WW 326 SEVERE TSTM IA MO 131405Z - 132000Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 326
NWS Storm Prediction Center Norman OK
905 AM CDT Sat Jun 13 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
South-Central Iowa
North-Central Missouri
* Effective this Saturday morning and afternoon from 905 AM until
300 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...Bowing line segment currently moving through far
west-central Iowa is expected to continue
east-southeastward/southeastward over the next several hours. Strong
to severe gusts have already occurred with this line, with the
threat for damaging gusts expected to continue into south-central
Iowa and north-central Missouri. Isolated hail is also possible with
any storms that develop in the wake of this line segment.
The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 50 miles west northwest
of Lamoni IA to 30 miles north northeast of Kirksville MO. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU6).
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 325...
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 500. Mean storm motion vector
28035.
...Mosier
WW 0326 Status Updates
STATUS REPORT ON WW 326
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NNE STJ
TO 5 N DSM.
..THORNTON..06/13/26
ATTN...WFO...DMX...EAX...
STATUS REPORT FOR WS 326
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC007-039-051-053-117-123-125-135-159-179-181-185-131740-
IA
. IOWA COUNTIES INCLUDED ARE
APPANOOSE CLARKE DAVIS
DECATUR LUCAS MAHASKA
MARION MONROE RINGGOLD
WAPELLO WARREN WAYNE
MOC001-061-075-079-081-115-117-121-129-171-197-211-227-131740-
MO
. MISSOURI COUNTIES INCLUDED ARE
ADAIR DAVIESS GENTRY
GRUNDY HARRISON LINN
LIVINGSTON MACON MERCER
PUTNAM SCHUYLER SULLIVAN
WORTH
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
WW 0325 Status Updates
STATUS REPORT ON WW 325
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 W BIE TO
15 S OLU TO 5 SE DNS.
..THORNTON..06/13/26
ATTN...WFO...OAX...GID...LBF...
STATUS REPORT FOR WS 325
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC071-085-129-137-145-155-165-131540-
IA
. IOWA COUNTIES INCLUDED ARE
FREMONT HARRISON MILLS
MONTGOMERY PAGE POTTAWATTAMIE
SHELBY
NEC023-025-055-109-131-151-153-155-159-177-131540-
NE
. NEBRASKA COUNTIES INCLUDED ARE
BUTLER CASS DOUGLAS
LANCASTER OTOE SALINE
SARPY SAUNDERS SEWARD
WASHINGTON
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.
No Mesoscale Discussions are in effect as of Sat Jun 13 16:40:15 UTC 2026.SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0753 AM CDT Sat Jun 13 2026
Valid 131300Z - 141200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE CENTRAL PLAINS AND LOWER MISSOURI VALLEY...
...SUMMARY...
Scattered severe thunderstorms are likely today and tonight across
parts of the central and southern Plains to Missouri Valley and
Middle Mississippi Valley. Swaths of damaging wind gusts, large
hail, and a few tornadoes are all possible.
...Central/Southern Plains to Middle Mississippi Valley...
An active severe-weather day is anticipated with multiple rounds of
severe storms expected regionally today into tonight. Near the nose
of a southwesterly low-level jet, an initial early day severe risk
will focus across southeast Nebraska, where elevated/increasingly
organized storms are ongoing just after dawn, into southern Iowa and
northern Missouri. Large hail will remain possible, but the
potential for damaging winds may increase relatively early today as
storms spread east-southeastward.
Meanwhile, a more complex scenario exists farther south,
attributable to persistent predawn storms across the Ozarks, as well
as a decayed convective cluster and one or more residual MCVs across
Oklahoma and far southeast Kansas. These MCVs, as they focus deeper
convection along modifying outflow/differential heating zones,
should inspire renewed deeper convective development this afternoon
across parts of the Ozarks toward the Mid-South/middle Mississippi
Valley. This includes the potential for some supercells and
organizing clusters, with damaging winds and some hail as the
primary hazards through evening.
Farther west and later in the day, strong diurnal heating/steepening
low-level lapse rates preceding the surface low will result in
scattered thunderstorm development near/ahead of the
southeast-moving cold front, with the most intense development
likely favoring where the front intercepts the west-southwest
periphery of early day storms and any residual cloud cover/modifying
outflow. This will likely include central/eastern Kansas and
possibly far southeast Nebraska into western/northern Missouri.
Steep mid-level lapse rates atop rich boundary-layer moisture will
yield a strongly unstable air mass, which combined with around 40 kt
of effective shear, will support initial intense semi-discrete
supercells as then organizing clusters. All hazards seem likely
including large hail, with damaging winds potentially evolving as
the most prominent risk this evening, potentially including some
significant (75+ mph) wind gusts. The potential for tornadoes will
also exist, particularly late afternoon into evening as the
low-level jet increases, with modifying outflow potentially another
factor across west/southwest Missouri and possibly far eastern
Kansas and vicinity.
...Carolinas/Coastal Southeast...
Ample heating within a moist environment south of a front will lead
to moderately strong diurnal destabilization, with convective
development aided by the front and coastal sea breeze. Some
pulse-type locally severe storms capable of downbursts/wind damage
may occur this afternoon through around sunset.
..Guyer/Broyles.. 06/13/2026
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1130 AM CDT Sat Jun 13 2026
Valid 131630Z - 141200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE CENTRAL PLAINS AND LOWER MISSOURI VALLEY...
...SUMMARY...
Scattered severe thunderstorms are likely today and tonight from
parts of the central and southern Plains to the Lower Missouri and
Middle Mississippi Valleys. Swaths of damaging wind gusts, large
hail, and a few tornadoes are all possible.
...Central/Southern Plains to Middle Mississippi Valley...
Several different areas are already convectively active this
morning, including south-central IA/north-central MO where a bowing
segment is moving southeastward through the region, and farther
south from central/southern MO into far west-central IL, where
elevated thunderstorm are being maintained by modest warm-air
advection. Most immediate severe potential is downstream of the
bowing segment in south-central IA/north-central MO where damaging
wind gusts and isolated hail are possible over the next few hours.
Thereafter, expansive coverage of the ongoing storms in
central/southern MO introduces notable uncertainty regarding the
extent and strength of afternoon destabilization.
General expectation is for the ongoing showers and thunderstorms to
persist, aided by mesoscale ascent attendant to an MCV traversing
the region. Cloud cover will limit heating, but ample low-level
moisture will still support moderate buoyancy. Moderate deep-layer
shear is anticipated over this area as well, with perhaps some more
mesoscale enhancement attendant to the MCV. As a result, a few
stronger embedded multicells and isolated supercells are possible.
Isolated large hail and damaging gusts could occur with the
strongest storms embedded within this likely broad area of showers
and thunderstorms.
A more complex scenario is anticipated along the western edge of the
MO cluster, extending back further westward into north-central KS.
Current surface analysis shows an outflow boundary over extreme
southeast NE arcing back through north-central KS to a low over far
northwest KS. A more substantial surface low exists over southwest
KS. Surface analysis also places a cold front from northwest IA
southwestward to just north of the northwest KS low in far southwest
NE. These boundaries should all influence convective evolution
today, with the outflow/differential heating boundary along the
western edge of the MO cluster likely playing a part as well.
Strong diurnal heating/steepening low-level lapse rates preceding
the surface lows will result in scattered thunderstorm development
near/ahead of the southeast-moving cold front, with the most intense
development likely favoring where the front intercepts the western
periphery of the outflow boundary. This intersection will most
likely be over central into northeast KS. Strong buoyancy and
moderate deep-layer shear will support robust updrafts capable of
large to very large hail early in the convective cycle, before
transitioning to a more linear mode as the front continues
southeastward.
Another area of afternoon thunderstorm development is anticipated
from southern MO into west-central MO and far southeast KS, along
the western edge of the outflow/differential heating associated with
the ongoing MO cluster. Like the area farther northwest, large to
isolated very large hail is anticipated initially. Additionally,
this region could act as a corridor for upscale growth as the
development along the cold front begins to interact with the more
in-situ development along this boundary. Damaging winds will be the
most prominent risk within this corridor this evening, potentially
including some significant (75+ mph) wind gusts.
Despite numerous boundaries, the environmental conditions (i.e. high
LCLs and modest surface wind) and anticipated convective evolution
(i.e. outflow-dominant storms with quick evolution towards a linear
mode) only suggest a low-probability tornado threat from discrete
storms. A somewhat higher tornado risk could materialize within any
more robust convective line that develops, particularly during
evening as the low-level jet increases.
...Lower MI...
Scattered thunderstorms are expected along and ahead of a cold front
moving through the region today. Strong low to mid-level flow could
support a few more organized storms, beginning across northern Lower
MI now and then extending back southwestward with time this
afternoon/evening. Primary risks are isolated large hail and
damaging gusts, but a brief tornado is possible as well.
...Carolinas/Coastal Southeast...
Ample heating within a moist environment south of a weak front will
result in moderately strong diurnal destabilization, with convective
development aided by the front and coastal sea breeze. Some
pulse-type locally severe storms capable of downbursts/wind damage
may occur this afternoon through around sunset.
..Mosier/Chalmers.. 06/13/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1137 AM CDT Sat Jun 13 2026
Valid 131700Z - 141200Z
...Morning Update...
Slight adjustments were made to the Dry Thunderstorm risk area based
on updated guidance. Surface observations across the Colorado
Plateau depict widespread RH values of 5-20%, owing to poor
overnight humidity recoveries across the Four Corners and central
Rockies. Mid/high-level water vapor satellite imagery portray
sufficient moisture surging northeastward from the Sonora and Baja
regions. Morning cloud cover over the Four Corners may inhibit
thunderstorm coverage this afternoon, however any isolated storms
that do materialize will remain elevated with little precipitation
efficiency. The 00z FGZ upper air sounding sampled 0.72" PWAT, which
is right at the 90th percentile of climatology. At 12z, the PHX
sounding sampled 1.23" PWAT, above the 90th percentile climatology
(and breaking the previous daily max of 1.08"). These observations
are on track with satellite derived total PWAT, with the highest
values (1" or greater) along/south of the Central Highlands where
the dry-to-wet thunderstorm transition likely exists. Some lightning
ignitions are possible this afternoon across portions the Great
Basin and western New Mexico, and erratic winds gusting to 30-35 mph
may exacerbate any new/ongoing wildfires (such as the Bear Fire in
western NM).
..Elizalde-Garcia.. 06/13/2026
.PREV DISCUSSION... /ISSUED 0111 AM CDT Sat Jun 13 2026/
...Synopsis...
Isolated dry thunderstorms are forecast from the Four Corners region
into parts of the Great Basin during the afternoon as deep boundary
layer mixing with meager moisture content results in deep inverted-V
profiles across the area. Precipitable water content of 0.5-0.75 in
and tall LCLs exceeding 3.5 km will significantly reduce
precipitation efficiency, and with ERCs in the 90th-98th percentile
ranges, lightning ignitions will be a concern. Precipitable water
content increases to 1.0-1.25 in with southward extent, suggesting
the dividing line between wet/dry thunderstorms will be somewhere in
the central portions of Arizona and New Mexico. While the exact
details of where the dry-to-wet thunderstorm transition will set up
remains unclear, some lightning ignitions may be supported on the
periphery of more precipitation efficient downdrafts as well.
...Please see www.spc.noaa.gov/fire for graphic product...
|
