SPC AC 160535
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 AM CDT Sat May 16 2026
Valid 161200Z - 171200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
COLORADO INTO WESTERN NEBRASKA AND KANSAS...
...SUMMARY...
Severe storms capable of large hail, wind damage and perhaps a
couple of tornadoes will be possible this afternoon and evening
across parts of the central Plains. Scattered thunderstorms will
also pose potential for strong to severe winds across the lower to
mid Missouri Valley.
...Synopsis...
An upper trough will develop over the western states today, with
increasing southwest winds aloft late in the day and overnight
across the Rockies and into the High Plains. Preceding the western
trough, a progressive shortwave will move from the Great Lakes and
into the Northeast, allowing temporary height rises across the upper
Midwest/MS Valley. Behind this wave, high pressure will bring stable
conditions into the northern Plains.
At the surface, low pressure will develop over the central High
Plains, with a trough extending from eastern WY into western TX.
Meanwhile, a stalled front will be situated across northeast CO into
northern KS and toward IA/northern IL, with easterly winds across NE
and IA. A moist air mass will reside south of this boundary, with
60s F dewpoints prevalent. Backed winds will help bring this
moisture westward toward northeast CO and western NE by late
afternoon as 850 mb winds increase toward evening. Shear profiles
will thus become increasingly favorable from late afternoon through
evening for supercells, with large hail, damaging winds and perhaps
a couple tornadoes from CO into western NE/KS.
East of there, another concentration of strong to severe storms is
expected from eastern NE into IA, northern MO and northeast KS near
the boundary.
Elsewhere, a broad fetch of 20-30 kt southerly 850 mb winds will
maintain a moist air mass across the lower to middle MS Valley and
across the OH Valley. Here, pockets of stronger instability will
support scattered strong storms during the afternoon.
...Central Plains...
Storms are likely to form near the Front Range after 21Z, with
activity developing eastward into NE and KS. A few supercells appear
likely with time, producing damaging hail and severe wind gusts.
Westerly winds aloft atop the deep low-level easterlies will
elongate hodographs with over 50 kt effective shear, while SRH
values favor supercells and severe bows through evening.
Farther east, strong instability will develop near the east-west
boundary, with scattered severe storms developing around 21Z. Some
of these storms may produce hail over 2.00" diameter as lapse rates
aloft will remain steep, and with ample moisture.
Additional isolated activity is possible along the dryline from
southwest KS into the eastern TX Panhandle and western OK. Here,
shear will be weak but a narrow zone of uncapped air mass with a
backing dryline may support isolated storms with locally severe hail
or wind gusts.
..Jewell/Squitieri.. 05/16/2026
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
SPC AC 160601
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0101 AM CDT Sat May 16 2026
Valid 171200Z - 181200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS CENTRAL
NEBRASKA TO SOUTHWEST MINNESOTA...
...SUMMARY...
Severe storms are expected Sunday afternoon into Sunday night from
portions of the central Plains into the Upper Midwest. Supercells
with very large hail and tornadoes are possible, before upscale
storm growth leads to an increase in the wind damage threat.
...Synopsis...
A mid-level trough currently across the Pacific Northwest will
deepen D2/Sunday, moving across Great Basin into the Four Corners
into early D3/Monday. Elevated convection will likely be ongoing at
the start of the period across portions of northern Nebraska into
Iowa. Westerly flow will overspread the central/northern Plains as a
lead shortwave moves across western Kansas into Nebraska through the
day before shifting into the Upper Midwest. A surface cyclone will
deepen across eastern Colorado/western Kansas with strong moist
southerly flow and mid 60s dew points extending across much of the
central and southern Plains. Thunderstorm development is expected by
the afternoon from a stationary boundary/warm front across central
Nebraska southward to the dryline across central Kansas and perhaps
as far south as the Oklahoma/Texas Panhandles.
...NE to MN...
Strong daytime heating and destabilization should occur behind
morning convection across Nebraska into Iowa through broken cloud
cover. Better clearing will be possible across
southeastern/south-central Nebraska where fewer clouds will be
present. Overall, a broad corridor of MLCAPE around 2000-3000 J/kg
and strong deep layer shear should extend across southern Nebraska
into western Iowa just south of the warm front. Strengthening
southerly 700-850 mb flow is expected through the afternoon, with a
low-level jet around 40-50 kts across central Kansas into eastern
Nebraska. By the afternoon, guidance suggests that supercells may
develop near the stationary front/warm front in eastern Nebraska.
Given the environment, these will be capable of large to very large
hail (some 2-3 inches), damaging wind, and a few tornadoes (some
strong). Through time, convection will likely cluster and grow
upscale with a damaging wind threat continuing downstream into
southeast SD, northwest IA and southwest MN through Sunday night.
...Western KS to TX Panhandles...
Forcing for ascent will be weaker with southern extent into western
Kansas/western Oklahoma near the dryline. Soundings across these
regions also indicate capping at the base of the EML, which may be
difficult to overcome. Nonetheless, a few isolated supercells may
develop along the dryline as the low-level jet increases through the
evening. These will pose a risk for large to very large hail and
damaging winds.
..Thornton.. 05/16/2026
WUUS02 PTSDY2
SPC AC 160736
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0236 AM CDT Sat May 16 2026
Valid 181200Z - 191200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
SOUTHERN/CENTRAL PLAINS INTO THE MIDWEST...
...SUMMARY...
Numerous strong thunderstorms are expected to develop Monday along a
cold front and dryline extending from the Great Lakes into the
central/southern Plains. Supercells capable of all hazards
(including very large hail and strong to intense tornadoes) will be
possible across central Kansas into southeastern Nebraska.
...Synopsis...
On Monday, the western trough will take on a negative tilt before
ejecting across the central Plains, with strong southwesterly flow
aloft overspreading the region. As a result, a strong surface low
will development across western Kansas. A surface cold front will
extend northward to a secondary surface low across the upper
Midwest. A dryline will extend southward across portions of western
Kansas into western Oklahoma. Numerous thunderstorms are expected to
develop along and ahead of the cold front and further south along
the dryline Monday afternoon and evening from Nebraska into central
Kansas.
...Central Kansas into southeastern Nebraska...
A volatile environment is expected to be in place ahead of the
dryline across central Kansas Monday afternoon, with moderate to
strong instability, strong deep layer shear, and steep low to
mid-level lapse rates. This will favor supercells as the primary
mode with developing thunderstorms along the dryline in the
afternoon, with potential for large to very large hail (some 2-4
inch). Through the afternoon and evening, a 40-50 kt southerly low
level jet will shift into central Kansas with large clockwise
enhancement of low-level hodographs. Should the mode be able to
remain discrete supercells, strong to intense tornadoes will be
possible across central Kansas into southeastern Nebraska. This in
combination with potential for very large hail may warrant higher
probabilities as mesoscale details become clearer.
As the front shifts southward through time, upscale growth will be
favored with increasing probabilities for damaging winds.
...Iowa into Wisconsin and the Great Lakes Region...
Widely scattered thunderstorm development is expected further north
along the front into Iowa/Wisconsin and north into the Great Lakes
Region. Early day convection may be ongoing at the start of the
period within these regions, which may limit how much
destabilization can occur before the afternoon. Nonetheless,
guidance suggests potential for damaging wind and perhaps a few
instances of severe hail with storms along the front Monday
afternoon and evening.
...Western Oklahoma into northern Texas...
Forcing for ascent will be weaker across the dryline into western
Oklahoma and northern Texas. Guidance does suggest that a few
isolated supercells could develop near the dryline, with potential
for large to very large hail, damaging winds, and perhaps a tornado.
Given the strong flow aloft and better large scale ascent will
reside further north in Kansas, mode may quickly become messy with
uncertainty in overall coverage at this time.
..Thornton.. 05/16/2026
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1930Z
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