748
FXUS62 KRAH 010600
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
200 AM EDT Tue Jul 1 2025

.SYNOPSIS...
A cold front will cross the Appalachians today, then stall out
across the Carolinas Wednesday and Thursday.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 200 AM Tuesday...

A cold front will extend from Lake Ontario southwest into Kentucky
and arc into Texas Tuesday morning. While previous forecasts
indicated that the front would likely sink south into North Carolina
and bring widespread rain, models are now indicating that the front
will move to the southeast much more slowly, likely not even
entering North Carolina by Wednesday morning. However, a surface
trough in advance of the front, in addition to an upper trough that
will move into North Carolina by Wednesday morning, will help to
trigger showers and thunderstorms. Although scattered convection is
expected east of US-1 during the daytime, the majority of rainfall
will fall to the west of US-1 during the day, with likely showers
and thunderstorms only extending as far east as I-95 overnight. The
Storm Prediction Center keeps the bulk of the area under a Marginal
(level 1 of 5) risk for severe weather today, with the primary
threat coming from damaging winds. Although instability is likely to
be between 1000-2000 J/kg, effective bulk shear will be minimal
across North Carolina, which will be a hindrance to organizing
severe storms. Although the new WPC Excessive Rainfall Outlook has
not been released yet, the Monday afternoon issuance had most of the
area to the west of I-95 in a Marginal (level 1 of 4) risk for
excessive rainfall. The heaviest rainfall rates would likely occur
during the evening.

The additional cloud cover should result in highs being a few
degrees cooler than the last several days, although highs will still
primarily be in the upper 80s and lower 90s. There will be minimal
changes to low temperature forecasts, with values in the upper 60s
and lower/mid 70s.

&&

.SHORT TERM /TUESDAY/...
As of 340 PM Monday...

* Continued hot and humid, with convection to become numerous over
  the srn and wrn Piedmont during the afternoon

The wrn periphery of a sub-tropical high centered near and south of
Bermuda will continue to weaken and break down through Tue. It will
do so owing to both the passage near the South Atlantic coast of a
mid/upr-level low now north of Grand Bahama and also with the
approach of a positive tilt mid/upr-level trough that will progress
from ON to the cntl Plains this afternoon to QC through the mid MS
Valley by 00Z Wed. The latter trough will be immediately preceded by
a convectively-amplified one, and MCVs from clusters of pre-frontal
convection now stretching from the Middle Atlantic to the srn
Plains. While a broad area of weak, 10-20 meter mid-level height
falls will result over VA and the Carolinas, stronger, mesoscale
forcing for ascent will be maximized along the track of any lower
predictability MCVs.

At the surface, a Piedmont trough will remain over cntl NC,
downstream of an outflow-reinforced and modulated front that will
approach from the northwest and extend from the nrn Middle Atlantic
coast to the mid-South or TN Valley by 00Z Wed.

Diurnal convection will become increasingly numerous over the
Piedmont during the afternoon. Swly lwr to mid-tropospheric flow
around 20 kts will support multi-cell development within a
moderately unstable and deeply and unseasonably moist environment
characterized by PWs of near 2", with an associated threat of strong
to tree-damaging wet microbursts and (especially) urban flooding.
High temperatures will be mostly in the lwr 90s, with some upr 80s
possible over the nw Piedmont where convection and outflow may
become increasingly prevalent prior to peak diurnal heating.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 230 PM Monday...

* Unseasonably warm weather continues into early next week, with the
  exception of Wednesday when widespread cloud cover and lingering
  rain chances will keep temperatures a few degrees below normal.

A parent shortwave will be motoring through Ontario into the
Newfoundland and Labrador province by Tues evening with the base of
the trailing trough axis over the lower Ohio Valley expected to
swing across the Carolinas through Wed afternoon. This feature,
along with any embedded MCV`s from prior upstream convection, will
act as the primary forcing mechanism for ongoing showers/storms over
the Piedmont of NC early Tues evening. This activity is expected to
continue, although gradually weakening and becoming more localized,
as it slowly shifts eastward through the overnight and into Wed.
Most locations along and west of I-95 should see at least trace
amounts up to around 0.5". Narrow swaths of 1.5" to 2.5" will be
possible and may result in localized areas of flash flooding mainly
in urban corridors. Given the low predictability of these MCVs, as
they depend entirely on the initiation and evolution of convection
that has yet to develop, confidence on more precise locations of
heavier rainfall remains low at this time.

A narrow band of unseasonably high deep-layer moisture extending
through the Mid-Atlantic into the Southeast, will slowly sag
southeastward immediately ahead of the trailing trough axis and
associated cold front reach the Carolina coast by late Wed
afternoon. Cloud cover and precipitation chances through peak
heating will likely keep temperatures up to 5 degrees below normal,
marking the coolest day in the Triangle since early June. Drier air
through a deep layer will overspread the region as surface high
pressure settles overhead through the holiday weekend. One caveat is
that aforementioned cold front is forecast across northern FL, and
models have signaled a chance a low developing along the front.
Models have been split on whether that low would develop over the
northeast Gulf or off the Florida east coast.  No local impacts are
evident in current model guidance, but there could be some
enhancement of POPs over the east by Sun into early next week.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
As of 120 AM Tuesday...

24 hour TAF period: Much of the TAF period is expected to have VFR
conditions. However, there is the potential for stratus to develop
overnight, most likely at FAY. Although it is only included in the
FAY TAF, cannot rule the stratus expanding north to RDU and RWI. All
locations should be VFR shortly after sunrise and through much of
the afternoon. Recent model guidance has suggested a slower arrival
of precipitation, and while prevailing rain has been added to
INT/GSO in the afternoon, the tempo groups for thunderstorms have
been slightly delayed. Similarly, the tempo group was delayed at
RDU, and prevailing showers were added after 00Z. Confidence is less
that widespread rain will reach FAY/RWI during the 06Z TAF period,
so have only gone with VCSH and a prob30 group for thunderstorms.

Outlook: Showers and thunderstorms will expand east late tonight
along with the arrival of widespread IFR/MVFR ceilings. Widespread
showers/storms will continue Wednesday, with restrictions expected.
Precipitation could linger at RDU/RWI/FAY Wednesday night into
Thursday, with a dry forecast into the weekend.

&&

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

&&

$$
SYNOPSIS...Green
NEAR TERM...Green
SHORT TERM...MWS
LONG TERM...Swiggett/BLS
AVIATION...Green