Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ..Moore.. 08/11/2025 ...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 0104 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ..Moore.. 08/11/2025 ...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 0104 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ..Moore.. 08/11/2025 ...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 0104 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ..Moore.. 08/11/2025 ...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 0104 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ..Moore.. 08/11/2025 ...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 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR EASTERN WISCONSIN AND UPPER MICHIGAN... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. ...Synopsis and Discussion... The main feature of interest will be a shortwave trough moving across the upper MS Valley and across the Great Lakes, with attendant cold front pushing east across Upper MI and WI through 00Z. Modest instability and lift along the front will likely result in scattered afternoon thunderstorms over these areas. While lapse rates will remain poor aloft, the combination of strengthening deep-layer shear and frontal passage near peak heating may yield a few stronger storms within an expected line across eastern WI. Mean wind speeds in the lowest 3km will not be very strong, nor will the mixed boundary layer be particularly deep. However, isolated damaging gusts or marginal hail may occur as cooling aloft overspreads the warmed air mass late. Elsewhere, scattered storms will occur over the Southern Plains beneath a weak midlevel disturbance, and over parts of the Midwest and Southeast where low-level moisture will favor sporadic afternoon development. ..Jewell.. 08/11/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN HIGH PLAINS AND RED RIVER VALLEY OF THE NORTH... ...SUMMARY... Strong thunderstorms accompanied by at least some risk for severe wind and hail may impact parts of eastern New Mexico into the Texas South Plains, as well as parts of eastern North Dakota into northwestern Minnesota, late this afternoon and evening. ...Synopsis... Late-evening water-vapor imagery depicts an upper trough/vorticity maximum settling into the southern/central High Plains. This feature is expected to stall and weaken over the Plains over the next 24 hours with a gradual abatement of mid-level flow. To the north, a pronounced mid-level wave is apparent over the Canadian Rockies/Prairies. This feature will continue southeastward into the northern Plains and upper Mississippi River Valley through tonight. Strong/severe thunderstorm chances will largely be attendant to these mid-level features. ...Southern High Plains... 05z surface observations across the southern Plains reveal a composite frontal zone/outflow boundary draped from far northeast NM through the TX/OK Panhandles and roughly along the OK/KS border. This boundary will likely be displaced southward as a result of early-morning convection, though precisely where this boundary resides by peak heating is somewhat uncertain. Regardless, thunderstorm development along this boundary is expected by late afternoon/early evening. To the south of this boundary, easterly winds on the northern periphery of a weak surface low over the Permian Basin will maintain an upslope flow regime along the eastern slopes of the Sacramento, Sandia Manzano, and Sangre de Cristo Mountains. Modest westerly mid-level flow atop easterly low-level winds should yield sufficient deep-layer shear for a few organized storms, including a supercell or two. With time, upscale growth and/or merging with additional convection developing along the surface boundary will promote an increased threat for severe gusts through early evening. While convection is expected northeastward along much of the boundary from central OK into adjacent portions of KS/MO, weaker mid-level winds with eastward extent casts doubt on the potential for a robust severe threat (aside from occasional strong wet downbursts). ...Red River Valley of the North... Modest surface cyclogenesis is anticipated across the central Canadian Prairies over the next 24 hours as the mid-level wave approaches the international border. An attendant cold front is forecast to spread across the northern Plains through late afternoon and will impinge on a plume of seasonal low-level moisture. While mid-level lapse rates will remain modest (around 6-7 C/km), adequate buoyancy should be in place for deep convection. 30-40 knot mid-level flow should provide sufficient deep-layer shear for organized storms, though the marginal thermodynamic environment will likely be a modulating factor in overall storm intensity. Strong frontal forcing should promote upscale growth through the evening hours with an associated threat for damaging/severe winds. ..Moore/Darrow.. 08/11/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN HIGH PLAINS AND RED RIVER VALLEY OF THE NORTH... ...SUMMARY... Strong thunderstorms accompanied by at least some risk for severe wind and hail may impact parts of eastern New Mexico into the Texas South Plains, as well as parts of eastern North Dakota into northwestern Minnesota, late this afternoon and evening. ...Synopsis... Late-evening water-vapor imagery depicts an upper trough/vorticity maximum settling into the southern/central High Plains. This feature is expected to stall and weaken over the Plains over the next 24 hours with a gradual abatement of mid-level flow. To the north, a pronounced mid-level wave is apparent over the Canadian Rockies/Prairies. This feature will continue southeastward into the northern Plains and upper Mississippi River Valley through tonight. Strong/severe thunderstorm chances will largely be attendant to these mid-level features. ...Southern High Plains... 05z surface observations across the southern Plains reveal a composite frontal zone/outflow boundary draped from far northeast NM through the TX/OK Panhandles and roughly along the OK/KS border. This boundary will likely be displaced southward as a result of early-morning convection, though precisely where this boundary resides by peak heating is somewhat uncertain. Regardless, thunderstorm development along this boundary is expected by late afternoon/early evening. To the south of this boundary, easterly winds on the northern periphery of a weak surface low over the Permian Basin will maintain an upslope flow regime along the eastern slopes of the Sacramento, Sandia Manzano, and Sangre de Cristo Mountains. Modest westerly mid-level flow atop easterly low-level winds should yield sufficient deep-layer shear for a few organized storms, including a supercell or two. With time, upscale growth and/or merging with additional convection developing along the surface boundary will promote an increased threat for severe gusts through early evening. While convection is expected northeastward along much of the boundary from central OK into adjacent portions of KS/MO, weaker mid-level winds with eastward extent casts doubt on the potential for a robust severe threat (aside from occasional strong wet downbursts). ...Red River Valley of the North... Modest surface cyclogenesis is anticipated across the central Canadian Prairies over the next 24 hours as the mid-level wave approaches the international border. An attendant cold front is forecast to spread across the northern Plains through late afternoon and will impinge on a plume of seasonal low-level moisture. While mid-level lapse rates will remain modest (around 6-7 C/km), adequate buoyancy should be in place for deep convection. 30-40 knot mid-level flow should provide sufficient deep-layer shear for organized storms, though the marginal thermodynamic environment will likely be a modulating factor in overall storm intensity. Strong frontal forcing should promote upscale growth through the evening hours with an associated threat for damaging/severe winds. ..Moore/Darrow.. 08/11/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Aug 11 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN HIGH PLAINS AND RED RIVER VALLEY OF THE NORTH... ...SUMMARY... Strong thunderstorms accompanied by at least some risk for severe wind and hail may impact parts of eastern New Mexico into the Texas South Plains, as well as parts of eastern North Dakota into northwestern Minnesota, late this afternoon and evening. ...Synopsis... Late-evening water-vapor imagery depicts an upper trough/vorticity maximum settling into the southern/central High Plains. This feature is expected to stall and weaken over the Plains over the next 24 hours with a gradual abatement of mid-level flow. To the north, a pronounced mid-level wave is apparent over the Canadian Rockies/Prairies. This feature will continue southeastward into the northern Plains and upper Mississippi River Valley through tonight. Strong/severe thunderstorm chances will largely be attendant to these mid-level features. ...Southern High Plains... 05z surface observations across the southern Plains reveal a composite frontal zone/outflow boundary draped from far northeast NM through the TX/OK Panhandles and roughly along the OK/KS border. This boundary will likely be displaced southward as a result of early-morning convection, though precisely where this boundary resides by peak heating is somewhat uncertain. Regardless, thunderstorm development along this boundary is expected by late afternoon/early evening. To the south of this boundary, easterly winds on the northern periphery of a weak surface low over the Permian Basin will maintain an upslope flow regime along the eastern slopes of the Sacramento, Sandia Manzano, and Sangre de Cristo Mountains. Modest westerly mid-level flow atop easterly low-level winds should yield sufficient deep-layer shear for a few organized storms, including a supercell or two. With time, upscale growth and/or merging with additional convection developing along the surface boundary will promote an increased threat for severe gusts through early evening. While convection is expected northeastward along much of the boundary from central OK into adjacent portions of KS/MO, weaker mid-level winds with eastward extent casts doubt on the potential for a robust severe threat (aside from occasional strong wet downbursts). ...Red River Valley of the North... Modest surface cyclogenesis is anticipated across the central Canadian Prairies over the next 24 hours as the mid-level wave approaches the international border. An attendant cold front is forecast to spread across the northern Plains through late afternoon and will impinge on a plume of seasonal low-level moisture. While mid-level lapse rates will remain modest (around 6-7 C/km), adequate buoyancy should be in place for deep convection. 30-40 knot mid-level flow should provide sufficient deep-layer shear for organized storms, though the marginal thermodynamic environment will likely be a modulating factor in overall storm intensity. Strong frontal forcing should promote upscale growth through the evening hours with an associated threat for damaging/severe winds. ..Moore/Darrow.. 08/11/2025 Read more