WW 660 SEVERE TSTM GA NC SC 061845Z - 070100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 660
NWS Storm Prediction Center Norman OK
245 PM EDT Sun Sep 6 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Far Eastern Georgia
Western North Carolina
Western and Central South Carolina
* Effective this Sunday afternoon and evening from 245 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms clusters will be capable of producing
scattered damaging winds as they move generally south-southeastward
this afternoon and evening. Isolated hail also appears possible with
the strongest cores that can develop.
The severe thunderstorm watch area is approximately along and 80
statute miles north and south of a line from 5 miles south of
Anderson SC to 55 miles east northeast of Columbia SC. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU0).
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
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
33025.
...Gleason
WW 0660 Status Updates
STATUS FOR WATCH 0660 HAS NOT BEEN ISSUED YET
MD 2252 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN/CENTRAL MS/AL
Mesoscale Discussion 2252
NWS Storm Prediction Center Norman OK
0128 PM CDT Sun Sep 06 2026
Areas affected...Northern/central MS/AL
Concerning...Severe potential...Watch unlikely
Valid 061828Z - 062030Z
Probability of Watch Issuance...20 percent
SUMMARY...Localized damaging winds are possible this afternoon.
DISCUSSION...Storms have begun to develop this afternoon across
parts of northern MS/AL, within a very warm, moist, and uncapped
environment. MLCAPE of 2500-3500 J/kg is already in place as
temperatures approach 100 F. Steep low-level lapse rates and
relatively large PW will support downburst potential across a broad
region. Deep-layer shear is weak (generally 20 kt or less), though
northerly deep-layer flow may eventually support one or more
southward-moving clusters, if sufficient coverage of storms and
attendant outflow can be realized.
Within the broader area, 12Z HREF guidance generally depicts greater
storm coverage later this afternoon across northern/central MS.
Greater coverage of building cumulus across northern MS supports
this scenario, which may lead to a relatively greater wind-damage
threat in this area. However, the thermodynamic environment will be
similarly favorable for downbursts across AL, even if storm coverage
is somewhat less.
..Dean/Gleason.. 09/06/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BMX...HUN...MEG...JAN...LZK...
LAT...LON 34649051 34668949 34698799 34448567 32228505 32588814
32748932 32949060 33089109 33509124 34649051
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MD 2251 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF THE OZARKS VICINITY
Mesoscale Discussion 2251
NWS Storm Prediction Center Norman OK
1248 PM CDT Sun Sep 06 2026
Areas affected...Parts of the Ozarks vicinity
Concerning...Severe potential...Watch unlikely
Valid 061748Z - 062015Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated downbursts are possible this afternoon.
DISCUSSION...Storms have recently developed across the higher
terrain of northern AR, with building cumulus noted elsewhere from
eastern OK into southern MO. Temperatures are warming quickly to
near/above 100 F, and additional storm development is expected
through the afternoon as any remaining MLCINH diminishes across the
region. Weak deep-layer shear should limit storm organization,
though deep mixing and steep low-level lapse rates will support
potential for localized downbursts. It remains unclear if storm
coverage will become sufficient for substantial outflow
amalgamation, but weak north-northeasterly deep-layer flow could
lead to one or more small outflow-driven clusters that would tend to
move southward later this afternoon.
..Dean/Gleason.. 09/06/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MEG...LZK...SGF...SHV...TSA...
LAT...LON 34669516 36509525 37339450 37749359 37569181 37069130
36159110 35459098 34369179 34199471 34669516
MOST PROBABLE PEAK WIND GUST...55-70 MPH
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CDT Sun Sep 06 2026
Valid 061630Z - 071200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...MONTANA...AND NORTH DAKOTA...
...SUMMARY...
Scattered damaging winds should occur across parts of the Southeast
this afternoon/early evening. Scattered large hail is forecast
across portions of Montana and North Dakota this afternoon and
evening. Isolated strong to severe thunderstorms may also occur
today across parts of the northern Great Basin, northern/central
Plains, and Missouri Valley to the Ozarks.
...Southeast/Lower Mississippi Valley...
Recent visible satellite imagery shows mostly clear skies across
GA/SC late this morning, with surface temperatures already in the
mid/upper 80s to low 90s. A weak front is draped from northwest to
southeast from the southern Appalachians to the Atlantic Coast, with
generally low to mid 70s surface dewpoints present to its south.
Continued diurnal heating of this moist airmass will support the
development of moderate to strong instability (greater with
southward/westward extent into GA/AL and north FL). Compared to the
past couple of days, this region will be displaced from the stronger
mid-level west-northwesterly flow present across the
Mid-Atlantic/Northeast. Corresponding deep-layer shear is expected
to remain rather modest (less than 25 kt), with only loosely
organized updrafts forecast. Even with these kinematic limitations,
steepening low-level lapse rates through the afternoon may still
promote isolated to scattered damaging winds with clusters that
develop and spread south-southeastward through the early evening.
Isolated hail may also occur with the more robust cells that can
develop initially. The damaging wind threat should be more isolated
with westward extent into the lower MS Valley compared to GA and the
Carolinas, where the Slight Risk has been maintained with some
expansion.
...Northern Great Basin into the Northern Rockies/High Plains...
A closed mid/upper-level low over the Pacific Northwest and British
Columbia will pivot towards the northern Rockies through the period,
with a belt of enhanced mid-level flow overspreading the northern
Great Basin into the northern Rockies and adjacent High Plains in
MT. At the surface, mostly cloudy conditions are present over much
of western/central MT this morning. Even so, recent NAM/RAP forecast
soundings across this region show supercell profiles later this
afternoon and evening as mid/upper-level winds foster strong
deep-layer shear. Current expectations are for multiple supercells
to develop initially over the higher terrain and spread quickly
northeastward. While there is still some uncertainty regarding
boundary-layer destabilization, sufficient MUCAPE is forecast to
support supercell maintenance into the adjacent High Plains through
the evening. Large hail should be the main threat with this activity
(with some 2+ inches possible given the very favorable deep-layer
shear), but isolated severe gusts may also occur. The Slight Risk
has been adjusted/expanded a little eastward in MT based on latest
short-term guidance trends. High-based thunderstorms may also pose
an isolated threat for severe gusts across parts of the northern
Great Basin this afternoon.
...Northern/Central Plains into the Upper Midwest/Missouri Valley
and Ozarks...
Ongoing and likely elevated supercells with a threat for large hail
across parts of western ND are being aided by a subtle mid-level
shortwave trough cresting the upper ridge that is anchored over the
central CONUS. Favorable lapse rates aloft and modestly enhanced
mid/upper-level southwesterly flow is likely supporting updraft
organization/intensity with this ongoing activity. The airmass
downstream across central/eastern ND should gradually destabilize
through the afternoon, with a moist low-level airmass present to the
east of a weak surface low over eastern MT/southwest ND/northwest
SD. It remains unclear whether these ongoing supercells will be
maintained farther east across ND, but given the favorable airmass
and sufficient deep-layer shear present, have opted to add a
targeted Slight Risk for the large hail potential.
Additional convection is occurring farther south in SD, southwest
MN/northwest IA, and northeast NE in association with a mid-level
vorticity maximum evident on water vapor satellite imagery moving
eastward across SD/NE. There is a narrow corridor of greater
instability present across this region southward to the Ozarks,
generally along/near a weak surface front. Isolated hail may occur
with the stronger cores in the short term, but it remains unclear if
convection will be able to form into a southward-moving cluster
across eastern NE/western IA later this afternoon and evening. If
this does occur, then a greater threat for severe/damaging winds
would exist. Have deferred a possible upgrade to Slight Risk given
the uncertainty with how ongoing convection will evolve/impact the
developing warm sector, and due to the presence of the large-scale
mid/upper-level ridge and generally modest flow aloft. A separate
area of high-based thunderstorms that should develop this afternoon
along/east of a surface lee trough across the central High Plains
could produce occasional hail and severe gusts, even as deep-layer
shear remains modest.
..Gleason/Thornton.. 09/06/2026
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1216 PM CDT Sun Sep 06 2026
Valid 071200Z - 081200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE NORTH-CENTRAL UNITED STATES...
...SUMMARY...
Strong to severe thunderstorms are possible across portions of the
northern and central Plains into Minnesota on Monday.
... Synopsis ...
A mid-level shortwave trough will take on increasingly negative tilt
on Monday as it lifts north-northeast along the northwest periphery
of a central CONUS ridge. At the same time, a subtle, low-amplitude
short-wave trough currently over the Pacific Ocean off the coast of
Southern California will quickly move northeast ahead of the main
wave.
At the surface, an anticyclone over the Upper Great Lakes will
maintain south-southeasterly flow across the Plains, sustaining
mid-to-upper-60Fs dewpoints across the Missouri Valley into the
Dakotas and western Minnesota. A weak low across eastern Montana
will eventually redevelop northward into the Canadian Prairies
overnight. As this happens, a cold front will move east across the
Northern Plains.
... Northern Plains into the Upper Midwest ...
The lead short-wave trough will be approaching the north-central US
at the start of the forecast period (Monday morning). As the
associated mid-level jet approaches, the low-level jet will increase
and spread northward across the Plains. On the nose of this jet,
elevated convection is likely to be ongoing in response to the
warm-air advection. Latest model guidance maintains the low-level
jet through the day and subsequently the morning convection is
likely to persist through the day as it moves northeast toward
western Minnesota. Although widespread cloud cover and moist
mid-level profiles will limit instability, the degree of the
cloud-layer shear will support at least some potential for hail with
these elevated storms.
To the southwest of the morning convection, clearing clouds will
give way to robust heating allowing surface temperatures to climb
into the upper-80Fs to mid-90Fs, with even hotter surface
temperatures across western Nebraska. This will allow strong
instability to develop by late afternoon ahead of the surface cold
front/dry line.
Isolated to perhaps scattered thunderstorms are possible during the
afternoon along the surface front/dryline. However, low-level
convergence along this boundary will be somewhat weak, with
southerly/southwesterly flow ahead of it. At the same time,
large-scale subsidence will likely be occurring in the wake of the
morning convection. This should limit storm coverage across western
South Dakota and western Nebraska. Northwest North Dakota and
eastern Montana will be closer to the main wave as its associated
better large-scale ascent. Thus, storm coverage may be slightly
higher here during the afternoon. Isolated large hail and strong
wind gusts will be possible with any of these storms.
Overnight, the low-level jet increases in response to the main wave
approaching the area. This should result in additional elevated
thunderstorm development from northeast Nebraska into the eastern
Dakotas. This activity should continue east across Minnesota through
the overnight. Overall instability should be on the low side given
the convection from the lead shortwave, but strong cloud-layer shear
could support a hail and wind threat with the strongest elevated
convection.
..Marsh.. 09/06/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1133 AM CDT Sun Sep 06 2026
Valid 061700Z - 071200Z
...NO CRITICAL AREAS...
Along the northwestern periphery of a prominent ridge over the
central U.S., a shortwave trough and accompanying forcing for ascent
amid increasing midlevel moisture will support the development of
high-based thunderstorms across portions of the northern Plains.
Locally heavy rainfall will be possible with any thunderstorm as
forecast soundings depict PWATs ranging from 0.9-1.0" or greater;
however, lightning on the fringes of accumulating rainfall could
trigger new ignitions where very dry fuels exist, particularly
across eastern Wyoming and southwestern South Dakota (80-90th
percentile ERCs). In addition, gusty/erratic outflow winds could
exacerbate new fire starts (see the Day 1 Convective outlook for
details). The rest of the forecast remains on track, see the
previous discussion for more information.
..Elizalde-Garcia.. 09/06/2026
.PREV DISCUSSION... /ISSUED 0150 AM CDT Sun Sep 06 2026/
...Synopsis...
Upper-level troughing will persist over the Pacific Northwest and
Northeast today, with upper ridging remaining in place over the
southern Plains. A series of shortwave troughs embedded within
strengthening southwesterly flow will traverse northeastward across
portions of the Great Basin and Northern Rockies, with subtropical
moisture beginning to advect into the Desert Southwest/Great Basin,
which will bring additional cloud cover and some chances for rain.
These factors will largely mitigate fire weather concerns across
much of the western U.S. today.
...Eastern Idaho into central/northern Wyoming and southern
Montana...
Dry and breezy conditions are forecast this afternoon from eastern
Idaho into far southern Montana and central/northern Wyoming.
Sustained southwesterly winds of 10-20 mph (locally up to 25 mph in
favored terrain areas) amid minimum RH values of 10-20% may support
locally elevated fire weather conditions across portions of this
region, particularly across central/northern Wyoming where
drier/more receptive fuels exist. Elevated highlights continue to be
withheld, however, due to the expected limited duration and spatial
extent of meteorological conditions combined with uncertainty
regarding cloud cover and its impact on RH reductions.
...Great Basin...
Dry, southwesterly flow will continue across portions of the central
Great Basin today, with locally elevated fire weather conditions
possible where pockets of drier fine fuels exist. Generally marginal
fuel receptiveness continues to preclude a broader fire weather
risk, however.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0153 PM CDT Sun Sep 06 2026
Valid 071200Z - 081200Z
Strong southwesterly flow aloft will overspread the northern Plains
on Day 2/Monday as an upper shortwave trough traverses the Northern
Rockies into south-central Canada. A surface low in eastern
Montana/western North Dakota will continue to strengthen as it lifts
into the Canadian Prairies, tightening a surface pressure gradient
across the northern Plains. An overlapping 30-40 kt 700 mb jet will
emerge Monday morning and translate eastward throughout the
afternoon, encouraging 30-40 mph wind gusts to reach the surface.
Despite modest RH values of 15-25% and slightly cooler daytime
temperatures in central-northern WY, sustained westerly winds of up
to 25 mph will support an Elevated fire weather threat where fuels
remain receptive. A cold front will span the Wyoming plains during
the late afternoon/early evening and redirect winds from broadly
westerly to northwesterly, though wind speeds are expected to
diminish after 06z. See the previous discussion for more
information.
..Elizalde-Garcia.. 09/06/2026
.PREV DISCUSSION... /ISSUED 0152 AM CDT Sun Sep 06 2026/
...Synopsis...
Upper-level troughing will shift slowly eastward on Day 2/Monday,
with modestly strong, southwesterly mid-level flow persisting across
the Northern Rockies/northern High Plains. As this eastward shift
occurs, an embedded shortwave trough will pivot northeastward across
southern Idaho/western Montana, with a surface cyclone forecast to
strengthen through the day across the northern Plains. This will
support dry, downslope flow and elevated fire weather concerns
across portions of the northern High Plains.
...Southern/southeastern Montana into central/northern Wyoming...
As the aforementioned surface low deepens over eastern Montana/the
northern Great Plains, a strengthening surface pressure gradient
will support dry, downslope flow across portions of
southern/southeastern Montana and central/northern Wyoming. Westerly
surface winds of 15-25 mph will overlap very low RH of 15-25% and
receptive fuels (ERCs ranging from the 80th to 95th percentiles),
supporting elevated fire weather concerns. Deep boundary layer
mixing and strengthening low- to mid-level flow will also promote
the potential for wind gusts up to 30-40 mph (perhaps higher in
favored terrain areas and/or along exposed areas of higher
elevation). Locally critical conditions may be possible should
minimum RH values fall below 15%; however, uncertainty remains
regarding the magnitude of RH reductions across the region,
especially given potential impacts from lingering cloud cover as
well as some potential for rain chances on Day 1/Sunday.
...Please see www.spc.noaa.gov/fire for graphic product...
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