549
FXUS62 KRAH 291846
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
246 PM EDT Mon Apr 29 2024

.SYNOPSIS...
An upper level trough will pass over North Carolina Tuesday and
Wednesday, with the next cold front approaching the region for the
weekend.

&&

.NEAR TERM /TONIGHT/...
As of 210 PM Monday...

High pressure remains over the southwestern Atlantic Ocean, with
southwesterly wind over North Carolina bringing warmer and more
moist air into the region. Some diurnal cumulus clouds are grazing
the southeastern portion of the forecast area near the coastline,
but otherwise clouds are few and far between. Mostly clear skies
will continue through the evening, then high clouds will begin to
increase from the west overnight. A light southerly wind should
continue overnight, and lows will remain similar or be slightly
warmer than last night`s values, ranging from the mid 50s to the low
60s.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 210 PM Monday...

While the surface high will remain off the southeastern United
States, the next weather maker will arrive Tuesday as an upper level
trough. Although the moisture through the vertical profile will be
modest, a deep saturated layer will be lacking with the system,
limiting the potential for heavy rain. Any showers associated with
the trough will not make it much farther east than the Triad through
the daytime hours Tuesday, then all locations will have at least a
slight chance of showers overnight, but the focus shifts south of US-
64. MUCAPE values around 500 J/kg should be enough to allow for a
slight chance of a thunderstorm during the afternoon and evening
hours, but the development of a low-level temperature inversion
should limit the thunderstorm potential after midnight. The GFS and
especially the NAM show a fair amount of moisture near the surface
Tuesday night, so even if showers don`t continue through the night,
some low stratus could develop late that night. Highs should be
similar to today`s values in the east despite the increasing cloud
cover, while highs in the west will be a few degrees cooler with the
additional cloud cover, around 80 degrees. Lows will be slightly
warmer with cloud cover, from the upper 50s to the mid 60s.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
As of 240 PM Monday...

...Unseasonably warm through the end of the work week with a
decaying cold front bringing slightly cooler temperatures and
increased rain chances this weekend...

A compact shortwave trough will be centered over the Carolinas Wed
morning and is expected to slowly slide off the coast by Wed
evening. The remnants of a decaying cold front, basically a
convergence axis at this point, will act as a focus for convection
Wed afternoon. Instability of 500 to 1000 J/kg will likely be enough
to support scattered showers and isolated storms given the overall
lack of dry air aloft on the immediate backside of the departing
shortwave. Little to no storm organization is expected outside of
cold pool organized clusters with deep layer shear less than 20 kts.
Increased cloud cover and precipitation in the area may lead to a
degree or two cooler for high temperatures compared to Tues
resulting in a range from the low to mid 80s with overnight lows in
upper 50s to low 60s. Depending on the amount of precipitation and
clearing that can occur overnight, lingering rich low-level moisture
and pockets of calm conditions may lead to some patchy fog to
develop, mainly in the Coastal Plain and into the Sandhills early
Thurs morning.

In the wake of the departing shortwave, the subtropical ridge will
again amplify over the Mid-Atlantic into the Northeast through Fri.
Thurs through Fri is expected to be the warmest period in the
extended with highs climbing into the mid/upper 80s. The highly
amplified mid/upper level flow will strengthen surface high pressure
centered over Newfoundland and eastern Ontario while ridging down
into the Mid-Atlantic coast while a decaying cold front approaches
from the west. These boundaries and the flattening of the sub-
tropical ridge will help support diurnal showers/storms possible
into the weekend, with the primary focus around where the
aforementioned boundaries ultimately set up. Confidence on timing,
placement, intensity, is less than average given model guidance
discrepancies. Trended forecast towards diurnally favored
showers/storms during the afternoon, with a lull overnight. Highs
should be tempered a bit due to increasing overall cloud cover and
slightly lower low-level thicknesses as the ridge collapses with
highs ranging from the upper 70s to mid 80s during the weekend.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
As of 105 PM Monday...

TAF period: VFR conditions are expected to dominate the TAF period.
The exception is the potential for some low stratus/fog around
sunrise at FAY/RWI, and this potential has been maintained in a
TEMPO group. Otherwise, south-southwest wind should persist through
the next 24 hours, with an occasional gust this afternoon, lighter
wind overnight, then a slight veering of the wind Tuesday morning.
While some diurnal cumulus should be around FAY this afternoon, only
expect high clouds at other sites. Late tonight high clouds will
begin to move in from the west, but no precipitation is in the
forecast through 18Z Tuesday.

Outlook: Convection will be possible Tuesday afternoon/evening at
INT/GSO and Tuesday night/Wednesday at RDU/FAY/RWI with restrictions
possible in showers/storms. There is a higher chance of stratus at
all terminals Wednesday morning than Tuesday morning, some of which
could be IFR. An additional round of low stratus will be possible
Friday morning, and scattered convection will be possible at all
terminals Saturday. Otherwise, the majority of the forecast period
should feature VFR conditions.

&&

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

&&

$$
SYNOPSIS...Green
NEAR TERM...Green
SHORT TERM...Green
LONG TERM...Swiggett
AVIATION...Green