Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
153 am EDT Monday Jul 25 2016
Remaining hot and muggy today. Cold front sinks in late today lingering
into Tuesday. Another system is slated for late week.
Near term /through tonight/...
another hot and humid day is expected today, with heat indices
around 100 across much of the middle Ohio River valley and
southwestern WV lowlands. Minor changes made to afternoon highs by
blending in European model (ecmwf) MOS, but heat advisory criteria is still well
covered by current advisory and no changes planned.
NAM and GFS seem a bit bullish on quantitative precipitation forecast early this morning, so
relied more on hrrr with pops mainly holding off until after 15z.
Cold front approaching northwestern County Warning Area late this afternoon, and
have likely pops developing around 20z-21z. That front should
slowly sink south through County Warning Area. Initially, sink an area of likely
pops south as well, but as we enter the typical diurnal minimum
for convection late tonight, have pops gradually waning into the
Lots of instability available in this hot and humid airmass, so
expect storms to grow quite tall. Not a whole lot in the way of
shear for much of the day, but an increase to 20-30kts bulk shear
is expected just ahead of the cold front. With this in mind,
thinking organized area of strong to severe thunderstorms not
likely, but isolated/pop up strong to severe storms possible. The
best chance of this will be across the northern quarter of the
cwa, near the front this afternoon and evening. Damaging wind
would be the most likely threat as storms pulse up and down.
Freezing level will be pretty high to get large hail, so it would
take a persistent tall storm to produce hail.
Precipitable water values also high late today into tonight --
topping out above 2 inches. Combined with the fairly weak flow,
downpours are likely and could lead to localized water issues.
Short term /Tuesday through Wednesday night/...
the front and associated upper level wave will slowly sag into the
area Monday night with a good chance for shra/tsra. High pwats and
relatively weak flow spells torrential downpours as the main
hazard. This system still looks to meander about southern sections
on Tuesday and the overall flow becomes more zonal and remains
weak. So have the best chances for shra/tsra across S zones
Tuesday with drier air taking hold across southeast Ohio/north WV. A slight
nudge further S on Wednesday but still sct mainly diurnally driven
shra/tsra generally S of i64 corridor. The heat wave will give way
to temps more close to normal for this time of year...but still a
Long term /Thursday through Sunday/...
this front dissolves later on Thursday as the next S/W trof and
surface low approach with another uptick in shra/tsra coverage
by Friday. An amplifying upper level trof will settle in for the
weekend with a cooler airmass taking hold.
Aviation /06z Monday through Friday/...
some River Valley fog beginning to form, but do not think it will
be quite as dense as last night. Still, included MVFR at most taf
sites, and IFR at ekn. Stayed pretty close to lamp guidance on
this. Fog should quickly dissipate around 12z. A cold front
approaches from the north today, so have some showers and
thunderstorms in the forecast -- mainly this afternoon into
tonight. Should individual cells approach taf sites, restrictions
would be needed.
Confidence and alternate scenarios...
Forecast confidence and alternate scenarios through 06z Tuesday...
Forecast confidence: medium.
Alternate scenarios: fog timing/intensity may vary from forecast.
A shower or thunderstorm may directly impact a taf site late today
into tonight with brief IFR conditions.
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 07/25/16
UTC 1hrly 03 04 05 06 07 08 09 10 11 12 13 14
EDT 1hrly 23 00 01 02 03 04 05 06 07 08 09 10
crw consistency M M M M M M l l l l M h
heights consistency h h M M M M M M M M M h
bkw consistency h h h h h h h h h h h h
ekn consistency M M l l l l l l l l l M
pkb consistency h M M M M M l l l l M M
ckb consistency h h M M M M M M M M M M
After 06z Tuesday...
early morning IFR fog possible into mid week depending on
WV...heat advisory from noon today to 8 PM EDT this evening for
Ohio...heat advisory from noon today to 8 PM EDT this evening for
Kentucky...heat advisory from noon today to 8 PM EDT this evening for