Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
827 PM EDT Monday Jun 1 2015
front and low pressure center push east of the area tonight.
Upper level low lingers much of the work week before a cold front
moves through this weekend.
Near term /through Tuesday/...
latest surface analysis indicates the cold front is likely along
or east of the mountains. Scattered showers and an isolated storm
continue to push northeast across the area. Based on radar and
latest hrrr/rap... have modified the probability of precipitation and associated weather.
End result is a quicker end to the precipitation overnight into
Temperatures have already fallen to forecasted overnight lows or
close across much of the area. Have tweaked overnight lows based
on latest lav temperature guidance.
the cold front that rolled into the area last night did not make
it through the mountains today...it retreated a bit if anything.
Sharp gradients in temperature...dew point...sky cover and cloud
heights accompany this shallow baroclinic zone. Convection fired
in the sunshine over the mountains east of the front. This should die
down / move out as the front moves east and the sun sets.
A low pressure wave will finally push the front east of the area
this evening...taking some of the gradient with it. It will also
take the large area of showers just west of the forecast area right
across the forecast area through tonight.
As the middle level flow backs in response to the upper low remaining
west of the area...showers are still possible in our eastern upslope
areas Tuesday. The warm...moist air will not be that far to our
southeast...and there could be enough afternoon instability for thunder
in our SW Virginia counties.
Tried to depict a tighter baroclinic zone in the temperature
grids but still ended up with mostly a blend of guidance.
Short term /Tuesday night through Thursday night/...
upper level low drifting should keep US in clouds through the
short term with scattered showers and thunderstorms in the
afternoons. Due to the nature of upper level lows...timing the
impulses is difficult making for a tough forecast.
So...expect daily afternoon showers and thunderstorms with more
pronouncement over the mountains.
Long term /Friday through Monday/...
upper level low remains in region through Friday night...then a
cold front drifts southeast and pushes through the area on Saturday. Kept
climatology temperatures and higher than climatology probability of precipitation.
Aviation /01z Tuesday through Saturday/...
00z Tuesday through 00z Wednesday...
latest radar mosaic show showers pushing northeast across the
area. A few thunderstorms continued across the mountain counties.
MVFR conditions prevailed across much of the area...with IFR
conditions in and around the precipitation.
Cold front...which was located west of the mountains at 18z...is
in the process of pushing east of the mountains at this time.
Current thinking is that IFR conditions should overspread much of
the area from the south and west between 00z and 06z...with much
of the remainder of the region seeing IFR conditions after 06z.
With abundant low-level moisture in place...improvement on Tuesday
will be rather slow.
Light north to calm wind should prevail across the area tonight and
then light and variable Tuesday...trending toward southeast by Tuesday afternoon.
Forecast confidence and alternate scenarios through 00z Tuesday...
Forecast confidence: low to medium.
Alternate scenarios: overall timing of MVFR/IFR conditions
throughout the area will vary.
After 00z Wednesday...
IFR in low stratus ceilings possible Wednesday morning...especially
over the eastern slopes.