228
FXUS62 KRAH 112343
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
743 PM EDT Wed Jun 11 2025

.SYNOPSIS...
A weak front extending from southeastern Virginia across the North
Carolina Piedmont into upstate SC will linger across the area
through Thursday before washing out on Friday. A Bermuda high
pressure system will build west into the region through early next
week, bringing warm and humid conditions.
&&

.NEAR TERM /THROUGH TONIGHT/...
As of 255 PM Wednesday...

* Showers and storms developing across eastern NC, with a Marginal
  Risk (Level 1 of 5) of severe weather in place from SPC

Early afternoon visible satellite imagery and surface obs continue
to depict a stationary boundary across the western Piedmont of NC,
stretching from roughly Roxboro to Wadesboro. While the cu field has
filled in across much of central NC, dewpoints west of the boundary
have mixed out into the lower 60s while remaining elevated in the
upper 60s to lower 70s to the east. Meanwhile, convection has
blossomed across eastern NC with the first hints of a sea
breeze/outflow moving inland. Additional isolated showers and storms
have started developing across the northern Coastal Plain as well.

MLCAPEs around 1500 J/KG are commonplace east of the stalled
boundary, as are PW`s around 1.5 to 1.75". Conditions are far less
favorable for convection to the west given dry air at the surface
and aloft, resulting in a cap of more than 200 J/KG. The previous
forecast thinking remains largely on track, with the best chances of
showers and thunderstorms along and east of US-1 through sunset. 12Z
HREF depicts the best chances for storm development across the
Coastal Plain, although if outflow boundaries collide we could see
additional development as far west as Raleigh. Some isolated 30-40kt
wind gusts can`t be ruled out with the strongest storms, nor can
some brief periods of heavy rain although widespread severe weather
and flooding are not anticipated today. CAMs typically struggle
within weakly forced environments so it`s hard to pin down exactly
how far west to draw in precip chances, but US-1 seems like a
relatively reasonable western edge based on obs and 12Z hi res model
data. PoPs will linger into the early evening hours before
conditions dry out tonight with the loss of daytime heating and BL
instability.

As for temps, the boundary will begin to slowly slosh back to the
north late tonight, yielding relatively uniform temperatures across
the area in the upper 60s to mid 70s.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
As of 255 PM Wednesday...

* Scattered storms are possible, mainly across southern areas during
  the late afternoon or evening, with weakening convection lifting
  northeast across the area overnight.

The weak surface boundary extending northeast to southwest across
the Carolina Piedmont will wash out on Thursday. As the boundary
dissipates, a south to southwesterly low level flow will
develop across the area. Afternoon and evening instability will
be maximized across the south and decrease with northern extent.
A disturbance in the southwesterly flow aloft may trigger
scattered convection across southwestern NC an western SC during
the afternoon that may spread slowly northeast and favor
subsequent convection to the northeast during the afternoon into
the evening across the Southern Piedmont and Sandhills. Some
convection allowing models suggest some lingering light showers
may spread northeast overnight.

Highs on Thursday should range in the upper 80s to around 90 with
max heat index values in the lower to mid 90s. It will be muggy on
Thursday night with lows in the upper 60s and lower 70s. -Blaes
&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 225 PM Tuesday...

* Chances of mainly afternoon and evening showers and storms
  increase later in the week into early next week.
* Humidity values increase with surface dew points reaching the
  lower 70s at times producing max heat index values in the 90s and
  moderate heat risk across southern and eastern areas over the
  weekend into early next week.

A Bermuda high pressure system will extend into the southeastern
U.S. over the weekend into early next week resulting in a general
southwesterly low-level flow. There are indications of some
weak surface troughing may develop in the lee of the mountains
across VA into northern NC late in the weekend into early next
week. Further aloft, ridging across the Southeast and FL combined
with forms and episodes of troughing across the Midwest and Great
Lakes will result in deep feed of warm moist air into the region.
PW values will increase to 1.75 to 2.25 inches late Friday into
Sunday which is about 150-175% of normal before values decrease
early next week. While the main westerlies will be well removed to
our north, there will be episodes of some weak disturbances dropping
into the region from the northwest over the weekend into early next
week.

The result will be an active pattern featuring largely diurnally
driven showers and thunderstorms across central NC. It`s worth
noting that the pattern supports limited predictability on the
details of the timing of storms for each day outside of diurnal
heating. The best storm chances should occur during the Friday
through Monday period with PoPs of 50-70%. Rather weak low and mid
level flow will limit the threat of organized and severe weather
but the deep moisture and potential for multiple days with storms
may result in an isolated flooding threat.

Highs will average 1 to 5 degrees above average and range in the mid
80s to around 90. There are signs of some slightly cooler highs on
Tuesday across the north. With a southwesterly flow it will be humid
with dew points mainly ranging in the upper 60s to lower 70s. This
will keep overnight lows elevated, generally 5 to 10 degrees above
average with lows mainly in the lower 70s with a few upper 60s in
the Triad and near the VA border and mid 70s across southeastern
areas. The combination of the heat and humidity will result in max
heat index values in the 90s and a moderate heat risk across
southern and eastern areas over the weekend into early next
week. The widespread cloudiness and risk of storms should keep
highs down enough to avoid widespread 90s and major heat risk
values. -Blaes

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
As of 740 PM Wednesday...

Convection continues in the vicinity of the eastern terminals
(FAY/RWI) with an outflow boundary pushing towards RDU where
additional showers and isolated thunder is possible. Showers and
storms should slowly fade after 8 to 10 PM. A brief period of VFR is
expected, but fog/stratus should fill back in across the area from
RDU, to RWI and FAY into early Thurs morning. Timing and cig
category remains low at this time, but moderate to heavy precip
around RWI and FAY increase confidence in some restrictions into
Thurs morning. A brief period of MVFR cigs are possible as patchy
fog/stratus lifts through Thurs morning returning to VFR by the
afternoon. Scattered showers/storms will again be possible Thurs
afternoon, best chances at FAY.

Outlook: Daily shower/thunderstorm chances, along with early morning
sub-VFR fog, are expected through the weekend into early next week.
Best chances for showers/storms appears to be Fri into the weekend
with less coverage into early next week.

&&

.EQUIPMENT...

...Computer System Upgrade at NWS Raleigh from June 16th
through 18th...

The National Weather Service Raleigh Weather Forecast Office
in Raleigh will be conducting a required, scheduled update
to our Advanced Weather Interactive Processing System (AWIPS)
computer system. NWS offices use AWIPS to display and integrate
weather and water information, and to send life-saving
information, such as weather and water warnings, to the public.

AWIPS is updated periodically, but this update is comprehensive
and requires that the system be taken completely offline for
approximately three days, from the morning of Monday, June 16th
through the afternoon hours of Wednesday, June 18th. During that
time, NWS Raleigh forecasters will produce and disseminate
products for the area using the AWIPS system at one of our
backup offices at NWS Blacksburg, VA. No impacts to our core
services of forecast products and weather watches, warnings
and advisories are expected during this period.

A few of our services will be impacted as they originate only
from AWIPS facilities at NWS Raleigh, namely:

* NOAA Weather Radio broadcast: The following NOAA Weather Radio
  transmitters, programmed by NWS Raleigh, will be off the air
  during most of the AWIPS update:

Buck Mountain (WWF 60 - 162.500 mhz)
Chapel Hill (WXL 58 - 162.550 mhz)
Ellerbe(WNG 597 - 162.400 Mhz)
Garner(WNG 706 - 162.450 mhz)
Henderson (WNG 586 - 162.500 mhz)
Tarboro (WXL 59 - 162.475 mhz)
Winston-Salem (WXL 42 - 162.400 mhz)

* Climate: Data will be updated in a limited fashion from Monday
  afternoon, June 16th through Wednesday, June 18th. Climate
  graphs for the Raleigh Forecast Area at
  https://www.weather.gov/rah/climatePlots will not be updated.

* Graphical Hazardous Weather Outlook images normally at
www.weather.gov/erh/ghwo?wfo=rah will not be updated.

* The Weather Story available at
https://www.weather.gov/rah/weatherstory will not be updated.

* Water level forecast services will be degraded due to a less
frequent update cycle. Forecasts will remain at
https://water.noaa.gov/wfo/rah through this period.

* NWS Raleigh will remain operational and staffed while AWIPS
is offline, taking public and partner phone calls, communicating
via social media, and performing other functions that can be
completed without AWIPS.

We apologize for any inconvenience. Please direct any questions
to Jonathan Blaes at jonathan.blaes@noaa.gov

&&

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

&&

$$

SYNOPSIS...Blaes
NEAR TERM...DL
SHORT TERM...Blaes
LONG TERM...Blaes
AVIATION...Swiggett/DL
EQUIPMENT...RAH