Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 281531
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
1031 AM EST Wed Feb 28 2024

.SYNOPSIS...
A strong low pressure system will track into Canada today with a
trailing cold front draped south into the Gulf States. This
front will cross the area today bringing a line of rain and
possibly isolated thunderstorms. Winds behind the front will be
gusty tonight. Temperatures will be unseasonably mild ahead of
the front today, and return to near normal as dry high pressure
builds into the area for Thursday. Another chance of
precipitation arrives by the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM EST Wednesday...

Key Messages:

1. No change to Wind Advisory

2. No chance to timing of the cold front

Timing if cold front and showers and thunderstorms along the
front is still from 11AM through 5PM. Morning soundings
continued to show high shear in the atmosphere. The potential
for strong to damaging wind with the line of showers and storms
remains high. Even though the storms are not particularly tall,
they could still produce damaging wind gusts. A lower
reflectivity on radar will not necessarily correlate with a
diminishing threat.

No change to post-frontal wind and falling afternoon
temperatures.


Previous Discussion
As of 230 AM EST Wednesday...


Surface low pressure is currently located over the Great Lakes
region this morning with a trailing cold front extending south into
the Gulf States. Main surface low will track into Canada later
today, but the trailing cold front will continue to push east,
eventually crossing the region this afternoon.

Just some light showery activity this morning associated with a warm
front moving north. Should continue to see off and on showers for
much of today as moisture is advected north under strong southerly
flow in advance of the cold front. Storms are expected to develop
over western Kentucky and southern Indiana/Ohio before daybreak
right along the cold front. Will continue to see coverage increase
throughout the morning as the front progresses east. Better
instability remains to the west of the area, therefore that is where
better thunderstorm chances remain. However, meager amounts of
MUCAPE/SBCAPE around 200 J/kg or less are showing up on model
sounding guidance within a very strongly sheared environment.
Although this does not seem like much, this is certainly enough
instability to produce isolated thunder as the line pushes through
late this morning and into the afternoon. Strong winds will be the
main threat as the line pushes through aided by the strong low-level
jet of 50-60 knots at 850mb. Any storm/shower with any vertical
depth could mix down strong damaging wind gusts.

Line of rain and isolated storms will push east of the area by 6 to
8pm this evening and strong post-frontal northwest winds are
expected, aided by rapid pressure rises and strong coinciding low-
level jet. Gusts into the 50mph range are likely tonight for the
crest of the Blue Ridge from northwest North Carolina and into
portions of southern Virginia. Either side of the Blue Ridge could
have gusts nearing 40mph at times. The window for the strongest wind
gusts will be from 7pm this evening through midnight.

High temperatures today will be set by late morning to early
afternoon, with a sharp temperature drop from west to east as the
front quickly passes across. Temperatures tonight drop into the 20s
and 30s. This will result in windchill values in the low teens for
the mountains.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
As of 330 AM EST Wednesday...

Key Messages:

1: Winds diminishing on Thursday, temperatures 5-7 degrees
below normal.

2: Pockets of freezing rain/sleet on Friday morning, possibly
lingering into afternoon along mountain ridges.

3: Drier & warmer conditions for Saturday.

For Thursday, will start the morning with continued gusty
northwest winds that will gradually diminish heading into
lunchtime as the center of an area of high pressure approaches
from the west. This high will bring with it very dry air,
pushing dewpoints into the teens across the lower Mid-Atlantic.
Northwesterly downslope windflow and abundant sunshine will make
for a wide gradient in afternoon temperatures, ranging from the
upper 30s/low 40s across southeast West Virginia to the low 50s
across the Virginia Southside, or roughly 5 to 7 degrees below
normal.

High pressure passes overhead Thursday night, allowing for
strong radiational cooling, pushing lows into the 20s. By dawn
however, precipitation from low pressure developing along the
Gulf coast begins to radiate northward across the lower Mid-
Atlantic. Weather forecast models are in good agreement that,
given the cool dry air in place this precipitation will fall
into, freezing rain will occur in pockets across the mountains,
more likely along the higher ridgelines. The earlier this
precipitation arrives in the morning, limiting the potential for
daytime heating, the more likely it will make for pockets of
freezing rain that may last into late afternoon before finally
changing to rain. Will continue to watch this possibility
closely in the next few updates of the weather models. Rain will
persist Friday afternoon into Saturday morning before the
supporting area of low pressure passes northeast along the
Atlantic coast, and eventually out over open ocean. This will
then leave weak high pressure over the central Appalachians,
situated in between the departing low and another low pressure
system developing over the Rockies.

Looking to Saturday, with no inflow of significantly drier air
into the region, spotty showers will remain in the forecast,
though with breaks in the cloud cover through the day to allow
occasional sunshine. Saturday afternoon highs will range from
generally the mid 50s for the mountains to the low/mid 60s for
the Piedmont.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
As of 345 AM EST Wednesday...

Key Messages:

1: Confidence in spring-like temperatures for early next week
increasing.

2: Low confidence in coverage or timing of any rainfall during
the period.

A deep low pressure system will exit the Rockies on Sunday, and
will push across the western Great Lakes on Monday into Canada.
This system will pull a cold front across the Ohio and
Tennessee Valleys on Monday and Tuesday, though low pressure
developing along the Gulf coast is likely to stall the front
from advancing across the Appalachian chain until the middle of
the week. As such, warm air pooling ahead of this front will
make for temperatures that are above normal for early March.
Daily high temperatures will reach into the 60s for much of our
area, while overnight lows will remain mainly in the 40s. Not
confident at this point in the timing or location of any
rainfall during this period given no strong trigger. Weather
forecast models are hinting at occasional shower activity from
time to time.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
As of 640 AM EST Tuesday...

Showers will arrive along/ahead of a front today, reaching
BLF/LWB by 17z, and DAN/LYH by 21z. Winds ahead of the showers
will pick up and gust 20-30kts, except higher in the
mountaintops. Surface winds still light enough in spots and
just above 1kft AGL, a strong low level jet is expected which
will result in low level wind shear this morning for a few more
hours for most.

With the showers and just behind the showers this afternoon,
expect winds to turn west then northwest with gusts up 30-40kts
possible but overall keeping terminals around 30kts. Some gusts
exceeding 45kt likely along and west of the Blue Ridge by
00z/Thu.

Keeping things sub-VFR east of the mountains through most of the
period. Vsbys with the showers could be reduced briefly in more
intense downpours.

Clearing will occur from west to east tonight as the front
pushes east. Some upslope MVFR clouds could linger for BLF/LWB,
but thinking all sites back to VFR before by midnight.

AVIATION OUTLOOK...

VFR Thursday as high pressure builds in.

A system will be developing in the Southern Plains and may
bring some showers to the our region Friday and Saturday with
sub- VFR. There is still a chance for showers on Sunday, but
over a smaller area.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Wind Advisory until 1 AM EST Thursday for VAZ007-009>020-
     022>024-032>035.
NC...Wind Advisory until 1 AM EST Thursday for NCZ001>003-018-019.
WV...Wind Advisory until 1 AM EST Thursday for WVZ042>044-507-508.

&&

$$
SYNOPSIS...BMG
NEAR TERM...AMS/BMG
SHORT TERM...NF
LONG TERM...NF
AVIATION...BMG/WP


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