Area Forecast Discussion
Issued by NWS Blacksburg, VA-- Remove Highlighting --
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FXUS61 KRNK 260905
Area Forecast Discussion
National Weather Service Blacksburg VA
405 AM EST Sun Feb 26 2017
High pressure will move from the Tennesse Valley this morning to
off the Carolina coast tonight. A warm front will lift
northeast toward the region Monday and Tuesday resulting in an
increasing chance of precipitation. By Wednesday and Thursday
low pressure tracking northeast out of the Central Plains will
push a cold front across the eastern United States.
.NEAR TERM /THROUGH TONIGHT/...
As of 350 AM EST Sunday...
Upslope stratocumulus extended down the west slopes of the
Appalachians through southeast West Virginia and into Tazwell
County this morning. Area radars showed light snow showers or
flurries in western Greenbrier county. Bufkit guidance and model
humidity forecast below 700MB showed snow ending and clouds
eroding by 15Z/10AM. Otherwise the air mass is dry and sunshine
is expected today. Highs will be near normal east of the Blue
Ridge and just below normal in the mountains. Surface and winds
through 850MB will diminish this morning and during the
afternoon and evening back to the west then southwest.
Surface high pressure over the Tennessee Valley this morning
will move east across the central and southern Appalachians this
afternoon then off the Carolina coast tonight. Return flow
around the high combined with a low developing in the Southern
Plains will spread high clouds into the Mid Atlantic region
mainly after midnight. Winds will decouple this evening and with
little cloud cover temperatures will have a sharp drop, then as
cloud cover increases overnight, a much smaller change in
temperatures is expected.
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
As of 320 AM EST Sunday...
High pressure will move further out into the Atlantic ocean Monday.
A west to southwest flow aloft will continue Monday into Wednesday.
Embedded shortwaves will rotate through the upper flow across our
region. A warm front will lift north across the Tennessee valley
Monday and across our region Monday night into Tuesday. The
combination of shortwaves, warm advection and increased moisture
will result in the potential for rain.
Initially trimmed back the pops for Monday morning with dry air mass
in place. Leaned ISC Grids towards the NAM for Monday morning.
By Monday afternoon, the southwest flow around the surface high
will push moisture into western portions of Forecast area. This
is supported by the GFS and ECMWF which have been fairly
consistent with moisture stringing out to the northeast with
Ohio Valley Shortwave. Monday high temperatures will be warmer
that Sunday with Readings from the mid 40s in the mountains to
the lower 60s in the Piedmont.
Under cloudy skies with some rain, low temperatures Monday night
will be mild with readings from the mid 30s in the northwest
mountains to the mid 40s in the Piedmont. Scattered showers will
move across the region Tuesday into Tuesday night with frontal
boundary traveling lifting northward. Temperatures continue to
moderate Tuesday with High temperatures ranging from the upper 50s
in the mountains to near 70 degrees in the Piedmont. It will feel
quite mild Tuesday night with low values from the upper 40s in the
mountains to the mid 50s in southeast portions of the forecast area.
A strong cold front will approach from the west Wednesday and moves
across the region Wednesday night into Thursday. High temperatures
Wednesday will vary from near 60 degrees in the northwest mountains
to the mid and upper 70s in the Piedmont. Behind the front, cold air
will push into our region. Low temperatures will feature readings
from the upper 20s in the north to the mid 40s in the southeast.
.LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 320 AM EST Sunday...
Upper trough moves east to the Mid-Atlantic by Thursday. A clipper
type system diving southeast across the Ohio Valley Thursday night
into Friday in northwest flow aloft behind the upper trough.
Canadian high pressure will settle in for Saturday into Sunday.
Moisture associated with another frontal boundary may arrive late
Sunday night into Monday.
Cooler temperatures expected Thursday into Friday, then temperatures
moderate Saturday into Sunday.
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
As of 1115 PM EST Saturday...
Upper cold pool will cross parts of the region overnight as
surface high pressure gradually builds east into the area later
tonight through Sunday. Upslope aided low clouds under the
passing shortwave energy aloft likely to result in periods of
VFR/MVFR cigs at KLWB/KBLF overnight, with some of these cigs
possibly spilling out to KBCB and KROA during the early morning
hours of Sunday. However quite uncertain to the eastward/southern
extent of the cloud cover and any snow showers given ongoing
mixing and dry air. For now will include mainly VFR cigs far
western locations, and TEMPO in some ocnl MVFR canopy espcly
around KBLF through daybreak Sunday. This while also leaving
out any snow shower mention attm.
Strong subsidence along with deepening cold advection should
also keep winds gusty across the mountains overnight into
Sunday morning, while speeds subside east of the ridges later
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.