Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/New England, and the southern and central High Plains on Wednesday. ...Synopsis... An MCS will be ongoing across the Midwest at the start of the D2/Wednesday period, with residual outflow becoming a focus for afternoon thunderstorm re-development. A shortwave will eject across the northern Rockies with modest upper-level flow for organization for thunderstorms across the southern and central High Plains. ..Southern and Central High Plains Vicinity... Upper-level flow will overspread the northern Rockies on Tuesday, with easterly upslope surface flow supporting scattered thunderstorm development in Colorado/Wyoming. Modest deep layer shear around 30-35 kts will support potential for a supercell or two capable of large hail and damaging wind. Further thunderstorm development is likely with the surface trough from eastern Colorado into New Mexico and along a front across central Oklahoma into the Texas Panhandle. Steep lapse rates and modest shear profiles will support some potential for strong to severe wind and hail. The Marginal Risk was extended southward into southeastern CO and the OK/TX Panhandles with this outlook. ...Midwest... An MCS will be ongoing at the start of the D2 period across portions of IA, southern MN, and MO. This will pose some risk for severe wind through the early D2 period before weakening. With daytime heating, additional thunderstorm development is likely in the vicinity of this residual outflow boundary and in the vicinity of a front across the Ohio Valley by the afternoon. Steep mid-level lapse rates and shear near the front should support a few organized storms capable of strong to severe wind. ...Northeast... Stronger mid-level flow is expected across the northeastern US as a jet streak moves through a broad upper-level low in Canada across portions of the northeast. Deep layer shear around 40-50 kts and marginal CAPE profiles will support potential for a supercell or two capable of large hail and damaging wind. The Marginal Risk was extended north into ME with this outlook to account for this risk. ..Thornton.. 07/29/2025 Read more

No Mesoscale Discussions are in effect as of Tue Jul 29 17:35:02 UTC 2025.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Jul 29 2025 Valid 291700Z - 301200Z ...17z Update... No major changes were made to the prior outlook. Isolated dry thunderstorms are expected across the higher terrain of northern CA, OR and western ID this afternoon and evening. A few of these storms are likely to pose a risk for lightning ignitions within dry fuels. A few storms my persist overnight across eastern OR with a continued threat for occasional lightning strikes. Will maintain the IsoDryT highlights with little change. ...Southern Great Basin... A few hours of dry and breezy conditions are possible this afternoon across parts of southern NV and far southwestern UT. Enhanced mid-level flow will overspread drier parts of the Great Basin. Isolated wind gusts of 15 mph and RH below 15% could support some locally elevated fire-weather potential this afternoon. Though the lack of stronger winds suggests this threat will remain isolated. ..Lyons.. 07/29/2025 .PREV DISCUSSION... /ISSUED 0140 AM CDT Tue Jul 29 2025/ ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Tue Jul 29 2025 Valid 291630Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of severe gusts will be possible, with hail most likely over western areas. ...CO/NE/IA... Surface analysis indicates a frontal zone draped from IA west-southwestward into the central High Plains. Moist conditions either side of the boundary and ample heating will promote a very to extremely unstable airmass as temperatures continue to warm through the mid afternoon. Initial storms are progged over the central High Plains with perhaps other activity continuing across the mid MS Valley through the afternoon. Hail/wind will be possible with the earlier storms, but a gradual increase in storm coverage is forecast this evening into the overnight near/north of the boundary. Severe gusts will tend to be the main severe hazard tonight. ...WY/MT... Water-vapor imagery late this morning shows a prominent shortwave trough over the northern Great Basin moving into eastern ID/WY this afternoon. A moist (dewpoints in the 50s to lower 60s) and destabilizing boundary layer near/northeast of a residual frontal zone, coupled with orographic and large-scale ascent, will lead to scattered afternoon thunderstorms. Easterly flow beneath moderate westerlies will yield effective shear supporting organized storms, including a few supercells and organized clusters. Hail/wind will be the primary severe hazards before a tendency for upscale growth into linear clusters during the evening. ...Southeast OR... A mid-level trough over the Sierra into the northern Great Basin, embedded within larger-scale trough over the West Coast, will move northward through this evening across the northern Great Basin into southern OR/ID. Scattered high-based thunderstorms will probably focus along the leading edge of ascent as low to mid tropospheric lapse rates exceed 9 deg C/km. A relatively dry sub-cloud layer will promote evaporatively cooled downdrafts capable of isolated severe gusts (60-70 mph) with the stronger cores/clusters, mainly during the 22-04 UTC period. ..Smith/Halbert.. 07/29/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0703 AM CDT Tue Jul 29 2025 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM PARTS OF THE NORTHERN HIGH PLAINS INTO THE CENTRAL PLAINS.... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of damaging winds will be possible, with hail most likely over western areas. ...CO/NE/IA... Morning water vapor loops show a large ridge over the central US, with a plume of ample mid-level moisture moving northward across the southern Rockies. Northeasterly surface winds across northeast CO will help moisten/destabilize the region, leading to thunderstorms off the foothills of central CO by mid-afternoon. These storms will be in a region of moderate CAPE, but rather weak vertical shear and winds aloft. Clusters of storms capable of small hail and gusty winds will build eastward through the afternoon into a progressively more moist/unstable airmass, and may eventually intensify into an organized MCS across NE/western IA. This activity may persist well into the night with a risk of locally damaging wind gusts. ...WY/MT... Multiple weak shortwave troughs are tracking northward across the Great Basin today toward the northern Rockies. This will lead to scattered afternoon thunderstorms over the mountains of southwest MT and northern WY. Surface dewpoints in the 50s along with strong daytime heating will result in considerable CAPE, along with sufficient westerly winds aloft for some convective organization. Initial storms over the higher terrain will pose some risk of hail and gusty winds. As the activity builds eastward into the plains, a greater risk for large hail and severe winds will likely develop through the evening. ..Hart/Grams.. 07/29/2025 Read more