814
FXUS61 KRNK 161719
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
119 PM EDT Tue Jul 16 2024

.SYNOPSIS...
High pressure and hot temperatures will cover the Mid Atlantic
and southeast states through today. A cold front will track out
of the Ohio Valley, reaching the area late Wednesday into
Thursday with showers and thunderstorms. The front, along with
cooler temperatures, and a continued daily chance of
precipitation will remain in the region into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1230 PM EDT Tuesday...

No major changes have been made to the forecast since the last
update. We are starting to see the development of isolated
showers near the spine of the Blue Ridge from the Fancy Gap area
southwest into the northwest mountains of North Carolina. As we
progress through the afternoon, all locations will have the
potential for isolated showers/storms, but the greater
concentrations are expected to be over the mountains through the
mid-afternoon, and then start to shift east into the Piedmont by
the late afternoon and early evening. Heat Index values over 105
are still expected within the region of the Heat Advisory.

As of 945 AM EDT Tuesday...

Remnant cloud cover outflow from an MCS that was across the
Midwest last night reached western sections of the region
shortly after daybreak. Since then, this area of cloud cover has
continued southeast across the region. The bulk of this cloud
cover has been thin high cloud cover, however some low to mid-
level cloud cover has been among the mix as well. The existence
of these clouds has slowed the increase in temperatures through
the morning hours so that most locations are experiencing
values about three to five degrees cooler than what was
expected. However, we do expected these remnant clouds to
continue on their southeast heading. As they exit, the clearing
skies they leave in their wake will be replaced by developing
cumulus and by the early afternoon the first of the expected
isolated to scattered showers across the region. After a couple
of hours more the first isolated to scattered storms. Have
tweaked hourly grids for temperature, dew point, and sky cover
to better reflect the ongoing conditions and expected trends
into the early afternoon. We are forecasting no change in
expected high temperatures and resultant Heat Index values for
this afternoon.


As of 230 AM EDT Tuesday...

Key Messages:

1) Hot weather continues.

2) Slightly better coverage of thunderstorms this afternoon.

Quiet weather this morning across the region with patchy areas
of morning fog developing. Upstream MCS continues through the
Midwest and may have some cirrus spread southeast from the MCS
by daybreak. Overall flow remains westerly as the associated
upper wave responsible for the complex of storms to the west
passes through the Great Lakes today and then into New England
by this evening.

With slightly better moisture return today, could see slightly
better coverage of thunderstorms by this afternoon. Best chance
appears to be along the Blue Ridge and west, then possibly
spreading into the Piedmont through the evening. Best forcing
still remains to the north, but could have a few stronger storms
capable of isolated wind damage and localized heavy rainfall.

Highs this afternoon still look to be quite hot. Still
questionable if any cirrus from upstream convection makes it
here, which if it does, this could limit heating a
bit...especially across the mountains. Another limitation would
be sooner initiation of storms. With that said, still think a few
spots from Roanoke and east will be flirting with 100F. No
changes to the current Heat Advisory that is currently in
effect.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
As of 245 AM EDT Tuesday...

Key Messages:

1) Confidence is high for scattered showers and thunderstorms during
Wednesday and Thursday from a cold front.

2) Temperatures will trend lower to end the work week as the cold
front stalls across North Carolina.

A cold front will approach the Appalachian Mountains on Wednesday.
CAPE could reach around 1,500 J/kg by the afternoon as temperatures
rise into the 80s and 90s, so scattered showers and thunderstorms
are likely to develop in the mountains first and spread eastward
across the Blue Ridge by the evening. Heavy downpours and gusty
winds from outflow of any stronger storms should be the biggest
concerns. An upper level trough will pass to the north by Wednesday
night into Thursday, which should push the cold front through
Virginia and West Virginia. The threat for strong storms should move
towards North Carolina by Thursday afternoon with the same concerns
of heavy rain and gusty winds.

Meanwhile, cooler air will begin to arrive from the northwest after
the frontal passage. Temperatures should trend notably lower with
highs only in the 70s and 80s by Friday. However, the cold front
will become oriented parallel to the flow aloft and stall across
North Carolina. While the thunder chances should be considerably
reduced in coverage, a few storms may be possible across North
Carolina during Friday afternoon. Some showers might spill northward
into Virginia and West Virginia but will run into more stable air to
limit any threat of convection.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
As of 245 AM EDT Tuesday...

Key Messages:

1) Confidence is increasing for scattered showers and thunderstorms
each day due to a stalled frontal boundary.

2) Temperatures should stay near or slightly below normal.

The models reveal a stalled frontal boundary staying across North
Carolina throughout the upcoming weekend and into early next week. A
blocking upper level ridge across the western Atlantic Ocean will
prevent any movement in the overall synoptic pattern for the
foreseeable future. Although temperatures should stay near or
slightly below normal with highs only reaching the 70s and 80s, the
close proximity of the stalled frontal boundary will keep the chance
of afternoon showers and thunderstorms each day throughout this time
period. This chance should be maximized along the North Carolina and
Virginia border as the frontal boundary slowly buckles northward
over time.

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
As of 111 PM EDT Tuesday...

Primarily VFR conditions are expected across the region during
the valid TAF forecast period concluding at 18Z/2PM EDT
Wednesday. The exceptions to VFR will be some very patchy
IFR/MVFR river valley fog late tonight. Additionally, isolated
to scattered showers and storms are expected this afternoon, and
then again starting mid-day Wednesday. Look for brief sub-VFR
cigs/vsbys associated directly with this activity. Winds will
generally be light from the southwest or west through the
period with some gusts across the mountains close to 10 to 15
kts during daylight hours. Under and around any thunderstorms
wind direction will be variable with temporary gusts close to
40kts.

Confidence in the above aviation scenario is high.

AVIATION OUTLOOK...

Probability of showers and storms increase Wednesday afternoon
and evening with the arrival and passage of a cold front.

This front will be slow to exit the region, or be positioned
just south of the area into the weekend. This will keep showers
and storms in the forecast, especially for areas near and south
of the VA/NC border.

Confidence in the extended aviation scenario is moderate.

&&

.CLIMATE...
As of 315 AM EDT Tuesday...

Temperatures may come close to record high temperatures and/or
record warm low temperatures for today, July 16.

Below is a table that lists these values for locations in our
region and the years those records were set.


************* RECORDS FOR July 16 *************
+=============================================+
|  LOCATION   | RECORD HIGH  | RECORD WARM LOW |
| Blacksburg  |  93 in 1983  |   70 in 2020    |
| Bluefield   |  96 in 1988  |   71 in 1980    |
| Danville    | 102 in 1934  |   77 in 1920    |
| Lynchburg   | 103 in 1934  |   76 in 1937    |
| Roanoke     | 100 in 1988  |   74 in 2020    |
+=============================================+

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Heat Advisory until 8 PM EDT this evening for VAZ044>047-058-
     059.
NC...Heat Advisory until 8 PM EDT this evening for NCZ006.
WV...None.

&&

$$

SYNOPSIS...BMG
NEAR TERM...BMG/DS
SHORT TERM...PW
LONG TERM...PW
AVIATION...DS
CLIMATE...BMG