Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Jul 02 2025 Valid 031200Z - 041200Z ...Northern Great Basin and Western Nevada... An approaching short wave trough and stronger mid-level flow will support shower and thunderstorm development across northeastern CA into southeastern OR Thursday. Faster northeast thunderstorm trajectories will limit precipitation amounts supporting an isolated dry thunderstorm threat. A corridor of daytime instability and precipitable water values of 0.5 to 0.7 inches will bring an isolated dry thunderstorm threat to the higher terrain of far northern NV, northern UT as well as far southeastern ID. The incoming trough will also promote stronger downslope flow east of the Sierra Crest across northwestern NV. Enhanced downslope winds from the west of 15-20 mph and relative humidity of around 15% supports continuation elevated fire weather highlights. ...Western Slope and Eastern Utah... A broad plume of monsoon moisture over the region along with daytime heating will promote a mix of wet and dry thunderstorms over higher terrain of the Western Slope as well as eastern UT. Some lightning ignitions are possible within remaining pockets of receptive fuels. ..Williams.. 07/02/2025 .PREV DISCUSSION... /ISSUED 0227 AM CDT Wed Jul 02 2025/ ...Synopsis... Broad troughing over the western US will continue as a compact shortwave trough moves across northern CA Thursday. 40-50 kt westerly flow will overspread the northern Great Basin. This will encourage dry downslope flow across parts of western NV. At the same time, continued monsoon moisture will allow widespread showers and thunderstorms over the Intermountain West. ...Northwest Great Basin... Continued westerly flow aloft will overspread the northern Great Basin Thursday afternoon. Dry downslope winds of 15-25 mph are expected, aided by the increasing winds aloft. Very warm temperatures, and the dry downslope trajectories, will support widespread RH values below 15%. The increase in surface winds amid a warm and dry boundary layer and dry fuels will support elevated wildfire spread potential Thursday. ...Western Slope... Another day of widespread showers and thunderstorms is expected across the eastern Great Basin and western Rockies Thursday. A continued surge of robust monsoon moisture (PWATS above 0.8 inches) will support a mixed mode of wet and occasionally dry storms. Widespread QPF of 0.1-0.25 inches in the preceding days suggest area fuels are likely to become less receptive to lightning ignitions with time. However, the coverage of storms does support at least isolated potential for dry strikes in receptive fuels across western CO/WY into eastern UT. ...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 0258 PM CDT Wed Jul 02 2025 Valid 031200Z - 041200Z ...Northern Great Basin and Western Nevada... An approaching short wave trough and stronger mid-level flow will support shower and thunderstorm development across northeastern CA into southeastern OR Thursday. Faster northeast thunderstorm trajectories will limit precipitation amounts supporting an isolated dry thunderstorm threat. A corridor of daytime instability and precipitable water values of 0.5 to 0.7 inches will bring an isolated dry thunderstorm threat to the higher terrain of far northern NV, northern UT as well as far southeastern ID. The incoming trough will also promote stronger downslope flow east of the Sierra Crest across northwestern NV. Enhanced downslope winds from the west of 15-20 mph and relative humidity of around 15% supports continuation elevated fire weather highlights. ...Western Slope and Eastern Utah... A broad plume of monsoon moisture over the region along with daytime heating will promote a mix of wet and dry thunderstorms over higher terrain of the Western Slope as well as eastern UT. Some lightning ignitions are possible within remaining pockets of receptive fuels. ..Williams.. 07/02/2025 .PREV DISCUSSION... /ISSUED 0227 AM CDT Wed Jul 02 2025/ ...Synopsis... Broad troughing over the western US will continue as a compact shortwave trough moves across northern CA Thursday. 40-50 kt westerly flow will overspread the northern Great Basin. This will encourage dry downslope flow across parts of western NV. At the same time, continued monsoon moisture will allow widespread showers and thunderstorms over the Intermountain West. ...Northwest Great Basin... Continued westerly flow aloft will overspread the northern Great Basin Thursday afternoon. Dry downslope winds of 15-25 mph are expected, aided by the increasing winds aloft. Very warm temperatures, and the dry downslope trajectories, will support widespread RH values below 15%. The increase in surface winds amid a warm and dry boundary layer and dry fuels will support elevated wildfire spread potential Thursday. ...Western Slope... Another day of widespread showers and thunderstorms is expected across the eastern Great Basin and western Rockies Thursday. A continued surge of robust monsoon moisture (PWATS above 0.8 inches) will support a mixed mode of wet and occasionally dry storms. Widespread QPF of 0.1-0.25 inches in the preceding days suggest area fuels are likely to become less receptive to lightning ignitions with time. However, the coverage of storms does support at least isolated potential for dry strikes in receptive fuels across western CO/WY into eastern UT. ...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 0258 PM CDT Wed Jul 02 2025 Valid 031200Z - 041200Z ...Northern Great Basin and Western Nevada... An approaching short wave trough and stronger mid-level flow will support shower and thunderstorm development across northeastern CA into southeastern OR Thursday. Faster northeast thunderstorm trajectories will limit precipitation amounts supporting an isolated dry thunderstorm threat. A corridor of daytime instability and precipitable water values of 0.5 to 0.7 inches will bring an isolated dry thunderstorm threat to the higher terrain of far northern NV, northern UT as well as far southeastern ID. The incoming trough will also promote stronger downslope flow east of the Sierra Crest across northwestern NV. Enhanced downslope winds from the west of 15-20 mph and relative humidity of around 15% supports continuation elevated fire weather highlights. ...Western Slope and Eastern Utah... A broad plume of monsoon moisture over the region along with daytime heating will promote a mix of wet and dry thunderstorms over higher terrain of the Western Slope as well as eastern UT. Some lightning ignitions are possible within remaining pockets of receptive fuels. ..Williams.. 07/02/2025 .PREV DISCUSSION... /ISSUED 0227 AM CDT Wed Jul 02 2025/ ...Synopsis... Broad troughing over the western US will continue as a compact shortwave trough moves across northern CA Thursday. 40-50 kt westerly flow will overspread the northern Great Basin. This will encourage dry downslope flow across parts of western NV. At the same time, continued monsoon moisture will allow widespread showers and thunderstorms over the Intermountain West. ...Northwest Great Basin... Continued westerly flow aloft will overspread the northern Great Basin Thursday afternoon. Dry downslope winds of 15-25 mph are expected, aided by the increasing winds aloft. Very warm temperatures, and the dry downslope trajectories, will support widespread RH values below 15%. The increase in surface winds amid a warm and dry boundary layer and dry fuels will support elevated wildfire spread potential Thursday. ...Western Slope... Another day of widespread showers and thunderstorms is expected across the eastern Great Basin and western Rockies Thursday. A continued surge of robust monsoon moisture (PWATS above 0.8 inches) will support a mixed mode of wet and occasionally dry storms. Widespread QPF of 0.1-0.25 inches in the preceding days suggest area fuels are likely to become less receptive to lightning ignitions with time. However, the coverage of storms does support at least isolated potential for dry strikes in receptive fuels across western CO/WY into eastern UT. ...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 0258 PM CDT Wed Jul 02 2025 Valid 031200Z - 041200Z ...Northern Great Basin and Western Nevada... An approaching short wave trough and stronger mid-level flow will support shower and thunderstorm development across northeastern CA into southeastern OR Thursday. Faster northeast thunderstorm trajectories will limit precipitation amounts supporting an isolated dry thunderstorm threat. A corridor of daytime instability and precipitable water values of 0.5 to 0.7 inches will bring an isolated dry thunderstorm threat to the higher terrain of far northern NV, northern UT as well as far southeastern ID. The incoming trough will also promote stronger downslope flow east of the Sierra Crest across northwestern NV. Enhanced downslope winds from the west of 15-20 mph and relative humidity of around 15% supports continuation elevated fire weather highlights. ...Western Slope and Eastern Utah... A broad plume of monsoon moisture over the region along with daytime heating will promote a mix of wet and dry thunderstorms over higher terrain of the Western Slope as well as eastern UT. Some lightning ignitions are possible within remaining pockets of receptive fuels. ..Williams.. 07/02/2025 .PREV DISCUSSION... /ISSUED 0227 AM CDT Wed Jul 02 2025/ ...Synopsis... Broad troughing over the western US will continue as a compact shortwave trough moves across northern CA Thursday. 40-50 kt westerly flow will overspread the northern Great Basin. This will encourage dry downslope flow across parts of western NV. At the same time, continued monsoon moisture will allow widespread showers and thunderstorms over the Intermountain West. ...Northwest Great Basin... Continued westerly flow aloft will overspread the northern Great Basin Thursday afternoon. Dry downslope winds of 15-25 mph are expected, aided by the increasing winds aloft. Very warm temperatures, and the dry downslope trajectories, will support widespread RH values below 15%. The increase in surface winds amid a warm and dry boundary layer and dry fuels will support elevated wildfire spread potential Thursday. ...Western Slope... Another day of widespread showers and thunderstorms is expected across the eastern Great Basin and western Rockies Thursday. A continued surge of robust monsoon moisture (PWATS above 0.8 inches) will support a mixed mode of wet and occasionally dry storms. Widespread QPF of 0.1-0.25 inches in the preceding days suggest area fuels are likely to become less receptive to lightning ignitions with time. However, the coverage of storms does support at least isolated potential for dry strikes in receptive fuels across western CO/WY into eastern UT. ...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 0258 PM CDT Wed Jul 02 2025 Valid 031200Z - 041200Z ...Northern Great Basin and Western Nevada... An approaching short wave trough and stronger mid-level flow will support shower and thunderstorm development across northeastern CA into southeastern OR Thursday. Faster northeast thunderstorm trajectories will limit precipitation amounts supporting an isolated dry thunderstorm threat. A corridor of daytime instability and precipitable water values of 0.5 to 0.7 inches will bring an isolated dry thunderstorm threat to the higher terrain of far northern NV, northern UT as well as far southeastern ID. The incoming trough will also promote stronger downslope flow east of the Sierra Crest across northwestern NV. Enhanced downslope winds from the west of 15-20 mph and relative humidity of around 15% supports continuation elevated fire weather highlights. ...Western Slope and Eastern Utah... A broad plume of monsoon moisture over the region along with daytime heating will promote a mix of wet and dry thunderstorms over higher terrain of the Western Slope as well as eastern UT. Some lightning ignitions are possible within remaining pockets of receptive fuels. ..Williams.. 07/02/2025 .PREV DISCUSSION... /ISSUED 0227 AM CDT Wed Jul 02 2025/ ...Synopsis... Broad troughing over the western US will continue as a compact shortwave trough moves across northern CA Thursday. 40-50 kt westerly flow will overspread the northern Great Basin. This will encourage dry downslope flow across parts of western NV. At the same time, continued monsoon moisture will allow widespread showers and thunderstorms over the Intermountain West. ...Northwest Great Basin... Continued westerly flow aloft will overspread the northern Great Basin Thursday afternoon. Dry downslope winds of 15-25 mph are expected, aided by the increasing winds aloft. Very warm temperatures, and the dry downslope trajectories, will support widespread RH values below 15%. The increase in surface winds amid a warm and dry boundary layer and dry fuels will support elevated wildfire spread potential Thursday. ...Western Slope... Another day of widespread showers and thunderstorms is expected across the eastern Great Basin and western Rockies Thursday. A continued surge of robust monsoon moisture (PWATS above 0.8 inches) will support a mixed mode of wet and occasionally dry storms. Widespread QPF of 0.1-0.25 inches in the preceding days suggest area fuels are likely to become less receptive to lightning ignitions with time. However, the coverage of storms does support at least isolated potential for dry strikes in receptive fuels across western CO/WY into eastern UT. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Wed Jul 2 20:01:01 UTC 2025.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Jul 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTH CENTRAL MONTANA... ...SUMMARY... Scattered severe thunderstorm gusts are possible across Montana this afternoon into the evening. Isolated severe thunderstorms may occur today across parts of the Great Basin and Upper Midwest/Great Lakes. ...20z Update... There are no changes are needed to the D1 Convective Outlook. See previous discussion below for more information. ..Thornton.. 07/02/2025 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 02 2025/ ...Northern Rockies into the Northern High Plains... Recent satellite imagery shows expansive upper ridging extending from the southern Plains into central AB/SK. An upper low is slowly drifting eastward into southern CA, impinging on the western periphery of this upper ridging. This upper low is forecast to stay well south of the region throughout the day, but a modest vorticity maximum, generated by convection east of this upper low, is forecast to move into the northern Rockies this afternoon. Ascent associated with this vorticity max coupled with orographic ascent, and perhaps additional large-scale ascent ahead of weak shortwave trough moving across OR, is expected to result in thunderstorms over the high terrain as the airmass diurnally destabilizes this afternoon. Persistent southwesterly flow aloft will then take these storms north/northeastward into more of the MT High Plains. Highest storm coverage is expected from central ID into western MT during the afternoon, before transition to more of central MT this evening. Vertical shear is strong enough for occasionally organized storm structures. The high cloud bases and steep low-level lapse rates will contribute to the potential for strong to severe wind gusts, particularly across central MT as storms become outflow dominant. ...Western Great Basin... Increasing thunderstorm coverage is anticipated this afternoon and evening east of a slow-moving upper low currently moving into central/southern CA. Moderate mid-level flow through the eastern periphery of the upper low combined with modest buoyancy and high LCLs will result in an environment favorable to isolated to scattered strong to severe wind gusts. Highest overall thunderstorm coverage and relatively greater chance for strong/severe gusts is over southern NV. ...AZ... 12Z PHX sounding sampled a precipitable water of 1.4" this morning and the expectation is that this moisture will support the development of numerous thunderstorms across the region this afternoon/evening. Development is anticipated over the higher terrain first, before then slowly moving westward toward lower elevations. This overall pattern generally favors strong to severe gusts across central AZ. However, very weak mid-level flow suggests the westward push off the terrain will be slow, if it occurs at all, which should limit the overall severe potential. ...Upper Midwest/Great Lakes... A weak cold front is forecast to move into northern MN, northern WI, Upper MI this afternoon. Thunderstorms are anticipated along this front as it interacts with the modest buoyancy (i.e. MLCAPE around 1000 J/kg) over this region. Isolated pre-frontal storms are possible across Lower MI as well. Moderate mid-level flow will support the potential for damaging gusts with any of the stronger storms. Additional thunderstorms are possible later this evening farther west from far southeast SD into southern MN and northern IA. There is some chance development occurs along the front during the afternoon, but low-level convergence will likely be too weak to overcome the convective inhibition. Later, isolated coverage appears more likely as warm-air advection, supported by modest low-level jet, increases. Given the expected combination of buoyancy and vertical shear, one or two more organized storms capable of large hail are possible. ...Eastern NC... Weak upper troughing and attendant surface cold front will advance eastward today across the southern Mid-Atlantic and Carolinas. Widespread thunderstorm development is anticipated ahead of these features. However, poor lapse rates aloft will likely limit updraft strength, with deep-layer shear limiting storm organization as well. A few water-loaded downbursts are possible within the strongest storms. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0156 PM CDT Wed Jul 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ON FRIDAY OVER PARTS OF THE EASTERN DAKOTAS AND UPPER MIDWEST... ...SUMMARY... Scattered strong to severe thunderstorms are expected across portions of the northern Plains and Upper Midwest on Friday. ...Dakotas and Upper Midwest... The band of primary westerly flow will be relegated to the northern tier of states on Friday, with a pronounced shortwave trough moving across southern SK/MT and into the northern Plains. Models are in general consensus that scattered afternoon thunderstorms will develop along the associated cold front over the eastern Dakotas. Relatively warm/moist and unstable conditions ahead of the front, coupled with favorable westerly flow aloft, will promote a risk of severe storms capable of damaging winds and some hail. There remain differences between the various 12z model solutions regarding timing and intensity of the approaching trough. This lends sufficient uncertainty to the corridor of greatest concern to maintain only MRGL risk at this time. However, parts of the area will likely need upgraded in later outlooks as details become clearer. ...ID/MT... A strong shortwave trough will track into the western states on Friday, promoting scattered afternoon thunderstorm development over parts of the northern Great Basin and northern Rockies. There is some concern for a few storms capable of damaging winds and hail over the region Friday evening, but model solutions remain to diverse to add a risk area at this time. ..Hart.. 07/02/2025 Read more