Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Sun Aug 17 2025 Valid 171200Z - 181200Z ...Synopsis... Broad ridging is forecast to expand over the central US today and tonight as a mid-level trough strengthens over the West. Monsoon moisture will lift north ahead of the trough and surface cold front supporting scattered showers and a few dry thunderstorms. Dry and breezy conditions are also possible over parts of the Southwest. ...Dry Thunder Northern Rockies... As western US troughing gradually consolidates, stronger mid-level flow will move eastward across the northern Great Basin and Rockies. The surface cold front will impinge on the western edge of monsoon moisture over the regions supporting another day of showers and thunderstorms. With PWATs near 1 inch, a wetter storm mode is expected, along with some wetting rainfall. Still, the increased flow aloft and faster storm speeds could support a few storms with lower precipitation efficiency. With the threat for lightning overlapping with drier fuels (especially east) isolated dry thunderstorms remain possible. ...Eastern Great Basin... South of the intensifying upper trough, enhanced southwesterly flow will overspread portions of the Great Basin beneath the western fringes of the upper ridge. Very warm temperatures are expected and fuels remain very dry/receptive to spread. A modest increase in surface winds to near 15 mph is expected through the afternoon along with RH below 15%. With some record to near record high ERC values remaining across portions of the Great Basin, a few hours of Elevated fire-weather conditions are possible. ..Lyons.. 08/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE NORTHERN PLAINS EASTWARD TO THE UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Monday over parts of the central and northern Plains eastward into the upper Mississippi Valley and western Great Lakes. ...Central and Northern Plains/Mid Missouri Valley... At mid-levels, a ridge will build over the northern Plains on Monday, as flow over much of the north-central U.S. remains from the west-northwest. At the surface, a post-frontal airmass will be in place over much of the central and eastern Dakotas. Along the southern and western periphery of this airmass, moderate instability will likely develop by afternoon from parts of eastern Montana southeastward into Nebraska. Large-scale ascent will likely remain limited over much of the region, helping to keep convective development isolated. Although deep-layer shear should remain below 35 knots in most areas, low to mid-level lapse rates will be steep. This could be enough for a marginal severe threat, mainly in the late afternoon and early evening. Severe wind gusts and hail will be the primary threats. ...Upper Mississippi Valley/Western Great Lakes... A subtle mid-level shortwave trough is forecast to move eastward into the upper Mississippi Valley on Monday afternoon. To the east of the trough, moderate to strong instability is forecast to develop from central Iowa eastward into northern Illinois. The greatest convective coverage is expected to develop further to the north across parts of Wisconsin, where instability will be weaker but deep-layer shear will be greater. The combination of instability and deep-layer shear across Wisconsin could be sufficient for a marginal wind-damage threat during the late afternoon and early evening. This threat, along with a potential for hail could extend southwestward into central Iowa where strong instability is forecast. ..Broyles.. 08/17/2025 Read more

WW 0597 Status Updates
STATUS REPORT ON WW 597 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..08/17/25 ATTN...WFO...BIS...ABR...UNR... STATUS REPORT FOR WS 597 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC021-029-045-047-051-085-170640- ND . NORTH DAKOTA COUNTIES INCLUDED ARE DICKEY EMMONS LAMOURE LOGAN MCINTOSH SIOUX SDC013-017-019-021-031-033-041-045-049-055-059-063-065-069-071- 075-081-085-089-093-103-105-107-115-117-119-129-137-170640- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BROWN BUFFALO BUTTE CAMPBELL CORSON CUSTER DEWEY EDMUNDS FAULK HAAKON HAND HARDING HUGHES HYDE JACKSON JONES LAWRENCE LYMAN MCPHERSON MEADE PENNINGTON PERKINS POTTER SPINK STANLEY SULLY WALWORTH ZIEBACH Read more

WW 0597 Status Updates
STATUS REPORT ON WW 597 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..08/17/25 ATTN...WFO...BIS...ABR...UNR... STATUS REPORT FOR WS 597 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC021-029-045-047-051-085-170640- ND . NORTH DAKOTA COUNTIES INCLUDED ARE DICKEY EMMONS LAMOURE LOGAN MCINTOSH SIOUX SDC013-017-019-021-031-033-041-045-049-055-059-063-065-069-071- 075-081-085-089-093-103-105-107-115-117-119-129-137-170640- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BROWN BUFFALO BUTTE CAMPBELL CORSON CUSTER DEWEY EDMUNDS FAULK HAAKON HAND HARDING HUGHES HYDE JACKSON JONES LAWRENCE LYMAN MCPHERSON MEADE PENNINGTON PERKINS POTTER SPINK STANLEY SULLY WALWORTH ZIEBACH Read more