways. Current forecast has this well covered and
not really making any changes here. Lows Sunday night will be
milder with upper 60s to around 70 in most locations. Mondays highs
will be similar to Sunday with readings in the upper 80s to around
90, along with a return of muggy conditions.

As we get into Tuesday and through the middle of the workweek, the
latest model trends continue to advertise a rather unsettled pattern
setting up from the Midwest through the Ohio Valley. A
northwesterly flow pattern will amplify as middle-level wave drops from
the northern plains and into the Ohio Valley. This middle-level wave
looks to drop into the region on Wednesday and exit Thursday
bringing one or more rounds of showers and thunderstorms to the
region. While the global models have generally good temporal timing
with the wave coming through on Wednesday, there remains a bit of
spread on the actual path...whether it passes more north or more
south. Given the model biases of this season...likely path will be
more across our area as the surface frontal boundary should be
stalled out across US. This wave looks to pull out Thursday with a
return of cooler and drier air for Thursday and Friday.

Temperatures through midweek will likely be modulated by clouds and
precipitation. In general...highs at or below seasonal averages
look likely with daytime highs in the middle-upper 80s and overnight
lows in the lower 70s through Wednesday. Thursday and Friday will
see much cooler readings in the north with upper 70s to lower
80s...while Lower-Middle 80s will still be found across southern parts
of Kentucky.

Rainfall with convection next week may be on the heavy sides as well
with a stalled out front and multiple middle-level waves passing
overhead. Distinct differences in the quantitative precipitation forecast fields between the GFS
and Euro do exist...with the GFS maintaining higher quantitative precipitation forecast amounts to
our north...while the Euro paints them right over The Heart of the
Ohio Valley. Utilizing the ensemble does appear that a
round of 2-4 inch rainfall with localized higher amounts may occur
next week. This may result in some hydrologic problems in some
areas that remain quite damp from recent rains in the last several


Aviation (00z taf update)...
issued at 640 PM EDT Friday Jul 31 2015

Benign weather for this taf period as dry air and surface high
pressure prevail. Few-scattered cumulus today will dissipate with the
setting sun, leaving little if any cloud cover overnight. East-west
axis of surface ridge bisects Kentucky currently. As this drifts
south, predominant wind flow will become northwest under 5 kts at all


Lmk watches/warnings/advisories...


Short term........jbs
long term.........Mj

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