Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jun 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN AND WESTERN LAKE SUPERIOR... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Upper Mississippi Valley/Upper Midwest... Bands/clusters of convection are ongoing at this time, from the Minnesota Arrowhead southward across northern Wisconsin, and southwestward across southern Minnesota into the Mid Missouri Valley region. This convection continues moving eastward, toward a less unstable airmass, which should temper severe risk over the next few hours. Greatest potential for a couple of marginally severe storms appears to exist over southwestern Minnesota and adjacent portions of southeastern South Dakota and northwestern Iowa, where the greatest instability resides. Greater severe risk is forecast to evolve later this afternoon, north of the ongoing storms. Here, daytime heating ahead of an advancing cold front (associated with a low-amplitude short-wave trough embedded in fast westerly flow aloft, and moving eastward along the international border) will result in moderate to strong instability (2500 to 3500 J/kg mixed-layer CAPE) within the pre-frontal warm sector. Weakly veering but strengthening flow with height across the region will provide favorable shear for organized/rotating storms. Initial convection -- expected to initiate in the 12/20Z to 12/21Z time frame -- should quickly organize/become supercellular, with very large hail likely to be the initial/primary severe risk. A couple of tornadoes will also be possible, though veered low-level flow should temper overall tornado risk. With time, storms are expected to cluster/grow upscale, with small-scale bowing expected, which should yield a gradual increase in damaging-wind potential. Storms will spread rather quickly eastward/southeastward with time, with some severe risk likely to linger through the evening before gradually diminishing overnight. ...South Florida... Widespread convection is ongoing across southern Florida, within a zone of low-level warm advection south of a weak cold front lying across central portions of the Peninsula. Modest lapse rates aloft, but a very moist/tropical boundary layer is resulting in deep CAPE, which will continue to support the widespread convection. While mid-level flow remains rather weak, flow veers/increases with height through the lower troposphere. This is providing ample shear for generally weak/transient updraft rotation. Given the associated potential for a brief tornado or two, low (2%) tornado probability/MRGL risk is being introduced across portions of South Florida. For additional short-term information, please refer to SWOMCD #1237. ..Goss/Moore.. 06/12/2024 Read more

MD 1236 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST NEBRASKA...EASTERN SOUTH DAKOTA...SOUTHWEST MINNESOTA...AND NORTHWEST IOWA
Mesoscale Discussion 1236 NWS Storm Prediction Center Norman OK 0716 AM CDT Wed Jun 12 2024 Areas affected...northeast Nebraska...eastern South Dakota...southwest Minnesota...and northwest Iowa Concerning...Severe potential...Watch unlikely Valid 121216Z - 121345Z Probability of Watch Issuance...20 percent SUMMARY...An isolated large hail threat is expected to continue this morning. DISCUSSION...Ongoing elevated thunderstorm activity across eastern South Dakota, western Minnesota, and northern Nebraska has been somewhat more robust than anticipated, particularly amid relatively weak instability (500 to 1000 J/kg MUCAPE). This is likely aided by the 40 to 45 knot low-level jet which continues to intensify based on the OAX, LNX, and FSD VWP. In addition, strong deep layer shear (50+ knots) supports supercells and a threat for large hail with the more robust/longer-lived updrafts. Storms are forming on the eastern edge of the instability plume and moderately strong storm speeds are leading to them moving east of this better instability. However, some thunderstorms may continue to develop on the western periphery of this ongoing activity where greater instability is present. If storms had a longer residence time before exiting the greater buoyancy, a severe thunderstorm watch may be necessary. However, the threat is expected to remain somewhat isolated and only for a few more hours. Therefore, a watch is not anticipated. ..Bentley/Hart.. 06/12/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...DMX...FSD...OAX...ABR...LBF...UNR... LAT...LON 45239879 45569648 45359496 44379466 42469539 42149693 42199877 42449920 43149980 43660016 44739973 45239879 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0702 AM CDT Wed Jun 12 2024 Valid 121300Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN... ...SUMMARY... Scattered severe thunderstorms capable of very large hail, damaging wind gusts, and a few tornadoes will be possible across parts of the Upper Midwest late afternoon and early evening. ...Southern MN/WI early today... Morning water vapor imagery shows a fast-moving shortwave trough over the western Dakotas. Lift and enhanced low-level thermal/moisture advection ahead of the trough has resulted in scattered thunderstorm development over western MN and eastern SD. These storms may persist through the morning, tracking across central/southern MN by early afternoon with some risk of large hail. Daytime heating and increasing low-level moisture will eventually result in moderate CAPE and a risk of organized strong/severe thunderstorms - mainly from central MN eastward after 18z. These storms may grow upscale and track into central WI before weakening, posing a continued risk of damaging winds and hail. ...Northern MN/WI later today... In the wake of the aforementioned morning convection, strong daytime heating and moisture advection will result in a corridor of moderate CAPE across central/northeast MN by mid/late afternoon. Temperatures west of this area will heating to near 90F, with forecast soundings showing little cap, very steep mid-level lapse rates, and MLCAPE values around 3000 J/kg. Large scale forcing will be subtle, leading to the development of discrete supercells. Several overnight CAM runs suggest intense storms that form will track into the Arrowhead region of MN and areas around Duluth by early evening, posing a risk of very large hail, damaging winds, and a few tornadoes. Forecast soundings show substantial low-level shear with effective SRH values of 300+ m2/s2. It is uncertain how the early storms over southern MN will affect moisture return. If high dewpoint air can make it into the ENH risk area, higher tornado probabilities may become warranted. These storms will likely congeal and spread eastward across northern WI during the evening with a continued risk of damaging winds and some hail. ..Hart/Bentley.. 06/12/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Jun 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... ...Saturday/Day 4 to Saturday/Day 5... On Saturday, an upper-level trough is forecast to move northeastward across the southern and central High Plains. An axis of instability is forecast to be further to the northwest across the western Dakotas. As a mid-level jet passes northeastward across the northern Rockies, large-scale ascent and deep-layer shear should be strong enough for an isolated severe thunderstorms in parts of the northern High Plains. Large hail and severe wind gusts will be possible, but uncertainty exists concerning the spatial distribution of the threat. The trough in the central Plains is forecast to move into the upper Mississippi Valley on Sunday, with a large pocket of instability located in its wake across the central Plains. Although large-scale ascent within this unstable airmass is expected to be weak, isolated severe storms could develop in the late afternoon and early evening. Further to the northwest, model forecasts show potential for storm development in parts of the northern High Plains Sunday evening. If this were to occur, MCS development, and an isolated severe threat, could occur across parts of the northern Plains Sunday night. ...Monday/Day 6 to Wednesday/Day 8... On Monday, a mid-level jet is forecast to move northeastward into the northern Plains, as a moist and unstable airmass remains in place across the Upper Midwest. Severe thunderstorms may develop across parts of the region during the afternoon and evening, in association with any shortwave trough that can translate through the flow. The models suggest there is enough potential on Monday for a more widespread severe threat, to add a 15 percent contour in parts of the eastern Dakotas and Minnesota. On Tuesday, an upper-level trough is forecast to move across the northern Plains. Isolated strong to severe thunderstorms would be possible ahead of the trough in parts of the upper Mississippi Valley. As the trough moves through southeastern Canada on Wednesday, severe storms would be possible in parts of the Northeast. However, uncertainty is considerable at this range in the forecast period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Jun 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... ...Saturday/Day 4 to Saturday/Day 5... On Saturday, an upper-level trough is forecast to move northeastward across the southern and central High Plains. An axis of instability is forecast to be further to the northwest across the western Dakotas. As a mid-level jet passes northeastward across the northern Rockies, large-scale ascent and deep-layer shear should be strong enough for an isolated severe thunderstorms in parts of the northern High Plains. Large hail and severe wind gusts will be possible, but uncertainty exists concerning the spatial distribution of the threat. The trough in the central Plains is forecast to move into the upper Mississippi Valley on Sunday, with a large pocket of instability located in its wake across the central Plains. Although large-scale ascent within this unstable airmass is expected to be weak, isolated severe storms could develop in the late afternoon and early evening. Further to the northwest, model forecasts show potential for storm development in parts of the northern High Plains Sunday evening. If this were to occur, MCS development, and an isolated severe threat, could occur across parts of the northern Plains Sunday night. ...Monday/Day 6 to Wednesday/Day 8... On Monday, a mid-level jet is forecast to move northeastward into the northern Plains, as a moist and unstable airmass remains in place across the Upper Midwest. Severe thunderstorms may develop across parts of the region during the afternoon and evening, in association with any shortwave trough that can translate through the flow. The models suggest there is enough potential on Monday for a more widespread severe threat, to add a 15 percent contour in parts of the eastern Dakotas and Minnesota. On Tuesday, an upper-level trough is forecast to move across the northern Plains. Isolated strong to severe thunderstorms would be possible ahead of the trough in parts of the upper Mississippi Valley. As the trough moves through southeastern Canada on Wednesday, severe storms would be possible in parts of the Northeast. However, uncertainty is considerable at this range in the forecast period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Jun 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... ...Saturday/Day 4 to Saturday/Day 5... On Saturday, an upper-level trough is forecast to move northeastward across the southern and central High Plains. An axis of instability is forecast to be further to the northwest across the western Dakotas. As a mid-level jet passes northeastward across the northern Rockies, large-scale ascent and deep-layer shear should be strong enough for an isolated severe thunderstorms in parts of the northern High Plains. Large hail and severe wind gusts will be possible, but uncertainty exists concerning the spatial distribution of the threat. The trough in the central Plains is forecast to move into the upper Mississippi Valley on Sunday, with a large pocket of instability located in its wake across the central Plains. Although large-scale ascent within this unstable airmass is expected to be weak, isolated severe storms could develop in the late afternoon and early evening. Further to the northwest, model forecasts show potential for storm development in parts of the northern High Plains Sunday evening. If this were to occur, MCS development, and an isolated severe threat, could occur across parts of the northern Plains Sunday night. ...Monday/Day 6 to Wednesday/Day 8... On Monday, a mid-level jet is forecast to move northeastward into the northern Plains, as a moist and unstable airmass remains in place across the Upper Midwest. Severe thunderstorms may develop across parts of the region during the afternoon and evening, in association with any shortwave trough that can translate through the flow. The models suggest there is enough potential on Monday for a more widespread severe threat, to add a 15 percent contour in parts of the eastern Dakotas and Minnesota. On Tuesday, an upper-level trough is forecast to move across the northern Plains. Isolated strong to severe thunderstorms would be possible ahead of the trough in parts of the upper Mississippi Valley. As the trough moves through southeastern Canada on Wednesday, severe storms would be possible in parts of the Northeast. However, uncertainty is considerable at this range in the forecast period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Jun 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... ...Saturday/Day 4 to Saturday/Day 5... On Saturday, an upper-level trough is forecast to move northeastward across the southern and central High Plains. An axis of instability is forecast to be further to the northwest across the western Dakotas. As a mid-level jet passes northeastward across the northern Rockies, large-scale ascent and deep-layer shear should be strong enough for an isolated severe thunderstorms in parts of the northern High Plains. Large hail and severe wind gusts will be possible, but uncertainty exists concerning the spatial distribution of the threat. The trough in the central Plains is forecast to move into the upper Mississippi Valley on Sunday, with a large pocket of instability located in its wake across the central Plains. Although large-scale ascent within this unstable airmass is expected to be weak, isolated severe storms could develop in the late afternoon and early evening. Further to the northwest, model forecasts show potential for storm development in parts of the northern High Plains Sunday evening. If this were to occur, MCS development, and an isolated severe threat, could occur across parts of the northern Plains Sunday night. ...Monday/Day 6 to Wednesday/Day 8... On Monday, a mid-level jet is forecast to move northeastward into the northern Plains, as a moist and unstable airmass remains in place across the Upper Midwest. Severe thunderstorms may develop across parts of the region during the afternoon and evening, in association with any shortwave trough that can translate through the flow. The models suggest there is enough potential on Monday for a more widespread severe threat, to add a 15 percent contour in parts of the eastern Dakotas and Minnesota. On Tuesday, an upper-level trough is forecast to move across the northern Plains. Isolated strong to severe thunderstorms would be possible ahead of the trough in parts of the upper Mississippi Valley. As the trough moves through southeastern Canada on Wednesday, severe storms would be possible in parts of the Northeast. However, uncertainty is considerable at this range in the forecast period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Wed Jun 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... ...Saturday/Day 4 to Saturday/Day 5... On Saturday, an upper-level trough is forecast to move northeastward across the southern and central High Plains. An axis of instability is forecast to be further to the northwest across the western Dakotas. As a mid-level jet passes northeastward across the northern Rockies, large-scale ascent and deep-layer shear should be strong enough for an isolated severe thunderstorms in parts of the northern High Plains. Large hail and severe wind gusts will be possible, but uncertainty exists concerning the spatial distribution of the threat. The trough in the central Plains is forecast to move into the upper Mississippi Valley on Sunday, with a large pocket of instability located in its wake across the central Plains. Although large-scale ascent within this unstable airmass is expected to be weak, isolated severe storms could develop in the late afternoon and early evening. Further to the northwest, model forecasts show potential for storm development in parts of the northern High Plains Sunday evening. If this were to occur, MCS development, and an isolated severe threat, could occur across parts of the northern Plains Sunday night. ...Monday/Day 6 to Wednesday/Day 8... On Monday, a mid-level jet is forecast to move northeastward into the northern Plains, as a moist and unstable airmass remains in place across the Upper Midwest. Severe thunderstorms may develop across parts of the region during the afternoon and evening, in association with any shortwave trough that can translate through the flow. The models suggest there is enough potential on Monday for a more widespread severe threat, to add a 15 percent contour in parts of the eastern Dakotas and Minnesota. On Tuesday, an upper-level trough is forecast to move across the northern Plains. Isolated strong to severe thunderstorms would be possible ahead of the trough in parts of the upper Mississippi Valley. As the trough moves through southeastern Canada on Wednesday, severe storms would be possible in parts of the Northeast. However, uncertainty is considerable at this range in the forecast period. Read more