WW 662 SEVERE TSTM MT 062355Z - 070700Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 662
NWS Storm Prediction Center Norman OK
555 PM MDT Sun Sep 6 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central and North-Central Montana
* Effective this Sunday afternoon and Monday morning from 555 PM
until 100 AM 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...Widely scattered to scattered thunderstorms are forecast
to continue to develop and intensify this evening. The stronger
storms will be capable of a risk for large hail (1 to 2 inches in
diameter) and severe gusts (60 to 70 mph).
The severe thunderstorm watch area is approximately along and 75
statute miles east and west of a line from 35 miles northeast of
Havre MT to 30 miles east southeast of Helena MT. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 660...WW 661...
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 450. Mean storm motion vector
25025.
...Smith
WW 661 SEVERE TSTM IA KS MO 062140Z - 070300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 661
NWS Storm Prediction Center Norman OK
440 PM CDT Sun Sep 6 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest into Central Iowa
Eastern Kansas
West-Central into Northwest Missouri
* Effective this Sunday afternoon and evening from 440 PM until
1000 PM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Scattered thunderstorms will continue to develop this
afternoon and pose a risk for severe gusts (mainly 60 to 70 mph) and
isolated large hail. The severe threat will likely continue through
the early to mid evening before gradually diminishing.
The severe thunderstorm watch area is approximately along and 50
statute miles east and west of a line from 80 miles north northeast
of Shenandoah IA to 30 miles southeast of Olathe KS. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).
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 660...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
29015.
...Smith
WW 0662 Status Updates
STATUS REPORT ON WW 662
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ESE HLN
TO 35 NE HVR.
..KERR..09/07/26
ATTN...WFO...TFX...
STATUS REPORT FOR WS 662
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC005-007-015-027-041-045-059-070340-
MT
. MONTANA COUNTIES INCLUDED ARE
BLAINE BROADWATER CHOUTEAU
FERGUS HILL JUDITH BASIN
MEAGHER
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.
WW 0661 Status Updates
STATUS REPORT ON WW 661
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 W SDA TO
10 S SDA TO 30 N STJ TO 10 NNW CDJ.
..CHALMERS..09/07/26
ATTN...WFO...DMX...OAX...EAX...
STATUS REPORT FOR WS 661
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
KSC005-043-091-103-121-209-070140-
KS
. KANSAS COUNTIES INCLUDED ARE
ATCHISON DONIPHAN JOHNSON
LEAVENWORTH MIAMI WYANDOTTE
MOC003-005-021-025-037-047-049-061-063-087-095-101-107-165-177-
070140-
MO
. MISSOURI COUNTIES INCLUDED ARE
ANDREW ATCHISON BUCHANAN
CALDWELL CASS CLAY
CLINTON DAVIESS DEKALB
HOLT JACKSON JOHNSON
LAFAYETTE PLATTE RAY
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
WW 0660 Status Updates
STATUS REPORT ON WW 660
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WSW AGS
TO 20 SSW OGB TO 30 S OGB.
..CHALMERS..09/07/26
ATTN...WFO...CAE...GSP...
STATUS REPORT FOR WS 660
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
GAC033-070140-
GA
. GEORGIA COUNTIES INCLUDED ARE
BURKE
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.
MD 2260 CONCERNING SEVERE THUNDERSTORM WATCH 662... FOR PARTS OF NORTH CENTRAL MONTANA
Mesoscale Discussion 2260
NWS Storm Prediction Center Norman OK
0841 PM CDT Sun Sep 06 2026
Areas affected...parts of north central Montana
Concerning...Severe Thunderstorm Watch 662...
Valid 070141Z - 070345Z
The severe weather threat for Severe Thunderstorm Watch 662
continues.
SUMMARY...Thunderstorms may still intensify as they approach areas
to the southwest and west of Glasgow through 9-10 PM MDT,
accompanied by increasing potential for large hail and localized
severe wind gusts.
DISCUSSION...Storms thus far have remained fairly small in size and
of modest intensity, with cells tending to propagate with the
south-southwesterly cloud-bearing layer mean flow (on the order of
30 kt). Through 03-04Z, ongoing cells to the west through
north-northwest of Lewistown may still acquire more substantively
unstable updraft inflow as they propagate into areas near and
southwest through west of Glasgow, where post-frontal surface dew
points remain in the lower to mid 60s F, perhaps supporting CAPE as
high as 2000 J/kg.
..Kerr.. 09/07/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GGW...TFX...
LAT...LON 47511061 48420978 48920906 48720797 47470889 46870980
46771043 47511061
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 PM CDT Sun Sep 06 2026
Valid 070100Z - 071200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
WESTERN AND CENTRAL MONTANA AND OVER A SMALL PART OF THE LOWER
MISSOURI VALLEY...
...SUMMARY...
Widely scattered large hail occurrences with hailstones up to two
inches are expected over portions of western and central Montana
this evening into tonight. More sporadic occurrences of large hail
and severe wind gusts appear possible over the northern and central
High Plains, and across parts of the lower Missouri Valley.
...Northern Rockies into the northern Plains...
Separate vorticity lobes and associated wind maxima will progress
into the northern Rockies and northern High Plains tonight with a
resultant zone of height falls/forcing for ascent overspreading the
region. In the lower levels, a surface cyclone will be maintained
over southeast MT while a nocturnal jet develops over the northern
and central High Plains.
Thunderstorms currently intensifying over western MT are expected to
increase in coverage and intensity while spreading into
north-central MT ahead of the western vorticity lobe rounding the
base of the Pacific Northwest upper low. While the boundary layer is
somewhat cool/stable, the presence of steep mid-level lapse rates,
MUCAPE up to 1000-1500 J/kg, and 40-45 kt of effective bulk shear
will be supportive of supercells with the primary hazard being large
hail up to two inches.
Farther east, isolated to widely scattered storms have developed
along and ahead of a lee trough and the MT surface low from western
ND into northeast CO within a steep lapse rate and moderately
unstable environment (see the 00Z UNR and LBF soundings). Veering
winds with height with up to 35-40 kt of deep-layer shear are
sufficient to support an observed supercell storm mode with the
primary hazards being large hail potentially in excess of two inches
and locally severe wind gusts. A tornado was recently reported with
a slow-moving supercell over McKenzie County, ND. However, sizable
temperature-dewpoint spreads within the inflow air mass, and the
tendency for increasing convective inhibition in the coming hours
are likely to limit a continuing tornado threat despite increasing
low-level shear.
Storm coverage is expected to remain limited through the remainder
of the evening with a potential increase later tonight with the
arrival of the eastern vorticity lobe and strengthening low-level
jet. As such, the threat for sporadic large hail and severe wind
gust occurrences may linger into the overnight hours from eastern MT
into the western parts of the Dakotas and NE.
For additional information, see recently issued mesoscale discussion
#2259.
...Lower Missouri Valley...
Widely scattered strong to severe storms are ongoing this evening
over parts of southeast NE, northeast KS, and northwest MO with
activity focused along outflow boundaries and a synoptic front in
the area. The inflow air mass remains hot and relatively moist as of
00Z with observed soundings indicating steep low-level lapse rates
with MLCAPE up to 1500-3000 J/kg. The 00Z TOP sounding sampled
around 30 kt of deep-layer shear, which will remain supportive of
episodic supercell structures for the next couple of hours with an
associated risk for large hail and locally damaging wind gusts.
For additional information, see recently issued mesoscale discussion
#2258.
..Mead.. 09/07/2026
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0443 PM CDT Sun Sep 06 2026
Valid 081200Z - 141200Z
...Discussion...
An upper shortwave trough will eject from the Intermountain West
into the Upper Midwest early this week, allowing high pressure to
retrograde into the western CONUS through Day 4/Wednesday.
Meanwhile, persistent ridging over the southern Plains will continue
to promote above normal temperatures and dry conditions through the
forecast period, although accompanied by relatively light surface
winds. Predictability wanes beyond Day 6/Friday with disagreement in
extended ensemble guidance on the evolution of the upper pattern --
particularly with eastern Pacific troughing and the remnants of
Hurricane Marie. However, members are generally in agreement for
another shortwave trough to sag into the Pacific Northwest from
British Columbia on Days 5-6/Thursday-Friday, increasing dry
southwesterly flow over the northern Great Basin. Fuels are expected
to remain marginal (60-80th percentile ERCs), thus hindering broader
fire concerns.
As the aforementioned upper trough translates eastward on Day
3/Tuesday, strong southwesterly flow aloft should allow dry and
breezy conditions to continue across the north-central states. 40%
Critical probabilities have been maintained across parts of the
northern Plains on Day 3/Tuesday where RH values of less than 20%
and sustained winds of 15-20 mph will overlap rainfall-neglected
fuels (and forecast ERCs remain at the 80-95th percentiles). On Days
4-6/Wednesday-Friday, dry and locally breezy conditions will
continue across southern Wyoming, although displaced from the most
receptive fuels.
..Elizalde-Garcia.. 09/06/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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