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129
FXUS62 KRAH 251947
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
345 PM EDT Sat May 25 2024

.SYNOPSIS...
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Unsettled weather will continue through Memorial Day, with the
potential for severe weather on Monday. After a cold front moves
through Monday night, drier and cooler air will move in for the rest
of the week.
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&&

.NEAR TERM /THROUGH TONIGHT/...
As of 255 PM Saturday...

The latest radar supports the hi-res models suggestion that
scattered thunderstorms will track off the Blue Ridge ESE into the
Triad late this afternoon. Differential heating may combine with
potential outflow boundaries to help initiate the convection. In
addition, 20-30 knots of bulk shear is forecast that will aid in
convection to become loosely organized for several hours late this
afternoon. Scattered thunderstorms may reach the Triangle and
Fayetteville areas between 7 and 9 PM.

Low-level lapse rates will become steep as surface temperatures rise
into the upper 80s to 90 and may pose a strong to severe wind gust
threat ahead of any organized clusters. Over the Piedmont into the
Coastal Plain, weaker instability (~1000 J/kg) and bulk shear (10-20
kts) will likely result in isolated pulse type storm mode.

Skies will clear behind the departing showers/storms with weak
pressure gradient over central NC overnight. This will favor another
night of patchy fog with areas of fog possible in locations that
receive the heaviest rainfall. Lows will mostly fall into the mid
60s.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
As of 250 PM Saturday...

Sunday will start off dry across the area, some might see patchy fog
early morning but will clear shortly after sunrise. By the afternoon
an increase of showers and thunderstorms is expected. As the
enhanced shortwave trough progresses east from the IL/IN area during
the day, by the afternoon it is expected to be on the door step of
the Appalachian Mountains by late evening. Isolated to scattered
storms are expected to begin to evolve across the region late
afternoon. With loss of heating the severe threat is expected to
diminish through the overnight hours Sunday.  HiRes CAMs are showing
a bit more consistency with timing of the first round of storms
moving across the region late Sunday night through early Monday
morning. While this round of storms are expected to move across the
region swiftly, PW values are expected to be above normal (1.5-
2.0inches), thus some heavy rain could cause some minor flooding in
poor drainage areas. Drivers should be be extra cautious driving in
these storms at night. CAPE values will be lower than what is
expected with Mondays storms, but some storms could be strong. Kept
PoPs higher across the Northern Piedmont region, but chance PoPs are
generally across the region. Sunday will be warm, 5-7 degrees above
normal. Highs will be in the mid/upper 80s some areas reaching 90,
lows will range from upper 60s to low 70s.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
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As of 345 PM Saturday...

There is the potential for Sunday night`s showers/storms to still
remain across eastern counties on Monday morning, but the primary
chance for rain will come Monday afternoon and evening, driven by a
surface cold front and upper level trough. Considering the hot and
humid air mass in place, even if there are showers lingering into
Monday, there should be time for instability to recover and for
strong to severe thunderstorms to occur. The severe weather threat
remains highly conditional based on the previously mentioned
showers, but also on whatever upstream MCS moves into the region,
which will have limited predictability. Hopefully tonight`s 00Z high-
resolution model runs will have a better handle on how the system
will evolve through Monday afternoon. The only high-resolution model
that currently goes out through Monday afternoon is the 12Z NAM
Nest, which shows a small cluster of thunderstorms approaching the
Triad late Monday afternoon. Forecast CAPE values appear to be
slightly higher than they were forecast 24 hours ago, with values up
to 2500 J/kg. Shear remains generally unidirectional at around 30
kt. The bulk of the precipitation should move east of the area by
midnight Tuesday, although a slight chance of thunderstorms will
linger along the I-95 corridor Tuesday afternoon. The region will be
in a bit of a low-level synoptic lull on Wednesday before high
pressure builds in from the Great Lakes on Thursday and remains the
primary surface feature through Saturday. While the GEFS suggests
there could be an isolated thunderstorm across western counties late
Saturday afternoon, this is not supported by the deterministic
GFS/ECMWF and have kept the forecast dry.

Monday is likely to be the warmest of the next 7 days, with highs
ranging from the mid 80s to the low 90s. After the cold front passes
Monday night, highs should be in the 80s everywhere Tuesday with
highs eventually being in the upper 70s for most locations Thursday.
Normal high temperatures for June 1 range from 82 at Greensboro to
86 in Fayetteville, and forecast values for Saturday appear to be
seasonable. There will be several days with lows in the 50s, but
it`s a little early to forecast the potential for any locations to
drop into the upper 40s overnight late in the week (normal low
temperatures are in the low to mid 60s).
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&&

.AVIATION /20Z SATURDAY THROUGH WEDNESDAY/...
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As of 345 PM Saturday...

TAF period: Although flight categories should be predominantly VFR,
there was enough confidence in thunderstorm coverage to include a
MVFR tempo mention of thunderstorms at INT/GSO/RDU. While
precipitation coverage should be less at FAY and RWI, a thunderstorm
cannot be completely ruled out at these sites. Otherwise there
should be scattered high clouds with light and variable winds over
the next 24 hours.

Outlook: Scattered showers/thunderstorms will be possible at
terminals Sunday afternoon, with the most widespread coverage of
showers/storms occurring Monday afternoon/evening. Category
restrictions will be possible with any thunderstorm, and Monday`s
storms could bring especially gusty winds. By Tuesday, VFR
conditions are expected under high pressure.
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&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Green
NEAR TERM...Badgett
SHORT TERM...Hartfield
LONG TERM...Green
AVIATION...Green