Scientific Forecaster Discussion
fxus61 krnk 252318
Area forecast discussion
National Weather Service Blacksburg Virginia
618 PM EST Sat Feb 25 2017
a cold front will continue to push east of the area and
offshore this evening. High pressure will build in from the west
overnight into Sunday before passing off the southeast coast
later Sunday night and Monday. A warm front will lift northeast
toward the region early next week resulting in an increasing
chance of showers by Tuesday into Wednesday.
Near term /through Sunday/...
as of 320 PM EST Saturday...
The cold front/line of convection will move east of the Piedmont and
away from the forecast area by 4pm, therefore we will cancel the
Severe Thunderstorm Watch #39. As the cold front tracks to the coast
this evening, modest pressure rises and a 45kt cross barrier jet
will bring breezy conditions to the region. Winds will begin to
subside over the Piedmont after midnight but remain breezy across
the mountains, especially along the Blue Ridge where subsidence will
be the greatest. Gusts up to 45 mph are possible this evening. High
pressure builds in by noon Sunday allowing the winds to subside.
An upper level trough will pivot over the Ohio Valley to the mid
Atlantic region overnight. A short wave axis and lingering low level
moisture may produce light snow across western Greenbrier this
evening. Flow becomes zonal after midnight and trajectories are lost
from the Great Lakes to end snow showers shortly after midnight. Dry
high pressure will keep the area dry with clear skies Sunday.
Lows tonight will drop into the low to mid 20s across the mountains
and lower 30s east of the Blue Ridge. Believe it or not, these
temperatures are normal for this time of year. Couple the cold
temperatures and wind, Sunday morning temperatures will feel like
they are in the teens across the mountains and low 20s in the east.
Once the wind relaxes, abundant sunshine will help warm temperatures
into the mid 40s west to mid 50s east.
Short term /Sunday night through Tuesday night/...
as of 230 PM EST Saturday...
High pressure heads off the coast Sunday night. A warm front lifts
north across US Monday into Tuesday bringing a threat of rain,
albeit low chance as main low and energy stay over the Midwest.
Temperatures warm back to above seasonal levels Tuesday as we get
into the warm sector.
Long term /Wednesday through Saturday/...
as of 130 PM EST Saturday...
Not much change from previous forecast. Will see upper trough move
east to the mid-Atlantic by Thursday. A strong cold front moves
across the region Wednesday night into Thursday. Temperature slide
back to normal or below normal as we dry out Friday into Saturday.
Aviation /00z Sunday through Thursday/...
as of 615 PM EST Saturday...
Cold front and associated moisture now east of the region with
ongoing drying leading to VFR under gusty winds to start this
evening. Strong subsidence along with deepening cold advection
should then keep winds gusty across the mountains overnight
into Sunday morning, while speeds subside east of the ridges
later this evening. Upslope clouds under the passing cold pool
may spill far enough south to result in a return to low end VFR
cigs for kblf/klwb later this evening with ocnl MVFR possible
overnight. However quite uncertain to the extent of the cloud
cover and any snow showers given ongoing mixing and dry air. For
now will include some cigs western mountains overnight but keep
them VFR until seeing just how expansive the canopy may become.
Otherwise high pressure to build in overnight and Sunday before
sliding offshore by Monday. This looks to keep VFR under
overall light winds in place from Sunday into early next week
with perhaps some increase in mid/high clouds by Monday.
Extended aviation discussion...
A warm front is expected to lift northeast toward the region
Monday night into Tuesday before passing to the north on
Wednesday. This will keep a threat of showers in place
including periods of sub-VFR Tuesday into Wednesday. A cold
front pushes east into the area late Wednesday into Wednesday
night with potential for more widespread MVFR/IFR in showers
until the boundary exits the area early Thursday. Strong
northwest winds along with mountain sub-VFR in upslope low
clouds and light precip will likely follow the front for much of
Thursday. Expect downslope drying to return VFR to eastern
locations by Thursday afternoon.