There has been a Tornado Emergency in this watch!

MOST PROBABLE PEAK TORNADO INTENSITY...120-145 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN

ACUS11 KWNS 172214
SWOMCD
SPC MCD 172213
NEZ000-KSZ000-172315-

Mesoscale Discussion 0757
NWS Storm Prediction Center Norman OK
0513 PM CDT Sun May 17 2026

Areas affected...portions of central and eastern Nebraska into
northern Kansas

Concerning...Tornado Watch 214...

Valid 172213Z - 172315Z

The severe weather threat for Tornado Watch 214 continues.

SUMMARY...The severe threat will continue to increase through the
evening hours. 2+ inch diameter hail, 75+ mph wind gusts, and
tornadoes are all possible with mature, sustained supercells. Swaths
of severe wind may become the predominant concern if storm mergers
occur and storms get undercut by the cold front.

DISCUSSION...Supercells are maturing across central/eastern
Nebraska, ahead of the merging cold front/dryline. These storms are
rapidly maturing in an environment characterized by 3500+ J/kg
MLCAPE and 40+ kts of effective bulk shear, which is more than
adequate for intense supercells. Current live streams depict a
strong tornado in progress over Howard County, NE, or roughly 15
miles north of Grand Island.

Low-level shear, while currently modest will increase markedly ahead
of the ongoing storms, which will support larger, curved hodographs.
As such, supercells that mature and sustain themselves will have the
potential to produce 2+ inch diameter hail and tornadoes, with
additional strong tornadoes possible. However, the ongoing storms in
Nebraska may become undercut by the cold front soon, which could
also counter future strong tornado potential with those particular
storms. Therefore, mesocyclonic tornado potential is strongly
conditional on supercells remaining discrete ahead of the cold front.

High-resolution deterministic and ensemble guidance strongly
suggests that storms across eastern NE into northern KS will merge
into one or more bowing segments. Should this occur, 75+ mph winds
and EF0-EF2 QLCS tornadoes will become the main concerns.

..Squitieri.. 05/17/2026

ATTN...WFO...OAX...TOP...ICT...GID...

MOST PROBABLE PEAK TORNADO INTENSITY...120-145 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN

 ***

MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
 
ACUS11 KWNS 172246
SWOMCD
SPC MCD 172245
MNZ000-IAZ000-172345-

Mesoscale Discussion 0760
NWS Storm Prediction Center Norman OK
0545 PM CDT Sun May 17 2026

Areas affected...portions of northern Iowa into southern Minnesota

Concerning...Severe potential...Tornado Watch likely

Valid 172245Z - 172345Z

Probability of Watch Issuance...80 percent

SUMMARY...The severe threat will increase over the next few hours.
Severe wind and hail are likely, with tornadoes also possible. A
Tornado Watch may be needed soon to address the impending threat.

DISCUSSION...A bowing QLCS is traversing the far western IA/MN
border, with a recent history of marginal severe hail/wind occurring
with an embedded supercell structure. This QLCS is tracking eastward
toward the axis of a 30-40 kt low-level jet, where low-level shear
is increasing (i.e. 200+ m2/s2 effective SRH per 22Z mesoanalysis).
Furthermore, 8+ C/km mid-level lapse rates are overspreading upper
60s to near 70 F surface dewpoints in the warm sector ahead of the
QLCS, yielding up to 3000 J/kg MLCAPE. With 40+ kts of effective
bulk shear also in place, potential exists for the QLCS to
strengthen, with a corresponding increase in severe wind and hail
potential. Line-embedded tornadoes may also occur, especially with
portions of the QLCS that interact with an approaching warm front. A
Tornado Watch may need to be issued in the next couple of hours.

..Squitieri/Smith.. 05/17/2026

ATTN...WFO...ARX...MPX...DMX...FSD...

MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN

$$


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