Scientific Forecaster Discussion
fxus61 krlx 270534
Area forecast discussion
National Weather Service Charleston WV
134 am EDT Sat may 27 2017
weakening mesoscale convective system moves into the area early Saturday. Storms
Saturday with a frontal boundary and high instability. Another
thunderstorm complex on Sunday followed by a cold front Sunday
night into Monday.
Near term /through today/...
as of 1000 PM Friday...
upped pops and quantitative precipitation forecast overnight as radar indicates a better line
of storms (mcs) moving through eastern Indiana and western Ohio
and expect those to make it to our forecast area though should
weaken before arriving. Speeds suggest arrival into our
forecast area by 1 am. Storm Prediction Center mesoscale convective system maintenance parameter suggests
best air south of line which may act to pull the mesoscale convective system further
south than previously forecast...perhaps into the
Huntington/Charleston Metro areas though not confident in this.
As of 800 PM Friday... not much change,
severe threat for tomorrow doesn't look as good as the water
threat, but still bears watching closely.
As of 225 PM Friday...
Synoptically, flow aloft will turn zonal tonight, while a warm
front pushes northward. Awaiting a cold front dropping back
southward through the County Warning Area Saturday as a result of a surface wave
High res and synoptic models remain keen on the development of
a mesoscale convective system in northern Illinois/Indiana later this afternoon and
evening, tracking into middle/upper Ohio Valley. Biggest
question here is the exact track with the high res models taking
the southern extent closer to the I-64 corridor, despite
steering flow suggesting that it should stay a bit further
north. Concentrating those pops tonight along US 50, but this
complex will likely be on the wane as it enters the cwa, or
Atmosphere should have plenty of time to recover after dawn in
the warm sector. Cape values are in line with the frontal
position as expected, and with the cold front sinking southward
through the afternoon, this should be a southern two thirds of
the County Warning Area severe/water event. Will need to carry slight to low
chance however north of the boundary. Decent 0-6km flow around
40kts and instability warranting the slight risk for the area
south of the front, with the enhanced area closer to our area
from the latest Storm Prediction Center issuance.
Water cannot be ignored either. Very saturated in terms of
surface conditions and creek/stream levels, and any sort of
repetitive activity will cause problems. Flash flood guidance
values are quite low given the recent wet trend.
Convective activity Saturday will largely dictate the weather
heading into Saturday night and Sunday.
Short term /tonight through Monday/...
as of 245 PM Friday...
Models still showing a disturbance moving through the area early
Sunday. Depending on the timing of the system, could see enough
recovery for afternoon thunderstorms. A cold front then pushes
through Sunday night into Monday. With the ground so saturated,
still concerned with the potential for flash flooding. Will
highlight heavy rain in the forecast wording.
Long term /Monday night through Friday/...
as of 245 PM Friday...
An upper level trough will dominate the weather for Monday night
through Thursday. This will provide relatively cool weather. A
reinforcing cold front moves through on Tuesday, followed by another
front Wednesday into Thursday. Models have quite a bit of
variability in the timing of the later front. Some showers are
possible with both these systems. Model differences become even
greater by Friday, leading to considerable uncertainty in the
Aviation /06z Saturday through Wednesday/...
as of 125 am Saturday...
Weakening convection across southeast Ohio and northern WV
through 10z. Expect brief MVFR conditions, and gusty winds up to
30 kts with passage, affecting sites kpkb and kckb, possibly
kekn if able to hold together.
Otherwise, VFR conditions initially, although convection will
develop once again, particularly after 18z, with MVFR and IFR
conditions, heavy rain, and strong-damaging winds in vicinity
Bulk of convection will diminish after 03z Sunday, however,
widespread MVFR and IFR conditions are possible in Post rain
stratus or fog.
Alternate scenarios: timing and location of convection today may
be different from current forecast.
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 Friday 05/26/17
UTC 1hrly 05 06 07 08 09 10 11 12 13 14 15 16
EDT 1hrly 01 02 03 04 05 06 07 08 09 10 11 12
crw consistency h M h M h h M M h h h h
heights consistency M h h M h h h h h h h h
bkw consistency l M l M M l M M h M M l
ekn consistency M l M l l l l M h h h l
pkb consistency h M h h h h h h h h h h
ckb consistency h M l M l h M l h h h M
After 06z Sunday...
IFR likely in storms Sunday and Monday.