109
FXUS61 KRNK 030733
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
333 AM EDT Fri May 3 2024

.SYNOPSIS...
Frontal system over the Ohio and Mid-Mississippi valleys will
move east, bringing clouds, scattered showers, and a few
thunderstorms to our region later today, these showers becoming
more prolific this weekend. Unseasonably warm temperatures today
will transition to somewhat cooler conditions this weekend as
clouds and an easterly wind become established over the forecast
area.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 300 AM EDT Friday...

Key Messages:

1. Continued unseasonably warm today.

2. Increasing clouds today with showers arriving across the
mountains during the afternoon.

3. Scattered showers areawide tonight with isolated
thunderstorms.

A cold front stretches from the Southern Plains into the
western Great Lakes with low pressure centered near Chicago. A
warm front extended east from the low across the northern Mid-
Atlantic. Within the warm sector temperatures were well above
the seasonal norm with both temperatures and dewpoints more like
late spring or early summer.

As we transition through the next 24 hours, the airmass will
get a little more humid as south winds ahead of the approaching
mid-west cold front bring higher dewpoints into the region.
There will be an increase in cloud cover to go along with the
increasing moisture and at some point, early-mid afternoon for
the mountains, we should begin to see development of shower
activity. Models suggest the best chance for showers today will
be west of I-77 from the NC High Country northward through Mount
Rogers and far southwest Virginia, and along and west of the
Appalachian Divide in West Virginia. There may also be some
showers along the warm front north of I-64. To the south and
east of these favored areas, most of the day should remain dry
with temperatures attempting a repeat of yesterday. Forecast
numbers reflect readings well above normal with highs in the
mid-upper 80s for the piedmont and upper 70s to lower 80s for
the mountains.

For tonight, the showers should begin to spill east of the Blue
Ridge with increasing chances as the front to our west gets
closer, in addition to areas to our northeast. As the upper
ridge near the Atlantic coast breaks down, expect warm front to
our north to become a back-door cool front, a northeast to
easterly surge of wind accompanying this feature as it moves
south through the piedmont early tonight. By Saturday morning,
all areas east of the mountains should transition to a cooler
northeast to easterly wind. In spite of the cooling trend,
overnight temperatures will continue to favor the warmer side
of normal.

Thunderstorm threat today and tonight looks minimal. Even with
daytime heating today, CAPE for our forecast area is not
expected to exceed 1000 j/kg. For now will advertise isolated
thunder threat, but nothing severe.

&&

.SHORT TERM /This Weekend/...
As of 130 PM EDT Thursday...

Key Messages:

1) Confidence is high for scattered showers and thunderstorms
throughout this upcoming weekend.

2) A marginal risk of flooding exists on Saturday and Saturday
night.

A cold front will approach the Appalachian Mountains during
Friday night into Saturday. Scattered showers and
thunderstorms will spread eastward, but the highest chances and
coverage are more likely by Saturday afternoon and evening. Due
to the prevalent moisture expected in the atmosphere, some of
these storms could produce heavy downpours. While antecedent
conditions are rather dry, the storms could train over the same
locations as the cold front slows upon crossing the Blue Ridge.
Consequently, a marginal risk of flooding exists during late
Saturday into Saturday night.

The primary area of low pressure with this cold front will stay
well to the north across eastern Canada. While the northern
part of the cold front will eventually head offshore, the
southern part will become parallel with the zonal upper level
flow and stall across the Mid Atlantic. As a result, the chance
of showers and thunderstorms will continue into Sunday and
Sunday night. Temperatures will start a little below normal for
highs on Saturday but trend warmer by Sunday, but lows should
remain quite elevated due to the prevalence of cloud cover.

&&

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

Key Messages:

1) Confidence is moderate for ongoing chances of showers and
thunderstorms each day.

2) Temperatures will trend warmer as the week progresses.

With a stalled frontal boundary draped across the Mid Atlantic,
several waves of low pressure will track eastward to bring a
daily chance of showers and thunderstorms. Some upper level
ridging should occur by the middle of the week, which will push
temperatures above normal but fuel more instability for
convection. Deciphering which days will be the most active for
showers and thunderstorms remains difficult due to the subtle
timing differences of these waves of low pressure in the models.
The frontal boundary may budge northward as a warm front
towards Tuesday and Wednesday. Even though a cold front may
arrive by Thursday, there does not appear to be any appreciable
change in the air mass to end this unsettled pattern.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
As of 300 AM EDT Friday...

Widespread VFR conditions at all terminals this morning, with
VFR expected through most of the day. Cirrus will be on the
increase today with scattered afternoon high based cumulus. At
some point the cumulus may form a lower cloud base with
opportunity for showers later in the afternoon. An isolated
thunderstorm or two cannot be ruled out along and west of the
Blue Ridge.

Showers will gradually overspread the entire region tonight in
addition to a few thunderstorms. Sever weather is not
anticipated, but do expect lowering cloud bases tonight with
transition to MVFR and possibly IFR by daybreak Saturday
morning.

Light/calm winds expected early this morning, becoming south
southwesterly late morning and early afternoon 5-8kts. A
backdoor cold front will introduce a northeast wind across areas
east of the mountains tonight.

Extended Aviation Outlook...

Rain showers and the potential for isolated thunderstorms are
expected through the weekend. This will bring periods of
MVFR/IFR TSRA/SHRA at times. There is also a chance for LIFR
associated with development of easterly upslope wind vcnty of
the Blue Ridge which may impact terminals for Saturday and
Sunday.

Unsettled weather is expected next week. Scattered mainly
afternoon and evening SHRA/TSRA continue Monday and Tuesday with
periods of MVFR ceilings/ visibilities.

Easterly winds this weekend will shift back around to the south
and southwest for Monday and Tuesday.

&&

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

&&

$$

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