Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Apr 17 2025 Valid 172000Z - 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. ...20Z Update... Very minor changes were made to the outlook with this update. A cluster of thunderstorms is evolving immediately ahead of the surface low over southern MN, where low-level convergence is maximized amid boundary-layer heating and decreasing inhibition. Given around 40 kt of deep-layer shear (per MPX VWP), this activity should gradually intensify through the afternoon, with a risk of large hail and locally damaging wind gusts. Reference MCD #458 for more information. Farther south, the latest surface observations and radar imagery depict gradually increasing boundary-layer convergence ahead of a well-defined triple point over south-central/southeast NE. While satellite imagery still suggests strong capping at the base of the EML, expectations are still for isolated/discrete storm development near the triple point in southeast NE later this afternoon into the evening. The primary concern will be large to very large hail with initially discrete supercells, with an increasing risk of damaging winds and a couple of tornadoes into this evening. For additional details, reference MCD #459. ..Weinman.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Apr 17 2025/ ...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. Read more

MD 0458 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF NWRN IA...ADJACENT SERN SD...SWRN INTO CNTRL MN
Mesoscale Discussion 0458 NWS Storm Prediction Center Norman OK 1246 PM CDT Thu Apr 17 2025 Areas affected...parts of nwrn IA...adjacent sern SD...swrn into cntrl MN Concerning...Severe potential...Watch possible Valid 171746Z - 172015Z Probability of Watch Issuance...60 percent SUMMARY...Strong to severe thunderstorm development, accompanied by a risk for severe hail and wind, appears increasingly likely by the 2-4 PM CDT time frame. A severe weather watch seems probable, though timing remains a little uncertain. DISCUSSION...Low-level moisture return (characterized by surface dew points increasing into the mid/upper 50s F) is ongoing in a narrow corridor northeast of Norfolk NE, across and northeast of the Redwood Falls MN vicinity. This is focused along modestly deep surface troughing, south through east of an initial surface low center now near Brookings SD, where it appears that further insolation and low-level warm advection may contribute to mixed-layer CAPE in excess of 1500 J/kg within the next few hours. This instability axis remains capped by an initially warm, dry layer between 850-500 mb, beneath large-scale mid/upper ridging. At upper levels, it appears that flow may remain anticyclonic through mid/late afternoon. However, models suggest that subtle mid-level height falls, beneath increasingly difluent upper flow near the exit region of a strong jet streak in the 300-250 layer, will be accompanied sufficient large-scale forcing for ascent to erode the mid-level inhibition. Based on various short-term model output, it appears that this may support the initiation of boundary-layer based thunderstorm development, perhaps as early as 19Z, with increasingly likelihood through 21-22Z. It appears that deep-layer shear will become conducive to organizing convection, including a couple of supercells initially, posing a risk for severe wind and hail. ..Kerr/Smith.. 04/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...DMX...FSD... LAT...LON 45259496 45339379 44569317 42699537 43039671 44529554 45259496 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Thu Apr 17 2025 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN/EASTERN NEW MEXICO INTO FAR WEST TEXAS... A slight eastward and northward expansion of Elevated fire weather conditions was warranted across portions of the Texas Panhandle and western Texas. Latest model guidance consensus delays/stalls the cold front intrusion into the Texas Panhandle until Friday early evening. This will act to prolong at least elevated fire weather conditions across the Cap Rock area, including southwest winds of up to 20 mph and relative humidity in falling into the lower teens by mid-afternoon. Critical fire weather conditions are still expected across much of southeast New Mexico and far west Texas as an upper-level trough deepens across the Intermountain West. ...Florida... Expect increased east winds Friday across the Florida Peninsula as high pressure translates eastward into the Atlantic. Winds of 10-15 mph coupled with relative humidity in the 25-35 percent range amid dry fuels will promote Elevated fire weather conditions for much of central and southwest Florida. ..Williams/Moore.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1256 AM CDT Thu Apr 17 2025/ ...Synopsis... The upper trough will shift to the east with the stronger mid-level winds within the southern/central Plains on Friday. Another surface low, though weaker than Thursday, will develop along the New Mexico/Texas border. A cold front will push farther south into parts of the southern Plains. Fire weather concerns will remain across parts of the Southwest and southern High Plains. ...New Mexico into West Texas... Though mid-level flow will be weaker than the previous day, moderate flow should remain across the region during the afternoon. Coupled with the modest surface low, surface winds of 15-25 mph will be possible. RH could fall around 10% for some locations, but will more broadly be around 15-20%. Critical fire weather is most likely in parts of southern and eastern New Mexico and the Trans-Pecos. There is greater confidence in critically low RH as well as fuels being more receptive here. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Thu Apr 17 2025 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN/EASTERN NEW MEXICO INTO FAR WEST TEXAS... A slight eastward and northward expansion of Elevated fire weather conditions was warranted across portions of the Texas Panhandle and western Texas. Latest model guidance consensus delays/stalls the cold front intrusion into the Texas Panhandle until Friday early evening. This will act to prolong at least elevated fire weather conditions across the Cap Rock area, including southwest winds of up to 20 mph and relative humidity in falling into the lower teens by mid-afternoon. Critical fire weather conditions are still expected across much of southeast New Mexico and far west Texas as an upper-level trough deepens across the Intermountain West. ...Florida... Expect increased east winds Friday across the Florida Peninsula as high pressure translates eastward into the Atlantic. Winds of 10-15 mph coupled with relative humidity in the 25-35 percent range amid dry fuels will promote Elevated fire weather conditions for much of central and southwest Florida. ..Williams/Moore.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1256 AM CDT Thu Apr 17 2025/ ...Synopsis... The upper trough will shift to the east with the stronger mid-level winds within the southern/central Plains on Friday. Another surface low, though weaker than Thursday, will develop along the New Mexico/Texas border. A cold front will push farther south into parts of the southern Plains. Fire weather concerns will remain across parts of the Southwest and southern High Plains. ...New Mexico into West Texas... Though mid-level flow will be weaker than the previous day, moderate flow should remain across the region during the afternoon. Coupled with the modest surface low, surface winds of 15-25 mph will be possible. RH could fall around 10% for some locations, but will more broadly be around 15-20%. Critical fire weather is most likely in parts of southern and eastern New Mexico and the Trans-Pecos. There is greater confidence in critically low RH as well as fuels being more receptive here. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Thu Apr 17 2025 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN/EASTERN NEW MEXICO INTO FAR WEST TEXAS... A slight eastward and northward expansion of Elevated fire weather conditions was warranted across portions of the Texas Panhandle and western Texas. Latest model guidance consensus delays/stalls the cold front intrusion into the Texas Panhandle until Friday early evening. This will act to prolong at least elevated fire weather conditions across the Cap Rock area, including southwest winds of up to 20 mph and relative humidity in falling into the lower teens by mid-afternoon. Critical fire weather conditions are still expected across much of southeast New Mexico and far west Texas as an upper-level trough deepens across the Intermountain West. ...Florida... Expect increased east winds Friday across the Florida Peninsula as high pressure translates eastward into the Atlantic. Winds of 10-15 mph coupled with relative humidity in the 25-35 percent range amid dry fuels will promote Elevated fire weather conditions for much of central and southwest Florida. ..Williams/Moore.. 04/17/2025 .PREV DISCUSSION... /ISSUED 1256 AM CDT Thu Apr 17 2025/ ...Synopsis... The upper trough will shift to the east with the stronger mid-level winds within the southern/central Plains on Friday. Another surface low, though weaker than Thursday, will develop along the New Mexico/Texas border. A cold front will push farther south into parts of the southern Plains. Fire weather concerns will remain across parts of the Southwest and southern High Plains. ...New Mexico into West Texas... Though mid-level flow will be weaker than the previous day, moderate flow should remain across the region during the afternoon. Coupled with the modest surface low, surface winds of 15-25 mph will be possible. RH could fall around 10% for some locations, but will more broadly be around 15-20%. Critical fire weather is most likely in parts of southern and eastern New Mexico and the Trans-Pecos. There is greater confidence in critically low RH as well as fuels being more receptive here. ...Please see www.spc.noaa.gov/fire for graphic product... Read more