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577
FXUS61 KRNK 061812
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
212 PM EDT Mon May 6 2024

.SYNOPSIS...
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An upper level trough of low pressure, over the lower Ohio
and Tennessee Valleys, will move east and across the mid
Atlantic Region through tonight. This will result in the
formation of scattered to numerous showers and thunderstorms
this afternoon and evening. Storms this afternoon and evening may
contain heavy rain and small hail. The weather pattern will
remain unsettled for much of the upcoming week with a daily
threat of afternoon and evening thunderstorms.
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&&

.NEAR TERM /THROUGH TUESDAY/...
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As of 130 PM EDT Monday...

Key Messages:

1. Scattered showers and thunderstorms today through this evening.
2. Main hazards today are locally heavy rain that may produce
flash flooding, and small hail.
3. Showers and thunderstorms again Tuesday afternoon and
evening, with some potential to be severe.

A mid level shortwave crosses the area late tonight, as a low
surface tracks along a boundary oriented roughly northeast to
southwest across the Ohio Valley. Showers and thunderstorms
are already developing in west along and west of the Blue Ridge
today. Expect coverage to increase through this afternoon and
evening, as the shortwave approaches and as instability over the
area increases with daytime heating. Precipitable water on this
morning`s sounding was 1.15 inches, which is above the 90th
percentile relative to climatology for today. Forecast soundings
for this evening show an increase in PWATs, anywhere from 1.25
inches to 1.55 inches, depending on the high res model. Thus,
there is strong potential for locally heavy rainfall with any
of the storms today, which could lead to flash flooding,
especially in urban and low lying areas. Coverage of storms will
decrease after sunset with the loss of solar heating, and any
lingering showers should dissipate by midnight.

Weak mid and upper level ridging builds into the area briefly
tomorrow, and the warm front lifts northward into the lower Great
Lakes. Another shortwave will move through the upper Midwest ahead
of a deep upper low over the northern Plains Tuesday, which will
trigger some showers and thunderstorms over the Mid Atlantic and
Ohio Valley again later in the day. While the ridging aloft
will help to suppress a widespread severe threat, less cloud
cover tomorrow will result in more instability, and deep layer
shear will be sufficient enough to support more organized
convection, with a marginal threat for damaging wind and severe
hail. The stronger storms look to be mainly west of the
mountains on Tuesday, closer to the better dynamics, and where
terrain can add an additional source of lift.

Temperatures will be in the mid to upper 70s in the west and
around 80 in the east. Tuesday will be a few degrees warmer.
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&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
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As of 130 PM EDT Monday...

Key Messages:

   - Increasing flash flood threat
   - Periods of numerous showers and thunderstorms

Short range starts with south west flow between large upper low over
the Northern Plains and upper ridging over the western
Atlantic. Then by Thursday a long wave troughing digs over the
eastern United States. The upper trough axis moves the coast for
Sunday and Monday.

At the surface the main cold front will cross the area Thursday.
Temperatures remain above normal ahead of the front, especially
overnight. Precipitable water values remain just above two
standard deviations above normal ahead of the front through
Thursday as forecast by the North American Ensemble. Plus
multiple days of numerous thunderstorms will steadily saturate
the soil leading to a higher probability of flooding by
Thursday.
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&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
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As of 130 PM EDT Sunday...

Key Messages:

  - Temperatures cool off
  - Daily threat of thunderstorms continues

Overall synoptic scale pattern during this time frame features broad
troughing in the eastern United States and lower 5000 MB heights. No
particular focus to aid in development of precipitation but region
remains cooler than earlier in the week, but warm enough for a daily
chance of afternoon and evening showers and thunderstorms. For now,
enough of a break from the deep moisture to the forecast for Monday
dry.
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&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
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As of 200 PM EDT Monday...

Showers and thunderstorms are ongoing along and west of the Blue
Ridge, and a few in the Piedmont and Southside VA. Coverage of
showers and storms will increase through this afternoon and
evening, but decreasing after sunset with the loss of daytime
heating. Some showers may linger in the west overnight. Locally
heavy rain and gusty winds are possible in the vicinity of the
showers and storms. Mainly southwesterly flow will keep the
storms moving generally southwest to northeast through the rest
of the day.

Clouds will linger through the overnight and into Tuesday
morning, sub-VFR ceilings expected again. Reductions in
visibilities are possible with the development of patchy fog
overnight and through Tuesday morning. Ceilings will be variable
through at least midday Tuesday, but improve to VFR for much of
the area by Tuesday afternoon.

Showers and thunderstorms are expected again Tuesday afternoon,
towards the end of the current TAF period ending at 18Z. There
is a marginal risk for strong wind gusts and hail with the
thunderstorms Tuesday afternoon.

Forecast confidence is average.

Extended Aviation Outlook...

Unsettled weather is expected for much of the upcoming week.
Daily threat of SHRA/TSRA through Friday. This will bring
periods of MVFR/IFR ceilings and visibilities at times. Winds
through Wednesday will favor a SW direction and may be gusty at
times.
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&&

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

&&

$$

SYNOPSIS...AS/PM
NEAR TERM...AS
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...AS/PM