362
FXUS61 KRNK 100025
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
825 PM EDT Sun Jun 9 2024

.SYNOPSIS...
A cold front tracks across the area this evening with breezy
conditions and a scattered showers and thunderstorms mainly in
the mountains. Dry cooler weather returns Monday. Next
opportunity for showers looks like it will hold off until the
end of the week or weekend. The week as a whole is expected to
be dry.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 800 PM EDT Sunday...

Key Messages:

1. Breezy through sunset, winds subsiding overnight. Another
breezy afternoon expected Monday.

2. Scattered showers/storms mainly west I-77 and south of the
VA/NC border this evening as a cold front moves through.

3. Cooler temperatures tonight and Monday.

Expanded PoPs for the next hour or so to include a slight
chance for most of the mountains west of the Blue Ridge. A few
very light showers are appearing on radar, which will quickly
dissolve once drier air enters from the west tonight. In fact,
dewpoints at some of our western AWOS/ASOS are already beginning
to drop. Rain will likely cease before 11PM for all areas in our
CWA.

Winds remain blustery but are expected to quiet down a bit
overnight.

From the previous discussion...

Surface cold front is moving through the forecast area,
extending from the central Mid-Atlantic to eastern Oklahoma.
The front is moving to the southeast with highest CAPE across
the Mid-MS and upper TN valleys. Expecting showers and
thunderstorms along the southern extent of the front across TN
and into the Carolinas. Farther north into Virginia, some
isolated showers ongoing just ahead of the front, but activity
is getting pounded by a westerly downslope wind which is
subjecting much of our forecast area to subsidence on the east
side of the mountains...the showers drying up as they pass east
of the Appalachian Divide. Plan is to maintain chance for a few
showers and storms through this evening west of I-77 and into
the NC Piedmont...otherwise focus will be on the drying trend
behind the front. Gusty northwest winds will persist through
this evening per strong WNW LLJ. These winds should subside over
all but the highest elevations overnight.

Upper trough will swing through the Great Lakes and into the
northern Mid-Atlantic Monday. This will result in cold air
advection and cooler temperatures. Cyclonic flow and will
promote enough lift for a fairly large cumulus field during the
day with potential for some isolated showers north of I-64
during the late afternoon and evening. As a whole, expecting
mainly dry conditions Monday and this looks like it is going to
be the start of a multi-day stretch of mainly dry weather for
the work week.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 300 PM EDT Sunday...

Key Points:

1. Temperatures will average values slightly below normal.
2. Little to no chance of showers.

A look at the 9 June 00Z NCEP Ensemble Mean 500 mb Geopotential
heights shows a longwave trough over the region Monday evening.
Through Wednesday, this feature trends broader and weaker and pivots
northeast to over the Canadian Maritimes. By Wednesday, our region
will be under nearly zonal flow. The orientation be closer to west-
northwest to east-southeast. Also on Wednesday, a trough is depicted
over the Lower Mississippi Valley region into the Gulf of Mexico. At
the surface, Monday evening, cold front will be just east of our
region heading east, while high pressure approaches from the mid-
West. On Tuesday, a west-east oriented ridge of high pressure is
expected to be over our area. On Wednesday, little change is
expected for our region as the surface ridge holds fast. Low
pressure, or a series of low pressure systems, are depicted
developing between Saskatchewan and Ontario.

Output from the 9 June 00Z Ensemble Situational Awareness Table
shows 850mb temperatures for Monday night in the +8C to +10C range,
with the low end of that range across western portions of our area.
It is also this same western region that corresponds to values which
fall into the 2.5 to 10 percentile of the 30-year climatology. By
Tuesday afternoon, temperatures across the area will be closer to
+12C to +13C. Temperatures trend milder into Wednesday, with
readings by the afternoon around +16C for region. Precipitable Water
values Monday night into Tuesday night will average around or
slightly less than 0.75 inches. Western sections will see values
within the 2.5 to 10 percentile of the 30-year climatology. For
Wednesday into Wednesday night, the average values increases to
around 1.00 inch.

The above weather scenario points toward a forecast with limited
chances of precipitation. The best chance, although still a small
chance, may be Monday evening across parts of Southeast West
Virginia. Initially, temperatures will be on the cool side of normal
Monday night into Tuesday, but trend to values around normal by
Wednesday and Wednesday night.

Confidence in this portion of the forecast is moderate to high.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 300 PM EDT Sunday...

Key Points:

1. Above normal temperatures through Friday, than near normal over
the weekend.
2. Isolated showers, perhaps a rumble of thunder, possible Friday
across the mountains.
3. Low confidence precipitation chances next weekend.

A look at the 9 June 00Z NCEP Ensemble Mean 500 mb Geopotential
heights shows our region within a west-northwest to east-southeast
flow for Thursday. The axis of an expansive Arctic low will extend
south into the Great Lakes region. While some deterministic guidance
has been showing this feature the past few days, the quantity of
individual members and consistency of location has allowed the
ensemble average to now depict an area of low pressure across the
central to eastern Gulf of Mexico on Thursday. For Friday, the Great
Lakes trough is expected to shift east, and cross our region.
Concurrently, the ensemble average loses its definition of a defined
low centered for the GofM system, and depicts a generic broad region
of low pressure over GA/FL. For Saturday, the trough over our region
shifts to over New England. The broad averaged area of low pressure
remains depicted over AL/GA/FL. Ridging is expected over the mid to
upper Mississippi River Valley. On Sunday, this ridge shifts east to
be almost centered over our region. The averaged broad low bordering
the the GofM retrogrades to TX/LA/MS. At the surface for Thursday, a
west-east oriented ridge of high pressure remains across our area.
Low pressure heads east into Quebec with a cold front trailing
southwest into the central Great Lakes region. For Friday, a cold
front crosses our area. The surface ridge retrogrades into the mid-
West. Some weak troughiness is noted in the Gulf of Mexico. For
Saturday, the cold front from Saturday will be over the far western
Atlantic. High pressure will be centered near Lake Erie. A general
area of troughiness will exist across roughly 110 to 100 West
Longitude portion of CONUS, then curve eastward into the GofM. For
Sunday, our area will be in a southeast flow regime with high
pressure centered over the western Atlantic and low pressure over
the western sections of central CONUS.

Output from the 9 June 00Z Ensemble Situational Awareness Table
shows 850mb temperatures will be close to +18C on Thursday. For
western parts of the area, this corresponds to values within the 90
to 97.5 percentile of the 30-year climatology. For Friday, these
numbers are slightly higher with our entire area within the 90 to
97.5 percentile. For Saturday and Sunday, forecast numbers and
percentile ranges are close to those of Thursday. Precipitable Water
on Thursday will average 1.00 to 1.25 inches, 1.25 inches on Friday,
a tight nw-se gradient of 1.00 to 1.50 inches on Saturday, and
around 1.25 inches for Sunday.

The above weather pattern depicts a warming trend through Friday to
above normal temperatures. Friday, a cold front crosses the region
and brings, but precipitation chances will be minimal. For the
weekend, temperatures will be closer to normal values for this time
of year. Saturday into Sunday, high pressure will enter the region.
The question will be if its center progresses east of the area, and
thus allow for anti-cyclonic flow to advance moisture back into the
region. If there is enough moisture, and a weaker cap aloft since
the center of the high would be east of the area, peak heating
showers could develop, especially across the mountains.

Confidence in the temperature trend during this portion of the
forecast and timing of precipitation on Friday is moderate. For
Saturday and Sunday confidence in precipitation chances is low.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 800 PM EDT Sunday...

SLight chance of showers for areas south of the VA/NC border
will only last a couple more hours. Virga has been observed from
the office here in Blacksburg, so even areas that show light
radar returns may not be experiencing precipitation at the
surface. Westerly to northwesterly winds are gusting 15-20 kts,
but will calm and cease gusting during the overnight period.
Tomorrow afternoon may see the return of some westerly gusts
around 15kts.

Cigs in the 6-10kft range will be the norm tomorrow afternoon,
and winds will be high enough to prevent any fog formation.
Expect VFR conditions with consistent winds out of the west to
northwest for most of this TAF period.

Confidence in the above forecast is above normal.


EXTENDED AVIATION OUTLOOK...

VFR anticipated through the upcoming week.

Mainly dry conditions expected Monday through Friday.

&&

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

&&

$$

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