170
FXUS61 KRNK 061833
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
233 PM EDT Thu Jun 6 2024

.SYNOPSIS...
A warm and moist airmass will remain over the area through
today promoting showers and thunderstorms. A cold front will
move through the region this evening, with drier and cooler
weather to start the weekend.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 200 PM EDT Thursday...

Key Messages:

1) A few strong to severe storms possible east of Blue Ridge
through this evening...then partial clearing.

2) Drier and cooler weather arrives Friday

Forecast focus is on the passage of a cold front this evening
promoting showers and thunderstorms. Main threat for
thunderstorms is east of the Blue Ridge where surface heating
has allowed for higher buoyancy to support deep convection.
Pre-frontal trough lee of the Blue Ridge will likely enhance
storms as they move east across the piedmont so expect storm
activity to increase across southside VA and into the piedmont
before exiting the CWA early this evening.

Models are in good agreement on timing having best chance of
showers/storms through 21Z/5PM before exiting the CWA. After
that should see partial clearing with winds shifting to the
west. The front is actually coming through in pieces...the main
push of moisture this evening, followed by a secondary front
associated with the drier air late tonight. Aside for a few
isolated showers overnight the overall trend will be for drying.
Friday should feature a much drier day with winds out of the
west or northwest and associated with falling dewpoints. It will
be breezy at times with gusts up to 25 mph.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 100 PM EDT Thursday...

Key Points:

1. Around or slightly above normal temperatures.
2. Scattered showers on Sunday into Sunday night.

A look at the 6 June 00Z NCEP Ensemble Mean 500 mb Geopotential
heights shows a persistent upper low centered near the
Ontario/Quebec border through the period. However, a couple
associated shortwave troughs are expected to progress around this
low and cross our region. The first of these is expected Friday
evening just east of the region, with the second on Sunday evening.
At the surface, a cold front is expected to extend from far eastern
VA southwest along the coast of the Carolinas Friday evening. By
Saturday, a weak high pressure center moves into the area. On
Sunday, our next cold front is expected to cross the area and be
east of the region by the end of Sunday night.

Output from the 6 June 00Z Ensemble Situational Awareness Table
shows 850mb temperatures averaging +16C on Saturday, +14C to +16C
for Saturday and +12C to +14C for Sunday. Precipitable Water values
are expected to average 0.75 inches or slightly less Friday night
into Saturday and 1.25 inches Sunday. The values Friday night into
Saturday fall within the 2.5 to 10 percentile range of the 30-year
climatology.

The above weather scenario points to a period with around or
slightly above normal temperatures. Primarily dry conditions are
expected through Saturday night. Sunday into Sunday night, look for
a return of showers with the passage of the cold front and residual
activity from upslope northwest flow across Southeast West Virginia
late Sunday night. Thunderstorm potential looks low with forecast
CAPE on most models under 500 J/kg.

Confidence in the above weather pattern is moderate to high.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
As of 130 PM EDT Thursday...

Key Points:

1. Temperatures trending from slightly below to slightly above
average.
2. While precipitation chances will not be zero through the period,
the vast majority of the region will be dry.
3. While at most scattered in coverage, the mountains have the
greatest potential to experience showers.

A look at the 6 June 00Z NCEP Ensemble Mean 500 mb Geopotential
heights shows a persistent long wave trough extending from southeast
Canada into the Ohio Valley. Each day Monday through Thursday, the
trough is expected to remain nearly stationary, but there will a
gradual trend towards less amplification as ridging across western
CONUS shifts into the center of the nation. At the surface, on
Monday, a cold front will be positioned along the Atlantic coast.
High pressure will be centered across the Central Plains States and
Upper Mississippi River Valley. On Tuesday and into Wednesday, a
ridge of high pressure will be over the region. On Thursday, is
still expected to be over the general area, but potentially trending
weaker.

Output from the 6 June 00Z Ensemble Situational Awareness Table
shows 850mb temperatures around +14C for Monday, +14C to +16C for
Tuesday, +16C on Wednesday and a little over +16C for Thursday.
Precipitable Water values on Monday are expected to average 1.00
inch on Monday and Tuesday, 1.25 inch on Wednesday and 1.00 to 1.25
inches for Thursday.

The above weather scenario points towards a time period with limited
precipitation chances and temperature around or slightly cooler than
normal for this of year through Tuesday. Around or slight above
normal temperatures are expected Wednesday into Thursday. The best
chances for showers will come on Monday, and perhaps Monday night
while we are still within a northwest flow pattern. For Tuesday
through Thursday, while precipitation chances will be low, they are
not expected to be zero. While we expect a general region of surface
high pressure over the region, additionally over the area aloft will
be a weakening upper level trough. The trough, and its expected
steep lapse rate aloft, will help promote convection development
above where any fledgling towering cumulus develop during the peak
heating of the afternoon. Coverage will be isolated with the vast
majority of the area receiving no precipitation.

Confidence in the above weather pattern is moderate.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
As of 130 PM EDT Thursday...

Scattered to broken line of deep convection to move
east/southeast through the piedmont late afternoon and into
tidewater of VA by evening impacting areas mainly east of ROA.
Will maintain a few hours of TSRA at LYH/DAN but overall
expecting just SHRA for the remaining TAF sites until 21Z/5PM.
After 21Z/5PM, expecting partial clearing.

A cold front is in the process of passing across the
mountains...winds shifting to the west-northwest. A few gusts
to 20kts possible ahead of the front...then diminishing
overnight. A secondary front will cross the mountains late
tonight, this second front the leading edge of a more bonafide
drier airmass. Some low topped showers may accompany this
frontal passage around midnight, otherwise just another period
of clouds before skies clear out for the day Friday. Winds will
increase out of the west-northwest Friday with some surface
gusts to 20 kts from late morning through the afternoon.

Forecast confidence is average on all elements.

EXTENDED AVIATION OUTLOOK...

Mainly VFR through the extended period.

&&

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

&&

$$

SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...DS
LONG TERM...DS
AVIATION...PM