355
FXUS62 KRAH 222005
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
404 PM EDT Wed Jul 22 2026

.WHAT HAS CHANGED...

* No significant changes to the heavy rainfall threat through
  Thursday night, but a slightly drier trend for Friday and Saturday.

&&

.KEY MESSAGES...
As of 400 PM Wednesday...

1) Waves of showers and storms with a risk for excessive rainfall
and flooding will focus along a slow-moving, outflow-
reinforced/strengthened cold front that passes through central NC
from now through Thursday night.

2) The slow moving cold front across the Carolinas will settle south
and stall across the southern Carolinas for Friday and into the
weekend with the area of widespread rain shifting south and the
rainfall intensity decreasing on Friday and especially Saturday.

&&

.DISCUSSION...
As of 400 PM Wednesday...

KEY MESSAGE 1... Waves of showers and storms with a risk for
excessive rainfall and flooding will focus along a slow-moving,
outflow-reinforced/strengthened cold front that passes through
central NC from now through Thursday night.

Scattered thunderstorms will begin to move into the NW Piedmont over
the next few hours. These cells will then develop into a broken
convective line pushing eastward through the Triangle during the
evening and overnight hours, maintaining the threat for isolated to
scattered strong to severe storms. It is fairly cool and stable near
the VA border with temperatures only in the upper-70s, so it may be
difficult to get much of a damaging wind threat there. Across the NW
Piedmont, on the other hand, temperatures are still in the upper-80s
with SBCAPE around 1500-2000 J/kg. If storms can outrun the boundary
into the warm sector, this is likely where the greatest severe
threat will be. However, while 0-1 km shear is not impressive (10-15
kts), still can`t rule out a quick spinup with any convection, even
on the cool side of the boundary. Localized excessive rainfall and
flash flooding will be the bigger threat, particularly in urban
areas.

By late tonight and Thursday morning, the activity is expected to
spread south and east into the Sandhills and Coastal Plain as well.
While the severe threat will generally subside tonight with loss of
instability, storm motion running parallel to the stalling boundary
will cause repeating waves of heavy rain to train over the same
areas, shifting the primary hazard to more widespread flash
flooding. Thus a Flood Watch is in effect for all of central NC,
beginning across the northern half this afternoon and evening, then
across our southern half overnight tonight. The WPC Excessive
Rainfall Outlook for today/tonight highlights a Moderate Risk (Level
3/4) clipping the northeastern Coastal Plain (near Roanoke Rapids)
with a Slight Risk (Level 2/4) across roughly the northern half.
Urban areas, small streams, and creeks will be particularly
vulnerable to rapid runoff and localized flash flooding. Mainstem
rivers will also begin to rise in response to heavy rainfall, though
they are expected to remain below minor flood stage through at least
Thursday morning.

The cold front will move only slightly south and east on Thursday,
and with rich Gulf moisture from Tropical Storm Bertha continuing to
funnel NE along the front, another day of heavy rainfall and
possible flash flooding is expected, this time across all of central
NC. WPC QPF on Thursday and Thursday night is 1-2 inches on average
across the region, except across our far north as the front sags
south of there. As always, locally higher amounts will be possible,
with 12z HREF LPMM depicting potential for 2-4 inches to the south
and east of Raleigh. The 12z HREF and REFS depict neighborhood
probabilities of exceeding 6-hour FFG peaking across our area from
12-18z Thursday. Thus there is a moderate (level 3 of 4) risk for
excessive rainfall across eastern NC that includes much of our
Coastal Plain, with a slight (level 2 of 4) risk for the rest of
central NC outside of the far NW. No mainstem rivers are forecast to
reach minor flood stage at this time, but it can`t be ruled out if
excessive rain falls directly over a basin. Still, urban and small
stream flash flooding will be the biggest and most widespread threat.

One silver lining is the severe threat at least looks to decrease on
Thursday. This is due to the Eastern US troughing beginning to
flatten, resulting in a weakening of the mid-level flow, and the
best instability shifting to our southern zones where shear will be
less. However, a few strong storms with water-loaded downbursts or a
quick spinup still can`t be totally ruled out, mainly in the south.


KEY MESSAGE 2... The slow moving cold front across the Carolinas
will settle south and stall across the southern Carolinas for Friday
and into the weekend with the area of widespread rain shifting south
and the rainfall intensity decreasing on Friday and especially
Saturday.

While there will still be a threat for heavy rainfall on Friday, it
looks to be less overall compared to today and Thursday and shifts
to mainly south and east of Raleigh, as the cold front shifts south
and stalls from SC to the southern NC coast. WPC QPF from Friday
into Saturday has decreased compared to yesterday, with just 0.25-
0.5 inches expected on average for most of the area, except 0.5-1.5
inch totals across the southern Piedmont, Sandhills, and
central/southern Coastal Plain. A shortwave trough moving through
the TN Valley and southern Appalachians may actually enhance the
moist air mass again on Saturday as PW values increase to 2-2.5
inches, along with providing additional forcing for ascent. However,
we will still be on the cool side of the boundary, which should keep
rainfall rates lower than they had been.

Conditions will turn drier from Sunday through early next week as
the mid/upper troughing finally pushes to our east and the flow
aloft turns northwesterly. However, as temperatures heat back up,
isolated diurnally-driven convection still can`t be ruled out each
day, especially by Tuesday and Wednesday.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
As of 255 PM Wednesday...

VFR conditions will prevail through late afternoon ahead of the
slowly approaching cold front. A pre-frontal broken line of
convection is expected to slowly move west-to-east across the
region, impacting KINT/KGSO late this afternoon, KRDU by late
evening, and KFAY/KRWI during the overnight/early morning Thursday
hours. Expect temporary restrictions to IFR/LIFR in heavier
thunderstorms, along with erratic convective gusts. Behind the
initial convective line, persistent low-level moisture and a weak
boundary-layer will support widespread low stratus through Thursday
morning before gradual lifting occurs late in the period with a wind
shift to the northeast. A strengthening 35-40kt southwesterly low-
level jet between 1500-2k feet will cross the eastern terminals
(KRDU, KFAY, KRWI) overnight. While decoupling at the surface could
briefly create localized LLWS conditions between 03z and 11z,
boundary mixing from where it rained/stormed and any convective
outflows reduces the confidence in development and duration, so kept
the WS group from the 18Z TAF package.

Outlook: Widespread showers and storms will result in adverse
aviation conditions with VSBY and CIG restrictions on Thursday
and Thursday night across central NC. The focus for the convection
will shift slowly south into southern NC late Thursday and Friday
with coverage decreasing notably and shifting further south on
Saturday. Aviation conditions will improve on Sunday with a limited
chance of showers.

&&

.CLIMATE...

Record Low Maximum Temperatures:

July 23: KGSO: 73/2019 KRDU: 76/1921

July 24: KFAY: 81/1985

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 9 AM EDT this morning through Thursday evening for
NCZ007>011-021>025.
Flood Watch from this evening through Thursday evening for
NCZ026>028-038>041.
Flood Watch from late tonight through Friday morning for NCZ042-043-
073>078-083>086-088-089.

&&

$$

DISCUSSION...Danco/CA
AVIATION...MWS/CA