Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 251435
Area Forecast Discussion
National Weather Service Louisville KY
1035 AM EDT SAT JUN 25 2016
Issued at 1030 AM EDT Sat Jun 25 2016
A sunny sky exists over much of central KY and south-central IN this
morning, with the exception of some clouds over western parts of
south-central KY. This area should remain partly sunny this
afternoon with a mostly sunny sky elsewhere. Lower surface dewpoints
exist over northern KY, and some of this lower humidity air should
slip into the eastern parts of south-central IN and the northern
Bluegrass. However, it should remain fairly humid elsewhere. Have
raised maximum high temperatures this afternoon a degree or two in
some areas so it will definitely be a very warm afternoon.
Conditions should remain dry. No real changes to the forecast
tonight or Sunday at this time.
.SHORT TERM (Now through Sunday)...
Issued at 255 AM EDT Sat Jun 25 2016
Well...Short term concerns are fog this morning and storms chances
Surface high pressure over CLE will usher in slightly drier airmass
today. UPS crossover method for fog shows the best potential will be
over the Bluegrass Region and far southern KY. The positives for
the fog are clear skies...moist llvls...light winds and the main
inhibitor is the Friday strong mixing out. The high resolution
models show the LTE 1 mile vsby is over the LEX area. Will be
watching web cams...obs and enhanced fog loops.
For now, not planning on headline, but likely will reissue the SPS
at press time.
For the rest of today...a dry day with zeniths today in the upper
80s to the lower 90s. The MOS numbers seem a tad high due to
moist ground from this past weeks rains.
The high resolution models are initiating scattered convection in
the late afternoon across our southwestern KY (I-24), but will keep
area dry but will have 14 pops in Logan to Ohio Counties.
Lows Saturday night will cool into the upper 60s to the lower 70s.
Mid-level ridge from Show State to Land of 10K Lakes will break down
as 560m low over Big Sky Country. This will drive a cold front
towards the Ohio valley. The new 00z models show the ridge holding
long enough to delay majority of precip til at least 18z. Plan to
do a bunch of tweaking to the POPs and weather grids and hit most
of the precip til Sunday evening.
Highs Sunday and Monday look to warm into the upper 80s to the lower
90s with overnight lows in the lower 70s. With dew points climbing
into the lower 70s...heat indices will climb to around 100,,,with
low 100s across southern KY.
.LONG TERM (Sunday night through Friday)...
Issued at 305 AM EDT Sat Jun 25 2016
...Round of Strong Storms Possible Sunday Night into Monday...
...Much Cooler and drier Weather Expected for Mid to Late Week...
Well...by Sunday evening...classic summer time set up with 2 inch
PWATs...MUCAPEs around 3K J/kg and weak wind field. Deterministic
Models diverge with some taking most of the energy to the N with the
stronger mid level winds and gap KY but others develops scattered
convection from 22-09z.
Should be a few strong to severe storms with wind and extremely
heavy rain the threats. The current SPC outlook looks very
reasonable especially considering DCAPE of 1000j/kg. Wind fields are
extremely light in the entire column and combined with sultry
airmass, localized flooding is possible.
Looks like chc-sct pops Sunday evening especially across the nrn
Monday the front slowly sags and will add another day of storms
especially for the srn and ern 1/2 of the CWA. Highs Monday look
to warm into the upper 80s with abundant cloud cover. overnight
lows in the lower 70s.
After the front goes through the region, we`ll see cooler and much
drier weather return to the region. The 1000-500mb thickness drop
precipitously as amplifying ridge across the silver state out
dominates out west. Dew points will be dropping into the 50s (yes
you read that right, the 50s) with afternoon highs 7 to 12 degrees
below normal. Soundings would yield around 80 on Wednesday...
Possibly 75 to 80 across northeastern areas. The upper trough will
keep us cooler and drier through Thursday with a big Hudson Bay low
the dominating feature for the east coast with torrid air across the
desert southwest. Low temperatures will bottom out in the valley and
better drainage areas such as Frankfort and Cynthiana. Lows will be
in the 50s.
Fri-weekend (from previous forecaster)
The forecast becomes more challenging as we head into the later part
of the week. The overall flow pattern will be one with a ridge out
west and a baggy trough axis in the east. This will place the Ohio
Valley in a notorious northwest flow. During this time, we`ll have
to watch for perturbations moving along the periphery of the ridge
and then riding down into the Ohio Valley. While there has been a
constant signal from the Euro of one these arriving around Thursday,
the models really struggle with these type flow regimes.
Nonetheless, we will keep chance PoPs in the forecast at this time.
Temperatures will remain below normal for late June and early July
with highs mainly in the lower 80s with overnight lows in the 60s.
.AVIATION (12Z TAF Update)...
Issued at 642 AM EDT Sat Jun 25 2016
Generally VFR conditions are expected through the period. Light
patchy fog may be possible for BWG and LEX, but will quickly burn
off in the next hour or two.
For today, winds are light out of the ENE. Scattered diurnal CU at
FL040-060 are expected this afternoon. For tonight, expect clear
conditions with light and variable winds.