Area Forecast Discussion Issued by NWS Blacksburg, VA
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000
FXUS61 KRNK 031740
AFDRNK
Area Forecast Discussion
National Weather Service Blacksburg VA
140 PM EDT Sat Jun 3 2023
.SYNOPSIS...
Showers and thunderstorms will develop as a backdoor cold front
pushes southward this evening. Cooler air will follow for
Sunday. A lingering upper level low should provide daily
chances of showers and thunderstorms into the next work week.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 130 PM EDT Saturday...
Confidence is high for showers and thunderstorms later this
afternoon and evening due to a backdoor cold front.
A backdoor cold front will arrive from the northeast this
evening as a closed upper level low dives southward from
eastern Canada. Ahead of this front, compressional warming has
boosted temperatures well into the 80s but also raised the CAPE
to about 1,000 J/kg. The 12Z RNK sounding showed DCAPE also
approaching 1,000 J/kg. This combination of instability for
updrafts and downdrafts has resulted in a marginal risk of
severe weather due to damaging winds this afternoon. A couple
showers and thunderstorms are already developing in southeast
West Virginia and will continue to spread and intensify this
afternoon. There is not much wind shear or steering momentum
aloft, so these storms will be slowly moving and could produce
some heavy downpours.
While thunderstorms will reach North Carolina this evening,
activity further north in Virginia and West Virginia should
taper to lingering showers overnight. Patchy fog and low clouds
should spread across the Mid Atlantic after midnight in the wake
of the backdoor cold front. Temperatures should fall into the
50s by early Sunday morning. Clouds may linger for most of the
day, but some clearing appears possible towards Sunday afternoon
as temperatures make it towards the lower 60s to the lower 70s.
A couple showers and thunderstorms could develop west of the
Blue Ridge in the afternoon along the periphery of the cool
northeasterly flow wedged against the eastern Appalachian
Mountains. Any activity should be much weaker due to more
stable air and the backdoor front stalling in North Carolina.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
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As of 140 PM EDT Saturday...
Cool Sunday night, then moderating temperatures into Tuesday.
Closed upper low meanders eastward into Tuesday. A ridge of high
pressure will build south along the lee of the Appalachians Sunday
into Sunday night. Any afternoon convection created by upslope flow,
low level moisture and heating will diminish at sunset. Light winds
combined with limited cloud cover will result in patchy fog late
Sunday night into Monday morning. Low temperatures Sunday night will
range from the upper 40s in the deeper mountain valleys to the mid
50s in the Piedmont.
For Monday into Tuesday, low level flow switches to northwest across
the area in response to a tightening pressure gradient as an upper
low drifts around New England. Weak disturbances heading southeast
through the prevailing flow will trigger convection. The best chance
for storms on Monday will be in the southwest. Extended the slight
chance of a thunderstorms further east to match up better with RAH.
High temperatures Monday will be in the mid 70s in the mountains to
the mid 80s in the Piedmont. Afternoon storms will wane quickly with
the loss of solar heating Monday night. Lows will vary from near 50
degrees in the west to near 60 degrees in the east. An isolated
shower or storm is possible in western sections Tuesday afternoon.
The trend of the models recently have been to decrease pops. High
temperatures Tuesday will warm into the mid 60s in the northern
mountains to the mid 80s in the Piedmont.
Confidence in the Short Term Period is moderate.-- End Changed Discussion --
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.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
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As of 140 PM EDT Saturday...
Slightly cooler with isolated showers mainly in the mountains.
A cut-off upper low over New England will slowly move eastward into
the weekend. Within the broad circulation around the low, periodic
weak shortwave troughs will cross over or just north of the region.
The combination of low level moisture and heating will generate
isolated showers and perhaps a thunderstorm mainly to the mountains
into Thursday. For the weekend chances actually decrease as the
upper low opens into a broad trough and lift into the Canadian
Maritimes. Then, it looks like the chances of rain increase Sunday
into Monday.
Temperatures are expected to average slightly below normal, then
rise into early next week.
Confidence in the Long Term Forecast is low to moderate.-- End Changed Discussion --
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.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
As of 130 PM EDT Saturday...
Confidence is increasing for showers and thunderstorms to impact
all terminals later this afternoon starting with LWB first and
spreading southward towards the other sites. In any of the
thunderstorms, restrictions to visibilities and a potential
gust of wind from the north to northeast is possible. Ceilings
will eventually fall overnight to IFR, especially for any
locations that receive rainfall. Some patchy fog is possible
with LWB and BCB having the best chances. Poor flying
conditions are likely by Sunday morning as ceilings will be
slow to lift towards MVFR. Some partial clearing and a return to
VFR might be possible by Sunday evening.
EXTENDED AVIATION OUTLOOK...
More patchy fog and low ceilings appear likely for Sunday night
into Monday morning. Shower and thunderstorm chances may occur
along the southern Blue Ridge during Monday afternoon as
ceilings try to rise again. VFR conditions should become more
favorable during the remainder of the week, but there will still
be chances each afternoon of isolated showers and thunderstorms
in the mountains.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...KK
LONG TERM...KK
AVIATION...PW