Tornado Warning 12, NWS Omaha, NE

Area Forecast Discussion
National Weather Service Omaha/Valley NE
143 PM CDT Sun May 17 2026

.KEY MESSAGES...

- Sunday and Monday will be days to watch very closely if you
  live within the Omaha area of forecast responsibility.
  Multiple rounds of severe thunderstorms are expected bringing
  the potential for large hail, damaging winds, tornadoes and
  flash flooding.

&&

.DISCUSSION...
Issued at 142 PM CDT Sun May 17 2026

This afternoon, an elongated sfc low will be in place from SE
Colorado/SW Kansas up into the Dakotas. A dryline is set up toward
the KS/CO border and a warm front is located across central
Nebraska. Temps are currently in the 80s in the warm sector with
dewpoints in the mid-60s. SBCAPE values of 3500+ J/kg, MLCAPE values
of 3000+ J/kg and DCAPE values of 1200+ J/kg are expected. Expect
good instability through the afternoon/evening and fairly steep
lapse rates, particularly down into central and eastern Nebraska.

Portions of northeastern Nebraska in particular are showing
potential for an environment favorable for strong updrafts and
potentially some longer lived supercells. Any storms that are able
to get going and become sustained in that favorable environment
would have the best chance of developing a tornado, with some
potential to be strong. Storms are expected to develop into a line,
posing a damaging wind threat along with hail and tornadoes
possible.

Heading into Monday, a broad trough extends from the PACNW up into
eastern Nebraska/western Iowa. Another system moves in through the
day, bringing additional chances for strong to severe storms,
particularly for areas along and south of Interstate 80. There still
remain some questions as to how far north the warm front and system
get. The environment is expected to be primed with strong
instability and deep layer shear conducive for supercell development
and maintenance. With this type of set up, large hail and damaging
winds are to be expected in addition to the possibility for a few
strong and potentially long-lived tornadoes. Flash flooding will be
possible, particularly in areas that have also received a few inches
of rain over the last 48 hours.

Expect cooler temperatures for much of the week as a cold front
pushes into the region Monday. Tuesday and Wednesday bring relief
from the recent storms.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1256 PM CDT Sun May 17 2026

KOFK: MVFR conditions persist at the terminal at the early onset of
the forecast period. Expect a chance for strong to severe
thunderstorms by 23Z. Any storms that do develop will have the
potential of producing strong wind gusts, large hail, and heavy
rainfall resulting in reductions to visibility. An isolated tornado
cannot be entirely ruled out. Winds shift from southeasterly
this afternoon to northwesterly by 23Z. Ceilings may fall to IFR
levels toward the end of the TAF period, after 11Z.

KOMA: VFR ceilings will deteriorate to MVFR as storms develop
this evening. Strong to severe thunderstorms with all hazards
are to be expected after 00Z with better chances closer to 02Z
at the terminal. South winds shift to the north tomorrow morning
by 13Z with ceilings expected to lower to IFR levels.

KLNK: VFR ceilings will lower to MVFR by 23Z as a storm system
moves into the region. Expect strong to severe thunderstorms as
early as 00Z with better potential after 02Z. All severe types
(hail, wind, isolate tornado) will be possible. South winds
persist through the afternoon, becoming northerly after 05Z.
Ceilings are expected to fall to IFR levels by 14Z.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Flood Watch from 7 PM CDT this evening through Tuesday morning
     for NEZ065-066-068-078-088>093.
IA...None.

&&

DISCUSSION...ANW
AVIATION...ANW

Hazardous Weather Outlook
National Weather Service Omaha/Valley NE
151 PM CDT Sun May 17 2026

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-181900-
Monona-Harrison-Shelby-Pottawattamie-Mills-Montgomery-Fremont-Page-
Knox-Cedar-Thurston-Antelope-Pierce-Wayne-Boone-Madison-Stanton-
Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-Saunders-Douglas-
Sarpy-Seward-Lancaster-Cass-Otoe-Saline-Jefferson-Gage-Johnson-
Nemaha-Pawnee-Richardson-
151 PM CDT Sun May 17 2026

This Hazardous Weather Outlook is for southwest Iowa, west central
Iowa, east central Nebraska, northeast Nebraska and southeast
Nebraska.

.DAY ONE...This afternoon and tonight.

Strong to severe thunderstorms are expected to develop after 4 PM,
initially across northeast Nebraska before spreading south and east.
Large hail (2+ inches), damaging wind gusts, and a few tornadoes
(possibly strong) are the expected hazards. Heavy rain due to
several storms moving over the same area may result in some concerns
for flash flooding. A Tornado Watch has been issued for the northern
portion of the outlook area through 10 PM.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Additional strong to severe storms are forecast for Monday
afternoon, with an increased threat for large hail (2-4+ inches) and
strong tornadoes. Additional chances for heavy rainfall on top of
what has already fallen since Friday night will result in a potential
for flash flooding, particularly for portions of southeastern
Nebraska. Chances to see severe storm activity is maximized over
southeast Nebraska.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Any reports of hail, strong winds,
tornadoes, flooding or damage are greatly appreciated today and
Monday.

Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
410 PM CDT Sun May 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     Rain             1 S Tecumseh            40.36N 96.19W
05/17/2026  M3.45 Inch       Johnson            NE   CO-OP Observer

            24 hour total.

&&

tsn

Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
608 PM CDT Sun May 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0605 PM     Tstm Wnd Gst     6 NNE Newman Grove      41.83N 97.73W
05/17/2026  M64 MPH          Madison            NE   Public

            Personal weather station.

&&

DAC