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Area forecast discussion 
National Weather Service Jackson Kentucky
733 PM EDT Sat Aug 29 2015

issued at 732 PM EDT Sat Aug 29 2015

The forecast is on track so far this evening. A few stray rain
showers area affecting areas along and north of i64 and down in
Wayne County. This matches well with the slight chance probability of precipitation
currently in the latest hourly forecast grids for both those
areas. These showers will diminish steadily this evening as the
sun GOES down. The latest hourly observation and blended model data have
been ingested into the grids to establish new trends. Aside from
that the forecast was unchanged. update is
planned at this time.


Short term...(this evening through Sunday night)
issued at 355 PM EDT Sat Aug 29 2015

19z surface analysis shows high pressure exiting to the east while a
broad area of low pressure is drifting toward the state from the
Central Plains. The increase in moisture and lack of a cap have
allowed a few cells to develop through western and northern parts
of the area this afternoon. So far...the coverage has been fairly
sparse and that should be the case into the evening as the
diurnally driven instability wanes. Temperatures are in the middle
80s at most places with dewpoints in the middle 60s. Under partly
sunny skies winds are from the south to southwest at around 10

The models are in good agreement aloft through the short term
portion of the forecast. They all depict a broad and rather weak
trough over the Ohio and Tennessee valleys with slow moving
batches of energy caught over the region...stuck between
marginally higher heights to the west and southeast. Given the
broad agreement with the models have favored the higher resolution
guidance from the hrrr and nam12 for weather details.

Sensible weather will feature the isolated to scattered showers
and thunderstorms diminishing toward and after sunset with partly
cloudy skies anticipated through the night. Patchy valley fog will
again form towards dawn with a small ridge to valley temperature
split likely setting up. Sunday will see a better chance for
convection throughout the County Warning Area with more clouds helping to keep
temperatures about a category cooler...but with conditions equal
or even more humid than today. Again patchy fog and a minor ridge
to valley temperature split can be expected later Sunday night into
Monday morning.

Started with the shortblend for temperatures...dewpoints...and
winds through the evening before going with the superblend for
the rest of the period. Did adjust the min temperatures each night
for terrain differences. As for probability of precipitation...ended up closer to the
drier mav numbers throughout the short term period.

Long term...(monday through saturday)
issued at 330 PM EDT Sat Aug 29 2015

Upper level ridging will remain in place across much of the eastern
Continental U.S. Throughout the extended. Meanwhile...both the remnants of ts
Erika and a weak upper level low over the Mississippi River valley
will be the features that will prevent US from having a completely
dry and clear week ahead. The upper level ridge will be the main
player...keeping stable air across the region during the overnight
hours as the temperatures cool. However...during the
day...increasing temperatures and the above mentioned upper level
triggers will result in some isl to scattered showers and thunderstorms
across the region. Our best chances for seeing precipitation will be during
the day Monday as the low that was ts Erika moves far enough west to
impact far southeast Kentucky. It will quickly transition to the NE
however...with an approaching shortwave and the diminishing upper
level low over the Mississippi Valley shifting eastward across Kentucky
by middle week.

Most of the winds through this period will be from the east at the
surface...and from the west-southwest in the middle and upper levels. In other is not very favorable for sustainable thunderstorm
development. Not going to rule out some rumbles of did
keep mention of thunderstorms and rain in forecast...but Don/T expect storms to become
very tall or be fast movers. Not to mention latest GFS forecast
soundings Don/T show Li/S below -5c and cape above 1500 j/kg /with
the exception of Monday/ nothing too concernable expected
through the week at this point.

The overall ridge pattern and lack of widespread cloud cover will
allow temperatures to slowly increase each day throughout the week.
While high temperatures on Monday will still be contained in the low
to middle 80s...we could see upper 80s by Tuesday...and possibly even a
90 degree spot or two to round out the weekend.


Aviation...(for the 00z tafs through 00z Sunday evening)
issued at 732 PM EDT Sat Aug 29 2015

Isolated showers and storms will be around through the first part
of the evening...but the taf sites should be spared. The night
will be quiet with just some light fog anticipated in the
valleys... possibly affecting the loz and sme taf sites. Expect
more clouds with a bit lower ceilings during the day on Sunday...with
scattered showers and storms anticipated during the afternoon and
evening hours. Winds will light overnight...and from the south to
southwest on Sunday generally at 5 to 10 kts with some higher
gusts possible at sym.


Jkl watches/warnings/advisories...


short term...greif
long term...jmw

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