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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN ARIZONA... ...SUMMARY... Severe thunderstorm wind gusts are possible over parts of southern Arizona from mid-afternoon through early/mid-evening. Little change was necessary for the 20Z update. The primary of severe risk continues to be over parts of southern AZ, downstream of storms now developing along the Rim. The air mass is destabilizing with heating with 500-1000 J/kg MUCAPE currently. Modest northeast winds in the midlevels and the unstable surface air mass should foster west/southwestward propagation later today, with strong to locally severe gusts possible. For more information see mesoscale discussion 1579. ..Jewell.. 07/11/2024 .PREV DISCUSSION... /ISSUED 1145 AM CDT Thu Jul 11 2024/ ...Arizona... Widely scattered to scattered thunderstorms are expected to develop this afternoon over the Mogollon Rim, and smaller mountain ranges to the south. That will occur as strong insolation at those higher elevations preferentially removes MLCINH, in the presence of generally greater low-level moisture than previous days. Some strengthening of flow aloft is expected over this region on the southeast periphery of the upper anticyclone. This will support convective motion off the Rim (and small mountain ranges to its south), into strongly heated/deeply mixed boundary layers of the desert floor. Isolated strong-severe gusts are possible from the relatively early, more-discrete activity, and swaths of strong-severe gusts are possible as convection moves southwestward toward the international border. ...Northern High Plains... Isolated to widely scattered, high-based thunderstorms are expected to form near the lee trough, where both relatively maximized convergence and strong surface heating should contribute to enough lift for convective initiation. The main concern should be damaging to severe gusts, given the deeply mixed subcloud layer. Isolated severe hail also may occur, amidst enough deep-layer shear for some organized thunderstorms (effective-shear magnitudes of 30-40 kt). Lack of greater moisture and buoyancy will be a limiting factor for coverage and intensity of convection, which should diminish rapidly after sunset. ...Southeast Kansas/Southern Missouri... A few severe storms could develop today to the east-northeast of a surface wave near the Oklahoma/Kansas border in vicinity of front that extends into Missouri, which may be somewhat effectively augmented by lingering early day convection. Moderate to locally strong buoyancy will exist within a moist environment, with MLCAPE likely to reach 2500-3000 J/kg. A considerable vertical veering of winds will exist through the lower/middle troposphere, with around 30 kt effective shear. Instances of severe hail and/or wind gusts could occur. ...Southern Maine... Clouds have lingered much of the morning with rather weak lapse rates noted in the 12z KGYX/Gray Maine observed sounding, but clearing is occurring from the west and a narrow zone of modest destabilization should occur this afternoon, within a very moist environment (lower/middle 70s F surface dewpoints) ahead of a cold front. Pending sufficient destabilization, a locally severe storm or two could occur, potentially with an absence of lightning, in the presence of long/semi-straight hodographs (highlighted by 45-50 kt winds 3-6 km AGL). ...Central/south-central portions of Illinois and Indiana... Ample low-level CAPE (100+ J/kg 0-km AGL) near the southward-shifting boundary could lead to some potential for funnels or perhaps even a brief non-supercell tornado this afternoon. Some of the storms could otherwise pose a risk for gusty winds, but the overall potential for organized severe storms is currently expected to remain low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN ARIZONA... ...SUMMARY... Severe thunderstorm wind gusts are possible over parts of southern Arizona from mid-afternoon through early/mid-evening. Little change was necessary for the 20Z update. The primary of severe risk continues to be over parts of southern AZ, downstream of storms now developing along the Rim. The air mass is destabilizing with heating with 500-1000 J/kg MUCAPE currently. Modest northeast winds in the midlevels and the unstable surface air mass should foster west/southwestward propagation later today, with strong to locally severe gusts possible. For more information see mesoscale discussion 1579. ..Jewell.. 07/11/2024 .PREV DISCUSSION... /ISSUED 1145 AM CDT Thu Jul 11 2024/ ...Arizona... Widely scattered to scattered thunderstorms are expected to develop this afternoon over the Mogollon Rim, and smaller mountain ranges to the south. That will occur as strong insolation at those higher elevations preferentially removes MLCINH, in the presence of generally greater low-level moisture than previous days. Some strengthening of flow aloft is expected over this region on the southeast periphery of the upper anticyclone. This will support convective motion off the Rim (and small mountain ranges to its south), into strongly heated/deeply mixed boundary layers of the desert floor. Isolated strong-severe gusts are possible from the relatively early, more-discrete activity, and swaths of strong-severe gusts are possible as convection moves southwestward toward the international border. ...Northern High Plains... Isolated to widely scattered, high-based thunderstorms are expected to form near the lee trough, where both relatively maximized convergence and strong surface heating should contribute to enough lift for convective initiation. The main concern should be damaging to severe gusts, given the deeply mixed subcloud layer. Isolated severe hail also may occur, amidst enough deep-layer shear for some organized thunderstorms (effective-shear magnitudes of 30-40 kt). Lack of greater moisture and buoyancy will be a limiting factor for coverage and intensity of convection, which should diminish rapidly after sunset. ...Southeast Kansas/Southern Missouri... A few severe storms could develop today to the east-northeast of a surface wave near the Oklahoma/Kansas border in vicinity of front that extends into Missouri, which may be somewhat effectively augmented by lingering early day convection. Moderate to locally strong buoyancy will exist within a moist environment, with MLCAPE likely to reach 2500-3000 J/kg. A considerable vertical veering of winds will exist through the lower/middle troposphere, with around 30 kt effective shear. Instances of severe hail and/or wind gusts could occur. ...Southern Maine... Clouds have lingered much of the morning with rather weak lapse rates noted in the 12z KGYX/Gray Maine observed sounding, but clearing is occurring from the west and a narrow zone of modest destabilization should occur this afternoon, within a very moist environment (lower/middle 70s F surface dewpoints) ahead of a cold front. Pending sufficient destabilization, a locally severe storm or two could occur, potentially with an absence of lightning, in the presence of long/semi-straight hodographs (highlighted by 45-50 kt winds 3-6 km AGL). ...Central/south-central portions of Illinois and Indiana... Ample low-level CAPE (100+ J/kg 0-km AGL) near the southward-shifting boundary could lead to some potential for funnels or perhaps even a brief non-supercell tornado this afternoon. Some of the storms could otherwise pose a risk for gusty winds, but the overall potential for organized severe storms is currently expected to remain low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN ARIZONA... ...SUMMARY... Severe thunderstorm wind gusts are possible over parts of southern Arizona from mid-afternoon through early/mid-evening. Little change was necessary for the 20Z update. The primary of severe risk continues to be over parts of southern AZ, downstream of storms now developing along the Rim. The air mass is destabilizing with heating with 500-1000 J/kg MUCAPE currently. Modest northeast winds in the midlevels and the unstable surface air mass should foster west/southwestward propagation later today, with strong to locally severe gusts possible. For more information see mesoscale discussion 1579. ..Jewell.. 07/11/2024 .PREV DISCUSSION... /ISSUED 1145 AM CDT Thu Jul 11 2024/ ...Arizona... Widely scattered to scattered thunderstorms are expected to develop this afternoon over the Mogollon Rim, and smaller mountain ranges to the south. That will occur as strong insolation at those higher elevations preferentially removes MLCINH, in the presence of generally greater low-level moisture than previous days. Some strengthening of flow aloft is expected over this region on the southeast periphery of the upper anticyclone. This will support convective motion off the Rim (and small mountain ranges to its south), into strongly heated/deeply mixed boundary layers of the desert floor. Isolated strong-severe gusts are possible from the relatively early, more-discrete activity, and swaths of strong-severe gusts are possible as convection moves southwestward toward the international border. ...Northern High Plains... Isolated to widely scattered, high-based thunderstorms are expected to form near the lee trough, where both relatively maximized convergence and strong surface heating should contribute to enough lift for convective initiation. The main concern should be damaging to severe gusts, given the deeply mixed subcloud layer. Isolated severe hail also may occur, amidst enough deep-layer shear for some organized thunderstorms (effective-shear magnitudes of 30-40 kt). Lack of greater moisture and buoyancy will be a limiting factor for coverage and intensity of convection, which should diminish rapidly after sunset. ...Southeast Kansas/Southern Missouri... A few severe storms could develop today to the east-northeast of a surface wave near the Oklahoma/Kansas border in vicinity of front that extends into Missouri, which may be somewhat effectively augmented by lingering early day convection. Moderate to locally strong buoyancy will exist within a moist environment, with MLCAPE likely to reach 2500-3000 J/kg. A considerable vertical veering of winds will exist through the lower/middle troposphere, with around 30 kt effective shear. Instances of severe hail and/or wind gusts could occur. ...Southern Maine... Clouds have lingered much of the morning with rather weak lapse rates noted in the 12z KGYX/Gray Maine observed sounding, but clearing is occurring from the west and a narrow zone of modest destabilization should occur this afternoon, within a very moist environment (lower/middle 70s F surface dewpoints) ahead of a cold front. Pending sufficient destabilization, a locally severe storm or two could occur, potentially with an absence of lightning, in the presence of long/semi-straight hodographs (highlighted by 45-50 kt winds 3-6 km AGL). ...Central/south-central portions of Illinois and Indiana... Ample low-level CAPE (100+ J/kg 0-km AGL) near the southward-shifting boundary could lead to some potential for funnels or perhaps even a brief non-supercell tornado this afternoon. Some of the storms could otherwise pose a risk for gusty winds, but the overall potential for organized severe storms is currently expected to remain low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN ARIZONA... ...SUMMARY... Severe thunderstorm wind gusts are possible over parts of southern Arizona from mid-afternoon through early/mid-evening. Little change was necessary for the 20Z update. The primary of severe risk continues to be over parts of southern AZ, downstream of storms now developing along the Rim. The air mass is destabilizing with heating with 500-1000 J/kg MUCAPE currently. Modest northeast winds in the midlevels and the unstable surface air mass should foster west/southwestward propagation later today, with strong to locally severe gusts possible. For more information see mesoscale discussion 1579. ..Jewell.. 07/11/2024 .PREV DISCUSSION... /ISSUED 1145 AM CDT Thu Jul 11 2024/ ...Arizona... Widely scattered to scattered thunderstorms are expected to develop this afternoon over the Mogollon Rim, and smaller mountain ranges to the south. That will occur as strong insolation at those higher elevations preferentially removes MLCINH, in the presence of generally greater low-level moisture than previous days. Some strengthening of flow aloft is expected over this region on the southeast periphery of the upper anticyclone. This will support convective motion off the Rim (and small mountain ranges to its south), into strongly heated/deeply mixed boundary layers of the desert floor. Isolated strong-severe gusts are possible from the relatively early, more-discrete activity, and swaths of strong-severe gusts are possible as convection moves southwestward toward the international border. ...Northern High Plains... Isolated to widely scattered, high-based thunderstorms are expected to form near the lee trough, where both relatively maximized convergence and strong surface heating should contribute to enough lift for convective initiation. The main concern should be damaging to severe gusts, given the deeply mixed subcloud layer. Isolated severe hail also may occur, amidst enough deep-layer shear for some organized thunderstorms (effective-shear magnitudes of 30-40 kt). Lack of greater moisture and buoyancy will be a limiting factor for coverage and intensity of convection, which should diminish rapidly after sunset. ...Southeast Kansas/Southern Missouri... A few severe storms could develop today to the east-northeast of a surface wave near the Oklahoma/Kansas border in vicinity of front that extends into Missouri, which may be somewhat effectively augmented by lingering early day convection. Moderate to locally strong buoyancy will exist within a moist environment, with MLCAPE likely to reach 2500-3000 J/kg. A considerable vertical veering of winds will exist through the lower/middle troposphere, with around 30 kt effective shear. Instances of severe hail and/or wind gusts could occur. ...Southern Maine... Clouds have lingered much of the morning with rather weak lapse rates noted in the 12z KGYX/Gray Maine observed sounding, but clearing is occurring from the west and a narrow zone of modest destabilization should occur this afternoon, within a very moist environment (lower/middle 70s F surface dewpoints) ahead of a cold front. Pending sufficient destabilization, a locally severe storm or two could occur, potentially with an absence of lightning, in the presence of long/semi-straight hodographs (highlighted by 45-50 kt winds 3-6 km AGL). ...Central/south-central portions of Illinois and Indiana... Ample low-level CAPE (100+ J/kg 0-km AGL) near the southward-shifting boundary could lead to some potential for funnels or perhaps even a brief non-supercell tornado this afternoon. Some of the storms could otherwise pose a risk for gusty winds, but the overall potential for organized severe storms is currently expected to remain low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN ARIZONA... ...SUMMARY... Severe thunderstorm wind gusts are possible over parts of southern Arizona from mid-afternoon through early/mid-evening. Little change was necessary for the 20Z update. The primary of severe risk continues to be over parts of southern AZ, downstream of storms now developing along the Rim. The air mass is destabilizing with heating with 500-1000 J/kg MUCAPE currently. Modest northeast winds in the midlevels and the unstable surface air mass should foster west/southwestward propagation later today, with strong to locally severe gusts possible. For more information see mesoscale discussion 1579. ..Jewell.. 07/11/2024 .PREV DISCUSSION... /ISSUED 1145 AM CDT Thu Jul 11 2024/ ...Arizona... Widely scattered to scattered thunderstorms are expected to develop this afternoon over the Mogollon Rim, and smaller mountain ranges to the south. That will occur as strong insolation at those higher elevations preferentially removes MLCINH, in the presence of generally greater low-level moisture than previous days. Some strengthening of flow aloft is expected over this region on the southeast periphery of the upper anticyclone. This will support convective motion off the Rim (and small mountain ranges to its south), into strongly heated/deeply mixed boundary layers of the desert floor. Isolated strong-severe gusts are possible from the relatively early, more-discrete activity, and swaths of strong-severe gusts are possible as convection moves southwestward toward the international border. ...Northern High Plains... Isolated to widely scattered, high-based thunderstorms are expected to form near the lee trough, where both relatively maximized convergence and strong surface heating should contribute to enough lift for convective initiation. The main concern should be damaging to severe gusts, given the deeply mixed subcloud layer. Isolated severe hail also may occur, amidst enough deep-layer shear for some organized thunderstorms (effective-shear magnitudes of 30-40 kt). Lack of greater moisture and buoyancy will be a limiting factor for coverage and intensity of convection, which should diminish rapidly after sunset. ...Southeast Kansas/Southern Missouri... A few severe storms could develop today to the east-northeast of a surface wave near the Oklahoma/Kansas border in vicinity of front that extends into Missouri, which may be somewhat effectively augmented by lingering early day convection. Moderate to locally strong buoyancy will exist within a moist environment, with MLCAPE likely to reach 2500-3000 J/kg. A considerable vertical veering of winds will exist through the lower/middle troposphere, with around 30 kt effective shear. Instances of severe hail and/or wind gusts could occur. ...Southern Maine... Clouds have lingered much of the morning with rather weak lapse rates noted in the 12z KGYX/Gray Maine observed sounding, but clearing is occurring from the west and a narrow zone of modest destabilization should occur this afternoon, within a very moist environment (lower/middle 70s F surface dewpoints) ahead of a cold front. Pending sufficient destabilization, a locally severe storm or two could occur, potentially with an absence of lightning, in the presence of long/semi-straight hodographs (highlighted by 45-50 kt winds 3-6 km AGL). ...Central/south-central portions of Illinois and Indiana... Ample low-level CAPE (100+ J/kg 0-km AGL) near the southward-shifting boundary could lead to some potential for funnels or perhaps even a brief non-supercell tornado this afternoon. Some of the storms could otherwise pose a risk for gusty winds, but the overall potential for organized severe storms is currently expected to remain low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu Jul 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN ARIZONA... ...SUMMARY... Severe thunderstorm wind gusts are possible over parts of southern Arizona from mid-afternoon through early/mid-evening. Little change was necessary for the 20Z update. The primary of severe risk continues to be over parts of southern AZ, downstream of storms now developing along the Rim. The air mass is destabilizing with heating with 500-1000 J/kg MUCAPE currently. Modest northeast winds in the midlevels and the unstable surface air mass should foster west/southwestward propagation later today, with strong to locally severe gusts possible. For more information see mesoscale discussion 1579. ..Jewell.. 07/11/2024 .PREV DISCUSSION... /ISSUED 1145 AM CDT Thu Jul 11 2024/ ...Arizona... Widely scattered to scattered thunderstorms are expected to develop this afternoon over the Mogollon Rim, and smaller mountain ranges to the south. That will occur as strong insolation at those higher elevations preferentially removes MLCINH, in the presence of generally greater low-level moisture than previous days. Some strengthening of flow aloft is expected over this region on the southeast periphery of the upper anticyclone. This will support convective motion off the Rim (and small mountain ranges to its south), into strongly heated/deeply mixed boundary layers of the desert floor. Isolated strong-severe gusts are possible from the relatively early, more-discrete activity, and swaths of strong-severe gusts are possible as convection moves southwestward toward the international border. ...Northern High Plains... Isolated to widely scattered, high-based thunderstorms are expected to form near the lee trough, where both relatively maximized convergence and strong surface heating should contribute to enough lift for convective initiation. The main concern should be damaging to severe gusts, given the deeply mixed subcloud layer. Isolated severe hail also may occur, amidst enough deep-layer shear for some organized thunderstorms (effective-shear magnitudes of 30-40 kt). Lack of greater moisture and buoyancy will be a limiting factor for coverage and intensity of convection, which should diminish rapidly after sunset. ...Southeast Kansas/Southern Missouri... A few severe storms could develop today to the east-northeast of a surface wave near the Oklahoma/Kansas border in vicinity of front that extends into Missouri, which may be somewhat effectively augmented by lingering early day convection. Moderate to locally strong buoyancy will exist within a moist environment, with MLCAPE likely to reach 2500-3000 J/kg. A considerable vertical veering of winds will exist through the lower/middle troposphere, with around 30 kt effective shear. Instances of severe hail and/or wind gusts could occur. ...Southern Maine... Clouds have lingered much of the morning with rather weak lapse rates noted in the 12z KGYX/Gray Maine observed sounding, but clearing is occurring from the west and a narrow zone of modest destabilization should occur this afternoon, within a very moist environment (lower/middle 70s F surface dewpoints) ahead of a cold front. Pending sufficient destabilization, a locally severe storm or two could occur, potentially with an absence of lightning, in the presence of long/semi-straight hodographs (highlighted by 45-50 kt winds 3-6 km AGL). ...Central/south-central portions of Illinois and Indiana... Ample low-level CAPE (100+ J/kg 0-km AGL) near the southward-shifting boundary could lead to some potential for funnels or perhaps even a brief non-supercell tornado this afternoon. Some of the storms could otherwise pose a risk for gusty winds, but the overall potential for organized severe storms is currently expected to remain low. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...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 0250 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Sierras... Confidence has increased in sufficient moisture reaching the Sierras to support the inclusion of a Dry Thunder highlight for Friday. Any storms that develop over the Sierras could produce lightning over receptive fuels, and forecast profiles show deeply-mixed, inverted-V boundary layer profiles supportive of gusty thunderstorm outflow. ...Southwest Utah into Northern Arizona... A Dry Thunder highlight has been added to portions of Southern Utah and Northwestern Arizona. Dry thunder occurrence appears likely along the northern fringes of the monsoonal moisture, and fuels are currently receptive with minimal precipitation occurring over the last week. Given hot/dry boundary layer conditions, gusty thunderstorm outflow is likely with storms that develop. ...Northwest... No significant changes were made to the Elevated highlights over portions of the Northwest. See previous discussion for more detail. ..Halbert/Weinman.. 07/11/2024 .PREV DISCUSSION... /ISSUED 0201 AM CDT Thu Jul 11 2024/ ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Thu Jul 11 18:00:02 UTC 2024.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Locally damaging gusts are possible over parts of the northern Plains late Friday afternoon and evening. Hail will also be possible over North Dakota. ...Synopsis... An upper ridge will expand further across the Great Basin and Four Corners states on Friday, with gradually increasing midlevel westerlies across the northern Rockies. Meanwhile, a weak positive-tile upper trough will lift out of the lower Great Lakes and into southern Quebec, with rising heights over New England. Overnight, the influence of a broad trough across the Canadian prairies may result in strengthening flow and subtle height falls over MT into Saturday morning. At the surface, weak high pressure will extend from the Great Lakes southwestward along the MS Valley and into the northern Gulf of Mexico, and over much of the interior West beneath the upper ridge. A surface trough will deepen over the northern and central High Plains coincident with peak heating, with modest westerly winds over MT into the western Dakotas as boundary-layer mixing occurs. ...Northern High Plains... Strong heating will lead to an uncapped air mass within the surface trough, with scattered convection likely to form after 21Z over far eastern MT/WY into the western Dakotas and NE. Models differ with coverage through the evening, but prominent outflows should allow for a few clusters of storms to persist across the Dakotas and NE, and perhaps into northwest MN late, supported by a weak northwest flow aloft/southerly 850 mb flow regime. Cells that persist into the moister air mass east of the deeply mixed air mass may produce brief hail with the stronger cores. ..Jewell.. 07/11/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Locally damaging gusts are possible over parts of the northern Plains late Friday afternoon and evening. Hail will also be possible over North Dakota. ...Synopsis... An upper ridge will expand further across the Great Basin and Four Corners states on Friday, with gradually increasing midlevel westerlies across the northern Rockies. Meanwhile, a weak positive-tile upper trough will lift out of the lower Great Lakes and into southern Quebec, with rising heights over New England. Overnight, the influence of a broad trough across the Canadian prairies may result in strengthening flow and subtle height falls over MT into Saturday morning. At the surface, weak high pressure will extend from the Great Lakes southwestward along the MS Valley and into the northern Gulf of Mexico, and over much of the interior West beneath the upper ridge. A surface trough will deepen over the northern and central High Plains coincident with peak heating, with modest westerly winds over MT into the western Dakotas as boundary-layer mixing occurs. ...Northern High Plains... Strong heating will lead to an uncapped air mass within the surface trough, with scattered convection likely to form after 21Z over far eastern MT/WY into the western Dakotas and NE. Models differ with coverage through the evening, but prominent outflows should allow for a few clusters of storms to persist across the Dakotas and NE, and perhaps into northwest MN late, supported by a weak northwest flow aloft/southerly 850 mb flow regime. Cells that persist into the moister air mass east of the deeply mixed air mass may produce brief hail with the stronger cores. ..Jewell.. 07/11/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Locally damaging gusts are possible over parts of the northern Plains late Friday afternoon and evening. Hail will also be possible over North Dakota. ...Synopsis... An upper ridge will expand further across the Great Basin and Four Corners states on Friday, with gradually increasing midlevel westerlies across the northern Rockies. Meanwhile, a weak positive-tile upper trough will lift out of the lower Great Lakes and into southern Quebec, with rising heights over New England. Overnight, the influence of a broad trough across the Canadian prairies may result in strengthening flow and subtle height falls over MT into Saturday morning. At the surface, weak high pressure will extend from the Great Lakes southwestward along the MS Valley and into the northern Gulf of Mexico, and over much of the interior West beneath the upper ridge. A surface trough will deepen over the northern and central High Plains coincident with peak heating, with modest westerly winds over MT into the western Dakotas as boundary-layer mixing occurs. ...Northern High Plains... Strong heating will lead to an uncapped air mass within the surface trough, with scattered convection likely to form after 21Z over far eastern MT/WY into the western Dakotas and NE. Models differ with coverage through the evening, but prominent outflows should allow for a few clusters of storms to persist across the Dakotas and NE, and perhaps into northwest MN late, supported by a weak northwest flow aloft/southerly 850 mb flow regime. Cells that persist into the moister air mass east of the deeply mixed air mass may produce brief hail with the stronger cores. ..Jewell.. 07/11/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Locally damaging gusts are possible over parts of the northern Plains late Friday afternoon and evening. Hail will also be possible over North Dakota. ...Synopsis... An upper ridge will expand further across the Great Basin and Four Corners states on Friday, with gradually increasing midlevel westerlies across the northern Rockies. Meanwhile, a weak positive-tile upper trough will lift out of the lower Great Lakes and into southern Quebec, with rising heights over New England. Overnight, the influence of a broad trough across the Canadian prairies may result in strengthening flow and subtle height falls over MT into Saturday morning. At the surface, weak high pressure will extend from the Great Lakes southwestward along the MS Valley and into the northern Gulf of Mexico, and over much of the interior West beneath the upper ridge. A surface trough will deepen over the northern and central High Plains coincident with peak heating, with modest westerly winds over MT into the western Dakotas as boundary-layer mixing occurs. ...Northern High Plains... Strong heating will lead to an uncapped air mass within the surface trough, with scattered convection likely to form after 21Z over far eastern MT/WY into the western Dakotas and NE. Models differ with coverage through the evening, but prominent outflows should allow for a few clusters of storms to persist across the Dakotas and NE, and perhaps into northwest MN late, supported by a weak northwest flow aloft/southerly 850 mb flow regime. Cells that persist into the moister air mass east of the deeply mixed air mass may produce brief hail with the stronger cores. ..Jewell.. 07/11/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Locally damaging gusts are possible over parts of the northern Plains late Friday afternoon and evening. Hail will also be possible over North Dakota. ...Synopsis... An upper ridge will expand further across the Great Basin and Four Corners states on Friday, with gradually increasing midlevel westerlies across the northern Rockies. Meanwhile, a weak positive-tile upper trough will lift out of the lower Great Lakes and into southern Quebec, with rising heights over New England. Overnight, the influence of a broad trough across the Canadian prairies may result in strengthening flow and subtle height falls over MT into Saturday morning. At the surface, weak high pressure will extend from the Great Lakes southwestward along the MS Valley and into the northern Gulf of Mexico, and over much of the interior West beneath the upper ridge. A surface trough will deepen over the northern and central High Plains coincident with peak heating, with modest westerly winds over MT into the western Dakotas as boundary-layer mixing occurs. ...Northern High Plains... Strong heating will lead to an uncapped air mass within the surface trough, with scattered convection likely to form after 21Z over far eastern MT/WY into the western Dakotas and NE. Models differ with coverage through the evening, but prominent outflows should allow for a few clusters of storms to persist across the Dakotas and NE, and perhaps into northwest MN late, supported by a weak northwest flow aloft/southerly 850 mb flow regime. Cells that persist into the moister air mass east of the deeply mixed air mass may produce brief hail with the stronger cores. ..Jewell.. 07/11/2024 Read more