015
FXUS62 KRAH 271257
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
855 AM EDT Mon May 27 2024

.SYNOPSIS...
Unseasonably warm and humid airmass will continue unsettled
conditions through tonight. A series of cold fronts will move
through central NC through mid week with high pressure building
overhead for the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 855 AM Monday...

...There is a level 2 risk for severe storms today with another
unseasonably warm and humid airmass in place...

Continued uncertainty today wrt to thunderstorm coverage.  The well
forecasted upstream MCS has largely decayed east of the mountains.
Convective cloud debri has overspread much of the western to central
Peidmont, with some clearing out ahead across the southern
Piedmont/Sandhills/southern Coastal Plain. Given the extensive cloud
cover this morning, it`s still not entirely clear how much recovery
we`ll see later today. Nontheless, there is clearly a few MCV
features embedded within the decaying MCS evident on regional radar
that may generate convection along either a developing lee-trough or
along the cold pool.  It appears that the best coverage (after this
morning`s convection moves northeast of our area) potential may be
across the southern Piedmont/Sandhills/Coastal Plain through early
this afternoon. Guidance suggests an MCV embedded within the deeper
convection currently over Georgia may drive through these areas
later today (also where residual CIN will likely erode the
quickest). However, can`t rule out storms blossoming further north,
as a few weaker MCVs currently moving across southwestern VA and the
NC high terrain move east across the NC/VA border.

Overall, the parameter space still suggests any storm that fires
could become severe today with strong mid-level lapse rates and
plenty of effective shear to play with. Morning RAP-derived
hodographs, as well as VWP profiles depict some curvature in the
wind field across much of central NC thus far. Despite this, we have
some residual stable conditions near the sfc early this morning.
Thus, convection thus far has been largely elevated in nature. It
would appear that as we progress this morning, hail may be the
better threat at first, before transitioning to a more-so damaging
wind threat as that sfc stability erodes quite quickly this morning
(already see 70 temps over upper 60s dew points). The low-level flow
will also continue to strengthen as we progress into the afternoon
hours, and as such, better kinematics will support a non-zero chance
for a few tornadoes today. The better tornado probabilities still
appear to be east of US-1 (and moreso into MHX/AKQ`s CWAs), but
rotating storms will be possible across all of central NC through
early this evening. Overall storm motion should be quick enough to
preclude widespread flooding concerns. However, given how juicy the
atmosphere is, can`t rule out isolated urban and low-drainage
flooding from any heavier downpour today.

Rain chances should diminish later this evening as drier air punches
in from the west.  Persistent swly flow will promote highs in the
mid to upper 80s/lower 90s.


&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 305 AM Monday...

Aloft, a s/w should track through SC Tue then out over the Atlantic
Tue night as the base of the trough moves over central NC. Meanwhile
at the surface, the cold front should be over the NC Piedmont by
daybreak Tue, then continue eastward through the area through the
day and offshore Tue night. Expect NW flow in the wake of the front
Tue, however the arrival of cooler air may be delayed until Tue
night. Cannot rule out a shower/storm over the southern/central
Coastal Plain on Tue ahead of the cold front, but that activity will
move out with the passage of the front and dry weather is expected
area-wide Tue night. Highs Tue should generally range from low/mid
80s north and northwest to upper 80s south and southeast. Lows Tue
night will depend on the arrival of cooler air, but for now expect
upper 50s north to low/mid 60s south.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 230 AM Monday...

An upper level trough will amplify as it progresses eastward over
and through the mid-Atlantic and Carolinas. Several s/w disturbances
will pass over the area as they swing through the trough, however
for now they still appear relatively moisture-starved. The trough
should shift offshore over the weekend, with the sub-tropical ridge
slowly progressing eastward through the area behind it. At the
surface, with the cold front offshore by early Wed, a trough may
linger over central NC Wed before cool high pressure builds in from
the west Wed night through Fri. The high should be over central NC
Fri night/Sat. Forecast confidence decreases beyond Sat as model
solutions diverge. For now, expect largely dry weather through Sat
night, although will have to keep an eye on the passing s/w
disturbances for potential precipitation development. Temperatures
should be near normal for Wed, then near to below normal through the
remainder of the forecast period.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
As of 700 AM Monday...

Scattered to numerous showers have developed in multiple waves, the
first moving just north of RWI with the second just now developing
over the southern Piedmont and will track towards RDU through
roughly 15z. Expect mostly showers with isolated thunder, but given
the moist and unstable regime, have opted to TEMPO thunder given how
easily this has been achieved in some convection this morning. A
decaying MCS and outflow is currently traversing the southern
Appalachians and working its way into the western Piedmont. Model
guidance has continued to struggle with how this will impact GSO/INT
so have kept status quo with TEMPO storm potential. Intensification
is possible with eastward extent through the early afternoon, but
unmodeled showers across the southern Piedmont may add complexities
to the afternoon forecast. Southwesterly surface winds will become
gusty by late morning at all TAF sites with gusts up around 25 kts.
Afternoon showers and storms will again be possible, but will
largely be dependent on the activity from earlier convection.
Overnight fog/stratus may be possible, best chance FAY/RWI, ahead of
a cold front approaching from the NW.

Outlook: The first of several cold fronts will move through late Mon
night into Tues morning with high pressure building in behind and
VFR conditions expected through Fri.

&&

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

&&

$$
SYNOPSIS...Swiggett
NEAR TERM...Luchetti
SHORT TERM...KC
LONG TERM...KC
AVIATION...Swiggett