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729
FXUS62 KRAH 121710
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
110 PM EDT Sat Jul 12 2025

.SYNOPSIS...
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A weak trough and associated cold front will slowly approach into
early next week. The boundary will stall out and weaken to our
north, keeping us in a warm and humid airmass with daily showers and
storms.
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&&


.NEAR TERM /THROUGH TONIGHT/...
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As of 110 PM Saturday...

* Marginal risk of isolated damaging winds into this evening for
  areas mainly west of US-1
* Excessive rainfall possible nearly anywhere this evening, but
  widespread flooding potential not expected

Temperatures should continue to climb into the late afternoon hours
with highs topping out in the low to middle 90s. A few locales
across portions of the Triangle and Sandhills could briefly reach
heat indices of 104-105, but this is not expected to be prolonged.

As for storm chances into this evening, model guidance and ensemble
data suggest two primary focus areas, one over the eastern part of
the state, and a second across the mountains. The former may be tied
to a developing sea-breeze pushing inland with resultant outflows.
The latter across the mountains appears tied to a weak surface
trough  situated in western NC. Both of these areas will be the
focus for convergence for storm development. It would appear storms
across the mountains will be more widespread, with some of those
reaching the Triad and western Piedmont this evening, dying off by
late evening due to loss of heating. Regardless, resultant outflows
from either forcing areas could produce an isolated or scattered
storm or two over central NC into late evening with modest buoyancy
over 2000 J/kg. Overall coverage appears limited. Shear is weak, but
mesoanalysis and point forecast soundings suggest high DCAPE over
1000 J/kg, supportive of wet microbursts and resultant damaging
winds, especially west of US-1. While widespread flooding potential
is not expected, rain that falls over still saturated soils, mainly
in the Piedmont, will be favorable for isolated flash flooding.

After any storms die out later this evening, some patchy fog is
possible over areas that saw rain, with lows in the low/mid 70s.
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&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
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As of 110 PM Saturday...

* Heat indices upper 90s western Piedmont, to 100 to 104 along/east
  of US-1.
* Storm chances increase ahead of a weak cold front and shear axis
* Isolated flash flooding and a localized damaging wind threat
  possible

A weak surface cold front over the OH valley will slowly slide east
across western portions of the Mid-Atlantic and TN valley, tied to a
weak trough to our NW. While the trough will stay to our north over
the Great Lakes and OH valley, a subtle shear axis will be present
over the area. The closer proximity of the front will also help
shift the convergence axis for showers and storms to more of central
NC, as opposed to western NC on our Sat. Scattered showers and
storms should be diurnally driven once again with weak shear.
Precipitable water values will increase above 2 inches and high
DCAPE will again combine with 2000-3000 J/kg of CAPE for a localized
damaging wind threat and flash flood potential. Highs should again
be warm and muggy in the low to mid 90s. Heat indices are favored in
the upper 90s in the west, to 100 to 104 along/east of US-1. Cannot
rule out a few areas of the Triangle and Coastal Plain that briefly
reach heat advisory criteria.

Storms should gradually decay by late evening as convective
overturning/stabilization takes shape. Lows will be in the low/mid
70s.
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&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
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As of 110 PM Saturday...

* Flash flood threat continues into early next week Mon and Tue
* Isolated severe downbursts possible Mon and Tue
* Heat and humidity throughout the week with highs in the upper 80s
  to low 90s and heat indices in the lower 100s along/east of US-1

The aforementioned trough to our north on Sun will slide into the
Mid-Atlantic early next week Mon and Tue, before weakening by Wed.
The trough will largely stay to our north, but its shear axis and a
weakening surface front over the Appalachians will keep the focus
for scattered to numerous showers and storms for the beginning of
the coming week. Precipitable water values will also be above the
90th percentile aoa 2 inches during this time, supporting the
continued threat of flash flooding, especially over still saturated
soils of central NC. The wettest period based on a suite of guidance
appears to be Mon and Tue, when the trough and front are closer to
the region. During this time also, a few isolated storms could
produce severe downbursts as some AI guidance suggests still
favorable wet microbursts.

Come midweek, Bermuda high pressure will strengthen, the front will
have died out, and southerly moist flow will be the dominant
synoptic pattern. Storm chances on Wed and Thu will still be in the
forecast, but probably the more typical summertime diurnally driven
chances, closer to climatology, During this time as well, heat
indices may get close to advisory criteria, in the absence of
storms. By late week Fri and Sat, ensembles and some deterministic
solutions indicate that another trough and frontal system may try to
approach, especially by the upcoming weekend. This should favor
another uptick in storm chances above climatology, especially late
Fri and Sat.

As for temperatures, highs will generally range in the upper 80s to
lower 90s, and lows in the low/mid 70s.
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&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
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As of 110 PM Saturday...

24 hour TAF period: The first half of the TAF period will have
prevailing VFR conditions at all terminals, although a PROB30 for
thunderstorms remains in the forecast at all sites. Felt that the
PROB30 window was too large, especially at INT/GSO, and have shrunk
those down to the 4 hour windows that seem most likely for
thunderstorms to develop. Conditions should then be quiet during the
evening into the overnight hours before restrictions develop. At
this point, guidance is leaning more in the direction of fog instead
of stratus, which has been reflected in the forecast. With higher
confidence in lower visibilities across eastern sites, have added 1
mile tempo groups at RDU/RWI/FAY. Fog/stratus should be scattering
out by 12-13Z, and confidence in afternoon convection before 18Z
Sunday is not high enough to include in the forecast at this time.

Outlook: With a minimal change in airmass, the forecast during the
extended period is similar to the 18Z TAF, although today will
likely have lower coverage of showers/thunderstorms than the other
days. At least one terminal has a 60% chance of showers/storms
Monday through Thursday, so eventually the TAFs will likely carry
prevailing precipitation. In addition, fog/stratus will be possible
late each night into the morning hours.
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&&

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

&&

$$

SYNOPSIS...Kren
NEAR TERM...Kren
SHORT TERM...Kren
LONG TERM...Kren
AVIATION...Green