182
FXUS61 KRNK 022340
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
740 PM EDT Thu May 2 2024

.SYNOPSIS...
High pressure will be nudged out of the area over the next 24
hours as a frontal system moves east. A low pressure system
brings scattered showers to the region by tomorrow night, and
this trend only increases for the weekend. Unseasonably warm
temperatures and a daily threat of late day showers and
thunderstorms continue through next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 735 PM EDT Thursday...

No significant changes were made during this forecast update.
Some minor adjustments to hourly temperatures to account for
current trends.

Still some scattered cumulus across the mountain empire
associated with a weak boundary draped across the eastern
Appalachians. Although some look to have a little bit of depth
on visible satellite, no rain is being observed from this
cumulus field. Should have mostly clear skies overnight as any
cumulus diminishes after loss of heating.




As of 135 PM EDT Thursday...

Key Messages:

1. Possibility of tying/exceeding high temperature records this
afternoon.

2. Increasing clouds towards morning, with warm overnight lows.

3. Clouds and rain chances increase by tomorrow afternoon for
the southern Blue Ridge, gradually spreading to the remainder of
the area.

Water vapor imagery this afternoon shows a baroclinic zone
stretching from central Canada down to the TX Gulf Coast. The
Mid Atlantic region was under a 580 dam ridge. An upper low was
centered near southern Saskatchewan and northern Montana.
Overnight,expect mostly clear skies, with some patches of
clouds and fog possible towards morning. Lows will be warm under
a strong ridge, with cooler temperatures in the 50s for the
lower elevations, and as warm as the lower 60s for the ridges
and the Piedmont.

A short wave trough rotates from the Plains to the Great Lakes
region tomorrow. This will be the forcing that pushes the
baroclinic zone towards us. That said, 2-D frontogenesis looks
weak here tomorrow, with the heft of the short wave energy
concentrating over the southern Gulf Coast and the OH Valley.

Precipitation start time may vary, based on the actual location
of the baroclinic zone and attendant cloud cover. At any rate,
showers and storms will be scattered to begin with, so not
everywhere will receive rain tomorrow and tomorrow night.
Currently have convection first firing along the southern Blue
Ridge in the afternoon, and very gradually increasing in
coverage to include the remainder of the area, including the
Blue Ridge mountains westward, during the evening. This is
backed up by GEFS probabilities showing chances for more than
0.01 inches of rain to be near zero east of the mountains before
8 PM.

Output from the NAEFS situational awareness table shows 850mb
temperatures about 1-2 standard deviations above normal for the
thirty-year climatological period for Friday. This yields
temperatures pretty similar to today, but based on an expected
increase in mid and high clouds tomorrow, overall temperature
readings will be a tad cooler.

Confidence in the near term forecast is moderate.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
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 /00Z FRIDAY THROUGH TUESDAY/...
As of 735 PM EDT Thursday...

Widespread VFR conditions at all terminals this evening, with
VFR expected through tomorrow. Some cirrus may move in
overnight and more widespread clouds move in throughout the
daylight hours tomorrow. Cigs should lower as areas of scattered
showers are possible across the mountains late in the TAF
period. Even with increased clouds, VFR is expected through the
end of the TAF period.

Light/calm winds overnight increasing to 5kt to 8kt by early
afternoon, generally from the SSW.


Extended Aviation Outlook...

Rain showers and the potential for isolated afternoon
thunderstorms continues off and on through the weekend. This
will brings periods of MVFR TSRA/SHRA at times, with LIFR being
more likely Saturday and Sunday. Daily afternoon and evening
SHRA/TSRA continue Monday and Tuesday with periods of MVFR
ceilings/ visibilities.

Easterly winds across the Piedmont will shift to southerly along
with the mountains by Saturday, and become slightly gusty each
afternoon.

&&


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

&&

$$

SYNOPSIS...AMS/SH
NEAR TERM...BMG/SH
SHORT TERM...PW
LONG TERM...PW
AVIATION...BMG/SH
CLIMATE...AMS