Scientific Forecaster Discussion
fxus61 krlx 211846
Area forecast discussion
National Weather Service Charleston WV
246 PM EDT Mon Oct 21 2019
cold front tonight with widespread beneficial rainfall. Fair
weather through Friday as high pressure returns.
Near term /through Tuesday/...
as of 150 PM Monday...
Bulk of the area enjoying downslope warming/warm air advection
this afternoon with many locations likely seeing their last
upper 70s (may even 80 in a few spots) for the foreseeable
future ahead of a cold front progged to start to move through
the area this evening. While a little breezy across the area
this afternoon, warm air advection has largely kept a bulk of the momentum with
near 50kt h850 winds aloft. Mid-level cloudiness will increase
through the late afternoon and there should be plenty of virga
around given synoptic ascent and a rather dry sub-cloud layer
with minimal risk of any rain accumulation until the cold front
approaches this evening and through the overnight.
Despite rather impressive dynamics with this system, mid-level
lapse rates sourced from the High Desert of Mexico look to be
extensively worked over by upstream convection leaving US with
little, if any instability to work with. Can't completely rule
out the risk of few rumbles of thunder given strong forced
ascent especially across extreme western portions of the area
this evening and near the mountains Tuesday afternoon with any
lingering activity, but given low probability have only
maintained existing slight chance/isolated wording through
tonight for now. Some locally enhanced winds will be possible
ahead of the front with any heavier showers, but momentum
available for transport to the surface will quickly diminish
with frontal passage.
Precipitation tapers off from west to east through the afternoon
Tuesday as cold air begins filtering in. Winds in the boundary
layer will have trended down significantly by this point, but
enhanced momentum Transfer to the surface with the cold air
should continue to yield some breezy conditions through at least
Short term /Tuesday night through Thursday night/...
as of 230 PM Monday...
Upper trof axis crosses Tuesday night and with lingering
gradient winds, frost will be mitigated despite generally clear
Dry conditions prevail Wednesday and Thursday with the upper
level flow gradually veering and increasing out of the
southwest. Surface high passes just to the south and east but
close enough for some frost concern in the valleys and hollows
Thursday morning. Daytime temperatures will remain near normal.
Long term /Friday through Monday/...
as of 235 PM Monday...
The forecast for Friday and Saturday remain uncertain with the
global models struggling with energy amplifying into the High
Plains and whether it remains progressive on its trek east or
slows. Dependent on how this plays out will ultimately determine
if we remain dry or unsettled to start the weekend.
Aviation /19z Monday through Saturday/...
as of 150 PM Monday...
Breezy southeasterly winds will continue this afternoon as a
portion of winds approaching 50kts near 5000 ft mean sea level mix to the
surface. Clear skies this afternoon give way to increasing
mid/upper level cloudiness evening ahead of a cold front that
will swing through the terminals overnight. Likely to see virga
with these initial clouds, but a substantially dry sub-cloud
layer will likely keep the surface dry through at least sunset.
Conditions are expected deteriorate to MVFR/IFR overnight as
rain spreads across the area from west to east ahead of the
front. Can't completely rule out a rumble or two of thunder,
especially near heights this evening, but there is not much
instability to work with.
Rain comes to an end from west to east late Tuesday morning
with gradually improving conditions.
Forecast confidence and alternate scenarios through 18z Tuesday...
Forecast confidence: medium.
Alternate scenarios: some fog development possible near ekn
before it clouds up tonight. Timing of heavier precipitation may
vary by an hour or two.
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.
UTC 1hrly 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1hrly 14 15 16 17 18 19 20 21 22 23 00 01
crw consistency h h h h h h h h h h h h
heights consistency h h h h h h h h h h h h
bkw consistency h h h h h h h h h h h h
ekn consistency h h h h h h h h h h h l
pkb consistency h h h h h h h h h h h M
ckb consistency h h h h h h h h h h h h
After 18z Tuesday...
valley fog possible each morning Wednesday through Friday.