Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0248 PM CDT Tue Aug 04 2026
Valid 042000Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTHEAST ARIZONA...
...SUMMARY...
Scattered severe wind gusts are possible across southeast Arizona
during the late afternoon and evening.
...20Z Update...
No major changes have been made to the outlook. Initial high-terrain
storm development is expected to move west-southwestward across
southeast AZ from late afternoon into the evening, with a primary
threat of scattered severe gusts. Other strong to locally severe
storms are possible through the afternoon into the early evening
across parts of the Raton Mesa and south-central High Plains, parts
of IA/northern MO, and the southern Appalachians/western Carolinas
region. Late tonight, a few strong elevated storms may develop
across parts of southeast NE, IA, and northern MO. See the previous
discussion below for more information.
..Dean.. 08/04/2026
.PREV DISCUSSION... /ISSUED 1125 AM CDT Tue Aug 04 2026/
...Southeast Arizona...
A flattened mid/upper-level ridge over the Southwest will continue
to feature a belt of modestly enhanced mid-level easterlies across
northern Mexico into far southern portions of AZ/NM. Even with
convective overturning yesterday, a seasonably moist low-level
airmass across southeast AZ/southwest NM will undergo strong heating
this afternoon, with up to 1000-2000 J/kg MLCAPE forecast per latest
RAP/NAM forecast soundings. Initial widely scattered convective
development over the higher terrain will gradually move westward
across southeast AZ during the late afternoon and evening. A very
well-mixed boundary layer with steep low/mid-level lapse rates ahead
of this activity will support ample evaporative cooling potential
with the stronger thunderstorm downdrafts. The resultant microbursts
and associated outflow should yield a risk for 60-80 mph gusts as
thunderstorms potentially congeal into one or more small clusters
through the evening.
...Eastern Nebraska into Iowa and Northern Missouri...
Elevated thunderstorms are ongoing late this morning across parts of
NE to the north of a surface cold front extending from the southern
High Plains northeastward to the Upper Midwest. Stronger mid-level
flow and related large-scale ascent will tend to remain displaced to
the north of the front through the period. But, there may still be
some potential for a surface-based thunderstorm or two to develop
along/near the front late this afternoon/early evening across
IA/northern MO and vicinity in a moderately unstable airmass. While
still appearing fairly conditional, isolated hail/damaging winds may
occur if convection develops. Otherwise, a greater chance for
additional elevated thunderstorms should exist tonight into early
Wednesday morning from eastern NE into IA. This activity may also
pose an isolated hail/gusty wind threat.
...Raton Mesa into the Southern/Central High Plains...
Although overall magnitudes will remain limited, a local maximum in
instability should develop this afternoon near the Raton Mesa into
southeast CO, where widely scattered thunderstorms will likely
develop in a post-frontal low-level upslope regime. Recent
high-resolution guidance continues to show this activity moving
slowly southeastward into parts of the OK/TX Panhandles during the
early evening. While deep-layer shear is expected to remain modest
(20-30 kt), marginally severe hail is possible with the stronger
cores, and isolated severe gusts may occur with any loosely
organized clusters that can develop.
...Southern Appalachians/Western Carolinas...
A closed mid-level low will remain centered over GA today. To the
east/northeast of this low, filtered daytime heating of a moist
low-level airmass will support the development of moderate
instability over the western Carolinas into north GA and eastern TN
this afternoon. Scattered thunderstorms will continue to develop
across this region through 17-19Z as convective temperatures are
reached. Even though deep-layer shear will remain weak, an isolated
threat for damaging winds associated with microbursts may develop as
low-level lapse rates gradually steepen.
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