002
FXUS61 KRNK 201511
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
1111 AM EDT Thu Jun 20 2024

.SYNOPSIS...
High pressure will cover the region through the end of the
week. This will result in unseasonably warm temperatures and
mainly dry conditions. Any rainfall is expected to be isolated.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 1010 AM EDT Thursday...

Key Messages:

1) Confidence is very high for continued dry weather.

2) Upper level cloudiness may dim the sun for periods of time.

3) Temperatures will top out slightly above normal, but lack of
moisture in the air will keep the heat index lower than it
would be otherwise.

Another mostly sunny day with above normal temperatures
expected. Some higher clouds hanging on over the area, with some
cumulus clouds developing over eastern VA and NC, and spreading
westward thanks to the easterly flow off the Atlantic. Plenty of
drier mid level air per the morning sounding at RNK will keep
the weather dry today. Only minor adjustments made to the
forecast for this morning update based on temperature and sky
cover observations.

Previous discussion below...


As of 400 AM EDT Thursday...

Welcome to the official start of summer! The summer solstice
arrives at 4:51 PM EDT. The weather certainly supports the
occasion with hazy seasonally hot temperatures.

Similar to yesterday, the weather pattern remains stagnant.
Aside for some high clouds, not much in the way of moisture.
Large upper level ridge of high pressure will dominate regional
weather with subsidence squashing all but a few afternoon
cumulus...deep convection not happening. In spite of the
summer welcoming pattern, easterly flow off the Atlantic Ocean
will maintain lower temperatures at 85H and lower dewpoints
across our forecast area compared to the northern periphery of
the upper level ridge where temperatures are baking our
neighbors to the north. Lower dewpoints also mean our night time
temperatures will have a chance to return to something
tolerable for the overnight.

High temperatures today...78 to 85 mountains...86 to 92
foothills and piedmont. Lows tonight 58 to 62 mountains...63 to
67 foothills and piedmont.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 1100 AM EDT Thursday...

Key Messages:

1. The worst heat and humidity stay out of our forecast area,
but we will be hot and somewhat humid through Monday.

2. Weak front Sunday night into Monday will bring scattered
showers/storms mainly to the mountains.

3. Cooler and drier in the mountains behind the front for Monday.

High pressure at the surface drifts south and weakens its hold
somewhat over the Mid Atlantic on Friday night, and further
retreats east into the western Atlantic over the weekend. Aloft,
the oppressive ridge bringing heat to much of the area will be
over the TN Valley on Friday, and spreads west to cover most of
the southern/southwestern CONUS over the weekend. This puts us
just inside the envelope of the higher temperatures, and opens
the door for slightly higher humidity for the weekend. That
said, it is not exceptionally humid, with 925 dew points of
12-14C during this time close to the daily mean according to
ECMWF ENS percentiles for this time.

Looking at the Integrated Water Vapor forecast from NCEP, much
of the region`s mid and high level moisture actually funnels
clockwise from previous TS Alberto in northern Mexico, up
through the Plains and finally sags south from the OH Valley
Sunday and Monday.

A surface trough drifts into the area by Sunday night, and
should trigger showers and thunderstorms. A few storms may pop
up as early as Saturday afternoon over the higher terrain, but
spatial coverage will be low due to capping. For Sunday, models
indicate this feature may break up along the higher terrain, so
most if not all the measurable rain is expected over the western
mountains. CAPE does not look especially impressive, nor does
shear through the weekend, so if anything would be concerned
with brief heavy rain and lightning.

We are around 1-3 standard deviations above normal for
temperatures during this time, with temperatures in the 80s
and 90s for highs, and heat indices staying below 100 degrees,
even in the Piedmont. Overnight lows will be in the 60s with a
few 70s possible. Possible record high and record warm low
temperatures are in jeopardy Sunday and Monday, see Climate
section below. Of the 3 days, Sunday looks the worst as far as
heat, with the ECMWF Extreme Forecast Index pegging highest that
day for our area.

Confidence in the short term is high.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 1100 AM EDT Thursday...

Key Messages:

1. Heat and humidity continues, but remain below Advisory/
Warning criteria.

2. Scattered showers/storms Monday, but more widespread Wed/Thu.

On Monday we will be in NW flow aloft as a northern trough
swings east, and continues to push a weak front out of our
southwestern counties on Monday morning. The mountains remain a
touch cooler, with highs in the 80s, but the Piedmont remains
hot with heat indices just shy of 100 degrees.

Monday scattered showers and storms will be possible, mainly
over the mountains and ahead of and along a front which pushes
through in the heat of the day. Tuesday looks dry behind the
front, which will make things less humid, but it still looks
very hot, especially for the Piedmont. The heat continues in
this manner through mid week, with a stronger frontal passage
expected Wednesday or Thursday. 925mb dew points increase to
about 18C ahead of the front. CSU machine learning site show a
possibility of severe weather Monday and again Wednesday/
Thursday with these feature. Damaging winds currently look like
the main concern.

Heat indices remain below Heat Advisory/Excessive Heat Warning
criteria for both the mountains and the Piedmont, and this is
supported by GEFS probabilistic forecasts.

Confidence in the long term is moderate for most parameters, but
lower for timing of showers and storms.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
As of 700 AM EDT Thursday...

Expecting widespread VFR through the 24 hour TAF. Any morning
fog will be patchy and mainly confined to the river valleys.

Confidence is high.

EXTENDED AVIATION OUTLOOK...

Pattern favors dry conditions into Saturday with increasing
chance for storms Sunday into Monday. Overall VFR through the
period aside from any fog at LWB and storms Sun-Mon.

&&

.CLIMATE...
As of 1100 AM EDT Thursday...

The following record high and record warm low temperatures may
be in jeopardy this week:

Sunday 06/23/2024
ROA record high minimum, forecast 73, record 75 (set in 1996)
LYH record high, forecast 97, record 98 (set in 1911)

Monday 06/24/2024
ROA record high minimum, forecast 73, record 72 (set in 2010)

Wednesday 06/26/2024
LYH record high, forecast 99, record 98 (set in 1952)

&&

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

&&

$$

SYNOPSIS...PM
NEAR TERM...AS/PM
SHORT TERM...SH
LONG TERM...SH
AVIATION...PM
CLIMATE...SH