Area Forecast Discussion Issued by NWS Raleigh/Durham, NC
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 050147
AFDRAH
Area Forecast Discussion
National Weather Service Raleigh NC
947 PM EDT Sun Jun 4 2023
.SYNOPSIS...
-- Changed Discussion --
High pressure will drift across and offshore the Carolinas through
Monday, during which time a front will develop east and across the
southern Appalachians.-- End Changed Discussion --
&&
.NEAR TERM /TONIGHT/...
-- Changed Discussion --
As of 945 PM Sunday...
An upper-level trough over the Southeast will deamplify while moving
east and offshore tonight, while another will move from the lwr OH
Valley swd and across the srn middle Atlantic. The movement of those
features will cause sswly upper-level flow observed over the
Carolinas this evening to veer to wly and eventually nnwly through
early Mon; and as a consequence, the shield of cirrostratus now over
the ern Carolinas will get shunted ewd and sewd through the night.
At the surface, 1015 mb high pressure centered over VA will drift
south and across the Carolinas. Dry air related to the ridge will
continue to advect around it and from the middle Atlantic coast swd
and through the ern Carolinas, while low-level moisture will
otherwise linger over the wrn half of NC, including the wrn Piedmont.
As a result of the above, stratocumulus will linger over the wrn NC
Piedmont and favor mostly cloudy conditions there, with clear(ing)
skies elsewhere, as the aforementioned cirrostratus moves away from
cntl NC. Low temperatures will consequently display a range of low
50s with clearing skies over the Coastal Plain, to around 60 F or so
where stratocumulus lingers over the wrn Piedmont .-- End Changed Discussion --
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 325 PM Sunday...
A low-amplitude, sheared shortwave trough diving south on the back-
side of the large-scale upper trough in place across the Eastern US
will descend across the Ohio Valley and mid-Atlantic regions during
the afternoon and into the Carolinas Monday evening. Related
synoptic scale lift/forcing, including a period of rather decent
upper jet divergence will lead to the development of isolated to
scattered convection during the afternoon and into the evening,
mainly along a weak surface lee-side trough in place across the
eastern slopes of the so. Appalachians. The far NW Piedmont counties
will once again(similar to Saturday/yesterday)be the INVOF of the
instability maximum and while that is only forecast to be around 750-
1000 J/KG, deep layer shear between 30-40kts will be sufficient to
support a few strong to severe storms. Wind and hail will be the
primary threat. Severe threat will be diurnally driven, with
convective intensity waning quickly around sunset. There will
however be a chance for isolated to widely scattered showers to
spread southeastward across remainder of the forecast area through
through the early overnight hours( 06-09z)until the sheared
disturbance passes south of the area.
Skies will vary from partly cloudy in the west to mostly sunny in
the east. Highs ranging from mid/upper 70s north to lower 80s south.
Lows in the upper 50s to lower 60s, with some mid 50s expected in
the cooler, outlying rural areas.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 200 PM Sunday...
Tue: An upper trough over the NE US and Canadian Maritimes will
bring WNW flow aloft over central NC. A few ripples of energy in the
flow combined with a southward moving front/lee trough will warrant
the chance of some afternoon showers and storms. However, the
effective boundary, along with deeper moisture/instability appears
shunted mainly across the southern Piedmont, Sandhills, and southern
Coastal Plain. Depending on what convection, if any, develops Mon
with a lee trough, will impact where this boundary sets up for Tue.
Effective shear, though, combined with mid-level dry air/high DCAPE
seen in forecast soundings could favor a hail/wind threat. The best
chance of showers/storms should be mainly south/east of the
Triangle. Under an airmass that continues to modify from Mon, highs
should be in the mid to upper 80s.
Wed-Sun: The pattern during this period will continue to favor a
trough over the NE US that will slowly sag to the south into the Mid-
Atlantic and Carolinas by the end of the week/upcoming weekend. A
trend to more zonal flow looks to take place late Sat/Sun, but with
a potential system approaching from the west/northwest late Sun or
next week Mon. Models and their ensembles appear to be coming into
somewhat better agreement on timing and placement of shortwaves
rotating around the base of the trough in the NW flow aloft. Chances
of showers and perhaps a storm will be possible Wed and Thu as a
stalled frontal boundary combined with mid-level forcing slowly sags
along and south of the area. Models show the front passing through
sometime Thu, with weak high pressure settling in across the Mid-
Atlantic Fri/Sat. After highs Wed in the 80s, a return to below
normal temps in the 70s and low 80s will take shape for week`s end.
This surface high, moves offshore come Sun, with a return flow and
highs closer to normal for June in the mid/upper 80s. There could be
a chance of showers returning late Sun/Mon but model spread still
varies such that only slight chances are warranted thus far.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 745 PM Sunday...
24 hour TAF period: MVFR cigs have held at KINT and KGSO, and will
likely remain in place through around midnight. There is uncertainty
whether the MVFR cigs will scatter out after midnight or hold
through daybreak. There is also a chance for a period of IFR cigs at
KINT and possibly KGSO. A shower is also possible at KINT and KGSO
between 02Z and 06Z. Elsewhere, VFR conditions should generally
prevail, however there could be a period of some MVFR cigs at KRDU
and KFAY overnight. KRWI should remain VFR through the period.
Showers and storms could develop late Mon eve over the western
Piedmont and Foothills. -KC
Outlook: Isolated to widely scattered showers and storms will be
possible late Monday afternoon/evening, mainly INVOF of KINT and
KGSO. Some lingering showers and storms are possible Tuesday, mainly
across southern NC, INVOF FAY as a cold front moves into the area.
Thereafter, expect predominately VFR conditions. -CBL
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...CBL
LONG TERM...Kren
AVIATION...KC/CBL