RSS Mesoscale Discussions from Storm Prediction Center
WW 273 SEVERE TSTM SD 042225Z - 050600Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 273
NWS Storm Prediction Center Norman OK
525 PM CDT Thu Jun 4 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central and Eastern South Dakota
* Effective this Thursday afternoon and Friday morning from 525
PM until 100 AM CDT.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
A tornado or two possible
SUMMARY...Severe storms including a few supercells may develop
through early evening across central and east-central South Dakota,
mostly north of the I-90 corridor. Additional severe storms,
potentially as an organized line of storms, may move into the region
by late evening and the early overnight with damaging wind/hail
potential.
The severe thunderstorm watch area is approximately along and 75
statute miles north and south of a line from 50 miles west southwest
of Pierre SD to 15 miles south southeast of Brookings SD. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 272...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27025.
...Guyer
Read more
WW 272 SEVERE TSTM MT ND SD WY 042005Z - 050300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 272
NWS Storm Prediction Center Norman OK
205 PM MDT Thu Jun 4 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Far Southeast Montana
Far Southwest North Dakota
Western South Dakota
Far Northeast Wyoming
* Effective this Thursday afternoon and evening from 205 PM until
900 PM MDT.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Thunderstorms are developing within the modestly unstable
and moderately sheared airmass across eastern Montana and northeast
Wyoming. These storms are expected to move eastward/southeastward
into far southwest North Dakota and western South Dakota throughout
the afternoon and evening. Environmental conditions support
supercells capable of large to isolated very large hail and damaging
gusts.
The severe thunderstorm watch area is approximately along and 110
statute miles north and south of a line from 25 miles south
southwest of Broadus MT to 85 miles east northeast of Rapid City SD.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU2).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
27030.
...Mosier
Read more
WW 0273 Status Updates
STATUS REPORT ON WW 273
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0983
..LYONS..06/05/26
ATTN...WFO...FSD...ABR...UNR...
STATUS REPORT FOR WS 273
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
SDC003-005-011-015-017-023-025-029-035-039-041-043-049-053-057-
059-065-069-073-075-077-079-085-095-097-101-107-111-115-117-119-
121-123-050140-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
AURORA BEADLE BROOKINGS
BRULE BUFFALO CHARLES MIX
CLARK CODINGTON DAVISON
DEUEL DEWEY DOUGLAS
FAULK GREGORY HAMLIN
HAND HUGHES HYDE
JERAULD JONES KINGSBURY
LAKE LYMAN MELLETTE
MINER MOODY POTTER
SANBORN SPINK STANLEY
SULLY TODD TRIPP
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
Read more
WW 0272 Status Updates
STATUS REPORT ON WW 272
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 S GCC TO
65 SW 2WX TO 40 NNE BHK.
..LYONS..06/05/26
ATTN...WFO...BYZ...GGW...BIS...UNR...
STATUS REPORT FOR WS 272
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NDC001-011-041-087-050140-
ND
. NORTH DAKOTA COUNTIES INCLUDED ARE
ADAMS BOWMAN HETTINGER
SLOPE
SDC007-019-033-047-055-063-071-081-093-102-103-105-137-050140-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
BENNETT BUTTE CUSTER
FALL RIVER HAAKON HARDING
JACKSON LAWRENCE MEADE
OGLALA LAKOTA PENNINGTON PERKINS
ZIEBACH
WYC011-045-050140-
WY
. WYOMING COUNTIES INCLUDED ARE
Read more
MD 0983 CONCERNING SEVERE THUNDERSTORM WATCH 272...273... FOR PARTS OF SD AND EXTREME NORTHWEST NE
Mesoscale Discussion 0983
NWS Storm Prediction Center Norman OK
0731 PM CDT Thu Jun 04 2026
Areas affected...Parts of SD and extreme northwest NE
Concerning...Severe Thunderstorm Watch 272...273...
Valid 050031Z - 050230Z
The severe weather threat for Severe Thunderstorm Watch 272, 273
continues.
SUMMARY...The severe threat continues across parts of east-central
South Dakota, with an increasing threat possible with time into
south-central South Dakota.
DISCUSSION...A cluster of intense storms has recently developed
across east-central SD, to the west/north of Huron. This convection
developed within a low-level confluence zone, within an environment
characterized by MLCAPE of near/above 2000 J/kg and increasing
effective shear in the 30-40 kt range. Large to locally very large
hail and isolated severe gusts will continue to be a threat with
these storms through mid evening, and a tornado cannot be ruled out
given the presence of backed surface winds and modestly enhanced
effective SRH. To the southwest of this cluster, isolated supercell
development remains possible through dusk across south-central SD.
Later this evening, outflow associated with convection across
western SD may begin to intersect richer moisture and stronger
buoyancy along and north of a surface boundary. This could lead to
upscale growth and development of a small MCS (as depicted by recent
HRRR runs), though this evolution is uncertain due to a lack of
stronger low-level flow. Should such an evolution occur, a greater
threat for severe gusts could develop across southwest into central
SD later this evening.
..Dean.. 06/05/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...ABR...LBF...UNR...
LAT...LON 44219675 43509816 42850071 42850153 42820252 43830286
44290272 44510152 44580102 44879954 45019781 45049685
44219675
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
Read more
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0757 PM CDT Thu Jun 04 2026
Valid 050100Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS...
...SUMMARY...
Severe thunderstorms capable of large to very large hail and
damaging winds are possible this evening across much of South Dakota
into parts of northern Nebraska and south-central Minnesota.
Isolated large hail and severe wind gusts will also be possible in
parts of the central Plains and mid Missouri Valley.
...Northern Plains/Upper Mississippi Valley...
At mid-levels, west-southwesterly flow is evident over much of the
north-central U.S. A shortwave trough is evident on water vapor
imagery over the far western Dakotas. At the surface, a 1002 mb low
is analyzed in eastern Wyoming with a quasi-stationary front
extending northeastward into central South Dakota and north-central
Minnesota. An axis of low-level moisture is located from near the
Black Hills east-northeastward across South Dakota into
south-central Minnesota, where surface dewpoints are in the lower to
mid 60s F. Along and near this axis, the RAP has MLCAPE mostly in
the 1500 to 2500 J/kg range. Scattered strong to severe
thunderstorms are ongoing near the instability axis in the vicinity
of the Black Hills in southwestern South Dakota. The latest 00Z
sounding at Rapid City has 0-6 km shear around 50 knots with 700-500
mb lapse rates near 8 C/km. This will support supercells with large
hail. Hailstones of greater than 2 inches in diameter will be
possible for a few more hours this evening. The wind-damage threat
will likely increase if a cell cluster can become organized and move
into central South Dakota later this evening...see MCD 983. The
southern edge of any cluster could impact parts of northern Nebraska
later this evening.
Further east into eastern South Dakota, a cluster of strong to
severe thunderstorms is ongoing. The 00Z sounding at Aberdeen has
MUCAPE around 1800 J/kg with 0-6 km shear near 40 knots, and a
700-500 mb lapse rate just above 7 C/km. This should support
supercells with large hail early this evening. 0-3 km lapse rates
near 7.5 C/km will also be favorable for severe wind gusts. The
severe threat is expected to increase in southeast and central
Minnesota later this evening, as the storms in eastern South Dakota
move along the instability axis.
...Central Plains/Mid Missouri Valley...
A mid-level shortwave trough is evident on water vapor imagery over
eastern Kansas. At the surface, a moist airmass is in place from
much of central and eastern Kansas northeastward into Iowa, where
surface dewpoints are in the upper 60s to near 70 F. Moderate to
strong instability is analyzed by the RAP from central Kansas into
far western Missouri. Scattered thunderstorms are ongoing along the
northern edge of the stronger instability from northeast Kansas into
southwest Iowa. These storms are being supported by a low-level
speed max of 35 to 45 knots, and could be associated with a threat
for isolated severe wind gusts and hail this evening. As low-level
flow increases from this evening into the overnight period, the
redevelopment of storms may occur over parts of central and eastern
Kansas, where a continued marginal severe threat will be possible.
..Broyles.. 06/05/2026
Read more
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0500 PM CDT Thu Jun 04 2026
Valid 061200Z - 121200Z
...Synopsis...
The primary driver of synoptic fire weather risks shifts eastward
entering the weekend. On Day 3/Saturday, a potent upper-level
trough, having advanced from the northern Pacific, will move over
the Pacific Northwest. A cold front associated with this feature
will progress southeastward across the western third of the United
States. This front will introduce a major airmass transition,
dropping daytime temperatures below seasonal normals and temporarily
dampening fire risks across much of WA, OR, and northern CA. By Day
4/Sunday, this initial trough shifts northeastward over the Northern
Rockies. However, the tight surface pressure gradient ahead of the
front, coupled with enhanced mid-level westerly-to-southwesterly
flow, will maximize fire weather concerns across central/southern
portions of the Intermountain West. Broad southwesterly flow
dominates early next week before another potentially stronger,
deeper progressive trough is modeled to impact the western half of
the CONUS by mid-week. However, differing solutions exist as to how
far south this system will dive as it moves across the western
CONUS.
...Great Basin, Southwest, and Rocky Mountains...
...Day 3/Saturday...
As the primary upper-level trough carves into the Pacific Northwest,
a tightening surface pressure gradient will develop across the Great
Basin and Southwest. A mid-level jet max will mix down effectively
to the surface due to deep daytime boundary layer mixing. Sustained
southwest winds of 20 to 30 mph are anticipated. Coincident RH
values will plummet into the single digits and low teens, generally
widespread between 6 and 12 percent. A 70 percent probability of
Critical fire weather conditions has been introduced across portions
of eastern NV, southern UT, and northern AZ where critical
thresholds are expected to be met for multiple consecutive hours.
Surrounding areas of the Great Basin and Four Corners region
maintain a 40 percent Critical probability as fuels continue to dry
rapidly and burn periods lengthen under continued high vapor
pressure deficits. While confidence is not high enough to warrant a
drawn area, portions of southern ID will have some opportunity to
experience a mix of fast moving dry/wet thunderstorms.
...Day 4/Sunday...
The upper-level trough tracks northeastward toward the Northern
Rockies, pushing the trailing cold front further south and east.
Strong mid-level flow continues over the southern tier of the
system. The belt of strongest winds will shift slightly eastward,
impacting eastern UT, northern and eastern AZ, and western CO.
Expect sustained southwest winds of 20 to 25 mph. A dry slot aloft
will keep minimum relative humidity values critically low, between 8
and 15 percent, across the Southern Rockies and Southwest. The 70
percent Critical probability remains highlighted across southern and
eastern UT, northern AZ, and western CO. 40 percent Critical
probabilities encompass the remaining portions of southeast NV,
northwest NM, and central WY where fuels are receptive. While
confidence is not yet high enough to warrant a drawn area, a
non-zero chance of mixed dry/wet thunderstorms over northern UT will
be watched with future forecast guidance.
...Day 5/Monday...
The region enters a temporary synoptic transition phase between the
departing northern Rockies trough and the next approaching Pacific
system. While the core of the mid-level jet weakens slightly and the
surface pressure gradient slackens, broad and persistent
southwesterly flow remains established over the Southwest and Great
Basin. Deep mechanical mixing under clear skies will still generate
localized breezy conditions with 15 to 25 mph gusts alongside
persistent hot and dry air. Given the prolonged absence of moisture
and highly susceptible fine fuels, an additional 70 percent Critical
probability was introduced once again over portions of southern UT,
northern AZ, and nearby far southeastern NV. 40 percent Critical
probabilities encompass the remaining portions of southeast NV,
western CO, and central WY where fuels are receptive.
...Day 6/Tuesday - Day 7/Wednesday...
Medium-range global deterministic models and their respective
ensemble members show strong consensus for a secondary, potentially
more intense trough digging into the western US again by mid-week.
Ahead of this feature, a renewed and amplified pressure gradient
will trigger strong south/southwest surface winds. This will likely
cause continued widespread critical fire weather conditions across a
large swath of the Great Basin and Southwest. Thus, 70 percent
Critical probability was introduced yet again over portions of
southern UT and northern AZ where confidence is highest. The
existing 40 percent Critical probability continues Tuesday and
Wednesday in nearby areas including far eastern NV, western CO, and
portions of central WY. Expect this risk area to be significantly
expanded in spatial coverage and potentially extended later into the
week as forecast guidance converges on the exact timing and track of
this secondary upper level low.
..Stearns.. 06/04/2026
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
|
