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003
FXUS61 KRNK 261838
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
238 PM EDT Wed Jun 26 2024

.SYNOPSIS...
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A weak cold front will slowly track south through the Mid Atlantic
and Carolina states through Friday and resulting in showers and
thunderstorms tonight. Another front with thunderstorms comes across
the region Saturday and Sunday. The humidity will remain high
through the weekend.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 215 PM EDT Wednesday...

Key messages:

    - Scattered thunderstorms tonight
    - Front may stall on Thursday

Convective temperatures have been reached across much of the area
leading to the development of isolated thunderstorms along the
southern Blue Ridge, through the New River Valley and in southeast
West Virginia. Plenty of instability with Convective Available
Potential Energy in the 800-1500 J/kg range and downdraft CAPE up to
1200 J/KG. Most likely probability for wind gusts exceeding 50kts
north of Route 460.

Much of thunderstorms will be pulse variety with outflow and merging
cells aiding in triggering storms. A pre-frontal trough will push
through the region tonight followed by the weak cold front. The
surface front advances to the North Carolina border but the 850
front never making it that far south. This leaves areas of
convergence over Virginia tonight and Thursday. Thunderstorms will
continue overnight and into Thursday morning.

Surface dew points have climbed back into the upper 50s to mid 60s.
This will keep temperatures mild overnight. The cloud cover and any
rain will inhibit heating on Thursday. This will hold maximum
temperatures in the 70s and 80s.
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&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
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As of 130 PM EDT Wednesday...

Key Messages:

1. Daily chances of showers and thunderstorms through the period.
2. Near to above normal temperatures.

Lingering showers and thunderstorms may continue overnight Thursday
into early Friday morning, mainly in the eastern counties of the
forecast area, following the passage of a cold front. Surface high
pressure develops over the northeastern US, building down into the
Mid Atlantic behind the front for Friday, bringing some cooler and
drier air to the area. Not expecting much of a drop in high
temperatures with this airmass, but a few degrees lower than earlier
this week, and Friday will likely be the coolest day of this
forecast period. Easterly flow around the high will bring some
moisture into the area from the Atlantic, and could trigger some
afternoon showers and thunderstorms over the southern Blue Ridge of
Virginia and North Carolina.

Heading into the weekend, ridging aloft develops over the
southeastern states, and 500mb heights increase over the Mid
Atlantic, suggesting a warming trend in temperatures. An upper
trough amplifies over the Great Lakes late in the forecast period,
and a warm front lifts northward over the area through Saturday,
putting the area in the warm sector of the surface low pressure
system, so temperatures and dewpoints will increase through the day.
The cold front approaches the region from the Midwest, increasing
probabilities for more widespread convection by Saturday afternoon.
NBM thunderstorm probabilities range from 50% to 70% by late
Saturday, as dewpoints rise via the southwesterly flow. However,
chances for more organized convection increase with the passage of
the actual front.
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&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
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As of 145 PM EDT Wednesday...

Key Messages:

1. Showers and thunderstorms possible Sunday, though
   timing is uncertain.
2. Near normal temperatures, slightly cooler Monday and
Tuesday.

An upper trough digs into the Great Lakes and northeastern US into
Sunday, bringing a surface frontal system through the eastern
states. Ample moisture and warm air ahead of the front will
contribute to increasing instability, which will increase potential
for showers and thunderstorms on Sunday. Better forcing for storms
comes along with the front, and the trough will bring additional
upper level support, and would lead to more organized convection,
though those better dynamics appear to stay farther north, over the
northern Mid Atlantic and Northeast, at this time. With uncertainty
due to model differences in the timing of the frontal passage, and
with the system still being several days out in the forecast period,
confidence is lower on potential for severe storms. However, with
above normal precipitable water values, storms would have the
potential to produce moderate to heavy rainfall, and though most of
it would be beneficial with the very dry antecedent conditions
across much of the forecast area, there is a marginal risk for
flooding of urban and low lying areas.

Behind the front, high pressure returns to the area for the
beginning of the work week. Temperatures will drop a few degrees in
the cooler and drier airmass over the region, closer to seasonal
normals.
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&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
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As of 235 PM EDT Wednesday...

Convective temperatures have been reached across much of the area
leading to the development of isolated thunderstorms along the
southern Blue Ridge, through the New River Valley and in southeast
West Virginia. Plenty of instability with Convective Available
Potential Energy in the 800-1500 J/kg range and downdraft CAPE up to
1200 J/KG. Most likely probability for wind gusts exceeding 50kts
north of Route 460. HAve kept VCTS in the local TAFs mainly in
the 20Z/4PM to 02Z/10PM time range. Otherwise TAFs will be
modified on- the-fly based on the current radar trends.

Much of thunderstorms will be pulse variety with outflow and merging
cells aiding in triggering storms. A pre-frontal trough will push
through the region tonight followed by the weak cold front. The
surface front advances to the North Carolina border but the 850
front never making it that far south. This leaves areas of
convergence over Virginia tonight and Thursday. Thunderstorms will
continue overnight and into Thursday morning.

Expecting MVFR ceilings to develop in the mountains tonight.
Once mixing begins on Thursday, ceilings will return to VFR.

Surface dew points have climbed back into the upper 50s to mid 60s.
This will keep temperatures mild overnight. MVFR to IFR fog
is probable in the favored valleys tonight and into early
tomorrow morning, especially in locations that have rain
Wednesday afternoon and evening.

Average confidence on ceiling, visibility, and wind.
Average confidence on timing and location of thunderstorms this
afternoon and evening.


EXTENDED AVIATION OUTLOOK...

Isolated showers and thunderstorms are possible again each
afternoon and evening Thursday and Friday.

A greater coverage of thunderstorms and associated MVFR flight
conditions, is expected along and ahead of a cold front on
Saturday and Sunday.

Monday is expected to be drier and VFR, with a majority of the
showers and thunderstorms south of the region.
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&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

$$

SYNOPSIS...AMS
NEAR TERM...AS
SHORT TERM...AS
LONG TERM...
AVIATION...AMS/BMG