Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN IOWA...NORTHWEST ILLINOIS AND FAR NORTHEAST MISSOURI... ...SUMMARY... Severe storms are expected Tuesday across the Midwest, especially including portions of Iowa and Missouri into Wisconsin and western/northern Illinois. Tornadoes (a few strong), damaging wind gusts, and large hail are expected. ...Lower/Middle Missouri Valley to the Upper Great Lakes... A notably strong belt of cyclonically curved westerlies (70+ kt 500 mb) will extend from the south-central Great Plains to the Upper Midwest and Upper Great Lakes on Tuesday, with a lead/convectively augmented shortwave trough likely to spread from the central High Plains toward the Lake Superior vicinity late Tuesday night. An elongated surface low over eastern Nebraska Tuesday morning will deepen and lift northeast to northern Wisconsin/Upper Michigan by evening, with a surface warm front lifting northward ahead of the surface low, although its effective position will likely be influenced by the early day precipitation. Meanwhile, a trailing cold front will surge east across Iowa/eastern Kansas/northern Missouri from mid-afternoon into the evening. Remnant clusters of storms will likely be ongoing Tuesday morning across central/eastern Nebraska, with the possibility of additional storms farther east across southern Iowa/northern Missouri in association with a warm-advection regime. Some key uncertainties persist about the influences of this early day convection, but trends will be for quick air mass recovery given a progressive/highly dynamic pattern. Very steep mid-level lapse rates will overspread the increasingly moist warm sector, supporting aggressive diurnal destabilization especially on the southern fringe of lingering convection/cloud cover. Significantly strengthening mid-level winds and a diurnally persistent strong low-level jet will support initial supercells capable of large hail and a few tornadoes, including strong (EF2+) tornado potential. But a mixed/transitional mode is expected overall, as upscale growth occurs given the degree of forcing for ascent, with likely evolution into a well-organized/fast-moving QLCS capable of increasingly widespread/intense damaging winds and a continued QLCS-related tornado risk. This scenario currently appears to be most probable across southern/eastern Iowa into northwest Illinois and nearby far northern Missouri. The severe risk will persist into the Upper Great Lakes region and middle Mississippi Valley overnight. ...Southern Plains... Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast Oklahoma/northwest Arkansas by late afternoon/evening, and more conditionally with southwest extent near a dryline from central Oklahoma into central Texas. Large hail and severe gusts will be possible with this activity. ...Northeast States... A weak upper shortwave trough will move across southern Quebec and northern New England. This will result in a band of enhanced westerly deep-layer flow from northern New York into Maine. A seasonally moist airmass will be in place with surface dewpoints into the low 60s F, with strong heating and steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging wind gusts. ..Guyer.. 05/20/2024 Read more

WW 0267 Status Updates
STATUS FOR WATCH 0267 HAS NOT BEEN ISSUED YET Read more

WW 0267 Status Updates
STATUS FOR WATCH 0267 HAS NOT BEEN ISSUED YET Read more

No watches are valid as of Mon May 20 16:46:02 UTC 2024.

No Mesoscale Discussions are in effect as of Mon May 20 16:46:02 UTC 2024.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon May 20 2024 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN/WESTERN NM AND EASTERN AZ... The forecast remains on track, and only minor adjustments/expansions were made to the Critical highlights in AZ, based on the latest observational data and high-resolution guidance. See the previous discussion below for details. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon May 20 2024 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN/WESTERN NM AND EASTERN AZ... The forecast remains on track, and only minor adjustments/expansions were made to the Critical highlights in AZ, based on the latest observational data and high-resolution guidance. See the previous discussion below for details. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon May 20 2024 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN/WESTERN NM AND EASTERN AZ... The forecast remains on track, and only minor adjustments/expansions were made to the Critical highlights in AZ, based on the latest observational data and high-resolution guidance. See the previous discussion below for details. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon May 20 2024 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN/WESTERN NM AND EASTERN AZ... The forecast remains on track, and only minor adjustments/expansions were made to the Critical highlights in AZ, based on the latest observational data and high-resolution guidance. See the previous discussion below for details. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon May 20 2024 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN/WESTERN NM AND EASTERN AZ... The forecast remains on track, and only minor adjustments/expansions were made to the Critical highlights in AZ, based on the latest observational data and high-resolution guidance. See the previous discussion below for details. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon May 20 2024 Valid 201700Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN/WESTERN NM AND EASTERN AZ... The forecast remains on track, and only minor adjustments/expansions were made to the Critical highlights in AZ, based on the latest observational data and high-resolution guidance. See the previous discussion below for details. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more