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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sun Aug 10 2025 Valid 111200Z - 121200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/10/2025 .PREV DISCUSSION... /ISSUED 0134 AM CDT Sun Aug 10 2025/ ...Synopsis... Fire weather concerns are expected to abate on Monday across the Four Corners region, though some threat for isolated dry thunderstorms will continue for parts of central AZ to far western NM. A shortwave trough evident in water-vapor imagery over WY/UT is forecast to weaken and stall over the southern High Plains by late Monday. This will favor subtle surface pressure rises across the eastern Great Basin/Four Corners region with relatively weaker low-level winds. Although sustained winds will be modest, deep mixing will promote occasional gusts upwards of 15-25 mph across northern AZ to northwest NM where RH values should fall into the low teens. Transient elevated conditions are possible, but poor deterministic agreement and/or ensemble consensus precluded introducing risk highlights. However, weak orographic ascent along the Mogollon Rim within a deeply-mixed, but weakly buoyant, air mass will support some potential for isolated dry thunderstorms. Given recent dry lightning over the region within a similar thermodynamic environment, isolated dry thunderstorm highlights were maintained and focused along and north of the more prominent terrain features. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sun Aug 10 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Scattered strong thunderstorms may impact parts of the upper Great Lakes region Tuesday. While the risk for severe weather still appears low, locally strong gusts and hail might still be possible. ...Discussion... An initially prominent mid-level high centered offshore of the Pacific Northwest is forecast to become suppressed west-southwestward across the northern mid-latitude eastern Pacific during this period, as a consolidating short wave trough digs near the Canadian Rockies. As downstream flow trends more zonal, it appears that a pair of short wave perturbations will consolidate into a larger-scale short wave trough across northern Ontario into Quebec by late Tuesday night. This evolution may include a lead perturbation continuing to dig across parts of the upper Midwest and adjacent Great Lakes region, before pivoting east/northeast of the Lake Huron/Georgian Bay vicinity, in advance of a trailing impulse digging south of Hudson Bay. More uncertain, due to greater model spread, the lead short wave may be preceded across the Lower Michigan vicinity by an increasingly sheared, convectively generated perturbation emerging from the central Great Plains. The evolution of this regime is forecast to include an initial intrusion of somewhat cooler/drier air, which may maintain identity while advancing across the Great Lakes region, Midwest and lower Missouri Valley, before being overtaken by a more substantive reinforcing cool intrusion across the Great Lakes by late Tuesday night. Both fronts will be preceded by the increasingly diffuse remnants of a slow moving or stalled surface frontal zone extending from the lower Great Lakes into the southern Great Plains, and boundary layer moistening/destabilization ahead of the lead front advancing across Upper Michigan and Wisconsin by late Tuesday afternoon remains a bit unclear. Barring complications from lingering convective cloud cover/precipitation associated with the possible MCV emerging from the Great Plains, it might not be out of the question that the environment in a corridor along/ahead of the front could become supportive of organized thunderstorms with potential to produce strong wind gusts and hail. Depending on the strength of the MCV, which remains unclear due to model spread, wind fields may strengthen sufficiently to support at least some risk for organized strong/severe thunderstorm development across Lower Michigan, where stronger pre-frontal destabilization appears most probable. If/when these uncertainties become better resolved, it is possible that severe probabilities in excess of 5 percent, or higher, will be needed across parts of the Great Lakes region in later outlooks for this period. ..Kerr.. 08/10/2025 Read more