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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 20 2025 Valid 201630Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ARKANSAS AND MISSOURI VICINITY... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...Synopsis... A compact upper low currently moving into western Oklahoma will shift quickly northeastward this afternoon and tonight, crossing eastern Kansas and western Missouri this evening and then continuing northeastward across Iowa and into Wisconsin tonight. Fast southwesterly flow aloft will exist in advance of this system, within the tight height gradient between this feature and the persistent ridge centered over the Southeast. At the surface, a developing low analyzed over western Oklahoma at 15Z is forecast to progress northeastward across southeastern Kansas and Missouri through the afternoon, and then should continue northward toward -- and eventually into -- southern Wisconsin by early Monday morning. While a warm front lifts northward across the Mid Mississippi Valley/Midwest, a cold front trailing from the low will sweep eastward into/across Missouri and Arkansas this afternoon and evening, and then across the Mid and Lower Mississippi Valleys through the end of the period. ...Northeastern Texas northeastward to the western Illinois vicinity... An expansive area of multi-level cloud cover, along with ongoing convection, is evident across western and northern portions of the risk area late this morning, which continues to retard more substantial heating at this point. With that said, some breaks in the clouds are evident per recent visible imagery as far west as eastern Oklahoma, with thinning cloud cover with eastward/northeastward extent into Arkansas and the Ozarks. As the surface low over Oklahoma deepens through the day in tandem with the advance of the upper low, northward advance of the warm front with time will allow a moist boundary layer to likewise overspread much of Missouri and Illinois through sunset. This, combined with at least modest heating across portions of the area should yield an amply unstable environment (500 to near 1500 J/kg mixed-layer CAPE) to gradually evolve -- supporting a steady increase in convective coverage and intensity this afternoon. In contrast to the rather modest thermodynamic environment, a very favorable low-level and deep-layer wind field is evident, with respect to development of organized/rotating storms. An 80 kt mid-level jet will spread northeastward across the risk area with time, atop a 50-plus kt low-level jet. This will support vigorous updraft evolution, with all-hazards severe risk evolving as a result. At this time, it remains apparent that tornado potential -- including risk for a couple of strong tornadoes -- should maximize across the Ozarks, and areas just north and south, as surface winds back to southeasterly ahead of the deepening/advancing surface low. The primary risk should evolve with an anticipated, broken band of storms within the cold-frontal zone, including embedded supercells. Along with the tornado potential, fairly widespread coverage of damaging wind gusts is also expected, as complex, LEWP/bow-type structures are expected within the band of storms, as convection advances eastward across Missouri and Arkansas toward the Mississippi Valley through the afternoon and into the evening hours. Severe risk is expected to expand as far north as southeastern Iowa and adjacent western Illinois this evening, where weaker instability is expected, and as far south as eastern Texas where a weaker wind field with southward extent should limit severe potential on the southern fringe. Risk should very gradually diminish overnight as convection shifts eastward across the Mid-Mississippi Valley. ..Goss/Halbert.. 04/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 20 2025 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF ARKANSAS AND MISSOURI... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...ArkLaTex into the Ozarks and Mid Mississippi Valley... Extensive convection has occurred overnight and early this morning across the southern Plains into the Ozarks and mid MS Valley. Ongoing thunderstorms across south-central TX are expected to continue weakening over the next couple of hours as they encounter a strongly capped airmass. Activity over eastern OK into western AR and MO may pose an isolated hail/wind threat this morning, although instability will tend to remain weak for at least a few more hours. Otherwise, a strong mid-level shortwave trough will continue to eject northeastward from the southern Plains across the Ozarks and mid MS Valley through the period. An attendant 60-90 kt mid-level jet will likewise spread northeastward across eastern OK/KS and the Ozarks through the day. A weak surface low over OK this morning will also develop northeastward to northern MO by this evening, while a cold front continues moving eastward over the southern Plains towards the ArkLaTex. Ongoing cloudiness and precipitation lend some uncertainty regarding the degree of destabilization that will occur by this afternoon across the developing warm sector. Still, most guidance shows that at least low 60s surface dewpoints and related low-level moisture will attempt to stream northward across eastern OK and AR/MO in tandem with a strong southerly low-level jet today. Although daytime heating will likely be hampered to some extent, even 500-1000 J/kg of MLCAPE will support surface-based thunderstorms by this afternoon. This destabilization appears likely to occur in a narrow corridor along and just ahead of the surface low and related cold front. Rather strong deep-layer shear will easily support organized updrafts, including the potential for a mix of supercells and broken line segments. Current expectations are for robust thunderstorms to develop along/near the front across eastern OK and vicinity by early afternoon (17-19Z), as pronounced large-scale ascent associated with the ejecting shortwave trough impinges on the warm sector. Given a weakly unstable and strongly sheared environment, this convection should intensify fairly quickly as it moves east-northeastward into AR/MO. The linear forcing of the front suggests that a line or cluster mode should occur, although some high-resolution guidance does show more of a broken line of supercells given the strength of the deep-layer shear. Regardless, the threat for scattered to numerous severe/damaging winds and tornadoes will increase this afternoon and evening across the Enhanced Risk and vicinity, as a 40-55 kt southerly low-level jet aids in large 0-3 km hodograph curvature and elongation. Given the forecast strength of the low-level shear, some of these tornadoes could be strong (EF-2+), especially if a mixed supercell/cluster mode can be maintained versus linear. Hail may also occur with any sustained supercells. The overall severe threat this evening and overnight will be tempered on the north by limited low-level moisture and instability, and on the east by gradually increasing MLCIN. ..Gleason/Broyles.. 04/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 20 2025 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF ARKANSAS AND MISSOURI... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...ArkLaTex into the Ozarks and Mid Mississippi Valley... Extensive convection has occurred overnight and early this morning across the southern Plains into the Ozarks and mid MS Valley. Ongoing thunderstorms across south-central TX are expected to continue weakening over the next couple of hours as they encounter a strongly capped airmass. Activity over eastern OK into western AR and MO may pose an isolated hail/wind threat this morning, although instability will tend to remain weak for at least a few more hours. Otherwise, a strong mid-level shortwave trough will continue to eject northeastward from the southern Plains across the Ozarks and mid MS Valley through the period. An attendant 60-90 kt mid-level jet will likewise spread northeastward across eastern OK/KS and the Ozarks through the day. A weak surface low over OK this morning will also develop northeastward to northern MO by this evening, while a cold front continues moving eastward over the southern Plains towards the ArkLaTex. Ongoing cloudiness and precipitation lend some uncertainty regarding the degree of destabilization that will occur by this afternoon across the developing warm sector. Still, most guidance shows that at least low 60s surface dewpoints and related low-level moisture will attempt to stream northward across eastern OK and AR/MO in tandem with a strong southerly low-level jet today. Although daytime heating will likely be hampered to some extent, even 500-1000 J/kg of MLCAPE will support surface-based thunderstorms by this afternoon. This destabilization appears likely to occur in a narrow corridor along and just ahead of the surface low and related cold front. Rather strong deep-layer shear will easily support organized updrafts, including the potential for a mix of supercells and broken line segments. Current expectations are for robust thunderstorms to develop along/near the front across eastern OK and vicinity by early afternoon (17-19Z), as pronounced large-scale ascent associated with the ejecting shortwave trough impinges on the warm sector. Given a weakly unstable and strongly sheared environment, this convection should intensify fairly quickly as it moves east-northeastward into AR/MO. The linear forcing of the front suggests that a line or cluster mode should occur, although some high-resolution guidance does show more of a broken line of supercells given the strength of the deep-layer shear. Regardless, the threat for scattered to numerous severe/damaging winds and tornadoes will increase this afternoon and evening across the Enhanced Risk and vicinity, as a 40-55 kt southerly low-level jet aids in large 0-3 km hodograph curvature and elongation. Given the forecast strength of the low-level shear, some of these tornadoes could be strong (EF-2+), especially if a mixed supercell/cluster mode can be maintained versus linear. Hail may also occur with any sustained supercells. The overall severe threat this evening and overnight will be tempered on the north by limited low-level moisture and instability, and on the east by gradually increasing MLCIN. ..Gleason/Broyles.. 04/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 20 2025 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF ARKANSAS AND MISSOURI... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...ArkLaTex into the Ozarks and Mid Mississippi Valley... Extensive convection has occurred overnight and early this morning across the southern Plains into the Ozarks and mid MS Valley. Ongoing thunderstorms across south-central TX are expected to continue weakening over the next couple of hours as they encounter a strongly capped airmass. Activity over eastern OK into western AR and MO may pose an isolated hail/wind threat this morning, although instability will tend to remain weak for at least a few more hours. Otherwise, a strong mid-level shortwave trough will continue to eject northeastward from the southern Plains across the Ozarks and mid MS Valley through the period. An attendant 60-90 kt mid-level jet will likewise spread northeastward across eastern OK/KS and the Ozarks through the day. A weak surface low over OK this morning will also develop northeastward to northern MO by this evening, while a cold front continues moving eastward over the southern Plains towards the ArkLaTex. Ongoing cloudiness and precipitation lend some uncertainty regarding the degree of destabilization that will occur by this afternoon across the developing warm sector. Still, most guidance shows that at least low 60s surface dewpoints and related low-level moisture will attempt to stream northward across eastern OK and AR/MO in tandem with a strong southerly low-level jet today. Although daytime heating will likely be hampered to some extent, even 500-1000 J/kg of MLCAPE will support surface-based thunderstorms by this afternoon. This destabilization appears likely to occur in a narrow corridor along and just ahead of the surface low and related cold front. Rather strong deep-layer shear will easily support organized updrafts, including the potential for a mix of supercells and broken line segments. Current expectations are for robust thunderstorms to develop along/near the front across eastern OK and vicinity by early afternoon (17-19Z), as pronounced large-scale ascent associated with the ejecting shortwave trough impinges on the warm sector. Given a weakly unstable and strongly sheared environment, this convection should intensify fairly quickly as it moves east-northeastward into AR/MO. The linear forcing of the front suggests that a line or cluster mode should occur, although some high-resolution guidance does show more of a broken line of supercells given the strength of the deep-layer shear. Regardless, the threat for scattered to numerous severe/damaging winds and tornadoes will increase this afternoon and evening across the Enhanced Risk and vicinity, as a 40-55 kt southerly low-level jet aids in large 0-3 km hodograph curvature and elongation. Given the forecast strength of the low-level shear, some of these tornadoes could be strong (EF-2+), especially if a mixed supercell/cluster mode can be maintained versus linear. Hail may also occur with any sustained supercells. The overall severe threat this evening and overnight will be tempered on the north by limited low-level moisture and instability, and on the east by gradually increasing MLCIN. ..Gleason/Broyles.. 04/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 20 2025 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF ARKANSAS AND MISSOURI... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...ArkLaTex into the Ozarks and Mid Mississippi Valley... Extensive convection has occurred overnight and early this morning across the southern Plains into the Ozarks and mid MS Valley. Ongoing thunderstorms across south-central TX are expected to continue weakening over the next couple of hours as they encounter a strongly capped airmass. Activity over eastern OK into western AR and MO may pose an isolated hail/wind threat this morning, although instability will tend to remain weak for at least a few more hours. Otherwise, a strong mid-level shortwave trough will continue to eject northeastward from the southern Plains across the Ozarks and mid MS Valley through the period. An attendant 60-90 kt mid-level jet will likewise spread northeastward across eastern OK/KS and the Ozarks through the day. A weak surface low over OK this morning will also develop northeastward to northern MO by this evening, while a cold front continues moving eastward over the southern Plains towards the ArkLaTex. Ongoing cloudiness and precipitation lend some uncertainty regarding the degree of destabilization that will occur by this afternoon across the developing warm sector. Still, most guidance shows that at least low 60s surface dewpoints and related low-level moisture will attempt to stream northward across eastern OK and AR/MO in tandem with a strong southerly low-level jet today. Although daytime heating will likely be hampered to some extent, even 500-1000 J/kg of MLCAPE will support surface-based thunderstorms by this afternoon. This destabilization appears likely to occur in a narrow corridor along and just ahead of the surface low and related cold front. Rather strong deep-layer shear will easily support organized updrafts, including the potential for a mix of supercells and broken line segments. Current expectations are for robust thunderstorms to develop along/near the front across eastern OK and vicinity by early afternoon (17-19Z), as pronounced large-scale ascent associated with the ejecting shortwave trough impinges on the warm sector. Given a weakly unstable and strongly sheared environment, this convection should intensify fairly quickly as it moves east-northeastward into AR/MO. The linear forcing of the front suggests that a line or cluster mode should occur, although some high-resolution guidance does show more of a broken line of supercells given the strength of the deep-layer shear. Regardless, the threat for scattered to numerous severe/damaging winds and tornadoes will increase this afternoon and evening across the Enhanced Risk and vicinity, as a 40-55 kt southerly low-level jet aids in large 0-3 km hodograph curvature and elongation. Given the forecast strength of the low-level shear, some of these tornadoes could be strong (EF-2+), especially if a mixed supercell/cluster mode can be maintained versus linear. Hail may also occur with any sustained supercells. The overall severe threat this evening and overnight will be tempered on the north by limited low-level moisture and instability, and on the east by gradually increasing MLCIN. ..Gleason/Broyles.. 04/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 20 2025 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF ARKANSAS AND MISSOURI... ...SUMMARY... Severe thunderstorms are expected today across parts of the ArkLaTex into the Ozarks and mid Mississippi Valley, mainly this afternoon and evening. The best corridor for tornadoes (some of which could be strong) and scattered to numerous damaging winds should exist from central/northern Arkansas into Missouri. ...ArkLaTex into the Ozarks and Mid Mississippi Valley... Extensive convection has occurred overnight and early this morning across the southern Plains into the Ozarks and mid MS Valley. Ongoing thunderstorms across south-central TX are expected to continue weakening over the next couple of hours as they encounter a strongly capped airmass. Activity over eastern OK into western AR and MO may pose an isolated hail/wind threat this morning, although instability will tend to remain weak for at least a few more hours. Otherwise, a strong mid-level shortwave trough will continue to eject northeastward from the southern Plains across the Ozarks and mid MS Valley through the period. An attendant 60-90 kt mid-level jet will likewise spread northeastward across eastern OK/KS and the Ozarks through the day. A weak surface low over OK this morning will also develop northeastward to northern MO by this evening, while a cold front continues moving eastward over the southern Plains towards the ArkLaTex. Ongoing cloudiness and precipitation lend some uncertainty regarding the degree of destabilization that will occur by this afternoon across the developing warm sector. Still, most guidance shows that at least low 60s surface dewpoints and related low-level moisture will attempt to stream northward across eastern OK and AR/MO in tandem with a strong southerly low-level jet today. Although daytime heating will likely be hampered to some extent, even 500-1000 J/kg of MLCAPE will support surface-based thunderstorms by this afternoon. This destabilization appears likely to occur in a narrow corridor along and just ahead of the surface low and related cold front. Rather strong deep-layer shear will easily support organized updrafts, including the potential for a mix of supercells and broken line segments. Current expectations are for robust thunderstorms to develop along/near the front across eastern OK and vicinity by early afternoon (17-19Z), as pronounced large-scale ascent associated with the ejecting shortwave trough impinges on the warm sector. Given a weakly unstable and strongly sheared environment, this convection should intensify fairly quickly as it moves east-northeastward into AR/MO. The linear forcing of the front suggests that a line or cluster mode should occur, although some high-resolution guidance does show more of a broken line of supercells given the strength of the deep-layer shear. Regardless, the threat for scattered to numerous severe/damaging winds and tornadoes will increase this afternoon and evening across the Enhanced Risk and vicinity, as a 40-55 kt southerly low-level jet aids in large 0-3 km hodograph curvature and elongation. Given the forecast strength of the low-level shear, some of these tornadoes could be strong (EF-2+), especially if a mixed supercell/cluster mode can be maintained versus linear. Hail may also occur with any sustained supercells. The overall severe threat this evening and overnight will be tempered on the north by limited low-level moisture and instability, and on the east by gradually increasing MLCIN. ..Gleason/Broyles.. 04/20/2025 Read more