Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Thu Aug 14 2025
Valid 141630Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA...
...SUMMARY...
Thunderstorms capable of producing large hail and severe wind gusts
may occur this afternoon into tonight across parts of the
northern/central Plains and upper Mississippi Valley. Isolated
strong to severe gusts are also possible from the eastern Great
Basin into the central Rockies.
...Northern Plains into the Upper MS Valley...
Recent surface analysis places a low over northwest ND, along a cold
front arcing from west-central Manitoba into south-central MT. A
surface trough also extends southward from this low to another weak
low in southeast CO. Ample low-level moisture exists across the
Plains east of this surface troughing, with mid 60s dewpoints
extending up through central and eastern ND. Moist southerly
low-level flow is forecast to persist throughout the day. This
low-level moisture advection combined with evapotranspiration and
low-level convergence near the front is expected to result in upper
60s to perhaps low 70s dewpoints ahead of the front across the
eastern Dakotas by early evening. Cooling mid-level temperatures are
expected across the region, which will combine with the abundant
low-level moisture to support strong to very strong buoyancy by the
late afternoon/early evening. Recent guidance suggests MLCAPE will
range from 3000 to 4000 J/kg across the eastern Dakotas, western MN,
and central/eastern NE by 00Z Friday.
Despite this robust buoyancy, warm low to mid-level temperatures and
related capping introduce uncertainty regarding convective
initiation, particularly with southward extent. Greatest potential
for convective initiation remains across eastern ND where glancing
large-scale ascent attendant to the substantial shortwave trough
moving through Saskatchewan will augment low-level convergence along
the southeastward-progressing cold front.
Any convection which can be sustained could pose a threat for large
to isolated very large hail given a favorable thermodynamic and
kinematic environment. Given the warm and dry low to mid-levels,
strong downdrafts are possible as well. Upscale growth into clusters
along the front is possible, and some damaging gusts could occur
with these storms as well. Inhibition will quickly increase with
eastward extent across MN as nocturnal cooling of the boundary layer
occurs, limiting the eastward extent of the severe threat.
Additionally, the low-level jet will likely weaken throughout the
day but then strengthen again later this evening from western KS
into western IA. Associated warm-air advection could result in
isolated elevated convection across central MN. Most of these storms
should be sub-severe, but a few instances of hail are possible.
...Central High Plains/Central Plains...
Scattered high-based thunderstorms should develop across the central
Rockies this afternoon before the spreading eastward/southeastward
into the central High Plains. A deeply mixed boundary layer and high
cloud bases will support strong gusts with this activity as it moves
across central High Plains. As this convection spreads eastward and
encounters greater instability along/east of a surface lee trough,
it may reintensify, with the potential for
severe gusts continuing into central NE. The lack of stronger
forcing aloft and modest deep-layer shear should temper the overall
severe threat with southward extent.
...Eastern Great Basin into central Rockies...
The shortwave trough currently moving into central CA will continue
eastward/southeastward throughout the day. Lift associated with this
wave will interact with the modest mid-level moisture across the
Great Basin to support scattered thunderstorm development. High
cloud bases and a deeply mixed boundary layer could support strong
downdrafts within the strongest storms, particularly across northern
UT where the best overlap between forcing, buoyancy, and modest
southwesterly flow aloft exists.
..Mosier/Squitieri.. 08/14/2025
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