187
FXUS62 KRAH 021755
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
155 PM EDT Sun Jun 2 2024

.SYNOPSIS...
An upper trough crossing the region will provide some cloudiness and
widely scattered light showers today and tonight.  Otherwise, look
for a warmer temperatures, more humidity, and increasing chances for
daytime shower and thunderstorm activity as we head through the
first half of the week.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 942 AM Sunday...

Morning satellite imagery continues to show widespread cloud cover
across NC in advance of an approaching longwave trough over the TN
valley. A weak embedded wave within the trough, and associated
forcing for ascent, has produced some widely scattered
showers/sprinkles across the area, but for the most part there is
still too much mid level dry air to overcome for showers to reach
the ground (depicted well by the dry layer from 600-800mb per 12Z
GSO sounding). Cloud cover has held temperatures back a bit this
morning but given the relatively mild start to the day, temps are
slowly climbing through the upper 60s into the lower 70s as of
1330Z.

As the upper trough approaches, surface high pressure will continue
to migrate offshore allowing for continued moist advection into the
area. The combination of the approaching shortwave and lee troughing
east of the mountains should produce additional showers later this
afternoon, primarily across the western Piedmont and that is the
area where the highest PoPs have been depicted in today`s forecast
(30-40 percent). There is an outside chance of a rumble of thunder
in that area as well but instability is understandably meager given
extensive cloud cover and any storms that develop should remain well
below severe limits. As the wave slowly moves east tonight,
additional light showers are possible across much of central NC but
rainfall amounts will be light (a few hundredths of an inch at
most). A broad swath of 15-20 PoPs will remain in the forecast for
the evening/overnight period to account for the passage of the
trough but once we get back 00Z tonight, all mentions of thunder
will be removed from the forecast.

High temps today should reach the low to mid 80s. Look for a mild
night tonight given cloud cover and increasing dewpoints: low to mid
60s.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
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.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 317 AM Sunday...

The extended forecast continues to show an unsettled pattern, with
Saturday the only day with high confidence of dry conditions.
Perhaps the most difficult aspect of the long term forecast is that
the strongest features, a surface low and upper level low, should
primarily remain over Canada. Weaker features, a surface cold front
(which will bring some drier air but not much in the way of cooler
air) and an upper trough rotating around the upper low while the low
is over the Great Lakes, will be the forcing mechanisms for any
precipitation, which will have lower predictability.

Chance pops are expected on Tuesday primarily east of US-1, then all
locations should have high chance pops on Wednesday and Thursday.
Tonight`s model runs are showing the highest chances of rain
remaining to the west of central North Carolina on Wednesday, then
shifting the highest chances of rain north of the region on
Thursday, a slightly different solution than what was shown 24 hours
ago. There is fairly good agreement between deterministic and
ensemble models that the cold front should move through late
Thursday, then loiter along the coast Friday. This should keep
chance pops east of I-95 Friday, with slight chance pops across the
rest of the forecast area mainly due to the 00Z GEFS solution. With
the front shifting offshore Saturday, that is the one day in the
forecast with high confidence for dry conditions.

Expect minimal variations in the highs and lows through the period -
highs will range from the mid 80s to the low 90s while lows will be
in the 60s.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 110 PM Sunday...

Mainly light sprinkles across the area at the moment but conditions
remain VFR. Additional showers are expected later this afternoon,
primarily around INT/GSO and there could be brief periods of MVFR
ceilings within the strongest showers. Meanwhile to the east,
conditions should remain dry (outside of the aforementioned
sprinkle) through 00Z although some of the INT/GSO showers may make
a run at RDU right around 00Z and I included a few hours of VCSH.

Late tonight, most guidance indicates widely scattered showers
across the area as a trough moves through NC. Elected to include a
few hours of VCSH at RDU/FAY/RWI as this trough crosses the area
although confidence in how this late night scenario will play out
is low.

Outlook: Additional, mainly diurnally driven showers and storms, are
expected through much of this week as we return to a more typical
June pattern. Highest storm chances are likely at INT/GSO although
all 5 TAF sites could see impacts in the form of non-VFR cigs/vsbys
within any showers that develop.

&&

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

&&

$$
SYNOPSIS...np
NEAR TERM...Leins
SHORT TERM...Kren
LONG TERM...Green
AVIATION...Leins