Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
650 PM EDT Monday may 25 2015
increasingly warm and humid air mass. Middle/upper disturbances will bring
rounds of showers and thunderstorms through the week.
Near term /through Tuesday/...
will hold onto chance probability of precipitation through the night in tri state around heights...then
will increase probability of precipitation further east and north toward predawn hours...after 08z.
So have probability of precipitation increasing from the south...as most model solutions show a
500 mb vorticity maximum passing and lifting north during the morning...then exiting
northern counties after 18z. Thinking next disturbance approaches from
west-southwest toward evening. Still difficult to figure coverage of the overnight
and morning showers...plus what affects morning convection has on
redevelopment late in the day.
Short term /Tuesday night through Thursday/...
deep layer S to SW flow with Atlantic ridge to the east and
trough to the west. A few disturbances in SW flow will provide a
kicker for any shower development. Timing these features is
difficult...thus will carry convective development into the
overnight hours. Main focus for convection will be during the
afternoon hours with presence of diurnal heating. Will continue
mention with Storm Prediction Center marginal risk Tuesday and Wednesday while also covering for
For temperatures...stayed mainly with inherited values...with a slight
blend toward latest guidance values with did not result in much
change in forecast trends.
Long term /Thursday night through Monday/...
followed along with wpc guidance through the long term. Front
crosses late in the period with some cooling and drying north and
west. Still not confident enough to drop probability of precipitation completely out of
the forecast so late in the period...with front being in the
area. Thus...Summer like broad brush of chance probability of precipitation carry through
much of the forecast period.
Aviation /00z Tuesday through Saturday/...
confidence still set at medium...with uncertainty on the coverage
of showers with embedded thunderstorm overnight into Tuesday
morning...plus timing new rounds of convection arriving from the west-southwest late
in the day Tuesday.
Have layered clouds at 4 to 8 thousand feet broken/overcast thickening from the SW overnight.
Visibility 4 to 5 miles in any showers. Could be an embedded thunderstorm in
eastern Kentucky...southwest Virginia...southeast Ohio...and western West
Virginia...but probability of precipitation too low to insert in specific taf forecasts.
Will try to have an enhanced area of showers arriving on either side of
dawn Tuesday from the south. So will have some 5 miles in showers with
Thinking increase in the clouds will prevent late night thick fog in
mountain valleys around Elkins...currently have some MVFR in fog.
New convection may form during the afternoon...but timing uncertain and what
affects morning showers will have on the redevelopment. Current thinking
is...if any redevelopment it would be late in the day or not until evening...
after 21z Tuesday.
Forecast confidence and alternate scenarios through 18z Tuesday...
Forecast confidence: medium.
Alternate scenarios: timing of convection may differ from
After 00z Wednesday...local IFR in showers/storms Tuesday night into
Wednesday morning...and rain induced low stratus and fog. IFR may
linger through mountains counties Wednesday afternoon.