046
FXUS61 KRNK 022337
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
737 PM EDT Tue Jul 2 2024

.SYNOPSIS...
High pressure remain in control of the region`s weather into
mid-week, allowing dry weather to continue through Wednesday.
Temperatures will start to heat up again by the 4th of July as
the high starts moving east. The possibility of showers and
thunderstorms will return for the latter half of the week, as a
storm system moves into our area.

&&

.NEAR TERM /NOW THROUGH WEDNESDAY/...
Issued at 737 PM EDT Tue Jul 02 2024

Forecast seems to be on track early this evening, as ridging, both
at the surface and aloft, continue to dominate the region`s weather.
A shortwave trough, embedded in the northern stream, is expected to
push a storm system eastward from the Plains tomorrow, which could
start impacting our area by Independence Day. Between now and then,
the movement of the upper-level part of this system will gradually
push the surface high northeastward as the upper-level ridge axis
(more-or-less) moves overhead. The increased subsidence, combined
with a more southwesterly flow on the back side of the surface high,
will probably result in it feeling a bit more humid day Wednesday
afternoon.

For now, though, no changes were made to the ongoing forecast.

As of 150 PM EDT Tuesday...
Key Message:

1) Temperatures climb again for Wednesday.

2) No rain expected.


Skies will be mostly clear through the remainder of the day
today, overnight and most of Wednesday due to surface high
pressure sliding slowly to our northeast, and a powerful
subtropical ridge pushing even further northeast out of the
southern plains. This will also lead to increased heat and
moisture in the area. Highs Wednesday mostly in the 80s for
mountain areas, and just pushing into the 90s in the Piedmont,
Southside and central VA. Dewpoints in the mid 60s will start to
make it feel like a sticky heat Wednesday, while the previous
few days have been dry enough to avoid that.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 130 PM EDT Tuesday...

Key Messages:

1. Heat index values potentially exceeding advisory criteria Friday.
2. Afternoon thunderstorms on Thursday and Friday could potentially
bring locally damaging winds.

Model ensembles show high confidence that the anomalously strong
upper level ridge over our region is slightly flattened late this
week as an upper level trof moves east from the northern plains into
the western Great Lakes by Friday evening.

Despite this, a deepening southwest flow by Friday will push 850mb
temps several(2-3+)standard deviations above normal, especially on
Friday.  Forecast high temperatures on Friday, generally following
the NBM, will be within 2-5 degrees of record highs for most
locations on Friday (See climate section below for record highs
Friday and Saturday).

These abnormally warm temperatures combined with PWAT values
climbing 1-2 standard deviations above normal for both Thursday and
Friday will lead to potentially dangerous heat index values east of
the Blue Ridge, especially on Friday and will highlight this threat
in the HWO.

Another by-product of the flattening upper level ridge will be weak
upper level disturbances emanating from northern plains/western
Great Lakes upper level trof. These disturbances will help spark
afternoon and early evening thunderstorms. Forecast soundings show
the potential for long and skinny CAPES with a fairly healthy spread
in sfc dew points and temps, creating an environment conducive for
locally damaging winds and locally heavy downbursts of rain.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 130 PM EDT Sunday...

Key Messages:

1. Confidence remains high for above normal temperatures through the
period with the warmest day on Saturday.

2. Unsettled weather persists through the long term period with
afternoon/evening storms possible each day.

The CPC Cluster Analysis Tools indicate above average confidence in
the upper level pattern through Sunday in advance of an upper level
trof in the central U.S., with confidence with the location and
amplitude of the trof falls Monday and Tuesday.

850mb temps continue be 1-2 standard deviations above average on
Saturday with NBM forecast high temps still well into the 90s east
of the Blue Ridge with heat index values nearing advisory criteria
in the far east. With the model ensembles in good agreement that an
upper level trof sweeps through the northeast late Saturday/Saturday
night allowing a surface boundary will move into our area, which may
bring us the best chance for storms in the long term period.

Forecast soundings show fairly robust DCAPE values on Saturday and
even Sunday, suggesting storms will have the potential for damaging
winds.

Precip chances on Sunday are highest across the VA southside and NC
piedmont where the surface boundary is likely to stall and
temperatures may be a degree or two cooler, but still well above
average.

As upper level heights build back on Monday, PWAT anomalies also
increase meaning scattered afternoon storms are possible anywhere
across our forecast area with the continued threat for isolated
damaging winds.  The Colorado State Machine-Learning Probabilities
Prediction Page keeps some risk for severe weather in our area each
day through the period.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Issued at 737 PM EDT Tue Jul 02 2024

Satellite imagery shows SCTD cloud cover across the forecast area
early this evening, with the lowest heights averaging between 050-
060. Expect this coverage to diminish this evening, with basically a
CAVOK forecast through the rest of the forecast period. No flight
category reductions are anticipated as most cloud cover through
04/0000 UTC should be Ac/Cs. Wind speeds should mainly be from the
SE-S at speeds AOB 10 kts.

OUTLOOK WEDNESDAY NIGHT THROUGH SUNDAY...

Wednesday night: CAVOK conditions. No restrictions expected.

Independence Day: Odds of SHRA/TSRA increase from the W by Thursday
afternoon as a storm system starts impacting the region. Flight
category reductions will be possible.

Friday-Sunday: SCTD SHRA/TSRA remain possible as a storm system
continues impacting the region. Flight category reductions remain
possible.

&&

.CLIMATE...
Records for Friday July 5th:
BLF: 93/1948
BCB: 94/1930
ROA: 100/1999
LYH: 98/1934 and 1999
DAN: 103/1919

Records for Saturday July 6th:
BLF: 92/1948 and 2010
BCB: 94/1930 and 2010
ROA: 100/1977 and 1999
LYH: 98/1893
DAN: 102/1990

&&

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

&&

$$

SYNOPSIS...DB
NEAR TERM...DB/VFJ
SHORT TERM...PH
LONG TERM...PH
AVIATION...DB
CLIMATE...PH