Scientific Forecaster Discussion
fxus61 krlx 190715
Area forecast discussion
National Weather Service Charleston WV
315 am EDT Mon Aug 19 2019
upper level trough passes overhead today, increasing chances
for afternoon showers and storms. Hot weather continues for the
first half of the week. Cold front crosses late in the week.
Near term /through tonight/...
as of 215 am Monday...
Moisture in the lower levels along with an upper level trough
passing overhead today will provide assistance for diurnally
driven thunderstorms to develop. However, light flow aloft will
should not support any severe storms although any storms that
train or back build over an area will have potential to cause
water issues. The northern sector of the area across Ohio and
into WV is in a risk for excessive rainfall today. This area
will be more prone late in the day with moisture advection due
to a frontal boundary to the northwest initiating development
ahead of the front. Pwats are near 2 inches creating sufficient
fuel for storms to produce heavy rainfall and potential flash
flooding in the aforementioned areas.
Any convection should be confined to the northwest sector of
the County Warning Area mainly across Ohio and lightly into WV as well as along
the eastern mountain counties. With plenty of instability with
cape values >3000 j/kg, and sufficient lifting we cannot rule
out thunderstorm development in other areas as well. The
frontal band to the northwest will become quasi-stationary and
meander just north of the region causing inclement weather and
increasing chances for shower and storms into Tuesday.
Temperatures will reach in the low 90's in some places, however
cloud coverage should keep other areas from breaking the 90
Short term /Tuesday through Wednesday/...
as of 315 am Monday...
Will continue to see hot and humid conditions Tuesday with
diurnally driven showers and thunderstorms. Given rather modest
shear but decent instability would expect mostly multi-cellular
clusters of storms with a limited risk of a few damaging wind
gusts as well as heavy rain through the afternoon Tuesday.
Will likely see an mesoscale convective system emerging into the middle Ohio Valley
Tuesday night in response to approaching compact shortwave.
While convection will likely be on the downtrend before it
crosses into the forecast area could see a limited damaging wind
threat primarily across far northwestern portions of the
Will see similar diurnal convection Wednesday, although this may
be somewhat tempered by stabilizing influence from overnight
Long term /Wednesday night through Sunday/...
as of 315 am Monday...
Upper level trough and associated cold front approach Wednesday
night into Thursday morning bringing more widespread rain
showers and thunderstorms. Based on current overnight timing,
think severe risk along the front will be limited to isolated
The region will gradually dry out and cool off from northwest
to southeast Thursday evening into Friday as the front slowly
sags south with mostly dry conditions expected into the weekend.
Aviation /07z Monday through Friday/...
as of 140 am Monday...
Clouds will cover most of the area from a decaying system to the
west. This will aide to suppress most fog development this
morning as well the accompanying dry air in the low levels.
Crw/pkb/bkw will see a few hours of MVFR visible and the rest just
slightly restricted visible around 6sm mostly due to patchy fog.
Mainly a VFR day across the region for Monday and the rest of
this forecast period. There are chances for showers and possibly
an isolated storm around pkb/heights in the afternoon and at bkw
later in the day, however left mention of this out of the tafs
since confidence is low.
Light southerly flow changes over to westerly in the late
afternoon. With high instability and an upper level trough
providing lift in the afternoon we cannot rule out the
possibility of an isolated storm near or at any terminal during
daytime heating. With light flow and low shear any development
should be sub-severe, however storms have potential to train or
backbuild with weak flow. This could promote lengthly inclement
weather such as low cigs/visible as well as gusty winds. Expect any
convection to dissipate around sunset and a better chance for
fog development for Tuesday morning.
Forecast confidence and alternate scenarios through 06z Tuesday...
Forecast confidence: medium.
Alternate scenarios: diurnal thunderstorms in the afternoon
could be more prominent and affect more terminals, however
confidence and chances are low so mention of them where left
out of tafs. Fog intensity may vary at ekn/crw.
Experimental table of flight category objectively shows consistency
of weather forecast office forecast to available model information:
h = high: taf consistent with all models or all but one model.
M = medium: taf has varying level of consistency with models.
L = low: taf inconsistent with all models or all but one model.
Date Monday 08/19/19
UTC 1hrly 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1hrly 02 03 04 05 06 07 08 09 10 11 12 13
crw consistency h h h h l l l M h h h h
heights consistency h h h h M l l h h h h h
bkw consistency h h h h M M M M h h h h
ekn consistency h h M l l l l l h h h h
pkb consistency h h M M l l l h h h h h
ckb consistency h h h h M l l h h h h h
After 06z Tuesday...
IFR possible with showers and storms mid week, stratus and
valley fog redeveloping by Friday morning.