392
FXUS62 KRAH 030752
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
350 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 /TODAY AND TONIGHT/...
As of 155 PM Sunday...

The trough axis from Sunday will roughly be over the area to start
our Mon over the central Piedmont and along the US-1 corridor. This
axis will slide SE toward the coast in the afternoon to early
evening, with shortwave ridging building east from TN.

The latest CAMs depict a possible leftover MCV from Sunday`s
convection that may move across the Triangle, Sandhills, and Coastal
Plain in the morning hours. While confidence is low on this feature,
there will be very little CIN and some elevated CAPE of a few
hundred joules to support spotty showers into mid-morning.

As clouds start to erode by early afternoon and heating raises highs
into the low to middle 80s, most guidance indicates instability of
around 1000 J/kg and deep-layer shear of 10-20 kt with little to no
CIN. Most high-res models suggest isolated to widely scattered storm
activity could form just about anywhere in central NC with PW`s near
the 90th percentile of 1.6 inches.

Perhaps the more favored areas for isolated storms would be east of
US-1 along lingering outflows/lift from the MCV and a sea-breeze, as
well as over the northwest Piedmont where a lee trough should favor
storm activity over the higher terrain and tracking ESE with the NW
mid-level flow. We do not expect any storms to reach severe limits
given the low-end shear. Most storm activity should wane after
sunset with loss of daytime heating. Low temperatures should once
again be near the middle 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 /06Z MONDAY THROUGH FRIDAY/...
As of 215 AM Monday...

A mid and upper-level disturbance, and accompanying rain and
embedded showers/storms and flight restrictions, will move east
across cntl NC this morning. In their wake, areas of IFR-MVFR
ceilings will also expand across the Piedmont, lowest and longest at
INT/GSO where IFR ceilings have already recently developed. Those
ceilings should lift and scatter to VFR by ~14-15Z, after which time
diurnal convection may interrupt otherwise VFR conditions through
early tonight.

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...Kren
SHORT TERM...Green
LONG TERM...Green
AVIATION...MWS