SPC AC 060045
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0745 PM CDT Tue Aug 05 2025
Valid 060100Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTH DAKOTA AND FAR SOUTHEAST NORTH DAKOTA...
...SUMMARY...
Strong to severe thunderstorms with an accompanying risk for large
hail and severe wind gusts will persist the remainder of the
evening/early overnight.
...Northern Plains Vicinity...
Strong to severe storms may persist/develop over the next several
hours, mainly across parts of SD ahead of a surface low and cold
front. Some marginally severe storms have occurred, with hail from
around nickel to half dollar size noted in local storm reports the
past few hours. Wind gusts from 45-60 mph have also occurred.
Overall, convection outside of the ongoing cluster across southeast
ND has not been very robust. Looking at the 00z RAOB from ABR, 0-3km
lapse rate are lackluster (around 5.7 C/km), limiting vertical
accelerations in the low-levels. Nevertheless, steep midlevel lapse
rates are indicated (around 7.5 C/km 700-500 mb) amid 2000+ MLCAPE
across SD, decreasing with north and east extent. Vertical shear
also remains favorable for storm organization, if more robust
convection can evolve behind the ND cluster.
Evening CAMs guidance still suggests an MCS may develop across parts
of SD downstream into the Mid-MO Valley vicinity overnight. However,
stronger capping is evident into NE/IA. Given uncertainty amid an at
least modestly favorable environment, severe probabilities have only
been trimmed mainly across the western and northern outlook area
(WY/MT into ND) where confidence is greatest potential has lessened.
Severe probabilities across SD and vicinity will be maintained.
..Leitman.. 08/06/2025
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
SPC AC 051724
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1224 PM CDT Tue Aug 05 2025
Valid 061200Z - 071200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE
NORTH-CENTRAL STATES...
...SUMMARY...
Isolated severe thunderstorms are possible across parts of the
North-Central States on Wednesday into Wednesday night.
...North-Central States...
Low probability severe potential remains evident across the region
with multiple scenarios anticipated amid fairly nebulous large-scale
ascent. Initial threat should be in the southeastern lobe across the
Lower MO Valley vicinity with potential for an ongoing MCS. As
discussed in the SWODY1, considerable uncertainty exists overnight
with evolution of such an MCS but the overall signal is for a
weakening trend after 12Z. A distinct minority of guidance indicates
some potential for diurnal intensification with a remnant MCV.
Sporadic strong gusts capable of localized damage seems plausible in
the morning and perhaps into the afternoon.
Conditionally, the most favorable environment for severe should be
across the Black Hills vicinity and the NE Panhandle as convective
outflow from late D1 is pushed south into the central High Plains.
North of this outflow, a moderately supportive supercell environment
should exist. At least isolated thunderstorms should develop late
afternoon to early evening. But low-amplitude ridging between a
shortwave trough in the southern Canadian Prairies and a minor
trough in the Northwest should modulate overall coverage. Isolated
large hail and severe gusts should be anticipated into late evening.
Downstream low-level warm theta-e advection should be centered over
the Mid-MO to Upper MS Valleys on Wednesday night where a few
marginally severe storms are possible. A few strong storms may also
occur across northern MN during the afternoon, owing to trailing
influence of the southern Canadian Prairies wave. Scattered storm
coverage should be confined along the international border, but
modest mid-level lapse rates should temper convective vigor.
..Grams.. 08/05/2025
WUUS02 PTSDY2
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z
SPC AC 051927
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 PM CDT Tue Aug 05 2025
Valid 071200Z - 081200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE NORTHERN
GREAT PLAINS...
...SUMMARY...
Scattered severe thunderstorms are possible from late afternoon into
Thursday night across the northern Great Plains. Isolated very large
hail and significant severe wind gusts may occur.
...Northern Great Plains...
While mesoscale details at this timeframe are unclear, potential
exists for higher-end severe intensity and coverage on Thursday late
afternoon into the night. A shortwave trough will amplify across the
Northwest and northern Rockies, as a vigorous impulse digs
southeastward from coastal BC. Downstream, the elevated mixed layer
will expand across the Dakotas and MN. A lack of widespread
convective overturning on D2 will support seasonably rich
boundary-layer moisture advecting northwestward across the Dakotas
to eastern MT. This will yield large to potentially extreme buoyancy
by peak heating Thursday, centered on northern NE into southern ND.
Scattered thunderstorms will develop off the higher terrain of
southwest/south-central MT by late afternoon to early evening.
Storms will spread east-northeast and impinge on the pronounced
buoyancy plume during the evening/night, potentially sustaining an
intensifying MCS. Meanwhile, some guidance suggests separate
late-day storm development will occur along the strengthening
baroclinic zone in ND, with isolated storms possible southward along
a lee trough. This activity too could grow upscale, mainly in ND,
and progress towards the Red River Valley on Thursday night.
Significant severe appears most likely in the ND portion of the
level 2-SLGT risk. Very large hail is possible in initial
supercells, in addition to significant severe gusts during the
downstream cluster/MCS phase.
...Upper Midwest...
Nebulous, low-probability severe potential is evident along the
northeast lobe of the expansive buoyancy plume over the central
states on Thursday into Thursday night. Minor MCVs from remnants of
D2 convection may focus localized corridors of diurnal storm
development from the IA/IL/WI border region to western Upper MI.
More probable convective development should occur Thursday night,
north-northeast of the southern High Plains to Lower MO Valley
low-level jet. Amid modest northwesterlies but weak lapse rates in
the mid levels, mainly strong to perhaps marginally severe
intensities are anticipated.
..Grams.. 08/05/2025
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
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