WW 579 SEVERE TSTM NE 130035Z - 130800Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 579
NWS Storm Prediction Center Norman OK
735 PM CDT Wed Aug 12 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western and Central Nebraska
* Effective this Wednesday night and Thursday morning from 735 PM
until 300 AM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
SUMMARY...Thunderstorms currently over the Nebraska Panhandle and
northeast Colorado will congeal and spread eastward across the watch
area through the early morning hours. Damaging wind gusts and some
hail are expected with some of these storms.
The severe thunderstorm watch area is approximately along and 70
statute miles north and south of a line from 50 miles west southwest
of Mullen NE to 45 miles east of Burwell NE. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU9).
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 576...WW 578...
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
27035.
...Hart
WW 578 SEVERE TSTM CO NE WY 122030Z - 130300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 578
NWS Storm Prediction Center Norman OK
230 PM MDT Wed Aug 12 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northeast Colorado
The Nebraska Panhandle
Southeast Wyoming
* Effective this Wednesday afternoon and evening from 230 PM
until 900 PM MDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 80
mph possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
SUMMARY...Isolated storm development is underway across southeast
Wyoming, and additional storms are expected this afternoon into the
Nebraska Panhandle and northeast Colorado. Large hail (potentially
exceeding 2 inches in diameter) will be possible with
initial/discrete supercells, while the threat for severe outflow
gusts of 60-80 mph will increase with storm clustering later this
afternoon through late evening.
The severe thunderstorm watch area is approximately along and 75
statute miles east and west of a line from 20 miles northwest of
Chadron NE to 15 miles southwest of Akron CO. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 575...WW 576...WW 577...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
24035.
...Thompson
WW 0579 Status Updates
STATUS FOR WATCH 0579 HAS NOT BEEN ISSUED YET
WW 0578 Status Updates
STATUS REPORT ON WW 578
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NW ITR TO
30 WNW SNY TO 35 NW CDR.
..THORNTON..08/13/26
ATTN...WFO...BOU...GLD...CYS...LBF...
STATUS REPORT FOR WS 578
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
COC075-095-115-125-130240-
CO
. COLORADO COUNTIES INCLUDED ARE
LOGAN PHILLIPS SEDGWICK
YUMA
NEC013-033-045-049-069-123-161-130240-
NE
. NEBRASKA COUNTIES INCLUDED ARE
BOX BUTTE CHEYENNE DAWES
DEUEL GARDEN MORRILL
SHERIDAN
WYC027-130240-
WY
. WYOMING COUNTIES INCLUDED ARE
NIOBRARA
WW 0577 Status Updates
STATUS REPORT ON WW 577
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 SE LEX TO
40 SW LEX TO 45 SSW SDF TO 5 SSE OWB TO 40 ESE MVN.
..MOORE..08/12/26
ATTN...WFO...PAH...LMK...
STATUS REPORT FOR WS 577
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
KYC021-045-079-085-087-099-101-123-137-151-155-183-217-130040-
KY
. KENTUCKY COUNTIES INCLUDED ARE
BOYLE CASEY GARRARD
GRAYSON GREEN HART
HENDERSON LARUE LINCOLN
MADISON MARION OHIO
TAYLOR
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 0576 Status Updates
STATUS REPORT ON WW 576
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 50 ESE GCC
TO 40 SE Y22.
..THORNTON..08/13/26
ATTN...WFO...UNR...
STATUS REPORT FOR WS 576
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
SDC007-033-047-055-071-081-093-102-103-137-130140-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
BENNETT CUSTER FALL RIVER
HAAKON JACKSON LAWRENCE
MEADE OGLALA LAKOTA PENNINGTON
ZIEBACH
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 Thu Aug 13 02:02:14 UTC 2026.SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0758 PM CDT Wed Aug 12 2026
Valid 130100Z - 131200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS INTO WESTERN IOWA...
...SUMMARY...
Multiple supercells with large hail potential across the
northern/central High Plains should evolve into a bowing cluster
tonight while spreading eastward across Nebraska and eventually into
Iowa by early Thursday morning. This cluster will be capable of
producing scattered severe/damaging winds.
...Northern/Central Plains into Iowa...
A mix of clusters and supercells is ongoing this evening from far
northeast CO into western NE. The environment downstream into
central/eastern NE remains favorable to maintain severe convection
along/near a surface front. Large hail will remain possible with any
sustained supercells given 35-45+ kt of deep-layer shear, and
eventual upscale growth into a bowing cluster appears probable
tonight with modestly enhanced east-southeasterly low-level flow
providing an influx of warm/moist air. If this occurs, then the
threat for severe/damaging winds would increase across
central/eastern NE and perhaps eventually western IA, with isolated
gusts of 75+ mph possible. Severe probabilities have been adjusted
based on latest observational and short-term guidance trends.
Reference Mesoscale Discussion 1961 for more details regarding the
near-term severe threat across northeast CO/western NE.
...Mid Mississippi Valley into the Lower Ohio Valley...
Ongoing thunderstorm clusters across parts of the mid MS and lower
OH Valleys have mostly diminished in intensity as they have become
generally displaced south of the stronger mid-level flow across the
Midwest/Great Lakes. Even with the gradual weakening trend observed,
a couple of stronger clusters persist. Isolated damaging winds will
remain possible for a couple more hours this evening as this
activity spreads slowly southward.
...Northeast...
Loosely organized cells may continue to pose an isolated hail/gusty
wind threat for the next hour or two across southern NY and vicinity
along/near a surface front. The loss of daytime heating and gradual
decrease in instability should result in eventual weakening of
ongoing convection.
...Lower Colorado River Valley...
High-based thunderstorms which developed this afternoon in a hot and
well-mixed boundary layer across interior southern CA and western AZ
may remain capable of producing occasional severe gusts for a couple
more hours this evening.
..Gleason.. 08/13/2026
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0515 PM CDT Wed Aug 12 2026
Valid 141200Z - 201200Z
...Synopsis...
Troughing over the western CONUS will lead to high pressure nudging
eastward across the Plains and Southeast. Expect fire concerns to
continue across the southern Plains. Monsoonal moisture will at
least briefly impact the Southwest, Great Basin, and much of the
Rockies with increased chances for showers and thunderstorms.
Meanwhile, a large trough with additional shortwave disturbances
progressing through the flow will support increasing chances for
mixed wet and dry thunderstorms, especially along the west and
northern peripheries of this moisture surge. While more central and
southern portions of the Intermountain West are likely to receive
wetting rainfall with this event, recent large fires emerging over
the southern Great Basin have shown the resilience of very dry fuels
in perpetuating lightning started fires amid slightly wet
thunderstorms.
...Southern Plains...
Forecast model consensus continues to highlight an area across the
southern Plains where afternoon RH values are forecast to fall to
15-20% by peak heating on Day 3/Friday. With the tightening surface
pressure gradient, confidence has increased in more widespread
sustained southwest surface winds of 15-20 mph. A corridor of 40
percent probabilities for critical fire weather conditions exists
from northern TX through northern OK where fuels are increasingly
receptive.
...Northern California/Northwest...
The aforementioned trough and associated mid-level shortwave
disturbances will provide lift amid sufficient instability to
generate probabilities of isolated morning and afternoon
thunderstorms over portions of northwest CA and much of central OR
on Day 3/Friday and Day 4/Saturday. As such, 10% Dry Thunderstorm
probabilities have been expanded to include central OR. Additional
probabilities may be needed in future outlook cycles as thunderstorm
potential continues across the Pacific Northwest through the
weekend. However, with each consecutive day of thunderstorm
potential, storms will likely trend more wet than dry, precluding an
additional area on Day 4/Saturday over central OR with this forecast
issuance.
..Stearns.. 08/12/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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