Area Forecast Discussion Issued by NWS Blacksburg, VA
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000
FXUS61 KRNK 060732
AFDRNK
Area Forecast Discussion
National Weather Service Blacksburg VA
232 AM EST Wed Dec 6 2023
.SYNOPSIS...
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A cold front crosses the region today, bringing an end to rain
and snow showers except for the highest mountains. Otherwise,
winds will gust up to 20 to 30 mph today before diminishing
tonight. Much colder air filters in today and tonight.
Temperatures rebound slowly Thursday through Saturday with dry
weather. Rain chances increase once again Saturday night through
Sunday night, with snow showers possible for the mountains
Monday.-- End Changed Discussion --
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.NEAR TERM /THROUGH TODAY/...
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As of 210 AM EST Wednesday...
Key Message:
1. Snow/rain showers continue for mainly the western VA/NC
mountains and SE WV today before ending. Winter Weather
Advisories still in effect.
2. NW winds pick up after daybreak gusting to 15-30 mph.
3. Becoming sunny but still chilly east of the Blue Ridge
today. To the west clouds and even cooler temperatures will
linger.
Satellite imagery this morning shows a trough axis poised to
swing through the area shortly. This trough had its mid and
upper level origins in Saskatchewan and Manitoba. High pressure
moving out of the central Plains will build in behind the trough
and reinforce cooler and drier weather.
Precipitation remains hit and miss, and will continue to mainly
affect the western NC and VA mountains and southeastern WV.
Downwind towards the edge of the Blue Ridge, lighter rain and
snow showers were falling. Winter Weather Advisories are
currently in effect through at least this afternoon, depending
on the location. Newer guidance indicates the wind shift to the
NW and the beginning of the end of this precipitation may occur
sooner, so it is possible if not likely the advisories will be
cancelled early. That said, gusty upsloping NW winds will
continue to squeeze moisture out over the mountains, while the
same winds will downslope to the east and bring an end to any
precipitation there sooner.
QPF with this system has always looked low, and this is why we
are having such a hard time with accumulations of snow and rain.
Saturation in the dendritic growth zone shuts down in our area
after 10 AM, so not expecting much accumulation thereafter,
especially with incoming short wave radiation.
Gusty NW winds of 15-25 mph, (maybe 30 mph for the higher
peaks) will develop after daybreak and diminish this evening as
the PGF relaxes. Temperatures will struggle against moderate
cold air advection and the wind will only make it seem chillier.
Highs will only reach the low to upper 30s for the mountains,
and the mid to upper 40s for the piedmont. This is about 5-12
degrees below normal for today.
Tonight, calm winds and clear skies east of the Blue Ridge along
with CAA will allow for temperatures to drop into the mid to
upper 20s. To the west, slightly stronger CAA will battle with
insulating cloud cover and slightly higher wind speeds to
produce temperatures in the low to mid 20s. Thus not that much
of a difference between east and west. The highest ridges will
stay just a tad warmer.
Confidence in the near term forecast is high.-- End Changed Discussion --
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.SHORT TERM /TONIGHT THROUGH SATURDAY/...
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As of 200 AM EST Wednesday...
Key Messages:
1. Dry and Breezy.
2. Temperatures warm to above normal.
3. Moisture slowly increases Saturday.
Trough axis continues to push out into the Atlantic ocean,
allowing upper ridging to build into our region. By Saturday,
the upper trough to our west reaches the Ohio Valley.
Northwest to west flow aloft continues Thursday, before upper
ridging builds over the Southeast and into the Mid Atlantic
region in response to a trough deepening over the Southwest.
Therefore, the upper flow will transition to westerly and then
southwesterly by the end of the week.
Surface high pressure builds into our area and remains overhead
through Friday night. Then, the high center slides into the
Atlantic ocean on Saturday. This will result in moderating
temperatures and dry weather.
High temperatures on Thursday will vary from around 40 degrees
in the mountains to the lower 50s in the Piedmont. Highs warm
into mid 50s to lower 60s for Friday. Then, for Saturday high
temperatures range from the mid 50s in the west to the mid 60s
in the east with increasing clouds. Low temperatures for
Thursday and Friday night will generally be in the upper 20s to
the mid 30s.
Forecast confidence is moderate to high for the Short Term
Forecast.-- End Changed Discussion --
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.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
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As of 200 AM EST Wednesday...
Key Messages:
1. Increasing confidence for more widespread rainfall Saturday
Night and Sunday.
2. Dry weather returns Monday into Wednesday.
A strong upper trough moves into the east Saturday night and
Sunday. The associated cold front should reach the Central
Appalachians by Sunday. This system looks to bring more
widespread rainfall to the area, given that forecast
precipitable water values are near the 90th percentile of
climatology as southwesterly flow off the Gulf brings in
increased moisture. With the trough becoming more negatively
tilted as it moves into the Ohio Valley, some instability and
with higher dewpoints, decided to add the mention of a slight
chance for a thunderstorm for Sunday afternoon. Temperatures
cool enough Sunday night for some snow showers to mix in with
the rain for the higher elevations in southeast West Virginia.
The combination of steep pressure rises and strong cold air
advection behind the front could result in strong and gusty
winds later Sunday into Monday. The front will quickly cross the
area, and high pressure and dry weather return for the beginning
of the workweek.
Temperatures will be near to slightly above normal through the
weekend, but cooling down after the frontal passage on Sunday.
Then, cooler temperatures linger into Midweek.
Forecast confidence is low to moderate for Long Term Forecast.-- End Changed Discussion --
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.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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As of 210 AM EST Wednesday...
Ceilings and visibilities range from VFR to LIFR as a trough
crosses the area this morning with rain and snow showers. West
winds turn more to the NW and will gust 15-30 mph after 12Z with
higher gusts at higher elevations. Winds diminish after 21Z.
The NW winds will help clear out showers and clouds east of the
Blue Ridge likely well before noon. Snow showers should end for
BLF and LWB a little later than other TAF sites. It appears
MVFR clouds will hold in the mountains through at least 07/06Z
and possibly Thursday morning. To the east it will remain VFR.
Above average confidence for ceilings, visibilities, and winds.
Extended Aviation Discussion...
Once mountain stratus clears Thursday morning, conditions stay
VFR everywhere through Saturday.
Winds will come from the west or southwest Thursday through
Saturday.
Clouds will increase by Saturday night as a cold front
approaches. This front should bring widespread rain and
MVFR/IFR ceilings for Sunday.-- End Changed Discussion --
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.RNK WATCHES/WARNINGS/ADVISORIES...
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VA...Winter Weather Advisory until 4 PM EST this afternoon for
VAZ015.
NC...Winter Weather Advisory until 4 PM EST this afternoon for
NCZ001-018.
WV...Winter Weather Advisory until 10 PM EST this evening for
WVZ508.-- End Changed Discussion --
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SYNOPSIS...SH
NEAR TERM...SH
SHORT TERM...KK
LONG TERM...KK
AVIATION...PW/SH