152
FXUS62 KRAH 120711
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
310 AM EDT Thu Jun 12 2025

.SYNOPSIS...
A weak front extending from southeastern Virginia across the North
Carolina Piedmont into upstate SC will linger across the area
through today 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 /TODAY THROUGH TONIGHT/...
As of 300 AM Thursday...

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

The surface boundary that has been lingering across the region the
past few days is expected to dissipate today. As that happens upper
level ridge will move off the coast and a deepening  trough over the
Southern Plains will bring another plume of moist southwesterly flow
to the region mid to late morning. Showers with scattered storms
will begin to initialize in the early afternoon across the south and
quickly spread north through the afternoon and evening hours. While
most of the convection is expected to be sub-severe a few stronger
storms could develop in the late afternoon and evening hours
especially across the south where instability is highest. Isolated
to scattered showers are expected to linger overnight through Friday
morning.

High temperatures  will be in the upper 80s to near 90 with heat
indices in the low to mid 90s south and east of Triad. It will feel
muggy out again tonight as dew points will remain in the low 70s
across much of the region. Lows will be in the low 70s.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 345 AM Thursday...

* Unsettled continues with increasing coverage showers and storms

An upper ridge will set up over Florida and the Southeast coast by
Friday, while a weak cutoff low drifts over the Arklatex region,
putting most of the Deep South and Southeast in warm and moisture
return flow around a Bermuda high. Overall forcing for accent will
be weak and CAPE may be hindered by multilayer cloud cover, but weak
capping and the influx of moisture will support scattered to
numerous showers and storms, either from ongoing from Thursday night
or initiating fairly early on Friday. Confidence in favored areas of
central NC for the best coverage of storms is low, but there is some
signal that the southern Piedmont/Sandhills may be favored. While
model guidance does not indicate significantly high QPF overall,  PW
is forecast to increase from around 1 inch today to as much as 2-25
inches on Friday, which combined with nearly unidirectional weak
flows and weak MBE velocities may support isolated flooding
concerns.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 310 AM Thursday...

* Chances of mainly afternoon and evening showers and storms
  increase through early next week. Isolated flooding may become a
  concern after multiple days of rainfall.

* 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.

Upper ridging over the Southeast and the Bermuda high will persist
into the weekend before a shortwave emanating from a weak cutoff low
over the Arklatex region today approaches the region Sunday and
Monday.  The mean frontal zone will set up over the Mid-Atlantic
States, which is where models tend to favor higher QPF during the
period.  However, PW is forecast to rise to more than 200% of normal
over the weekend, supporting off and on periods of scattered to
numerous showers and storms each day, most likely peaking in the
afternoon and evening given no discernible focus in the form of a
boundary or clear upper level support outside of the aforementioned
upper trough, which is forecast to shear out as it approaches
Sunday/Monday.  Thus, confidence is low in the coverage and timing
of rounds of precip.  Ample cloud cover should also generally keep
temperatures near or perhaps even slightly below normal and keep
heat indices below 100.  That said it will be rather humid for
multiple days and the Heat Risk is forecast to reach Moderate in the
coastal plain through Monday.

With the passage of the shortwave Monday, things may tend to dry out
a bit toward the middle of next week, though with no airmass change,
which could lead to higher Heat Risk and heat indices exceeding 100
in some southern and eastern counties.  The overall pattern is
forecast to remain mostly zonal, with shortwave moving through the
flow and inherent uncertainty in daily convection.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 140 AM Thursday...

VFR conditions across the region through the next few hours.  Latest
model guidance and recent trends are showing patchy fog forming
across the area. This patchy fog could potentially bring MVFR and
possibly IFR conditions across the eastern 3 TAF sites early this
morning until it lifts shortly after the sunrises. Have TEMPO groups
generally from 08z-12z for reduced visibilities and lowered
ceilings. Winds will play a major role in the timing and coverage as
is the winds stay a little bit higher at RDU, I would not expect
fog/ low stratus to develop there. The consistency of nearly calm
winds at RWI and FAY gives higher confidence for reduced
visibilities and lower ceilings. After the sunrises, all sites will
be VFR for much of the day. In the afternoon and evening hours the
chance for thunderstorms return especially at the eastern TAF sites.

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...CA
SHORT TERM...BLS
LONG TERM...BLS
AVIATION...CA
EQUIPMENT...RAH