044
FXUS62 KRAH 191800
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
200 PM EDT Wed Aug 19 2026

.WHAT HAS CHANGED...

* The severe thunderstorm risk for Thursday afternoon has increased
  across the entire area.

* Heat Advisory issued for Cumberland, Harnett, Sampson, and Wayne
  counties for Thursday.

&&

.KEY MESSAGES...
As of 200 PM Wednesday...

1) Nearly the entire forecast area is now under either a level 1 or
2 risk for severe thunderstorms Thursday afternoon.

2) One more day of above normal temperatures is expected, with
forecast highs in the 90s everywhere on Thursday.

3) Rain/thunderstorm chances will increase Friday and Saturday.
Flash flooding and strong to damaging winds will be the main
threats.

&&

.DISCUSSION...
As of 200 PM Wednesday...

KEY MESSAGE 1... Nearly the entire forecast area is now under either
a level 1 or 2 risk for severe thunderstorms Thursday afternoon.

Ahead of an approaching cold front, an area of showers and
thunderstorms is expected to develop across the mid-Atlantic states,
extending southwest into the Carolinas. With the afternoon update,
the Storm Prediction Center has increased the severe risk across
most of the area for Thursday afternoon and evening. While their
previous issuance included a marginal (level 1 of 5) risk from Wake
County to the northeast, the newest issuance now has a slight (level
2 of 5) risk from Franklin County to the northeast, with a marginal
risk elsewhere. While large hail cannot be ruled out northeast of
Raleigh, the primary threat of severe weather will come from
damaging wind gusts. The newest runs of the HRW NSSL and HRW ARW
show that convection could start as early as 1-2pm along and west of
the US-1 corridor, although the primary threat for severe weather
will occur between 5-9pm.


Key message 2... One more day of above normal temperatures is
expected, with forecast highs in the 90s everywhere on Thursday.

A Heat Advisory remains in effect through 8pm tonight for Cumberland
and Sampson counties - although heat index values may not reach 105
in these counties due to lower dewpoints and moisture, the
experimental HeatRisk product indicates an extreme (level 4 of 4)
risk for portions of these counties. While dewpoints may increase by
a degree or two on Thursday, air temperatures are expected to rise
by a couple degrees on Thursday compared to today. A Heat Advisory
was issued for Cumberland and Sampson counties again, in addition to
Harnett and Wayne counties. While it is possible that other areas
could have the heat index rise to 105 degrees, there is more
uncertainty outside of these 4 counties due to the potential for
convection beginning earlier in the afternoon. If confidence
increases that thunderstorms will be delayed in arriving Thursday
afternoon, later shifts may choose to expand the heat advisory.


KEY MESSAGE 3... Rain/thunderstorm chances will increase Friday and
Saturday. Flash flooding and strong to damaging winds will be the
main threats.

An upper level trough will remain located over the Eastern US into
next week. There should be a few mid/upper level shortwave troughs
embedded within the upper flow, bringing a source of lift for a few
rounds of rain. The best chance for widespread rain will be on
Friday. A very moist airmass will be in place, as seen by an
increase of PWs to 2 to 2.1 in over the region. Current guidance
suggests widespread rainfall totals of around 1-2 inches on Friday,
with locally higher amounts possible where stronger cells train over
the same area. Thus, mostly localized flash flooding will be
possible, especially in urban and poor drainage areas. Additionally,
there should be adequate instability with the 50th percentile of the
LREF suggesting around 2500 J/kg of CAPE. This combined with around
20-30 kts of bulk shear should be sufficient for a few stronger
cells to form and sustain over the region Friday afternoon and
evening. Depending on the timing of any rain on Saturday, a similar
airmass will be in place, meaning that additional strong to severe
storms will be possible. With any severe storms that occur this
weekend, the main threat will be damaging winds, especially from
water-loaded downdrafts. Additionally, cloud cover could cause
lowered temperatures and instability, which would lessen the threat
of any severe weather both Friday and Saturday, so will need to see
trends in the guidance as we get closer. The trough axis should
shift eastward Sunday into Monday, bringing drier air to the region
and lessening rain chances at the start of the work week. Another
shortwave trough may pass over the region, bringing the next best
chance of rain.

With the trough overhead, temperatures should fall back closer to
normal for this time of year. This equates to high temperatures
generally being in the mid 80s to low 90s through the weekend into
next week.

&&

.AVIATION /17Z WEDNESDAY THROUGH MONDAY/...
As of 120 PM Wednesday...

TAF period: The odds of any terminal receiving an afternoon
shower/thunderstorm is less than 10%, but FAY would have the
greatest chance of any of those locations. It appears likely that a
shower would need to occur at FAY for their visibility to drop late
tonight into Thursday morning - while some model guidance suggests
fog will develop there tonight, their visibility did not drop this
morning and there has been no change to the air mass. While there is
more diurnal cloud cover than expected this afternoon, skies should
become mostly clear after sunset. The potential of a shower/storm at
any terminal before 18Z Thursday is too low to mention at this time.

Outlook: There will be a chance of thunderstorms Thursday afternoon
at all terminals except FAY, and showers are likely Thursday night
at GSO/RDU. Expect widespread showers/storms Friday into Saturday,
with coverage decreasing from west to east Saturday night into
Sunday. Flight restrictions are likely with the rain.

&&

.CLIMATE...

Record High Minimum Temperatures:

August 20: KRDU: 75/2007 KFAY: 78/2005
August 21: KRDU: 76/2009 KFAY: 77/2005
August 22: KRDU: 74/2017 KFAY: 75/2018

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 11 AM to 8 PM EDT Thursday for NCZ077-078-088-089.
Heat Advisory until 8 PM EDT this evening for NCZ088-089.

&&

$$

DISCUSSION...Green/Helock
AVIATION...Green