Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue Jul 22 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM UPPER MICHIGAN SOUTHWESTWARD TO NEBRASKA... ...SUMMARY... Organizing clusters of storms posing a risk for severe wind are possible across parts of the middle Missouri Valley and Upper Midwest into adjacent portions of the Great Lakes region Wednesday through Wednesday night. ...Synopsis... An upper high will remain over parts of the Southeast and Mid Atlantic on Wednesday, with ridge axis shifting east from the Upper Great Lakes into the Northeast as a low-amplitude shortwave trough moves across the northern Plains. This wave will bring cooling aloft from the northern Plains toward the Upper Great Lakes, with lift focused near a surface low moving from southern MN toward Lake Superior. A cold front will extend southwestward from the low, extending from Upper MI into KS by 12Z Thursday. Persistent south/southwest 850 mb winds across the Plains will aid boundary layer mixing and northward transport of moisture toward the frontal zone. Enhanced low-level shear may develop near the warm front as it moves across northern WI into western Upper MI. Well behind the cold front, veering surface winds into the northern High Plains will lead to a destabilizing air mass late in the day. ...Upper MI to NE... Storms are forecast to be ongoing along or just behind the cold front from northern SD into northwest MN Wednesday morning, with minimal wind risk. Area of heating and destabilization ahead of the front and outflows will then support numerous storms along the boundary from western KS/central NE northeastward into MN/WI/Upper MI, with one or more lines or MCSs producing severe gusts. Depending on air mass quality near the warm front across northern WI into the western MI Upper Peninsula, enhanced SRH could yield a tornadic storm or two. ...Central to northern High Plains... Southeast surface winds beneath modest west to northwest flow aloft will lead to elongated hodographs sufficient to sustain southeastward-moving cells capable of hail. Lapse rates aloft will not be particularly steep, but widely scattered instances of 1.00" hail appear likely from eastern WY to the Front Range during the late afternoon into early evening. ..Jewell.. 07/22/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue Jul 22 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM UPPER MICHIGAN SOUTHWESTWARD TO NEBRASKA... ...SUMMARY... Organizing clusters of storms posing a risk for severe wind are possible across parts of the middle Missouri Valley and Upper Midwest into adjacent portions of the Great Lakes region Wednesday through Wednesday night. ...Synopsis... An upper high will remain over parts of the Southeast and Mid Atlantic on Wednesday, with ridge axis shifting east from the Upper Great Lakes into the Northeast as a low-amplitude shortwave trough moves across the northern Plains. This wave will bring cooling aloft from the northern Plains toward the Upper Great Lakes, with lift focused near a surface low moving from southern MN toward Lake Superior. A cold front will extend southwestward from the low, extending from Upper MI into KS by 12Z Thursday. Persistent south/southwest 850 mb winds across the Plains will aid boundary layer mixing and northward transport of moisture toward the frontal zone. Enhanced low-level shear may develop near the warm front as it moves across northern WI into western Upper MI. Well behind the cold front, veering surface winds into the northern High Plains will lead to a destabilizing air mass late in the day. ...Upper MI to NE... Storms are forecast to be ongoing along or just behind the cold front from northern SD into northwest MN Wednesday morning, with minimal wind risk. Area of heating and destabilization ahead of the front and outflows will then support numerous storms along the boundary from western KS/central NE northeastward into MN/WI/Upper MI, with one or more lines or MCSs producing severe gusts. Depending on air mass quality near the warm front across northern WI into the western MI Upper Peninsula, enhanced SRH could yield a tornadic storm or two. ...Central to northern High Plains... Southeast surface winds beneath modest west to northwest flow aloft will lead to elongated hodographs sufficient to sustain southeastward-moving cells capable of hail. Lapse rates aloft will not be particularly steep, but widely scattered instances of 1.00" hail appear likely from eastern WY to the Front Range during the late afternoon into early evening. ..Jewell.. 07/22/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue Jul 22 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM UPPER MICHIGAN SOUTHWESTWARD TO NEBRASKA... ...SUMMARY... Organizing clusters of storms posing a risk for severe wind are possible across parts of the middle Missouri Valley and Upper Midwest into adjacent portions of the Great Lakes region Wednesday through Wednesday night. ...Synopsis... An upper high will remain over parts of the Southeast and Mid Atlantic on Wednesday, with ridge axis shifting east from the Upper Great Lakes into the Northeast as a low-amplitude shortwave trough moves across the northern Plains. This wave will bring cooling aloft from the northern Plains toward the Upper Great Lakes, with lift focused near a surface low moving from southern MN toward Lake Superior. A cold front will extend southwestward from the low, extending from Upper MI into KS by 12Z Thursday. Persistent south/southwest 850 mb winds across the Plains will aid boundary layer mixing and northward transport of moisture toward the frontal zone. Enhanced low-level shear may develop near the warm front as it moves across northern WI into western Upper MI. Well behind the cold front, veering surface winds into the northern High Plains will lead to a destabilizing air mass late in the day. ...Upper MI to NE... Storms are forecast to be ongoing along or just behind the cold front from northern SD into northwest MN Wednesday morning, with minimal wind risk. Area of heating and destabilization ahead of the front and outflows will then support numerous storms along the boundary from western KS/central NE northeastward into MN/WI/Upper MI, with one or more lines or MCSs producing severe gusts. Depending on air mass quality near the warm front across northern WI into the western MI Upper Peninsula, enhanced SRH could yield a tornadic storm or two. ...Central to northern High Plains... Southeast surface winds beneath modest west to northwest flow aloft will lead to elongated hodographs sufficient to sustain southeastward-moving cells capable of hail. Lapse rates aloft will not be particularly steep, but widely scattered instances of 1.00" hail appear likely from eastern WY to the Front Range during the late afternoon into early evening. ..Jewell.. 07/22/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue Jul 22 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM UPPER MICHIGAN SOUTHWESTWARD TO NEBRASKA... ...SUMMARY... Organizing clusters of storms posing a risk for severe wind are possible across parts of the middle Missouri Valley and Upper Midwest into adjacent portions of the Great Lakes region Wednesday through Wednesday night. ...Synopsis... An upper high will remain over parts of the Southeast and Mid Atlantic on Wednesday, with ridge axis shifting east from the Upper Great Lakes into the Northeast as a low-amplitude shortwave trough moves across the northern Plains. This wave will bring cooling aloft from the northern Plains toward the Upper Great Lakes, with lift focused near a surface low moving from southern MN toward Lake Superior. A cold front will extend southwestward from the low, extending from Upper MI into KS by 12Z Thursday. Persistent south/southwest 850 mb winds across the Plains will aid boundary layer mixing and northward transport of moisture toward the frontal zone. Enhanced low-level shear may develop near the warm front as it moves across northern WI into western Upper MI. Well behind the cold front, veering surface winds into the northern High Plains will lead to a destabilizing air mass late in the day. ...Upper MI to NE... Storms are forecast to be ongoing along or just behind the cold front from northern SD into northwest MN Wednesday morning, with minimal wind risk. Area of heating and destabilization ahead of the front and outflows will then support numerous storms along the boundary from western KS/central NE northeastward into MN/WI/Upper MI, with one or more lines or MCSs producing severe gusts. Depending on air mass quality near the warm front across northern WI into the western MI Upper Peninsula, enhanced SRH could yield a tornadic storm or two. ...Central to northern High Plains... Southeast surface winds beneath modest west to northwest flow aloft will lead to elongated hodographs sufficient to sustain southeastward-moving cells capable of hail. Lapse rates aloft will not be particularly steep, but widely scattered instances of 1.00" hail appear likely from eastern WY to the Front Range during the late afternoon into early evening. ..Jewell.. 07/22/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue Jul 22 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM UPPER MICHIGAN SOUTHWESTWARD TO NEBRASKA... ...SUMMARY... Organizing clusters of storms posing a risk for severe wind are possible across parts of the middle Missouri Valley and Upper Midwest into adjacent portions of the Great Lakes region Wednesday through Wednesday night. ...Synopsis... An upper high will remain over parts of the Southeast and Mid Atlantic on Wednesday, with ridge axis shifting east from the Upper Great Lakes into the Northeast as a low-amplitude shortwave trough moves across the northern Plains. This wave will bring cooling aloft from the northern Plains toward the Upper Great Lakes, with lift focused near a surface low moving from southern MN toward Lake Superior. A cold front will extend southwestward from the low, extending from Upper MI into KS by 12Z Thursday. Persistent south/southwest 850 mb winds across the Plains will aid boundary layer mixing and northward transport of moisture toward the frontal zone. Enhanced low-level shear may develop near the warm front as it moves across northern WI into western Upper MI. Well behind the cold front, veering surface winds into the northern High Plains will lead to a destabilizing air mass late in the day. ...Upper MI to NE... Storms are forecast to be ongoing along or just behind the cold front from northern SD into northwest MN Wednesday morning, with minimal wind risk. Area of heating and destabilization ahead of the front and outflows will then support numerous storms along the boundary from western KS/central NE northeastward into MN/WI/Upper MI, with one or more lines or MCSs producing severe gusts. Depending on air mass quality near the warm front across northern WI into the western MI Upper Peninsula, enhanced SRH could yield a tornadic storm or two. ...Central to northern High Plains... Southeast surface winds beneath modest west to northwest flow aloft will lead to elongated hodographs sufficient to sustain southeastward-moving cells capable of hail. Lapse rates aloft will not be particularly steep, but widely scattered instances of 1.00" hail appear likely from eastern WY to the Front Range during the late afternoon into early evening. ..Jewell.. 07/22/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Tue Jul 22 2025 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM UPPER MICHIGAN SOUTHWESTWARD TO NEBRASKA... ...SUMMARY... Organizing clusters of storms posing a risk for severe wind are possible across parts of the middle Missouri Valley and Upper Midwest into adjacent portions of the Great Lakes region Wednesday through Wednesday night. ...Synopsis... An upper high will remain over parts of the Southeast and Mid Atlantic on Wednesday, with ridge axis shifting east from the Upper Great Lakes into the Northeast as a low-amplitude shortwave trough moves across the northern Plains. This wave will bring cooling aloft from the northern Plains toward the Upper Great Lakes, with lift focused near a surface low moving from southern MN toward Lake Superior. A cold front will extend southwestward from the low, extending from Upper MI into KS by 12Z Thursday. Persistent south/southwest 850 mb winds across the Plains will aid boundary layer mixing and northward transport of moisture toward the frontal zone. Enhanced low-level shear may develop near the warm front as it moves across northern WI into western Upper MI. Well behind the cold front, veering surface winds into the northern High Plains will lead to a destabilizing air mass late in the day. ...Upper MI to NE... Storms are forecast to be ongoing along or just behind the cold front from northern SD into northwest MN Wednesday morning, with minimal wind risk. Area of heating and destabilization ahead of the front and outflows will then support numerous storms along the boundary from western KS/central NE northeastward into MN/WI/Upper MI, with one or more lines or MCSs producing severe gusts. Depending on air mass quality near the warm front across northern WI into the western MI Upper Peninsula, enhanced SRH could yield a tornadic storm or two. ...Central to northern High Plains... Southeast surface winds beneath modest west to northwest flow aloft will lead to elongated hodographs sufficient to sustain southeastward-moving cells capable of hail. Lapse rates aloft will not be particularly steep, but widely scattered instances of 1.00" hail appear likely from eastern WY to the Front Range during the late afternoon into early evening. ..Jewell.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Jul 22 2025 Valid 221630Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the northern Plains into the upper Mississippi Valley this afternoon into tonight. ...Northern Plains into the Upper Mississippi Valley... Visible-satellite imagery late this morning shows extensive cloud debris and convective outflow from ongoing and early morning shower/thunderstorm activity. A composite outflow/front is draped from the ND/MN Red River Valley west-southwestward into northwest SD, with another frontal segment extending into northern WY. Weak to neutral height rises across the northern Plains this afternoon will likely not support a northward oscillation of the boundary into southwest ND. A belt of moderate to strong southwesterly 500-mb flow overhead the north-central Rockies and adjacent plains will be downstream of a larger-scale trough pivoting east across the northern Rockies through tonight. In agreement with earlier forecast thinking, it appears probable that diurnal storms will favor the general area of northern WY/southern MT. This region will generally be post-frontal, but steep mid-level lapse rates and a modestly moist low-level airmass should still aid in the development of at least weak instability. Strong deep-layer shear should support supercells initially, with associated threat for large to perhaps isolated very large hail. Some potential should exist for this convection to grow upscale this evening across parts of the Dakotas and pose a greater threat for severe/damaging winds overnight. But, uncertainty remains high regarding the placement of this possible cluster, and whether it will remain surface-based or elevated. Farther east into the upper MS Valley, it appears less likely that robust convection will develop before this evening due to the stabilizing influence of the ongoing morning activity. If thunderstorms can develop later, most short-term guidance continues to suggest that sufficient airmass recovery will occur to support severe convection with mainly a hail/wind threat. Some diurnal hail/wind threat may develop across IA in association with the lower MO Valley MCV. Uncertainty remains high regarding this scenario. ...Central High Plains... Scattered to numerous high-based thunderstorms should develop this afternoon along/near the surface lee trough extending southward across the central High Plains. While low/mid-level flow and deep-layer shear are all expected to remain weak today across this region due to closer proximity to the upper ridge, heating will contribute to the development of steep 0-3 km lapse rates. Severe gusts will be the primary hazard. ...Southeast... A weak cold front will shift southward today across parts of GA/SC. A rather moist low-level airmass will be in place ahead of the front, with daytime heating encouraging the development of moderate to locally strong instability through the afternoon. Scattered thunderstorms that develop along/ahead of the front, and along various sea breeze circulations, may be capable of producing occasional damaging winds, even though shear will remain weak. ..Smith/Moore.. 07/22/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 22 2025 Valid 221700Z - 231200Z ...Update... Increasing west-southwesterly winds are expected near and west of the upper Snake River of ID this afternoon and evening. Although relative humidity will likely remain just above critical thresholds of 15 percent, sustained wind speeds at or above 20 mph should persist for a few hours across receptive fuels. Therefore, an additional small Elevated area has been included in the forecast for today for the aforementioned region. The rest of the forecast remains valid and accurate for NV. Please see the previous discussion for details pertaining to that region. ..Barnes.. 07/22/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Jul 22 2025/ ...Synopsis... While mid-level winds will steadily weaken across the Great Basin today, enough flow across the Sierra and strong heating in Nevada will promote a weak surface trough in northern Nevada. This feature will drive downslope winds into parts of southern and central Nevada. Winds around 15 to perhaps 20 mph will occur in a confined zone. RH will fall to 10-15% by the afternoon. Local, marginally critical conditions may occur very briefly as well. A few hours of elevated fire weather is expected. ...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 1132 AM CDT Tue Jul 22 2025 Valid 221700Z - 231200Z ...Update... Increasing west-southwesterly winds are expected near and west of the upper Snake River of ID this afternoon and evening. Although relative humidity will likely remain just above critical thresholds of 15 percent, sustained wind speeds at or above 20 mph should persist for a few hours across receptive fuels. Therefore, an additional small Elevated area has been included in the forecast for today for the aforementioned region. The rest of the forecast remains valid and accurate for NV. Please see the previous discussion for details pertaining to that region. ..Barnes.. 07/22/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Jul 22 2025/ ...Synopsis... While mid-level winds will steadily weaken across the Great Basin today, enough flow across the Sierra and strong heating in Nevada will promote a weak surface trough in northern Nevada. This feature will drive downslope winds into parts of southern and central Nevada. Winds around 15 to perhaps 20 mph will occur in a confined zone. RH will fall to 10-15% by the afternoon. Local, marginally critical conditions may occur very briefly as well. A few hours of elevated fire weather is expected. ...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 1132 AM CDT Tue Jul 22 2025 Valid 221700Z - 231200Z ...Update... Increasing west-southwesterly winds are expected near and west of the upper Snake River of ID this afternoon and evening. Although relative humidity will likely remain just above critical thresholds of 15 percent, sustained wind speeds at or above 20 mph should persist for a few hours across receptive fuels. Therefore, an additional small Elevated area has been included in the forecast for today for the aforementioned region. The rest of the forecast remains valid and accurate for NV. Please see the previous discussion for details pertaining to that region. ..Barnes.. 07/22/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Jul 22 2025/ ...Synopsis... While mid-level winds will steadily weaken across the Great Basin today, enough flow across the Sierra and strong heating in Nevada will promote a weak surface trough in northern Nevada. This feature will drive downslope winds into parts of southern and central Nevada. Winds around 15 to perhaps 20 mph will occur in a confined zone. RH will fall to 10-15% by the afternoon. Local, marginally critical conditions may occur very briefly as well. A few hours of elevated fire weather is expected. ...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 1132 AM CDT Tue Jul 22 2025 Valid 221700Z - 231200Z ...Update... Increasing west-southwesterly winds are expected near and west of the upper Snake River of ID this afternoon and evening. Although relative humidity will likely remain just above critical thresholds of 15 percent, sustained wind speeds at or above 20 mph should persist for a few hours across receptive fuels. Therefore, an additional small Elevated area has been included in the forecast for today for the aforementioned region. The rest of the forecast remains valid and accurate for NV. Please see the previous discussion for details pertaining to that region. ..Barnes.. 07/22/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Jul 22 2025/ ...Synopsis... While mid-level winds will steadily weaken across the Great Basin today, enough flow across the Sierra and strong heating in Nevada will promote a weak surface trough in northern Nevada. This feature will drive downslope winds into parts of southern and central Nevada. Winds around 15 to perhaps 20 mph will occur in a confined zone. RH will fall to 10-15% by the afternoon. Local, marginally critical conditions may occur very briefly as well. A few hours of elevated fire weather is expected. ...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 1132 AM CDT Tue Jul 22 2025 Valid 221700Z - 231200Z ...Update... Increasing west-southwesterly winds are expected near and west of the upper Snake River of ID this afternoon and evening. Although relative humidity will likely remain just above critical thresholds of 15 percent, sustained wind speeds at or above 20 mph should persist for a few hours across receptive fuels. Therefore, an additional small Elevated area has been included in the forecast for today for the aforementioned region. The rest of the forecast remains valid and accurate for NV. Please see the previous discussion for details pertaining to that region. ..Barnes.. 07/22/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Jul 22 2025/ ...Synopsis... While mid-level winds will steadily weaken across the Great Basin today, enough flow across the Sierra and strong heating in Nevada will promote a weak surface trough in northern Nevada. This feature will drive downslope winds into parts of southern and central Nevada. Winds around 15 to perhaps 20 mph will occur in a confined zone. RH will fall to 10-15% by the afternoon. Local, marginally critical conditions may occur very briefly as well. A few hours of elevated fire weather is expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more