WW 669 TORNADO IA MO NE 142150Z - 150500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 669
NWS Storm Prediction Center Norman OK
450 PM CDT Mon Sep 14 2026
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Western into Central Iowa
Far Northwest Missouri
Eastern Nebraska
* Effective this Monday afternoon from 450 PM until Midnight CDT.
* Primary threats include...
A couple tornadoes possible
Scattered damaging winds and isolated significant gusts to 80
mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
SUMMARY...Scattered severe thunderstorms are forecast to develop and
intensify this evening. A couple of tornadoes are possible, as well
as scattered severe gusts (60 to 80 mph) and large hail (1 to 2
inches in diameter). The greatest tornado risk will likely focus
with supercell activity this evening, but a lingering tornado threat
may extend into the late evening as storms grow upscale into a
squall line.
The tornado watch area is approximately along and 60 statute miles
north and south of a line from 30 miles west southwest of Lincoln NE
to 5 miles northeast of Des Moines IA. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 668...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 24030.
...Smith
WW 668 SEVERE TSTM KS NE 142045Z - 150300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 668
NWS Storm Prediction Center Norman OK
345 PM CDT Mon Sep 14 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western and Northern Kansas
South Central Nebraska
* Effective this Monday afternoon and evening from 345 PM until
1000 PM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 80
mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...High-based storms will continue to develop in a
hot/well-mixed environment, and otherwise develop/spread
northeastward through evening near a pre-frontal trough. Damaging
winds and some hail are the primary concerns.
The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 145 miles southwest of
Hill City KS to 50 miles east of Hastings NE. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU8).
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
1.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 600. Mean storm motion vector
25025.
...Guyer
WW 0669 Status Updates
STATUS FOR WATCH 0669 HAS NOT BEEN ISSUED YET
WW 0668 Status Updates
STATUS FOR WATCH 0668 HAS NOT BEEN ISSUED YET
MD 2296 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF WESTERN INTO NORTHERN IOWA
Mesoscale Discussion 2296
NWS Storm Prediction Center Norman OK
0632 PM CDT Mon Sep 14 2026
Areas affected...portions of western into northern Iowa
Concerning...Severe potential...Watch unlikely
Valid 142332Z - 150030Z
Probability of Watch Issuance...5 percent
SUMMARY...An instance or two of marginally severe hail may accompany
one of the stronger storms. The severe threat should remain sparse,
so a Severe Thunderstorm Watch issuance is not expected.
DISCUSSION...Thunderstorms are increasing in coverage and intensity
along a confluence zone, where maximized 925 hPa frontogenesis and
850 hPa WAA are taking place. These storms are developing atop a
stable boundary layer, with 1000+ J/kg MUCAPE constrained above 850
hPa. As such, the ongoing storms are likely elevated in nature, and
are benefiting from the strong tropospheric flow and 50 kts of
effective bulk shear. A couple of marginally severe hailstones may
occur with the stronger, sustained updrafts. However, any severe
threat that materializes will likely be limited, so a Severe
Thunderstorm Watch issuance is not anticipated.
..Squitieri/Smith.. 09/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ARX...DMX...FSD...OAX...
LAT...LON 42029543 41999586 42019594 42049603 42099609 42289591
42859504 43369406 43449336 43199293 42719313 42309404
42029543
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
MD 2295 CONCERNING TORNADO WATCH 669... FOR SOUTHEAST NEBRASKA INTO SOUTHWESTERN IOWA
Mesoscale Discussion 2295
NWS Storm Prediction Center Norman OK
0618 PM CDT Mon Sep 14 2026
Areas affected...southeast Nebraska into southwestern Iowa
Concerning...Tornado Watch 669...
Valid 142318Z - 150015Z
The severe weather threat for Tornado Watch 669 continues.
SUMMARY...Multiple severe gusts are possible over the next few
hours, especially across southeastern NE. A couple of tornadoes may
occur, mainly over southwestern IA.
DISCUSSION...Multiple linear segments have developed over the past
couple of hours, accompanied by severe gusts. These storms will
continue to progress eastward amid appreciably strong mid-level flow
atop a well-mixed boundary layer, accompanied by a severe gust
threat. At the moment, the greatest short-term severe threat exists
with storms over southeastern NE, where surface temperatures into
the 80s F to near 90 F, are promoting downward momentum mixing
potential. As these storms progress into southwestern IA, they will
traverse a baroclinic zone with somewhat cooler surface temperatures
(e.g. low 80s F), but with a more moist boundary layer given low 70s
F dewpoints. Destabilization of this boundary layer is somewhat
uncertain. However, should the southwest IA boundary layer
destabilize, backed low-level flow and accompanying enlarged
hodographs (per OAX VADs) suggest that a couple of QLCS tornadoes
may develop, with a severe gust threat also continuing.
..Squitieri/Smith.. 09/14/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DMX...EAX...OAX...TOP...
LAT...LON 40309736 41189682 41829559 42129455 41909384 41249348
40679416 40309540 40139627 39989729 40309736
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Mon Sep 14 2026
Valid 142000Z - 151200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
KANSAS AND SOUTHERN/EASTERN NEBRASKA INTO WESTERN/CENTRAL IOWA...
...SUMMARY...
Scattered strong to severe thunderstorms should occur across parts
of eastern Nebraska into western/central Iowa this afternoon and
evening. Large hail, severe wind gusts, and tornadoes all appear
possible. Severe thunderstorm winds will also be possible across
northern/western Kansas.
...20z Update...
Visible satellite shows an expansive area of persistent mid-level
cloud cover over much of Nebraska and adjacent regions of northwest
Kansas and western Iowa. Some attempts at surface-based convection
are apparent over portions of south-central Nebraska. Latest surface
mesoanalysis shows destabilization is occurring across much of
Kansas where skies are clear, with northward advancement now
occurring into central/eastern Nebraska as evidenced by 2232 J/kg of
MUCAPE in an 18z OAX observed sounding. This trend expected continue
into the early evening, with rapid destabilization occurring across
southeast Nebraska and southwest Iowa as the low-level jet shifts
east and intensifies.
An elongated area of convection is still expected to develop, from
north-central Kansas into south-central/eastern Nebraska and
west-central Iowa, favoring supercell modes early. Despite the noted
convective/environmental trends, the exact placement of convective
initiation remains uncertain, as exhibited in the most recent
HRRR/RRFS runs. Additionally, most guidance continues to suggest a
quick transition to mainly clusters/line segments. Therefore, no
changes were made in this outlook.
..Karstens/Wendt.. 09/14/2026
.PREV DISCUSSION... /ISSUED 1145 AM CDT Mon Sep 14 2026/
...Central Plains to Iowa...
Well to the northeast of a warm front, semi-extensive elevated
convection continues at midday across Iowa and the eastern Dakotas
into western/southern Minnesota, although there has been a
diminishing trend, and cloud cover otherwise remains semi-prevalent
across Nebraska and western/northern Kansas.
A key forecast uncertainty remains the spatial location of primary
late-day surface-based destabilization and uncertain likelihood of
deep convective development toward/just after peak heating. The
semi-persistent convection, residual cloud cover, and
autumnal-approaching sun angle (and ramifications for air mass
recovery) may be factors for confining the most-favorable
environment/surface-based potential to eastern Nebraska and western
Iowa.
This will be as a seasonably strong mid-level shortwave trough and
50-70+ kt mid-level jet spread quickly east-northeastward across the
northern Plains and Canadian Prairies today. While the primary
surface low will likely persist across western Kansas, a secondary
surface wave may materialize across east-central/northeast Nebraska.
Greater low-level moisture across Kansas and the lower Missouri
Valley quickly spread north-northeastward in tandem with a warm
front, although its exact late-day disposition/placement is a bit
uncertain. This will precede a cold front that will sweep
southeastward across the northern/central Plains through tonight. A
narrow corridor of moderate to strong instability (MLCAPE 2000-3000+
J/kg) still appears plausible across eastern Nebraska and western
Iowa into the 21-00Z time frame, coincident and roughly dependent
upon surface temperatures warming into at least the low to mid 80s
F.
Robust thunderstorms should develop along or just ahead of the cold
front by late afternoon/early evening across eastern Nebraska, with
strengthening/favorable deep-layer shear for supercells initially.
Large hail may occur, but modest lapse rates aloft and a quick mode
transition to mainly clusters/line segments will probably limit the
spatial/temporal extent of the hail threat. Most guidance continues
to show a favorable conditional environment for tornadoes across
eastern Nebraska/western Iowa as the supercells/clusters spread
quickly eastward this evening, with a 40-50 kt low-level jet aiding
the development of ample effective SRH. But, various RAP forecast
soundings across this region show lingering low-level inhibition,
and it remains unclear whether convection will be able to fully take
advantage of the strong low-level shear. Even with this uncertainty,
a sustained surface-based supercell in this environment would
conditionally be capable of producing a strong tornado.
Otherwise, severe/damaging winds should become an increasing concern
as clusters develop and spread east-northeastward this evening, with
other late-day high-based development also expected in vicinity of a
pre-frontal boundary across southern Nebraska and northern/western
Kansas. Regarding the eastern Nebraska/western Iowa regime, weak
instability with eastward extent in eastern Iowa and vicinity should
limit the severe risk deeper into the night. While deep-layer shear
will be somewhat weaker with southward extent across the central
Plains, at least isolated severe wind gusts may also occur with
high-based/loosely organized convection that develops this afternoon
from eastern Colorado into western/northern Kansas along a surface
trough.
...Southwest/Four Corners...
Scattered thunderstorm development will occur later today from
western Colorado and southeast Utah into parts of Arizona/New Mexico
as a fairly moist low-level airmass gradually destabilizes. Modestly
enhanced mid-level westerly flow should be present this afternoon
over parts of Utah/Colorado, though it is uncertain if diurnal
heating and related instability will be sufficient for an organized
severe risk. Still, isolated gusty winds and small to perhaps
near-severe hail could occur with the strongest thunderstorms.
Farther south, flow will be weaker across Arizona, resulting in
mostly disorganized convection. Even so, localized strong gusts
appear possible, especially where stronger heating occurs and
steeper low-level lapse rates develop during the afternoon. Overall,
confidence in an organized severe risk is too low to include 5%
hail/wind probabilities.
...Eastern North Carolina...
A cold front will move southward across North Carolina today.
Large-scale ascent will generally be weak, though isolated
convective development may occur as the front encounters greater
low-level moisture and sea breeze boundaries over coastal/eastern
North Carolina. Deep-layer shear within a northwesterly mid-level
flow regime will be sufficient for organized thunderstorms, but poor
mid-level lapse rates should tend to limit updraft intensity and the
overall severe threat. Regardless, any thunderstorms that can
develop and be sustained in this regime could produce locally gusty
winds and small hail mainly across near-coastal far eastern North
Carolina.
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0216 PM CDT Mon Sep 14 2026
Valid 161200Z - 171200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for severe thunderstorms appears negligible across the U.S.
on Wednesday.
...Discussion...
Stronger winds aloft will extend from the Northern Plains into the
Upper Great Lakes on Wednesday as a large upper ridge expands across
much of the central to southeastern states. A surface high will also
exist over the Upper MS Valley and Great Lakes which will keep the
more favorable instability well south of the stronger flow/shear.
While a secondary shortwave trough will swing across central Canada
and into the northern Plains late, instability should be minimal
that far north.
The greatest chance of thunderstorms will be near a weak/stalled
front from the Central Plains eastward across the Midwest and OH
Valley, where dewpoints of 65-70 F will be common. Early day
thunderstorms across this same zone will likely dissipate during the
day, with scattered redevelopment near peak heating. Given the
generally poor lapse rates aloft and weak shear, the severe storm
threat appears low.
..Jewell.. 09/14/2026
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0250 PM CDT Mon Sep 14 2026
Valid 151200Z - 161200Z
...East-central Nevada...
Dry and breezy conditions southeast of an upper-level trough across
the Pacific Northwest will effect portions of the Great Basin.
Elevated highlights remain for portions of east-central NV as
southwest winds of 15-20 mph and RH as low as 10% combine atop
drying fuels. No changes were needed to the existing Elevated
highlights.
...Southern Plains...
A surface trough south of an advancing cold front over the central
Plains will support modest south winds of 10-15 mph across TX and
much of OK Tuesday. Alignment of most receptive fuels and breezy
south winds will be across portions of southwest OK and northwestern
TX where Elevated fire weather highlights have been introduced.
Although winds will be incrementally lower than D1/Monday coupled
with RH reductions in the 25-30% range, a low-level jet evolving
this evening/overnight could limit boundary layer decoupling,
keeping temperatures in the upper 70s and limiting RH recoveries
going into Tuesday morning. The combined effects, in addition to
well above normal temperatures and drought stressed fuelscape, will
support an elevated fire weather risk across the area.
..Williams.. 09/14/2026
.PREV DISCUSSION... /ISSUED 0123 AM CDT Mon Sep 14 2026/
...Synopsis...
Dry southwesterly flow is forecast to return to the Great Basin on
Tuesday as an upper-level trough moves into the Pacific Northwest.
Elevated fire-weather conditions are expected over portions of
east-central Nevada.
...East-central Nevada...
Southwesterly to southerly winds of 15-20 MPH are forecast by
mid-afternoon across central and eastern Nevada, while relative
humidity is expected to be in the vicinity of 10-15%. Forecast
guidance for fuels has ERCs reaching the 80th annual percentile as
fuels continue to cure, supporting an Elevated fire-weather threat
for Tuesday.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0456 PM CDT Mon Sep 14 2026
Valid 161200Z - 221200Z
...Synopsis...
An upper-level low will pivot southward from the Pacific Northwest
and linger over northern CA for the middle of this week. Enhanced
southwest flow southeast of the low amid dry conditions and slowly
drying fuels, will promote a fire weather concern for portions of
the Great Basin for Days 3-4/Wednesday-Thursday. Thunderstorm
potential associated with the low exists for parts of northern CA
and southwestern OR on Day 3/Wednesday with a lightning threat
moving into the northern Rockies by Thursday. However, marginal
fuels should limit impact of lightning over the landscape through
midweek. Farther east, well above normal temperatures under a
persistent upper-ridge across the southeastern U.S. will promote
even drier fuels across the region. However, lighter winds under the
ridge and sufficient low-level moisture will limit broader fire
weather concerns through the week.
...Day 3-4/Wednesday-Thursday...
...Great Basin...
The upper low expected to be over northern CA will usher in a
corridor of 15-20 mph southwest winds over the Great Basin midweek.
The deep-layer southwest flow coupled with a dry air mass and
efficient daytime mixing should promote a fire weather threat
for portions of east-central NV both Wednesday and Thursday.
Although RH will likely fall below 10% in some valleys, marginal
fuel receptiveness will mute a more significant fire weather concern
across the area.
...Northern California, Southwest Oregon and Northern Rockies...
Thunderstorms associated with the upper low are expected Day
3/Wednesday across northern CA and southwestern OR, with a
thunderstorm threat extending into the northern Rockies by
D4/Thursday. Fuels continue to be a limiting factor in introducing
dry thunderstorm probabilities midweek with forecast ERC values only
climbing towards the 70th percentile by the end of the week.
..Williams.. 09/14/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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