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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Apr 17 2025 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA INTO CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... A belt of strong southwesterly mid-upper flow will extend from the southern High Plains to the central Great Plains and upper MS Valley, downstream of a large-scale trough over the West. Visible-satellite imagery late this morning shows a capped stratocumulus shield from eastern OK northward into eastern KS and the MO Valley. This low-level moisture depicted on satellite corresponds with a 10.0-11.5 g/kg lowest 100-mb mean mixing ratio and dewpoints in the upper 50s to lower 60s. Moisture will continue northward on southerly flow to the east of a weak surface wave which is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. Strong heating and continued moisture advection will result in moderate to strong destabilization from eastern KS to eastern NE/western IA and southern MN. Models continue to show initial thunderstorm development around 20z in southern MN and around 22z in eastern NE (near and just east of the cold front/dryline triple point). Model forecast soundings over southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph), and perhaps a brief tornado. Farther south, greater buoyancy and elongated hodographs will be more favorable for supercells. A long-track supercell or two is forecast from eastern NE this evening into western/central IA through early tonight. Large to giant hail (peak diameter 2.75 to 3.5 inches) will be possible with the more intense phase of the supercell activity. A narrow window of opportunity may exist for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. Severe gusts will be possible with the stronger storms before this activity wanes late this evening into the overnight. ..Smith/Jirak.. 04/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Apr 17 2025 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA INTO CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... A belt of strong southwesterly mid-upper flow will extend from the southern High Plains to the central Great Plains and upper MS Valley, downstream of a large-scale trough over the West. Visible-satellite imagery late this morning shows a capped stratocumulus shield from eastern OK northward into eastern KS and the MO Valley. This low-level moisture depicted on satellite corresponds with a 10.0-11.5 g/kg lowest 100-mb mean mixing ratio and dewpoints in the upper 50s to lower 60s. Moisture will continue northward on southerly flow to the east of a weak surface wave which is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. Strong heating and continued moisture advection will result in moderate to strong destabilization from eastern KS to eastern NE/western IA and southern MN. Models continue to show initial thunderstorm development around 20z in southern MN and around 22z in eastern NE (near and just east of the cold front/dryline triple point). Model forecast soundings over southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph), and perhaps a brief tornado. Farther south, greater buoyancy and elongated hodographs will be more favorable for supercells. A long-track supercell or two is forecast from eastern NE this evening into western/central IA through early tonight. Large to giant hail (peak diameter 2.75 to 3.5 inches) will be possible with the more intense phase of the supercell activity. A narrow window of opportunity may exist for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. Severe gusts will be possible with the stronger storms before this activity wanes late this evening into the overnight. ..Smith/Jirak.. 04/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Apr 17 2025 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA INTO CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... A belt of strong southwesterly mid-upper flow will extend from the southern High Plains to the central Great Plains and upper MS Valley, downstream of a large-scale trough over the West. Visible-satellite imagery late this morning shows a capped stratocumulus shield from eastern OK northward into eastern KS and the MO Valley. This low-level moisture depicted on satellite corresponds with a 10.0-11.5 g/kg lowest 100-mb mean mixing ratio and dewpoints in the upper 50s to lower 60s. Moisture will continue northward on southerly flow to the east of a weak surface wave which is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. Strong heating and continued moisture advection will result in moderate to strong destabilization from eastern KS to eastern NE/western IA and southern MN. Models continue to show initial thunderstorm development around 20z in southern MN and around 22z in eastern NE (near and just east of the cold front/dryline triple point). Model forecast soundings over southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph), and perhaps a brief tornado. Farther south, greater buoyancy and elongated hodographs will be more favorable for supercells. A long-track supercell or two is forecast from eastern NE this evening into western/central IA through early tonight. Large to giant hail (peak diameter 2.75 to 3.5 inches) will be possible with the more intense phase of the supercell activity. A narrow window of opportunity may exist for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. Severe gusts will be possible with the stronger storms before this activity wanes late this evening into the overnight. ..Smith/Jirak.. 04/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Apr 17 2025 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA INTO CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... A belt of strong southwesterly mid-upper flow will extend from the southern High Plains to the central Great Plains and upper MS Valley, downstream of a large-scale trough over the West. Visible-satellite imagery late this morning shows a capped stratocumulus shield from eastern OK northward into eastern KS and the MO Valley. This low-level moisture depicted on satellite corresponds with a 10.0-11.5 g/kg lowest 100-mb mean mixing ratio and dewpoints in the upper 50s to lower 60s. Moisture will continue northward on southerly flow to the east of a weak surface wave which is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. Strong heating and continued moisture advection will result in moderate to strong destabilization from eastern KS to eastern NE/western IA and southern MN. Models continue to show initial thunderstorm development around 20z in southern MN and around 22z in eastern NE (near and just east of the cold front/dryline triple point). Model forecast soundings over southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph), and perhaps a brief tornado. Farther south, greater buoyancy and elongated hodographs will be more favorable for supercells. A long-track supercell or two is forecast from eastern NE this evening into western/central IA through early tonight. Large to giant hail (peak diameter 2.75 to 3.5 inches) will be possible with the more intense phase of the supercell activity. A narrow window of opportunity may exist for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. Severe gusts will be possible with the stronger storms before this activity wanes late this evening into the overnight. ..Smith/Jirak.. 04/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Apr 17 2025 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA INTO CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... A belt of strong southwesterly mid-upper flow will extend from the southern High Plains to the central Great Plains and upper MS Valley, downstream of a large-scale trough over the West. Visible-satellite imagery late this morning shows a capped stratocumulus shield from eastern OK northward into eastern KS and the MO Valley. This low-level moisture depicted on satellite corresponds with a 10.0-11.5 g/kg lowest 100-mb mean mixing ratio and dewpoints in the upper 50s to lower 60s. Moisture will continue northward on southerly flow to the east of a weak surface wave which is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. Strong heating and continued moisture advection will result in moderate to strong destabilization from eastern KS to eastern NE/western IA and southern MN. Models continue to show initial thunderstorm development around 20z in southern MN and around 22z in eastern NE (near and just east of the cold front/dryline triple point). Model forecast soundings over southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph), and perhaps a brief tornado. Farther south, greater buoyancy and elongated hodographs will be more favorable for supercells. A long-track supercell or two is forecast from eastern NE this evening into western/central IA through early tonight. Large to giant hail (peak diameter 2.75 to 3.5 inches) will be possible with the more intense phase of the supercell activity. A narrow window of opportunity may exist for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. Severe gusts will be possible with the stronger storms before this activity wanes late this evening into the overnight. ..Smith/Jirak.. 04/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Apr 17 2025 Valid 171630Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA INTO CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... A belt of strong southwesterly mid-upper flow will extend from the southern High Plains to the central Great Plains and upper MS Valley, downstream of a large-scale trough over the West. Visible-satellite imagery late this morning shows a capped stratocumulus shield from eastern OK northward into eastern KS and the MO Valley. This low-level moisture depicted on satellite corresponds with a 10.0-11.5 g/kg lowest 100-mb mean mixing ratio and dewpoints in the upper 50s to lower 60s. Moisture will continue northward on southerly flow to the east of a weak surface wave which is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. Strong heating and continued moisture advection will result in moderate to strong destabilization from eastern KS to eastern NE/western IA and southern MN. Models continue to show initial thunderstorm development around 20z in southern MN and around 22z in eastern NE (near and just east of the cold front/dryline triple point). Model forecast soundings over southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph), and perhaps a brief tornado. Farther south, greater buoyancy and elongated hodographs will be more favorable for supercells. A long-track supercell or two is forecast from eastern NE this evening into western/central IA through early tonight. Large to giant hail (peak diameter 2.75 to 3.5 inches) will be possible with the more intense phase of the supercell activity. A narrow window of opportunity may exist for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. Severe gusts will be possible with the stronger storms before this activity wanes late this evening into the overnight. ..Smith/Jirak.. 04/17/2025 Read more

The City of Derby was aiming to produce its own water as drought continued to grip the region. Derby has purchased water from Wichita since 2002, but Wichita’s primary source, Cheney Reservoir, was lower than usual. KWCH 12 (Wichita, Kan.), April 15, 2025

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Apr 17 2025 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN NEBRASKA INTO WESTERN AND CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... Southwest mid-upper flow will persist through the period from the southern High Plains to the central Plains and upper MS Valley, downstream from a large-scale, positive-tilt trough from MB to the Great Basin. A weak surface wave is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. A modifying Gulf air mass (boundary-layer dewpoints in the mid 50s to low 60s) will continue to spread northward in the warm sector from the southern Plains to eastern KS, IA and southern MN, beneath the eastern extent of a relatively warm EML. A cluster of elevated storms, with embedded supercell structures, is ongoing over southwest MO. These storms are expected to weaken this morning as the low-level jet and associated warm advection diminish, coincident with the eastward expansion of the EML. In the interim, isolated large hail (around 1 inch diameter) and strong gusts (50-60 mph) will be possible for a couple of hours this morning across southwest MO. In the wake of the morning convection, surface heating and continued moisture advection will result in steady destabilization from eastern KS to eastern NE/western IA and southern MN. Thunderstorm development is expected near 20z into southern MN where the cap will be a little weaker, and after about 22z in eastern NE (near and just east of the cold front/dryline triple point). The storm environment into southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph). The environment farther south will favor a long-track supercell or two from eastern NE this evening into western/central IA through early tonight, potentially affecting Omaha and Des Moines. Steep midlevel lapse rates, MLCAPE of 2000-2500 J/kg and long hodographs through a deep layer will favor swaths of very large hail (up to 3 inch diameter or greater) and occasional severe gusts of 60-70 mph. There will be a narrow window of opportunity for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. ..Thompson/Grams.. 04/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Apr 17 2025 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN NEBRASKA INTO WESTERN AND CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... Southwest mid-upper flow will persist through the period from the southern High Plains to the central Plains and upper MS Valley, downstream from a large-scale, positive-tilt trough from MB to the Great Basin. A weak surface wave is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. A modifying Gulf air mass (boundary-layer dewpoints in the mid 50s to low 60s) will continue to spread northward in the warm sector from the southern Plains to eastern KS, IA and southern MN, beneath the eastern extent of a relatively warm EML. A cluster of elevated storms, with embedded supercell structures, is ongoing over southwest MO. These storms are expected to weaken this morning as the low-level jet and associated warm advection diminish, coincident with the eastward expansion of the EML. In the interim, isolated large hail (around 1 inch diameter) and strong gusts (50-60 mph) will be possible for a couple of hours this morning across southwest MO. In the wake of the morning convection, surface heating and continued moisture advection will result in steady destabilization from eastern KS to eastern NE/western IA and southern MN. Thunderstorm development is expected near 20z into southern MN where the cap will be a little weaker, and after about 22z in eastern NE (near and just east of the cold front/dryline triple point). The storm environment into southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph). The environment farther south will favor a long-track supercell or two from eastern NE this evening into western/central IA through early tonight, potentially affecting Omaha and Des Moines. Steep midlevel lapse rates, MLCAPE of 2000-2500 J/kg and long hodographs through a deep layer will favor swaths of very large hail (up to 3 inch diameter or greater) and occasional severe gusts of 60-70 mph. There will be a narrow window of opportunity for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. ..Thompson/Grams.. 04/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Apr 17 2025 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN NEBRASKA INTO WESTERN AND CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... Southwest mid-upper flow will persist through the period from the southern High Plains to the central Plains and upper MS Valley, downstream from a large-scale, positive-tilt trough from MB to the Great Basin. A weak surface wave is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. A modifying Gulf air mass (boundary-layer dewpoints in the mid 50s to low 60s) will continue to spread northward in the warm sector from the southern Plains to eastern KS, IA and southern MN, beneath the eastern extent of a relatively warm EML. A cluster of elevated storms, with embedded supercell structures, is ongoing over southwest MO. These storms are expected to weaken this morning as the low-level jet and associated warm advection diminish, coincident with the eastward expansion of the EML. In the interim, isolated large hail (around 1 inch diameter) and strong gusts (50-60 mph) will be possible for a couple of hours this morning across southwest MO. In the wake of the morning convection, surface heating and continued moisture advection will result in steady destabilization from eastern KS to eastern NE/western IA and southern MN. Thunderstorm development is expected near 20z into southern MN where the cap will be a little weaker, and after about 22z in eastern NE (near and just east of the cold front/dryline triple point). The storm environment into southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph). The environment farther south will favor a long-track supercell or two from eastern NE this evening into western/central IA through early tonight, potentially affecting Omaha and Des Moines. Steep midlevel lapse rates, MLCAPE of 2000-2500 J/kg and long hodographs through a deep layer will favor swaths of very large hail (up to 3 inch diameter or greater) and occasional severe gusts of 60-70 mph. There will be a narrow window of opportunity for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. ..Thompson/Grams.. 04/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Apr 17 2025 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN NEBRASKA INTO WESTERN AND CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... Southwest mid-upper flow will persist through the period from the southern High Plains to the central Plains and upper MS Valley, downstream from a large-scale, positive-tilt trough from MB to the Great Basin. A weak surface wave is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. A modifying Gulf air mass (boundary-layer dewpoints in the mid 50s to low 60s) will continue to spread northward in the warm sector from the southern Plains to eastern KS, IA and southern MN, beneath the eastern extent of a relatively warm EML. A cluster of elevated storms, with embedded supercell structures, is ongoing over southwest MO. These storms are expected to weaken this morning as the low-level jet and associated warm advection diminish, coincident with the eastward expansion of the EML. In the interim, isolated large hail (around 1 inch diameter) and strong gusts (50-60 mph) will be possible for a couple of hours this morning across southwest MO. In the wake of the morning convection, surface heating and continued moisture advection will result in steady destabilization from eastern KS to eastern NE/western IA and southern MN. Thunderstorm development is expected near 20z into southern MN where the cap will be a little weaker, and after about 22z in eastern NE (near and just east of the cold front/dryline triple point). The storm environment into southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph). The environment farther south will favor a long-track supercell or two from eastern NE this evening into western/central IA through early tonight, potentially affecting Omaha and Des Moines. Steep midlevel lapse rates, MLCAPE of 2000-2500 J/kg and long hodographs through a deep layer will favor swaths of very large hail (up to 3 inch diameter or greater) and occasional severe gusts of 60-70 mph. There will be a narrow window of opportunity for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. ..Thompson/Grams.. 04/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Apr 17 2025 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN NEBRASKA INTO WESTERN AND CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... Southwest mid-upper flow will persist through the period from the southern High Plains to the central Plains and upper MS Valley, downstream from a large-scale, positive-tilt trough from MB to the Great Basin. A weak surface wave is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. A modifying Gulf air mass (boundary-layer dewpoints in the mid 50s to low 60s) will continue to spread northward in the warm sector from the southern Plains to eastern KS, IA and southern MN, beneath the eastern extent of a relatively warm EML. A cluster of elevated storms, with embedded supercell structures, is ongoing over southwest MO. These storms are expected to weaken this morning as the low-level jet and associated warm advection diminish, coincident with the eastward expansion of the EML. In the interim, isolated large hail (around 1 inch diameter) and strong gusts (50-60 mph) will be possible for a couple of hours this morning across southwest MO. In the wake of the morning convection, surface heating and continued moisture advection will result in steady destabilization from eastern KS to eastern NE/western IA and southern MN. Thunderstorm development is expected near 20z into southern MN where the cap will be a little weaker, and after about 22z in eastern NE (near and just east of the cold front/dryline triple point). The storm environment into southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph). The environment farther south will favor a long-track supercell or two from eastern NE this evening into western/central IA through early tonight, potentially affecting Omaha and Des Moines. Steep midlevel lapse rates, MLCAPE of 2000-2500 J/kg and long hodographs through a deep layer will favor swaths of very large hail (up to 3 inch diameter or greater) and occasional severe gusts of 60-70 mph. There will be a narrow window of opportunity for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. ..Thompson/Grams.. 04/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Apr 17 2025 Valid 171300Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN NEBRASKA INTO WESTERN AND CENTRAL IOWA... ...SUMMARY... Isolated to scattered severe thunderstorms are expected, mainly from late afternoon into early tonight from eastern Nebraska into western and central Iowa. Very large hail to 3 inches in diameter or greater, isolated severe gusts of 60-70 mph, and a couple of tornadoes will all be possible. ...NE/IA/MN/MO through early tonight... Southwest mid-upper flow will persist through the period from the southern High Plains to the central Plains and upper MS Valley, downstream from a large-scale, positive-tilt trough from MB to the Great Basin. A weak surface wave is expected to move along an associated baroclinic from the mid MO Valley to the upper MS Valley, while a lee cyclone develops south-southeastward across the central High Plains. A modifying Gulf air mass (boundary-layer dewpoints in the mid 50s to low 60s) will continue to spread northward in the warm sector from the southern Plains to eastern KS, IA and southern MN, beneath the eastern extent of a relatively warm EML. A cluster of elevated storms, with embedded supercell structures, is ongoing over southwest MO. These storms are expected to weaken this morning as the low-level jet and associated warm advection diminish, coincident with the eastward expansion of the EML. In the interim, isolated large hail (around 1 inch diameter) and strong gusts (50-60 mph) will be possible for a couple of hours this morning across southwest MO. In the wake of the morning convection, surface heating and continued moisture advection will result in steady destabilization from eastern KS to eastern NE/western IA and southern MN. Thunderstorm development is expected near 20z into southern MN where the cap will be a little weaker, and after about 22z in eastern NE (near and just east of the cold front/dryline triple point). The storm environment into southern MN will favor a mix of supercells and storm clusters capable of producing large hail (generally 1-1.75 inch diameter) and isolated strong-severe gusts (50-60 mph). The environment farther south will favor a long-track supercell or two from eastern NE this evening into western/central IA through early tonight, potentially affecting Omaha and Des Moines. Steep midlevel lapse rates, MLCAPE of 2000-2500 J/kg and long hodographs through a deep layer will favor swaths of very large hail (up to 3 inch diameter or greater) and occasional severe gusts of 60-70 mph. There will be a narrow window of opportunity for a couple of tornadoes this evening with sufficient moisture (boundary-layer dewpoints near 60 F) as low-level shear increases. ..Thompson/Grams.. 04/17/2025 Read more

MD 0457 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWEST MO
Mesoscale Discussion 0457 NWS Storm Prediction Center Norman OK 0637 AM CDT Thu Apr 17 2025 Areas affected...southwest MO Concerning...Severe potential...Watch unlikely Valid 171137Z - 171300Z Probability of Watch Issuance...5 percent SUMMARY...An isolated severe wind/hail threat may persist for a couple more hours, but should diminish during the mid-morning. DISCUSSION...Early morning convection has largely consolidated into a cluster along the KS/MO border. This activity will probably continue southeastward into southwest MO over the next couple hours. While the leading cell in the cluster has lost its deep core, it may produce a swath of strong gusts. Upstream embedded cell has yielded marginally severe hail and may undergo a similar evolution to the lead cell. This activity will be moving into a progressively drier air mass in MO. In conjunction with diurnal weakening of the low-level jet, this cluster should weaken by late morning. ..Grams/Thompson.. 04/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX... LAT...LON 38439392 38519358 38259276 37929215 37509210 37169227 36929243 36939362 37069420 37739472 38149467 38439392 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Thu Apr 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... ...Day 4/Sun - ArkLaTex to the Mid-MS Valley... A compact upper shortwave trough is forecast to move from the southern High Plains to the Midwest on Sunday. While some forecast uncertainty continues with regard to exact position of this feature, the overall pattern suggests isolated to scattered severe thunderstorm potential will exist across portions of east TX into the Mid/Lower MS Valley. Strong southwesterly flow aloft will overspread a moist warm sector as a surface low lifts north/northeast from OK into the Lower MO Valley through early evening. A trailing cold front will spread east as this occurs, while a warm front extends eastward from the Mid-MS Valley into the OH Valley. Evolution of prior days convection is resulting in some uncertainty regarding the western/northern extent of severe potential. Nevertheless, a favorable environment supporting at least isolated severe storms should extend from east TX into parts of southern MO/IL ahead of the cold front. ...Days 5-8/Mon-Thu... Forecast ensemble guidance from both the GEFS and EPS suggest low-amplitude west/southwesterly flow will overspread the southern tier of the U.S. next week. Southerly low-level flow on Day 5/Mon across the western Gulf into the southern Plains in the wake of the cold frontal passage on Day 4/Sun will allow for northward transport of modified moisture. This should continue into Day 6/Tue across the Plains. Some localized severe risk could develop across parts of the southern Plains as an upper shortwave trough moves across the north-central U.S. on Day 6/Tue, but poor juxtaposition between higher quality moisture across OK/TX and stronger forcing across the northern Plains/Upper Midwest may limit overall potential. This low-amplitude pattern will continue through Day 8, resulting in low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Thu Apr 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... ...Day 4/Sun - ArkLaTex to the Mid-MS Valley... A compact upper shortwave trough is forecast to move from the southern High Plains to the Midwest on Sunday. While some forecast uncertainty continues with regard to exact position of this feature, the overall pattern suggests isolated to scattered severe thunderstorm potential will exist across portions of east TX into the Mid/Lower MS Valley. Strong southwesterly flow aloft will overspread a moist warm sector as a surface low lifts north/northeast from OK into the Lower MO Valley through early evening. A trailing cold front will spread east as this occurs, while a warm front extends eastward from the Mid-MS Valley into the OH Valley. Evolution of prior days convection is resulting in some uncertainty regarding the western/northern extent of severe potential. Nevertheless, a favorable environment supporting at least isolated severe storms should extend from east TX into parts of southern MO/IL ahead of the cold front. ...Days 5-8/Mon-Thu... Forecast ensemble guidance from both the GEFS and EPS suggest low-amplitude west/southwesterly flow will overspread the southern tier of the U.S. next week. Southerly low-level flow on Day 5/Mon across the western Gulf into the southern Plains in the wake of the cold frontal passage on Day 4/Sun will allow for northward transport of modified moisture. This should continue into Day 6/Tue across the Plains. Some localized severe risk could develop across parts of the southern Plains as an upper shortwave trough moves across the north-central U.S. on Day 6/Tue, but poor juxtaposition between higher quality moisture across OK/TX and stronger forcing across the northern Plains/Upper Midwest may limit overall potential. This low-amplitude pattern will continue through Day 8, resulting in low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Thu Apr 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... ...Day 4/Sun - ArkLaTex to the Mid-MS Valley... A compact upper shortwave trough is forecast to move from the southern High Plains to the Midwest on Sunday. While some forecast uncertainty continues with regard to exact position of this feature, the overall pattern suggests isolated to scattered severe thunderstorm potential will exist across portions of east TX into the Mid/Lower MS Valley. Strong southwesterly flow aloft will overspread a moist warm sector as a surface low lifts north/northeast from OK into the Lower MO Valley through early evening. A trailing cold front will spread east as this occurs, while a warm front extends eastward from the Mid-MS Valley into the OH Valley. Evolution of prior days convection is resulting in some uncertainty regarding the western/northern extent of severe potential. Nevertheless, a favorable environment supporting at least isolated severe storms should extend from east TX into parts of southern MO/IL ahead of the cold front. ...Days 5-8/Mon-Thu... Forecast ensemble guidance from both the GEFS and EPS suggest low-amplitude west/southwesterly flow will overspread the southern tier of the U.S. next week. Southerly low-level flow on Day 5/Mon across the western Gulf into the southern Plains in the wake of the cold frontal passage on Day 4/Sun will allow for northward transport of modified moisture. This should continue into Day 6/Tue across the Plains. Some localized severe risk could develop across parts of the southern Plains as an upper shortwave trough moves across the north-central U.S. on Day 6/Tue, but poor juxtaposition between higher quality moisture across OK/TX and stronger forcing across the northern Plains/Upper Midwest may limit overall potential. This low-amplitude pattern will continue through Day 8, resulting in low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Thu Apr 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... ...Day 4/Sun - ArkLaTex to the Mid-MS Valley... A compact upper shortwave trough is forecast to move from the southern High Plains to the Midwest on Sunday. While some forecast uncertainty continues with regard to exact position of this feature, the overall pattern suggests isolated to scattered severe thunderstorm potential will exist across portions of east TX into the Mid/Lower MS Valley. Strong southwesterly flow aloft will overspread a moist warm sector as a surface low lifts north/northeast from OK into the Lower MO Valley through early evening. A trailing cold front will spread east as this occurs, while a warm front extends eastward from the Mid-MS Valley into the OH Valley. Evolution of prior days convection is resulting in some uncertainty regarding the western/northern extent of severe potential. Nevertheless, a favorable environment supporting at least isolated severe storms should extend from east TX into parts of southern MO/IL ahead of the cold front. ...Days 5-8/Mon-Thu... Forecast ensemble guidance from both the GEFS and EPS suggest low-amplitude west/southwesterly flow will overspread the southern tier of the U.S. next week. Southerly low-level flow on Day 5/Mon across the western Gulf into the southern Plains in the wake of the cold frontal passage on Day 4/Sun will allow for northward transport of modified moisture. This should continue into Day 6/Tue across the Plains. Some localized severe risk could develop across parts of the southern Plains as an upper shortwave trough moves across the north-central U.S. on Day 6/Tue, but poor juxtaposition between higher quality moisture across OK/TX and stronger forcing across the northern Plains/Upper Midwest may limit overall potential. This low-amplitude pattern will continue through Day 8, resulting in low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Thu Apr 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... ...Day 4/Sun - ArkLaTex to the Mid-MS Valley... A compact upper shortwave trough is forecast to move from the southern High Plains to the Midwest on Sunday. While some forecast uncertainty continues with regard to exact position of this feature, the overall pattern suggests isolated to scattered severe thunderstorm potential will exist across portions of east TX into the Mid/Lower MS Valley. Strong southwesterly flow aloft will overspread a moist warm sector as a surface low lifts north/northeast from OK into the Lower MO Valley through early evening. A trailing cold front will spread east as this occurs, while a warm front extends eastward from the Mid-MS Valley into the OH Valley. Evolution of prior days convection is resulting in some uncertainty regarding the western/northern extent of severe potential. Nevertheless, a favorable environment supporting at least isolated severe storms should extend from east TX into parts of southern MO/IL ahead of the cold front. ...Days 5-8/Mon-Thu... Forecast ensemble guidance from both the GEFS and EPS suggest low-amplitude west/southwesterly flow will overspread the southern tier of the U.S. next week. Southerly low-level flow on Day 5/Mon across the western Gulf into the southern Plains in the wake of the cold frontal passage on Day 4/Sun will allow for northward transport of modified moisture. This should continue into Day 6/Tue across the Plains. Some localized severe risk could develop across parts of the southern Plains as an upper shortwave trough moves across the north-central U.S. on Day 6/Tue, but poor juxtaposition between higher quality moisture across OK/TX and stronger forcing across the northern Plains/Upper Midwest may limit overall potential. This low-amplitude pattern will continue through Day 8, resulting in low predictability. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0330 AM CDT Thu Apr 17 2025 Valid 201200Z - 251200Z ...DISCUSSION... ...Day 4/Sun - ArkLaTex to the Mid-MS Valley... A compact upper shortwave trough is forecast to move from the southern High Plains to the Midwest on Sunday. While some forecast uncertainty continues with regard to exact position of this feature, the overall pattern suggests isolated to scattered severe thunderstorm potential will exist across portions of east TX into the Mid/Lower MS Valley. Strong southwesterly flow aloft will overspread a moist warm sector as a surface low lifts north/northeast from OK into the Lower MO Valley through early evening. A trailing cold front will spread east as this occurs, while a warm front extends eastward from the Mid-MS Valley into the OH Valley. Evolution of prior days convection is resulting in some uncertainty regarding the western/northern extent of severe potential. Nevertheless, a favorable environment supporting at least isolated severe storms should extend from east TX into parts of southern MO/IL ahead of the cold front. ...Days 5-8/Mon-Thu... Forecast ensemble guidance from both the GEFS and EPS suggest low-amplitude west/southwesterly flow will overspread the southern tier of the U.S. next week. Southerly low-level flow on Day 5/Mon across the western Gulf into the southern Plains in the wake of the cold frontal passage on Day 4/Sun will allow for northward transport of modified moisture. This should continue into Day 6/Tue across the Plains. Some localized severe risk could develop across parts of the southern Plains as an upper shortwave trough moves across the north-central U.S. on Day 6/Tue, but poor juxtaposition between higher quality moisture across OK/TX and stronger forcing across the northern Plains/Upper Midwest may limit overall potential. This low-amplitude pattern will continue through Day 8, resulting in low predictability. Read more