Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Jul 19 2024 Valid 211200Z - 271200Z Mid/upper-level ridging is forecast to remain over the Western U.S. Day 3/Sunday through the middle of the week, promoting very warm and dry conditions. Meanwhile, a compact mid-level shortwave trough is forecast to slide northward along the Oregon and Washington coastlines Day 3/Sunday into Day 4/Monday. Thereafter, the latest ensemble guidance continues to suggest that the mid/upper-level ridging may begin to breakdown toward the middle of the week around Day 6/Wednesday into Day 7/Thursday across portions of the Northwest U.S. ...Dry Thunderstorms... Isolated dry thunderstorm coverage is expected to increase late Day 2/Saturday into Day 3/Sunday across portions of the Pacific Northwest as ascent increases associated with the aforementioned shortwave trough. Fast-moving thunderstorms and receptive fuels (ERCs exceeding the 90th percentile) will favor efficient lightning ignitions, especially along the periphery of heavier storm cores. Isolated dry thunderstorm potential is forecast to shift a bit further east Day 4/Monday into eastern portions of the Northwest U.S. and the northern Great Basin. However, confidence remains too low to introduce a dry thunderstorm area at this time. ...Winds and Relative Humidity... Surface winds are expected to increase in terrain-favored areas to the east of the Cascades in Oregon and Washington beginning as early as Day 3/Sunday and continuing through Day 5/Tuesday, as stronger mid-level flow impinges on the area. While elevated to locally critical conditions are possible, the coverage and/or duration of critical conditions currently appears too low to introduce a Critical probability area. A greater potential for larger-scale Elevated to Critical conditions across the Western United States is expected to accompany at least a partial breakdown of the aforementioned mid/upper-level ridge near the middle of the week. Though, at this time, there is too much uncertainty to introduce a Critical probability area. ..Elliott.. 07/19/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Jul 19 2024 Valid 211200Z - 271200Z Mid/upper-level ridging is forecast to remain over the Western U.S. Day 3/Sunday through the middle of the week, promoting very warm and dry conditions. Meanwhile, a compact mid-level shortwave trough is forecast to slide northward along the Oregon and Washington coastlines Day 3/Sunday into Day 4/Monday. Thereafter, the latest ensemble guidance continues to suggest that the mid/upper-level ridging may begin to breakdown toward the middle of the week around Day 6/Wednesday into Day 7/Thursday across portions of the Northwest U.S. ...Dry Thunderstorms... Isolated dry thunderstorm coverage is expected to increase late Day 2/Saturday into Day 3/Sunday across portions of the Pacific Northwest as ascent increases associated with the aforementioned shortwave trough. Fast-moving thunderstorms and receptive fuels (ERCs exceeding the 90th percentile) will favor efficient lightning ignitions, especially along the periphery of heavier storm cores. Isolated dry thunderstorm potential is forecast to shift a bit further east Day 4/Monday into eastern portions of the Northwest U.S. and the northern Great Basin. However, confidence remains too low to introduce a dry thunderstorm area at this time. ...Winds and Relative Humidity... Surface winds are expected to increase in terrain-favored areas to the east of the Cascades in Oregon and Washington beginning as early as Day 3/Sunday and continuing through Day 5/Tuesday, as stronger mid-level flow impinges on the area. While elevated to locally critical conditions are possible, the coverage and/or duration of critical conditions currently appears too low to introduce a Critical probability area. A greater potential for larger-scale Elevated to Critical conditions across the Western United States is expected to accompany at least a partial breakdown of the aforementioned mid/upper-level ridge near the middle of the week. Though, at this time, there is too much uncertainty to introduce a Critical probability area. ..Elliott.. 07/19/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Fri Jul 19 2024 Valid 211200Z - 271200Z Mid/upper-level ridging is forecast to remain over the Western U.S. Day 3/Sunday through the middle of the week, promoting very warm and dry conditions. Meanwhile, a compact mid-level shortwave trough is forecast to slide northward along the Oregon and Washington coastlines Day 3/Sunday into Day 4/Monday. Thereafter, the latest ensemble guidance continues to suggest that the mid/upper-level ridging may begin to breakdown toward the middle of the week around Day 6/Wednesday into Day 7/Thursday across portions of the Northwest U.S. ...Dry Thunderstorms... Isolated dry thunderstorm coverage is expected to increase late Day 2/Saturday into Day 3/Sunday across portions of the Pacific Northwest as ascent increases associated with the aforementioned shortwave trough. Fast-moving thunderstorms and receptive fuels (ERCs exceeding the 90th percentile) will favor efficient lightning ignitions, especially along the periphery of heavier storm cores. Isolated dry thunderstorm potential is forecast to shift a bit further east Day 4/Monday into eastern portions of the Northwest U.S. and the northern Great Basin. However, confidence remains too low to introduce a dry thunderstorm area at this time. ...Winds and Relative Humidity... Surface winds are expected to increase in terrain-favored areas to the east of the Cascades in Oregon and Washington beginning as early as Day 3/Sunday and continuing through Day 5/Tuesday, as stronger mid-level flow impinges on the area. While elevated to locally critical conditions are possible, the coverage and/or duration of critical conditions currently appears too low to introduce a Critical probability area. A greater potential for larger-scale Elevated to Critical conditions across the Western United States is expected to accompany at least a partial breakdown of the aforementioned mid/upper-level ridge near the middle of the week. Though, at this time, there is too much uncertainty to introduce a Critical probability area. ..Elliott.. 07/19/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Fri Jul 19 2024 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS... ...SUMMARY... Scattered to numerous severe gusts (60-75 mph) are possible this afternoon into tonight across portions of the central Great Plains. ...20Z Update... Primary adjustment to the ongoing forecast was to shift the northern bound of the Enhanced risk slightly farther south to account for the progression of convection in southwest Nebraska/northwest Kansas. An area of agitated cumulus have developed in south-central North Dakota. The environment and some CAM guidance suggest some potential for large hail and severe gusts should storms develop. The Marginal risk area has been expanded to account for this possibility. ..Wendt.. 07/19/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/ ...Central/southern Great Plains... Visible-satellite imagery late this morning shows several clusters of sub-severe thunderstorms over central/northern NE into SD ahead of a southeastward-migrating mid-level shortwave impulse. The disturbance is evident in water-vapor imagery and approaching the Black Hills vicinity. The mid- to upper-level anticyclone over the Great Basin/Desert Southwest will move little during the period, and aid in allowing the aforementioned disturbance to move southeastward into eastern NE/western IA later tonight. Morning surface analysis places a moist axis from western KS northward into west-central NE and SD with lower 60s deg F surface dewpoints. This adequately moist airmass will become moderately unstable by mid afternoon across southwest NE southward into extreme eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems plausible a southward-moving cluster will emerge from the midday ongoing thunderstorm activity over central NE and move into a boundary layer featuring steep 0-3 km lapse rates. Veering flow with height will support 35-45 kt effective shear and promote storm organization. Large hail and severe gusts will be possible with the stronger storms over mainly parts of NE and SD. As additional storms develop, a coalescing into one or more clusters will likely evolve by late afternoon over the central Great Plains. Additionally, scattered storm development is expected near/east of the Front Range with coverage forecast to increase as storms move into a more moist environment over eastern CO. Upscale growth into one or more linear clusters is expected before an MCS evolves (perhaps from a merging of thunderstorm clusters) over western KS by this evening. Severe gusts will be the primary hazard later this afternoon through the late evening. As storms move farther southwest into central KS and parts of northwest OK/TX Panhandle later this evening, weaker instability and greater CINH will likely lead to a gradual decrease in storm intensity and severe risk. Read more

MD 1682 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF FAR EASTERN COLORADO INTO EXTREME SOUTHWESTERN NEBRASKA AND NORTHWESTERN KANSAS
Mesoscale Discussion 1682 NWS Storm Prediction Center Norman OK 0130 PM CDT Fri Jul 19 2024 Areas affected...portions of far eastern Colorado into extreme southwestern Nebraska and northwestern Kansas Concerning...Severe potential...Watch possible Valid 191830Z - 192030Z Probability of Watch Issuance...60 percent SUMMARY...The severe threat should gradually increase through the afternoon. 60-75 mph gusts are the main concern, though a couple instances of 1+ inch hail cannot be ruled out. A WW issuance will eventually be needed pending favorable convective trends. DISCUSSION...Thunderstorms have been percolating in intensity across eastern CO into NE, where strong surface heating has supported temperatures rising into the upper 80s/low 90s F amid low 60s F dewpoints. MLCINH continues to erode as the boundary layer deepens, supporting the potential for robust thunderstorm development. Regional VADs and 18Z mesoanalysis show hodographs with slight low-level curvature and mid-level elongation, favoring the development of transient supercells merging into line segments through the afternoon. Low-level lapse rates have steepened to 8+ C/km, and they may steepen further through the afternoon, supporting severe gust potential (some of which may approach 75 mph). Some questions remain in terms of exactly when an uptick in greater storm coverage will occur. Nonetheless, a WW issuance will eventually be needed once these details become more clear. ..Squitieri/Smith.. 07/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...DDC...GLD... LAT...LON 39980267 40330205 40410120 40139996 39769938 39259910 38689925 38409966 38330040 38480121 38880206 39170234 39980267 Read more

WW 0555 Status Updates
STATUS FOR WATCH 0555 HAS NOT BEEN ISSUED YET Read more

WW 0555 Status Updates
STATUS FOR WATCH 0555 HAS NOT BEEN ISSUED YET Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0206 PM CDT Fri Jul 19 2024 Valid 201200Z - 211200Z The previous forecast remains largely on track, with the potential for isolated dry thunderstorms Day 2/Saturday afternoon into the overnight across portions of the Northwest into the Great Basin and northern Rockies. Primary change with this forecast was to expand the Isolated dry thunderstorm area further northwest along and west of the Cascades in Oregon, with ensemble guidance now suggesting greater coverage of isolated fast-moving nocturnal thunderstorms. Additionally, ERCs exceed the 97th percentile across much of the area, likely leading to efficient lightning ignitions with any dry thunderstorms. The isolated dry thunderstorm area may need to be expanded even further northwestward toward the Oregon Coast, but confidence remains a bit too low at this time. Please see the previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 07/19/2024 .PREV DISCUSSION... /ISSUED 0205 AM CDT Fri Jul 19 2024/ ...Synopsis... An upper ridge over the western Rockies will persist D2/Saturday as a broad Pacific trough moves onshore over the Northwest. To the east, northwesterly flow aloft will continue over the northern Rockies and Intermountain west, with seasonable monsoon moisture. Widely scattered thunderstorms appear likely through the afternoon with a risk for lightning within dry fuels. ...Northwest into the Great Basin and northern Rockies... With the approach of the West Coast trough, weak ascent will allow for isolated thunderstorm development along the higher terrain of the Sierra and Cascades by early afternoon. Initial PWAT values of 0.8 to 1 inches will favor drier storm over areas of significantly dry fuels and recent fire activity. Storm coverage may increase overnight as the upper trough continues onshore and ascent increases. While PWATs should also increase above 1 inch with onshore flow, faster storm motions will tend to limit wetting rainfall, favoring drier storms. While confidence in convective evolution toward the end of the period is lower, some guidance suggests the largest increase in storm coverage after dark may be focused west of the Cascades toward the coastal ranges of OR and northern CA. Farther east into the Great Basin and northern Rockies, confidence in dry storms is somewhat lower. Flow aloft along the eastern periphery of the ridge will be weaker with deeper monsoonal moisture in place. The combination of slower storm speeds and higher PWATs suggests storms may have greater rainfall efficiency. Still, the potential for lighting outside of the wetter cores from scattered storm coverage, and the possibility of a few drier storms, suggest some threat for lightning ignitions within mostly receptive fuels. ...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 0206 PM CDT Fri Jul 19 2024 Valid 201200Z - 211200Z The previous forecast remains largely on track, with the potential for isolated dry thunderstorms Day 2/Saturday afternoon into the overnight across portions of the Northwest into the Great Basin and northern Rockies. Primary change with this forecast was to expand the Isolated dry thunderstorm area further northwest along and west of the Cascades in Oregon, with ensemble guidance now suggesting greater coverage of isolated fast-moving nocturnal thunderstorms. Additionally, ERCs exceed the 97th percentile across much of the area, likely leading to efficient lightning ignitions with any dry thunderstorms. The isolated dry thunderstorm area may need to be expanded even further northwestward toward the Oregon Coast, but confidence remains a bit too low at this time. Please see the previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 07/19/2024 .PREV DISCUSSION... /ISSUED 0205 AM CDT Fri Jul 19 2024/ ...Synopsis... An upper ridge over the western Rockies will persist D2/Saturday as a broad Pacific trough moves onshore over the Northwest. To the east, northwesterly flow aloft will continue over the northern Rockies and Intermountain west, with seasonable monsoon moisture. Widely scattered thunderstorms appear likely through the afternoon with a risk for lightning within dry fuels. ...Northwest into the Great Basin and northern Rockies... With the approach of the West Coast trough, weak ascent will allow for isolated thunderstorm development along the higher terrain of the Sierra and Cascades by early afternoon. Initial PWAT values of 0.8 to 1 inches will favor drier storm over areas of significantly dry fuels and recent fire activity. Storm coverage may increase overnight as the upper trough continues onshore and ascent increases. While PWATs should also increase above 1 inch with onshore flow, faster storm motions will tend to limit wetting rainfall, favoring drier storms. While confidence in convective evolution toward the end of the period is lower, some guidance suggests the largest increase in storm coverage after dark may be focused west of the Cascades toward the coastal ranges of OR and northern CA. Farther east into the Great Basin and northern Rockies, confidence in dry storms is somewhat lower. Flow aloft along the eastern periphery of the ridge will be weaker with deeper monsoonal moisture in place. The combination of slower storm speeds and higher PWATs suggests storms may have greater rainfall efficiency. Still, the potential for lighting outside of the wetter cores from scattered storm coverage, and the possibility of a few drier storms, suggest some threat for lightning ignitions within mostly receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more