Convective Outlook
— Day 1
Enhanced Risk
Summary
Severe storms producing damaging winds and large hail are likely from Iowa into northeast Kansas. Isolated hail or damaging wind gusts are possible over a large area from western Texas into Wisconsin and western Illinois.
Synopsis and Discussion
Moderate westerly winds aloft will exist across the northern tier of states today, with several waves from the Pacific Northwest to the Great Lakes. The feature of interest will move across the Dakotas and toward the upper MS Valley late in the day, aiding storm development and severity from NE into WI. To the south, a weak shortwave trough will move out of NM and into TX, with mid and high level flow enhancement along with modest cooling aloft.
At the surface, low pressure will develop from southwest KS into the TX Panhandle, with a front extending into NE, southern MN, and into northern WI. Increasing southerly winds during the afternoon and evening will bring 60s F dewpoints northward toward these boundaries, with scattered severe storms likely late in the day and centered near Iowa.
Farther south, very steep lapse rates and a subtle upper trough should again result in widely scattered high-based storms producing severe gusts over the southern High Plains.
Ia Into Eastern Ne And Northeast Ks ?
Southerly winds and daytime heating will support moderate instability this afternoon near a surface trough which will extend from eastern NE into southern MN and northern WI. Dewpoints are expected to reach into the lower 60s F, and perhaps approach 65 F during the early evening. Meanwhile, midlevel temperatures will be cool, resulting in steep lapse rates and robust CAPE profiles.
Storms are most likely to initiate during the late afternoon near the IA/SD border, and extending northeastward into WI and perhaps the central MI Upper Peninsula. Large hail will be possible with the initial cells, supported by 60 kt deep-layer shear. Hail to 2.00" diameter will be possible even into WI.
Farther south into IA, the deeper theta-e plume and increasing low-level jet will enhance the severe wind risk, with an MCS expected to develop and move east/southeast across the region. Damaging winds with a few gusts over 70 mph are expected. Additional clusters of severe storms are expected from southeast NE into northeast KS as well, firmly within the low-level theta-e plume with maximally deepened moist layer to 700 mb. Shear will not be as strong, but the initial development is expected to be robust with large hail and damaging wind gusts.
Southwest Ks Into Western Texas ?
Strong heating will yield very deep mixed layers near and south of the Panhandles surface low, while midlevel temperatures remain cool enough to support instability despite very low dewpoints. Meanwhile, the aforementioned shortwave trough will enhance lift late in the day. The result will be scattered high-based thunderstorms, with severe wind gusts expected. Isolated gusts over 70 mph may occur. Cells that develop into southwest TX may contain marginal hail as well, with elongated hodographs in the mid to upper levels.
..Jewell/Squitieri.. 05/15/2026
000 ACUS01 KWNS 150601 SWODY1 SPC AC 150600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri May 15 2026 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF IOWA... ...SUMMARY... Severe storms producing damaging winds and large hail are likely from Iowa into northeast Kansas. Isolated hail or damaging wind gusts are possible over a large area from western Texas into Wisconsin and western Illinois. ...Synopsis... Moderate westerly winds aloft will exist across the northern tier of states today, with several waves from the Pacific Northwest to the Great Lakes. The feature of interest will move across the Dakotas and toward the upper MS Valley late in the day, aiding storm development and severity from NE into WI. To the south, a weak shortwave trough will move out of NM and into TX, with mid and high level flow enhancement along with modest cooling aloft. At the surface, low pressure will develop from southwest KS into the TX Panhandle, with a front extending into NE, southern MN, and into northern WI. Increasing southerly winds during the afternoon and evening will bring 60s F dewpoints northward toward these boundaries, with scattered severe storms likely late in the day and centered near Iowa. Farther south, very steep lapse rates and a subtle upper trough should again result in widely scattered high-based storms producing severe gusts over the southern High Plains. ...IA into eastern NE and northeast KS... Southerly winds and daytime heating will support moderate instability this afternoon near a surface trough which will extend from eastern NE into southern MN and northern WI. Dewpoints are expected to reach into the lower 60s F, and perhaps approach 65 F during the early evening. Meanwhile, midlevel temperatures will be cool, resulting in steep lapse rates and robust CAPE profiles. Storms are most likely to initiate during the late afternoon near the IA/SD border, and extending northeastward into WI and perhaps the central MI Upper Peninsula. Large hail will be possible with the initial cells, supported by 60 kt deep-layer shear. Hail to 2.00" diameter will be possible even into WI. Farther south into IA, the deeper theta-e plume and increasing low-level jet will enhance the severe wind risk, with an MCS expected to develop and move east/southeast across the region. Damaging winds with a few gusts over 70 mph are expected. Additional clusters of severe storms are expected from southeast NE into northeast KS as well, firmly within the low-level theta-e plume with maximally deepened moist layer to 700 mb. Shear will not be as strong, but the initial development is expected to be robust with large hail and damaging wind gusts. ...Southwest KS into western Texas... Strong heating will yield very deep mixed layers near and south of the Panhandles surface low, while midlevel temperatures remain cool enough to support instability despite very low dewpoints. Meanwhile, the aforementioned shortwave trough will enhance lift late in the day. The result will be scattered high-based thunderstorms, with severe wind gusts expected. Isolated gusts over 70 mph may occur. Cells that develop into southwest TX may contain marginal hail as well, with elongated hodographs in the mid to upper levels. ..Jewell/Squitieri.. 05/15/2026 $$