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289
FXUS62 KRAH 260137
AFDRAH

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

.SYNOPSIS...
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High pressure ridging will build into the area Sunday. A cold front
will approach Sunday night and move through the region Monday night.
Dry high pressure will settle into the region toward the middle of
next week.
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&&

.NEAR TERM /THROUGH TONIGHT/...
As of 902 PM Saturday...

Isolated to scattered showers and storms continue to pop up across
portions of the central Piedmont, Sandhills and southern Coastal
Plain. At one point this evening, there were numerous outflow
boundaries across the Triangle, Sandhills, and Coastal Plain. Little
if any storms developed over the northwest Piedmont/Triad and
northern Coastal Plain. Satellite imagery reveals a weak mid-level
circulation over the southern Piedmont to Charlotte area. This
shortwave trough should continue to progress south and east
overnight. As this happens, convection should start to collapse
south and east into late tonight, dissipating overnight. The latest
HRRR suggests this may be the case, though the southern Piedmont has
not really been worked over in the sense of there still being some
SBCAPE present. As such, lingering/new outflows may spawn new
isolated/scattered storm cells across our southern areas for the
next 2-4 hours. Activity should largely be sub-severe, though a few
stronger cells could produce heavy rain and strong wind gusts.
Convection should wane after midnight as the shortwave moves east
and subsidence ensues. Lows should hover in the low to mid/upper
60s. Patchy fog could develop almost anywhere in central NC, though
may be more prone in areas of Raleigh and the eastern Sandhills,
where rainfall amounts were higher.

&&

.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/...
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).

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
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As of 800 PM Saturday...

24-hour TAF period: Isolated thunderstorms will be possible in
mainly southern and eastern portions of central NC (including FAY
and RWI) through this evening. Brief gusty winds and sub-VFR
conditions may occur with any storm. Otherwise VFR conditions will
prevail through 06z. Then as skies become mostly clear and winds
very light to calm, patchy fog may develop overnight into early
Sunday morning, resulting in MVFR or IFR visibility restrictions.
The best chance for this looks to be in the east (including RDU, FAY
and RWI) where locally heavy rain fell today. More isolated
to widely scattered showers and storms are possible tomorrow
afternoon. A more organized line of showers and storms may begin to
move into the Triad (including INT and GSO) around 21z-00z.

Outlook: Showers and storms may continue on Sunday evening
into Sunday night, then again on Monday afternoon and evening.
The most widespread coverage looks to be on Monday. 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, which will last into
Thursday.
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&&

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

&&

$$
SYNOPSIS...Kren
NEAR TERM...Kren
SHORT TERM...CA
LONG TERM...Green
AVIATION...Danco/Green