392
FXUS61 KRNK 062155
AFDRNK

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

.SYNOPSIS...
The weather pattern will remain unsettled for much of the
week with a daily threat of afternoon and evening
thunderstorms.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 545 PM EDT Monday...

Key Messages:

1. Scattered showers and thunderstorms through this evening.
Some may bring locally heavy rainfall.

2. Showers and thunderstorms again Tuesday afternoon and
evening, with potential to be severe.

Keeping close to latest HRRR which has better handle on meso
situation. Should be a lull in activity in the southwest through
early evening so have cancelled the flood watch. A few more
showers, possible storms expected toward 10pm-midnight but
thinking is flash flood threat is too isolated/spotty at best to
have a watch. Only a few locations received over 2 inches of
rain.

Previous discussion...

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.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
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.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
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.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
As of 550 PM EDT Monday...

Showers/few storms may impact BLF/LWB/BCB in the 03z-06z time
frame but overall coverage tonight into Tuesday will be limited.
Fog and low stratus appears to become more of an issue
overnight. IFR to LIFR or lower is likely in places where it
rained and where any breaks in the cloud cover occur which could
be almost any site. Will lean toward MVFR/IFR east and lower in
the west.

Any fog will likely erode by 14z. 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,
but coverage looks too limited to have in the tafs.

Forecast confidence is average.

Extended Aviation Outlook...

Unsettled weather is expected for much of the 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.

&&

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

&&

$$

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