633
FXUS62 KRAH 230742
AFDRAH
Area Forecast Discussion
National Weather Service Raleigh NC
340 AM EDT Mon Jun 23 2025
.SYNOPSIS...
A strong ridge of high pressure will extend over the Mid Atlantic
and Carolinas through much of the upcoming week, bringing
dangerously hot weather.
&&
.NEAR TERM /TODAY AND TONIGHT/...
As of 250 AM Monday...
* Dangerous Heat Begins---Heat Advisory Has Been Expanded to include
all 31 counties of Central NC
A sprawling anomalous mid/upper level ridge --- running 2-3 standard
deviations above normal---will remain anchored over the region, with
increasing subsidence and warming beneath it. This ridge, combined
with Bermuda high pressure at the surface, will maintain a deep
fetch of hot, subtropical air.
1000-850 low-level thicknesses and 850 mb temps continue to climb
with 850mb temps progged to reach 22-23 C this afternoon. Based on
local climatology, this strongly correlates with triple-digit temps
across portions of central NC with widespread highs between 97-101
F.
Surface dewpoints will range from the the mid/upper 60s over the
piedmont to lower 70s coastal plain, resulting in oppressive heat
and humidity across the region with heat index values ranging from
lower 100s in the western Piedmont to 105 to 109 F across central
and eastern NC. While the heat indices across the NW Piedmont may
fall just shy of 105F criteria, the primary concern lies in the
cumulative impacts of it being the first prolonged period of
dangerous heat this season. With high temperatures and warm
overnight lows persisting for multiple days, the risk of heat-
related illnesses will increase, especially for vulnerable groups,
and those without access to adequate cooling. As such, will expand
the Heat Advisory to include all 31 counties within the forecast
area.
Rain chances are very low(<10%), as strong capping and a capped
profile will suppress deep convection. Any showers or storms that do
develop would be isolated and short-lived.
Tonight will remain very warm and muggy with overnight lows in the
mid 70s to near 80, which will challenge or exceed record warm
minimum temperatures (see climate section at the end of the
discussion).
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 230 AM Monday...
* Dangerous Heat Continues---Extreme Heat Watch In Effect
The anomalous ridge will remain entrenched across the region, with
Tuesday and Wednesday expected to mark the peak of the heat wave as
a core of 24-25C 850 mb temperatures build across the Carolinas.
For reference, the all-time highest observed 850mb temperature is
25.4C(set on 7/1/2012), highlighting the potential extremity of this
heat event.
These conditions will support afternoon highs in the upper 90s to
low 100s. The ECMWF continues to suggest modest afternoon mixing of
low-level moisture, potentially lowering dewpoints slightly. In
contrast, the GFS retains high sfc moisture, which would result in
more oppressive and dangerous heat impacts. Combined with dewpoints
in the upper 60 to lower 70s, heat index values of 105 to 112 F
across the area, with Heat Risk increasing into the Extreme Category
which signifies that everyone exposed to the heat is at risk. As a
result, an eventual upgrade to a Extreme Heat Warning is likely for
much if not all of Central NC.
The key wildcard during this period is rain/storm chances. As the
ridge axis begins to flatten and shift slightly westward, weak
disturbances and/or sea-breeze interactions may support isolated to
scattered convection, particularly during the afternoon and evening.
The GFS has been especially aggressive, depicting robust convection
initially developing across the southern and central Appalachians
during the afternoon, before propagating eastward into the area
during the evening and overnight hours. While the GFS appears to be
a wet outlier, both the EC AIFS and REFS lend some support to
introducing slight to low-end chance PoPs during that time frame.
Record warm overnight lows in the mid to upper 70s Tuesday night,
with some urban areas possibly failing to drop out of the lower 80s.
This will result in little relief from the daytime heat and will
increase the risk of heat stress.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 340 AM Monday...
* An Extreme Heat Watch remains in effect for all of central NC Tue
morning through Wed evening.
* Heat index values will dip a few degrees for Thu through the
weekend, but heat-health threats will continue as temperatures
stay well above normal.
Wed/Wed night: The peak of this heat wave will extend into Wed, with
a stagnant air mass and persistent Piedmont surface trough, although
the heights within the strong upper ridge will have fallen about 20-
30 m as its center drifts slowly W toward the mid Miss Valley. Our
500 mb heights will still be 2.5-3 SD above normal, while our
projected 925 mb temps will be close to the daily record. But we may
start to see increasing mid/high clouds, esp in the SE, as a weak
upper low over the Bahamas early Wed and its trough off the SE US
coast drifts WNW toward the SE coast. The weakening of NW/NNW low
level flow may allow the sea breeze to progress further inland, and
this coupled with the increasing moisture (as PWs rebound to 1.75-
2.0") and lowering stability in the mid levels should contribute to
isolated to scattered late-day storms amidst moderate CAPE. Coverage
should remain limited to discrete pop-ups at most, though, given the
poor mid level flow and lack of organization. Expect highs of 93-
100F, with heat index values around 100-110F areawide. The NWS
experimental HeatRisk will again be in the major to extreme
category, indicative of high potential for dangerous heat illnesses
among the entire population of central NC. For people without access
to cooling, this kind of heat can be deadly, particularly after
multiple very hot days and little recovery at night. Will keep the
Extreme Heat Watch in place, and if the current forecast holds, an
advisory or Extreme Heat Warning could ultimately be needed. Lows
mostly in the mid 70s.
Thu-Sun: Low level thicknesses and mid level heights will remain
above normal through the weekend, with 850 mb temps holding at 1.5-
2.5 SD above normal and a surface trough still lingering over the
Piedmont. But our heat will be a bit less intense by late week, as
the mid level low continues to push slowly WNW over the Southeast,
supplanting the core of the mid level ridge which will drift E,
moving briefly overhead before pushing to near Bermuda. The slight
downturn in heights aloft and increasing low level flow from the S
and SW should allow for daily late-day isolated to scattered storms
each day, with the better coverage over our NW with some upslope
component and potential for mountain convection to drift eastward.
The vast majority of each day will be dry, as coverage will continue
to be limited by the weak mid level flow and the lack of substantial
convective focus. Apart from the sea breeze, the isolated mostly
pulse-type storms may fire on subtle boundaries generated by
differential heating and discontinuities in land use or soil
moisture, resulting in low predictability in precise timing or
coverage at this time. Will keep pops near climatology, except a bit
higher in the Triad, in the path of mountain storms. Highs each day
should be mostly in the mid 90s, perhaps low 90s near the VA border
and a few upper 90s from the Triangle down through the Sandhills,
with lows generally in the low-mid 70s. -GIH
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
As of 120 AM Monday...
Latest guidance continues to trend away from significant fog
development, though very patchy fog is likely. As such, did not
include in the TAFs at this time. If any fog is to develop, the best
chance looks to be across eastern terminals(KRWI and KFAY) late
tonight/early morning.
Otherwise, VFR conditions are expected to prevail. Look for some
diurnal cu(4-6kft) developing in the afternoon, underneath
scattering cirrus aloft. Winds will remain light and variable
through the period.
Outlook: Predominately VFR conditions are expected through late
week, supported by strong high pressure aloft. Aside from some
patchy morning fog or stratus and isolated/widely scattered
afternoon convection, aviation impacts should remain minimal.
&&
.CLIMATE...
Weather Records/Record Daily High Minimum Temperatures...
Raleigh Greensboro Fayetteville
June 23 78 (2024) 74 (2024) 77 (2024)
June 24 76 (2024) 76 (2015) 79 (2010)
June 25 77 (2010) 75 (2015) 75 (1952)
June 26 77 (2024) 74 (2010) 76 (1997)
June 27 76 (1952) 76 (1969) 77 (1998)
June 28 76 (1952) 76 (1969) 78 (1914)
Weather Records/Record Daily Maximum Temperatures...
Raleigh Greensboro Fayetteville
June 23 100 (2024) 102 (1914) 102 (1981)
June 24 99 (2010) 103 (1914) 102 (1914)
June 25 100 (1952) 101 (1914) 102 (1914)
June 26 103 (2024) 102 (1914) 101 (1951)
June 27 104 (1954) 102 (1954) 102 (1998)
June 28 100 (1959) 99 (1959) 105 (1954)
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 11 AM this morning to 10 AM EDT Tuesday for
NCZ007>011-021>028-038>043-073>078-083>086-088-089.
Extreme Heat Watch from Tuesday morning through Wednesday evening
for NCZ007>011-021>028-038>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...Hartfield
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...Hartfield
AVIATION...CBL
CLIMATE...RAH