272
FXUS62 KRAH 031347
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
945 AM EDT Mon Jun 3 2024

.SYNOPSIS...
A series of mid-level disturbances will move east and interact with
a surface trough and unseasonably moist airmass over NC through
Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM Monday...

As the current surface trough slowly moves across the region
scattered showers continue to move across the eastern portions of
the CWA this morning. Another round of lighter rain is moving across
the Triad area but dissipating as it moves south east. Made minor
changes to the PoPs today as rounds of precipitation is expected
through the day. While chances reduce to 15-25 % for a few hours
during the day, the afternoon chances increase to 25-35% when the
lee trough enters the NW Piedmont later today and moves across the
region this afternoon and evening. While clouds are expected to thin
out later this morning between the features, some areas could see
some sunshine and heating, in result, temperatures ranging around
the low to mid 80s today.

As of 400 AM Monday... Amid an unseasonably moist airmass
characterized by PWs around 1.5" (~90th percentile at GSO), a
tropopause-based disturbance will move from cntl SC esewd and
offshore through 12Z. Meanwhile, an MCV evident in KRAX data over
wrn Chatham Co. will drift slowly, generally ewd and across the ne
NC Piedmont this morning/through ~16Z and across the Coastal Plain
this afternoon/through ~20-21Z.

At the surface, high pressure centered near Bermuda will continue to
extend wwd and across the South Atlantic states. Meanwhile, a lee
trough will sharpen with diurnal heating over the Foothills and wrn
Piedmont of the srn Middle Atlantic and Carolinas, while a sea
breeze will move inland and into the NC Coastal Plain and ern
Sandhills. A weak backdoor cold front will drift south and across
the Delmarva and Chesapeake Bay tonight.

While cloud tops have generally been warming with the area of
convection now moving across west-cntl NC, bursts of cooling and
deepening convection have been noted immediately surrounding the
center of the aforementioned MCV, as it moves east through a weakly
unstable environment over cntl NC. This compact area of convection
will probably be maintained as the MCV continues to move slowly ewd
through the day, and the airmass diurnally warms into the lwr-mid
80s and becomes moderately unstable throughout cntl NC. In the wake
of the MCV, additional, isolated/widely scattered showers/storms are
expected to develop along the lee trough and spread east and across
the wrn Piedmont later this afternoon-evening. A lack discernible
forcing features for tonight suggest today`s convection should
dissipate with nocturnal cooling, with seasonably muggy low
temperatures in the mid/upr 60s.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 350 AM Monday...

A lack of a synoptic forcing mechanism makes any details for
Tuesday`s forecast difficult, but precipitable water values will be
so high (GFS shows between 1.5-1.8") that any lift that does occur
should be able to develop showers/thunderstorms (with CAPE values
between 500-1000 J/kg). Models have shown the potential for a back-
door cold front entering the area, but this remains tenuous. In
addition, flow is less than 20 mph throughout the vertical column,
so any showers that do develop will be slow-moving in nature. After
a dry morning, have gone with chance pops in the afternoon and
evening, with at least slight chance pops lingering into the
overnight hours. Any flow in the vertical column that does occur
will have a southerly component, and this weak warm advection should
push highs into the mid/upper 80s. Tuesday night`s lows will be in
the mid/upper 60s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 350 AM Monday...

By Wednesday morning, a stacked low will be over Manitoba, with an
upper trough and surface cold front arcing southeast across
Minneapolis into Illinois and down across the southern Mississippi
River. Both of these features will approach North Carolina during
the day, and have expanded likely pops across the entire forecast
area on Wednesday. Southerly flow will continue to increase, and the
GFS indicates that PW values could approach 2", nearing record
territory. High chance pops will continue into Wednesday night, with
a lobe of energy breaking off both the surface and upper features
and another stacked low forming near Lake Huron by Thursday morning.
Slightly expanded the coverage of likely pops on Thursday, now
covering all areas southeast of US-1, although models are showing
some indecision in how quickly the cold front will move through.
While some parameters depict the front moving east late Thursday
into Thursday night, other parameters show the front bisecting the
region somewhere along the US-1/I-95 corridor Thursday night with a
more definitive push through the region Friday morning. Have
continued with the slight chance pops everywhere Friday afternoon
based on ensemble solutions despite deterministic solutions showing
all precipitation moving to the coast. Dry weather returns to the
forecast for the start of the weekend with dry conditions forecast
Friday night, Saturday, and Saturday night. Another front should
remain west of the region on Sunday, and with a lot of model
uncertainty, only have slight chance pops in the forecast for Sunday.

Thursday should be the warmest day, with highs ranging from the mid
80s to the lower 90s. The Thursday/Friday will only drop
temperatures by a couple degrees, but it will bring a noticeably
drier air mass into the region. The weekend should have highs in the
80s. Lows will mostly be in the 60s, with some upper 50s near the
Virginia border Friday and Saturday nights.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
As of 750 AM Monday...

A mid and upper-level disturbance, and accompanying rain and
embedded showers/storms and flight restrictions, will move east
across RDU, FAY, and RWI this morning. In their wake, an area of IFR
ceilings at INT/GSO should lift and scatter to VFR by ~14-15Z.
Otherwise, and elsewhere, daytime heating of a seasonably humid
airmass may support a brief period of convective cloud bases between
2-3 thousand ft AGL through early this afternoon. Associated cumulus
will probably deepen into scattered showers/storms with continued
heating and destabilization through the rest of the afternoon, but
nebulous and/or low predictability forcing mechanisms suggest
probability of occurrence at any particular TAF site will be just 20-
30 percent at this time range. Areas of IFR stratus will be possible
again late tonight-Tue morning, mainly over the Piedmont.

Outlook: Seasonably humid conditions will support a risk of late
night-early morning stratus and fog and mainly diurnal
showers/storms through at least Thu, after which time a late week
cold frontal passage, and following drier air, should end the threat
of both.

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...CA/MWS
SHORT TERM...Green
LONG TERM...Green
AVIATION...MWS