RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Mon Jun 15 17:49:02 UTC 2026.
MD 1149 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE NORTHERN GREAT PLAINS
Mesoscale Discussion 1149
NWS Storm Prediction Center Norman OK
1246 PM CDT Mon Jun 15 2026
Areas affected...portions of the northern Great Plains
Concerning...Severe potential...Watch unlikely
Valid 151746Z - 151945Z
Probability of Watch Issuance...20 percent
SUMMARY...The potential for strong to isolated severe wind gusts
will increase through the afternoon as isolated to widely scattered
high-based thunderstorms develop across portions of the northern
Great Plains.
DISCUSSION...Latest GOES water vapor imagery depicts a shortwave
trough moving out of Saskatchewan into northwestern North Dakota.
Downstream of this feature, warming surface temperatures ahead of a
surface cold front and cold mid-level temperatures are contributing
to weak destabilization (on the order of a couple hundred J/kg
MLCAPE) as of 1730 UTC. Latest objective analysis also suggests that
inhibition is quickly eroding, which is corroborated by recent
lightning activity along the ND/SD border. As surface heating
results in further destabilization through the afternoon (with
500-700 J/kg MLCAPE likely by peak heating), high-based thunderstorm
coverage is expected to increase. While the thermodynamic
environment will remain marginal at best, LCLs around 2.5 km will
support downward transport of increasing west-northwesterly
low-to-mid level flow attendant to the shortwave trough (30+ kts
sampled at 1 km AGL by the BIS VAD profile). This will promote an
increasing risk for strong to isolated severe wind gusts through
this afternoon. Watch issuance is unlikely at this time owing to the
limited magnitude and isolated coverage of the severe threat.
..Chalmers/Mosier.. 06/15/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...FSD...ABR...BIS...
LAT...LON 47670051 47750003 47729955 47609879 47439824 47189789
46549748 45739734 44919762 44239853 44119901 44179951
44279986 44410018 44580047 44950085 45320112 45880148
46650168 47140168 47530126 47670051
MOST PROBABLE PEAK WIND GUST...55-70 MPH
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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1111 AM CDT Mon Jun 15 2026
Valid 151630Z - 161200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTHERN HIGH PLAINS AND UPPER MIDWEST...
...SUMMARY...
Isolated large hail and severe thunderstorm winds may occur across
the southern High Plains and Dakotas/Upper Midwest this afternoon
and evening.
...Southern High Plains...
Northwesterly flow aloft will support a sharpening lee trough across
the southern High Plains today, with lee cyclogenesis yielding a
surface low over southeast CO by the late afternoon. Mass response
to the deepening lee trough and developing surface low will result
in moist low-level southeasterly/southerly flow across much of the
southern High Plains. This moistening will help offset mixing via
diurnal heating, keeping dewpoints in the 50s through the afternoon.
Steep mid-level lapse rates will be in place as well, with the
combination of low-level moisture and steep mid-level lapse rates
supporting airmass destabilization and moderate buoyancy by this
afternoon.
Thunderstorm development is initially expected over the high terrain
of south-central CO and central NM during the afternoon. Moderate
deep-layer westerly flow will take these storms into the lower
elevations of the southern High Plains during the late afternoon and
evening. Moderate buoyancy combined with 30 to 40 kt of effective
shear will support the potential for a few supercells and sustained
multicells, with potential consolidation into small organizing
southeastward-moving clusters. Hail is possible early in the
convective cycle, with a trend towards more damaging gusts within
any forward-propagating clusters during the late afternoon and
evening.
...Dakotas/Minnesota...
Morning satellite imagery shows a well-defined shortwave trough
dropping southeastward into the northern Plains within the western
periphery of a broad upper trough that extends over much of the
central and eastern CONUS. Surface moisture will be limited ahead of
this wave, but low to mid-level moisture attendant to the shortwave
and cold temperatures aloft will still support modest buoyancy
across the region this afternoon. This buoyancy coupled with ascent
from the shortwave will result in isolated to widely scattered
high-based thunderstorms. Additionally, strengthening
west-northwesterly flow attendant to the shortwave could yield some
strong/locally severe wind gusts this afternoon through around
sunset.
...Gulf Coast/Coastal Southeast...
A very moist airmass is in place in the vicinity of a weak frontal
zone that extends from the TX Coast northeastward through the
central Gulf Coast and southern GA. Numerous to widespread showers
and thunderstorms are anticipated across much of this region. The
airmass is weakly sheared, favoring a slow-moving, disorganized
storm evolution with heavy rain as the primary risk (as noted in the
Day 1 WPC Excessive Rainfall Outlook). However, a few damaging gusts
from water-loaded downbursts are still possible. Overall coverage is
expected to remain less than 5%.
..Mosier/Chalmers.. 06/15/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1228 PM CDT Mon Jun 15 2026
Valid 161200Z - 171200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE NORTHERN PLAINS INTO THE UPPER MIDWEST...THE GREAT LAKES TO THE
CENTRAL PLAINS...AND THE WESTERN/CENTRAL GULF COAST....
...SUMMARY...
Isolated to scattered strong to severe thunderstorms are possible
Tuesday afternoon and evening across parts of the Midwest into Lower
Michigan. Additional strong to severe storms are possible across the
northern Plains into the Upper Midwest Tuesday night.
...Synopsis...
A belt of moderate to strong mid-level flow will extend from the
Northwest to the northern Plains and the Midwest and to the
Mid-Atlantic on Tuesday. Within this flow, a mid-level shortwave
trough will move through the Great Lakes. An additional, stronger
shortwave trough will amplify across the northern Plains toward the
end of the period. A weak surface low will move through the northern
Great Lakes through the day and weaken while an associated cold
front moves across the Midwest and eventually stalls toward the end
of the period. A stronger surface low will develop across the
northern Plains Tuesday night and will be located somewhere near
eastern South Dakota by the end of the period.
...Midwest to the Central Plains...
Strengthening lower tropospheric flow will transport moisture
northward ahead of a cold front tomorrow morning/afternoon with weak
to potentially moderate instability expected. An initial line of
storms will likely develop on the leading edge of the returning
moisture in a more well-mixed and uncapped environment. This
activity will likely stay sub-severe, but a few isolated damaging
wind gusts will be possible given the steep low-level lapse rates
and strengthening flow. The greater severe weather potential is
expected along the cold front during the afternoon where upper 50s
to low 60s dewpoints should be present. Cloud-cover from initial
activity should limit overall instability (and a more substantial
threat), but cooling temperatures aloft should provide adequate
instability for strong to severe storms along the front. The strong
shear across the region will support the potential for rotating
updrafts capable of isolated large hail, damaging wind gusts, and
perhaps a tornado. If instability trends increase, an upgrade to
Slight Risk (Level 2/5) may be necessary in later outlooks across
northern Indiana, southern Michigan and northwest Ohio.
...Northern Plains to the Upper Midwest...
Tuesday night, as the mid-level trough amplifies across the northern
Plains, the frontal zone across the northern Plains will tighten.
Instability is forecast to be relatively weak initially, but strong
forcing from dCVA across the region, strengthening isentropic ascent
due to the strengthening cyclone, and strong shear beneath the 100+
knot 300mb jet streak will provide an environment that supports
isolated strong to severe storms along the frontal zone despite the
weak instability.
Within this larger marginal risk region, a greater severe threat may
exist shortly before 12Z across northern Iowa and vicinity. Here
richer 850 moisture, advected by the strengthening low-level jet,
will yield greater elevated instability (1500 to 2000 J/kg MUCAPE).
This will provide an environment featuring moderate instability and
strong shear amid strengthening isentropic ascent.
...Gulf Coast...
Most guidance shows a MCV developing across northern Mexico/south
Texas today, which is already somewhat apparent across the region.
This feature is forecast to move into the western Gulf on Tuesday.
Strengthening flow associated with this MCV will overspread the
Texas and Louisiana Coast tomorrow. A tropical environment will be
present with weak mid-level lapse rates. However, this strengthening
flow may support an isolated tornado threat from the central Texas
Coast to the eastern Louisiana Coast.
..Bentley.. 06/15/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1136 AM CDT Mon Jun 15 2026
Valid 151700Z - 161200Z
...Morning Update...
Good humidity recoveries occurred overnight across the central
Plains, however such relief is short-lived as fire weather
conditions return this afternoon. Daytime high temperatures will
range from 70-85F with RH declining to 15-20% at peak heating.
Behind a weak, dry cold front passing through the region late
morning, northwesterly winds will gradually increase to 15-20 mph
(gusts up to 30 mph). Elevated to locally critical fire weather
conditions are expected amid a drought stressed landscape and
widespread 80-95th percentile ERCs. See the previous discussion for
more information.
..Elizalde-Garcia.. 06/15/2026
.PREV DISCUSSION... /ISSUED 0144 AM CDT Mon Jun 15 2026/
...Synopsis...
Between a large-scale trough encompassing the eastern two-thirds of
the CONUS and an upper ridge over the West, a robust midlevel speed
max will overspread the northern/central Plains during the day. At
the same time, a related cold front will advance southeastward
across the region.
Along/behind the cold front/surface trough, ample diurnal heating
will result in a well-mixed boundary layer, with 15-20 percent RH
expected across parts of eastern WY into the NE Panhandle and
vicinity. Here, enhanced low/midlevel flow along the periphery of
the passing speed max and a tightening pressure gradient will result
in 15-25 mph sustained northwesterly surface winds. These dry/breezy
conditions atop dry/receptive fuels will yield elevated to locally
critical fire-weather conditions during the afternoon.
Despite relatively weaker upper-level support, strong terrain-driven
winds of 15-20 mph (locally greater in gap-flow areas and higher
elevations) and 10-15 percent RH will promote locally elevated fire
weather conditions across parts of the eastern Great Basin, Four
Corners, and Central Rockies. However, these conditions appear too
localized for highlights at this time.
...Please see www.spc.noaa.gov/fire for graphic product...
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