Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Tue May 21 2024 Valid 212000Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF IOWA...NORTHERN MISSOURI...SOUTHWEST WISCONSIN AND NORTHWEST ILLINOIS... ...SUMMARY... An outbreak of severe thunderstorms, including the potential for strong tornadoes, large hail, and widespread damaging winds, is expected this afternoon through evening, especially across Iowa, Missouri to northern Illinois, southeast Minnesota, and southern Wisconsin. ...20Z Update... A broken line of storms with supercells within continues to get better organized over southwest IA near the surface low, with a possible meso low developing near Red Oak IA as of 1930Z. Low-level shear is very favorable for intense tornadic supercells, with 0-500m SRH over 200 m2/s2 noted on the DMX radar. Pressure falls continue into this region, along with clearing and further destabilization. As such, tornadoes appear imminent across much of IA over the next few hours. Farther south into eastern KS and northern MO, a very unstable air mass has developed here as well, with an impressive 18Z TOP sounding. Steep midlevel lapse rates over 8 C/km with strong deep-layer shear including 50-60 kt speeds around 700 mb will favor downstream supercells producing very large hail with tornado risk. ..Jewell.. 05/21/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Tue May 21 2024/ ...Middle/Lower Missouri Valley and Midwest... As an outbreak precursor, a well-organized cluster of storms across south-central/east-central Iowa mid-late this morning has had a history of producing at least isolated/episodic severe weather since the predawn hours. These storms are focused along/north of an outflow-reinforced warm front that will lift northward through late today into tonight. This will be heavily influenced by a highly dynamic mass response to a northeast-moving mid-level shortwave trough that is readily evident in water vapor imagery over the central High Plains this morning. That said, some short-term uncertainties exist as of 15z observational data, with gusty post-convective northeasterly winds still present across south-central Iowa, which relates to some uncertainty with the northward extent of the higher-magnitude severe risk across Minnesota/Wisconsin later today, although latest 16z data features a recent abatement of those northerly winds. Regardless, intense storm development is anticipated into the afternoon across a broad north/south corridor. A synoptically evident and regional outbreak-favorable setup exists, especially by mid/late May standards, highlighted by a coupled upper jet structure over the Upper Midwest, strengthening deep-layer wind fields, and steady cyclogenesis from the Nebraska/Kansas border vicinity this morning northeastward toward the Minnesota/Wisconsin border tonight. Low-level winds will remain strong diurnally ahead of the primary cyclone, but a noteworthy strengthening of mid-level winds 3-7 km AGL (reference 700mb/500mb) will rapidly occur through the afternoon/evening, which will likely have direct outbreak-relevant influences on initial supercell intensity, QLCS evolution and overall fast east-northeastward storm motions later today. Steepening mid-level lapse rates, noted in upstream 12z observed soundings such as Topeka/Dodge City KS and Springfield MO, will overspread an increasingly moist airmass generally characterized by mid/upper 60s F surface dewpoints, contributing to warm-sector MLCAPE to upwards of 2500-3000 J/kg this afternoon. Scattered to numerous thunderstorms, including scattered fast-moving supercells, are expected to initially form over parts of eastern Nebraska by late morning/midday, and into Iowa and northern/central Missouri this afternoon. This will occur as the cold front impinges on a retreating outflow boundary from the morning storms, and an airmass destabilizing rapidly on both sides of the boundary from a combination of diurnal heating and intense warm advection. Additional, initially semi-discrete, supercellular development is also plausible farther east across Iowa this afternoon in vicinity of modifying outflow/warm front. Sufficient airmass recovery for a surface-based, all-hazards severe threat is expected across most of Iowa and potentially into southern Minnesota as well, spreading into parts of western/northern Illinois and Wisconsin. Several tornadoes, including some strong with EF2+ potential, are expected, along with large, damaging hail and severe downdrafts. This includes the possibility of long-track supercells/tornadoes and swaths of locally intense wind damage. Later tonight, storms should begin to gradually outrun the corridor of favorable surface-based buoyancy in the evening after crossing the Mississippi River, but may remain well-organized in terms of severe-wind threat across Lake Michigan vicinity. ...Ozarks/Oklahoma to south Texas... Isolated to scattered thunderstorms are expected to form from mid afternoon into evening near the front and dryline, offering large to very large hail and locally severe gusts. Hail at least 3 inches in diameter is possible. A tornado or two is not out of the question, especially in northern areas (Ozarks vicinity) under the fringes of the gradient-flow/deep-shear influence from the ejecting shortwave trough, and with high-CAPE storm-scale processes amid favorable deep shear elsewhere. Renewed storm development, potentially severe, could also occur in the predawn hours of Wednesday across Oklahoma near the front. Though capping from an EML will limit convective potential for much of the day, a combination of strong surface heating, rich boundary- layer moisture, and frontal/dryline lift will weaken MLCINH enough by mid/late afternoon to support deep convective development. Upper 60s to low 70s F surface dewpoints should become common beneath a high equilibrium level (deep troposphere) and steep mid-level lapse rates, supporting a corridor of 3000-4000 J/kg MLCAPE (locally higher). Sufficient veering of winds with height, and effective-shear magnitudes in the 45-60 kt range, will support supercell potential. Activity over Texas my weaken within a few hours after sunset as nocturnal boundary-layer cooling re-establishes the strong capping beneath the EML. However, farther north across parts of Arkansas/Missouri, a weaker EML influence may permit activity to persist later and farther east this evening, before weakening. ...Adirondacks region to northern New England... Widely scattered to scattered thunderstorms should develop over portions of the Adirondacks and White Mountains today, and perhaps also move into the area from nearby parts of extreme eastern Ontario and southernmost Quebec. Damaging gusts and isolated severe hail will be possible. A mid/upper-level shortwave trough and embedded MCV -- related to the significantly severe MCS over Kansas two days ago -- is apparent in satellite imagery over Lake Huron. This feature will move eastward toward northern New York/New England and times well with the diurnal-heating cycle there. Activity should form as large-scale DCVA/lift and enhancement of midlevel flow -- preceding the MCV/shortwave trough -- spread atop a destabilized, suitably moist boundary layer, heated to convective temperature over elevated terrain. These processes will erode MLCINH to negligible levels, fostering MLCAPE commonly in the 1000-1500 J/kg range, locally/briefly near 2000 J/kg. Deep shear should remain modest, with effective-shear magnitudes generally 25-35 kt, though enough veering with height in low levels may develop to shape somewhat enlarged hodographs. Multicell and transient supercell modes should predominate, with the severe threat diminishing markedly after sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Tue May 21 2024 Valid 212000Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF IOWA...NORTHERN MISSOURI...SOUTHWEST WISCONSIN AND NORTHWEST ILLINOIS... ...SUMMARY... An outbreak of severe thunderstorms, including the potential for strong tornadoes, large hail, and widespread damaging winds, is expected this afternoon through evening, especially across Iowa, Missouri to northern Illinois, southeast Minnesota, and southern Wisconsin. ...20Z Update... A broken line of storms with supercells within continues to get better organized over southwest IA near the surface low, with a possible meso low developing near Red Oak IA as of 1930Z. Low-level shear is very favorable for intense tornadic supercells, with 0-500m SRH over 200 m2/s2 noted on the DMX radar. Pressure falls continue into this region, along with clearing and further destabilization. As such, tornadoes appear imminent across much of IA over the next few hours. Farther south into eastern KS and northern MO, a very unstable air mass has developed here as well, with an impressive 18Z TOP sounding. Steep midlevel lapse rates over 8 C/km with strong deep-layer shear including 50-60 kt speeds around 700 mb will favor downstream supercells producing very large hail with tornado risk. ..Jewell.. 05/21/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Tue May 21 2024/ ...Middle/Lower Missouri Valley and Midwest... As an outbreak precursor, a well-organized cluster of storms across south-central/east-central Iowa mid-late this morning has had a history of producing at least isolated/episodic severe weather since the predawn hours. These storms are focused along/north of an outflow-reinforced warm front that will lift northward through late today into tonight. This will be heavily influenced by a highly dynamic mass response to a northeast-moving mid-level shortwave trough that is readily evident in water vapor imagery over the central High Plains this morning. That said, some short-term uncertainties exist as of 15z observational data, with gusty post-convective northeasterly winds still present across south-central Iowa, which relates to some uncertainty with the northward extent of the higher-magnitude severe risk across Minnesota/Wisconsin later today, although latest 16z data features a recent abatement of those northerly winds. Regardless, intense storm development is anticipated into the afternoon across a broad north/south corridor. A synoptically evident and regional outbreak-favorable setup exists, especially by mid/late May standards, highlighted by a coupled upper jet structure over the Upper Midwest, strengthening deep-layer wind fields, and steady cyclogenesis from the Nebraska/Kansas border vicinity this morning northeastward toward the Minnesota/Wisconsin border tonight. Low-level winds will remain strong diurnally ahead of the primary cyclone, but a noteworthy strengthening of mid-level winds 3-7 km AGL (reference 700mb/500mb) will rapidly occur through the afternoon/evening, which will likely have direct outbreak-relevant influences on initial supercell intensity, QLCS evolution and overall fast east-northeastward storm motions later today. Steepening mid-level lapse rates, noted in upstream 12z observed soundings such as Topeka/Dodge City KS and Springfield MO, will overspread an increasingly moist airmass generally characterized by mid/upper 60s F surface dewpoints, contributing to warm-sector MLCAPE to upwards of 2500-3000 J/kg this afternoon. Scattered to numerous thunderstorms, including scattered fast-moving supercells, are expected to initially form over parts of eastern Nebraska by late morning/midday, and into Iowa and northern/central Missouri this afternoon. This will occur as the cold front impinges on a retreating outflow boundary from the morning storms, and an airmass destabilizing rapidly on both sides of the boundary from a combination of diurnal heating and intense warm advection. Additional, initially semi-discrete, supercellular development is also plausible farther east across Iowa this afternoon in vicinity of modifying outflow/warm front. Sufficient airmass recovery for a surface-based, all-hazards severe threat is expected across most of Iowa and potentially into southern Minnesota as well, spreading into parts of western/northern Illinois and Wisconsin. Several tornadoes, including some strong with EF2+ potential, are expected, along with large, damaging hail and severe downdrafts. This includes the possibility of long-track supercells/tornadoes and swaths of locally intense wind damage. Later tonight, storms should begin to gradually outrun the corridor of favorable surface-based buoyancy in the evening after crossing the Mississippi River, but may remain well-organized in terms of severe-wind threat across Lake Michigan vicinity. ...Ozarks/Oklahoma to south Texas... Isolated to scattered thunderstorms are expected to form from mid afternoon into evening near the front and dryline, offering large to very large hail and locally severe gusts. Hail at least 3 inches in diameter is possible. A tornado or two is not out of the question, especially in northern areas (Ozarks vicinity) under the fringes of the gradient-flow/deep-shear influence from the ejecting shortwave trough, and with high-CAPE storm-scale processes amid favorable deep shear elsewhere. Renewed storm development, potentially severe, could also occur in the predawn hours of Wednesday across Oklahoma near the front. Though capping from an EML will limit convective potential for much of the day, a combination of strong surface heating, rich boundary- layer moisture, and frontal/dryline lift will weaken MLCINH enough by mid/late afternoon to support deep convective development. Upper 60s to low 70s F surface dewpoints should become common beneath a high equilibrium level (deep troposphere) and steep mid-level lapse rates, supporting a corridor of 3000-4000 J/kg MLCAPE (locally higher). Sufficient veering of winds with height, and effective-shear magnitudes in the 45-60 kt range, will support supercell potential. Activity over Texas my weaken within a few hours after sunset as nocturnal boundary-layer cooling re-establishes the strong capping beneath the EML. However, farther north across parts of Arkansas/Missouri, a weaker EML influence may permit activity to persist later and farther east this evening, before weakening. ...Adirondacks region to northern New England... Widely scattered to scattered thunderstorms should develop over portions of the Adirondacks and White Mountains today, and perhaps also move into the area from nearby parts of extreme eastern Ontario and southernmost Quebec. Damaging gusts and isolated severe hail will be possible. A mid/upper-level shortwave trough and embedded MCV -- related to the significantly severe MCS over Kansas two days ago -- is apparent in satellite imagery over Lake Huron. This feature will move eastward toward northern New York/New England and times well with the diurnal-heating cycle there. Activity should form as large-scale DCVA/lift and enhancement of midlevel flow -- preceding the MCV/shortwave trough -- spread atop a destabilized, suitably moist boundary layer, heated to convective temperature over elevated terrain. These processes will erode MLCINH to negligible levels, fostering MLCAPE commonly in the 1000-1500 J/kg range, locally/briefly near 2000 J/kg. Deep shear should remain modest, with effective-shear magnitudes generally 25-35 kt, though enough veering with height in low levels may develop to shape somewhat enlarged hodographs. Multicell and transient supercell modes should predominate, with the severe threat diminishing markedly after sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Tue May 21 2024 Valid 212000Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF IOWA...NORTHERN MISSOURI...SOUTHWEST WISCONSIN AND NORTHWEST ILLINOIS... ...SUMMARY... An outbreak of severe thunderstorms, including the potential for strong tornadoes, large hail, and widespread damaging winds, is expected this afternoon through evening, especially across Iowa, Missouri to northern Illinois, southeast Minnesota, and southern Wisconsin. ...20Z Update... A broken line of storms with supercells within continues to get better organized over southwest IA near the surface low, with a possible meso low developing near Red Oak IA as of 1930Z. Low-level shear is very favorable for intense tornadic supercells, with 0-500m SRH over 200 m2/s2 noted on the DMX radar. Pressure falls continue into this region, along with clearing and further destabilization. As such, tornadoes appear imminent across much of IA over the next few hours. Farther south into eastern KS and northern MO, a very unstable air mass has developed here as well, with an impressive 18Z TOP sounding. Steep midlevel lapse rates over 8 C/km with strong deep-layer shear including 50-60 kt speeds around 700 mb will favor downstream supercells producing very large hail with tornado risk. ..Jewell.. 05/21/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Tue May 21 2024/ ...Middle/Lower Missouri Valley and Midwest... As an outbreak precursor, a well-organized cluster of storms across south-central/east-central Iowa mid-late this morning has had a history of producing at least isolated/episodic severe weather since the predawn hours. These storms are focused along/north of an outflow-reinforced warm front that will lift northward through late today into tonight. This will be heavily influenced by a highly dynamic mass response to a northeast-moving mid-level shortwave trough that is readily evident in water vapor imagery over the central High Plains this morning. That said, some short-term uncertainties exist as of 15z observational data, with gusty post-convective northeasterly winds still present across south-central Iowa, which relates to some uncertainty with the northward extent of the higher-magnitude severe risk across Minnesota/Wisconsin later today, although latest 16z data features a recent abatement of those northerly winds. Regardless, intense storm development is anticipated into the afternoon across a broad north/south corridor. A synoptically evident and regional outbreak-favorable setup exists, especially by mid/late May standards, highlighted by a coupled upper jet structure over the Upper Midwest, strengthening deep-layer wind fields, and steady cyclogenesis from the Nebraska/Kansas border vicinity this morning northeastward toward the Minnesota/Wisconsin border tonight. Low-level winds will remain strong diurnally ahead of the primary cyclone, but a noteworthy strengthening of mid-level winds 3-7 km AGL (reference 700mb/500mb) will rapidly occur through the afternoon/evening, which will likely have direct outbreak-relevant influences on initial supercell intensity, QLCS evolution and overall fast east-northeastward storm motions later today. Steepening mid-level lapse rates, noted in upstream 12z observed soundings such as Topeka/Dodge City KS and Springfield MO, will overspread an increasingly moist airmass generally characterized by mid/upper 60s F surface dewpoints, contributing to warm-sector MLCAPE to upwards of 2500-3000 J/kg this afternoon. Scattered to numerous thunderstorms, including scattered fast-moving supercells, are expected to initially form over parts of eastern Nebraska by late morning/midday, and into Iowa and northern/central Missouri this afternoon. This will occur as the cold front impinges on a retreating outflow boundary from the morning storms, and an airmass destabilizing rapidly on both sides of the boundary from a combination of diurnal heating and intense warm advection. Additional, initially semi-discrete, supercellular development is also plausible farther east across Iowa this afternoon in vicinity of modifying outflow/warm front. Sufficient airmass recovery for a surface-based, all-hazards severe threat is expected across most of Iowa and potentially into southern Minnesota as well, spreading into parts of western/northern Illinois and Wisconsin. Several tornadoes, including some strong with EF2+ potential, are expected, along with large, damaging hail and severe downdrafts. This includes the possibility of long-track supercells/tornadoes and swaths of locally intense wind damage. Later tonight, storms should begin to gradually outrun the corridor of favorable surface-based buoyancy in the evening after crossing the Mississippi River, but may remain well-organized in terms of severe-wind threat across Lake Michigan vicinity. ...Ozarks/Oklahoma to south Texas... Isolated to scattered thunderstorms are expected to form from mid afternoon into evening near the front and dryline, offering large to very large hail and locally severe gusts. Hail at least 3 inches in diameter is possible. A tornado or two is not out of the question, especially in northern areas (Ozarks vicinity) under the fringes of the gradient-flow/deep-shear influence from the ejecting shortwave trough, and with high-CAPE storm-scale processes amid favorable deep shear elsewhere. Renewed storm development, potentially severe, could also occur in the predawn hours of Wednesday across Oklahoma near the front. Though capping from an EML will limit convective potential for much of the day, a combination of strong surface heating, rich boundary- layer moisture, and frontal/dryline lift will weaken MLCINH enough by mid/late afternoon to support deep convective development. Upper 60s to low 70s F surface dewpoints should become common beneath a high equilibrium level (deep troposphere) and steep mid-level lapse rates, supporting a corridor of 3000-4000 J/kg MLCAPE (locally higher). Sufficient veering of winds with height, and effective-shear magnitudes in the 45-60 kt range, will support supercell potential. Activity over Texas my weaken within a few hours after sunset as nocturnal boundary-layer cooling re-establishes the strong capping beneath the EML. However, farther north across parts of Arkansas/Missouri, a weaker EML influence may permit activity to persist later and farther east this evening, before weakening. ...Adirondacks region to northern New England... Widely scattered to scattered thunderstorms should develop over portions of the Adirondacks and White Mountains today, and perhaps also move into the area from nearby parts of extreme eastern Ontario and southernmost Quebec. Damaging gusts and isolated severe hail will be possible. A mid/upper-level shortwave trough and embedded MCV -- related to the significantly severe MCS over Kansas two days ago -- is apparent in satellite imagery over Lake Huron. This feature will move eastward toward northern New York/New England and times well with the diurnal-heating cycle there. Activity should form as large-scale DCVA/lift and enhancement of midlevel flow -- preceding the MCV/shortwave trough -- spread atop a destabilized, suitably moist boundary layer, heated to convective temperature over elevated terrain. These processes will erode MLCINH to negligible levels, fostering MLCAPE commonly in the 1000-1500 J/kg range, locally/briefly near 2000 J/kg. Deep shear should remain modest, with effective-shear magnitudes generally 25-35 kt, though enough veering with height in low levels may develop to shape somewhat enlarged hodographs. Multicell and transient supercell modes should predominate, with the severe threat diminishing markedly after sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Tue May 21 2024 Valid 212000Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF IOWA...NORTHERN MISSOURI...SOUTHWEST WISCONSIN AND NORTHWEST ILLINOIS... ...SUMMARY... An outbreak of severe thunderstorms, including the potential for strong tornadoes, large hail, and widespread damaging winds, is expected this afternoon through evening, especially across Iowa, Missouri to northern Illinois, southeast Minnesota, and southern Wisconsin. ...20Z Update... A broken line of storms with supercells within continues to get better organized over southwest IA near the surface low, with a possible meso low developing near Red Oak IA as of 1930Z. Low-level shear is very favorable for intense tornadic supercells, with 0-500m SRH over 200 m2/s2 noted on the DMX radar. Pressure falls continue into this region, along with clearing and further destabilization. As such, tornadoes appear imminent across much of IA over the next few hours. Farther south into eastern KS and northern MO, a very unstable air mass has developed here as well, with an impressive 18Z TOP sounding. Steep midlevel lapse rates over 8 C/km with strong deep-layer shear including 50-60 kt speeds around 700 mb will favor downstream supercells producing very large hail with tornado risk. ..Jewell.. 05/21/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Tue May 21 2024/ ...Middle/Lower Missouri Valley and Midwest... As an outbreak precursor, a well-organized cluster of storms across south-central/east-central Iowa mid-late this morning has had a history of producing at least isolated/episodic severe weather since the predawn hours. These storms are focused along/north of an outflow-reinforced warm front that will lift northward through late today into tonight. This will be heavily influenced by a highly dynamic mass response to a northeast-moving mid-level shortwave trough that is readily evident in water vapor imagery over the central High Plains this morning. That said, some short-term uncertainties exist as of 15z observational data, with gusty post-convective northeasterly winds still present across south-central Iowa, which relates to some uncertainty with the northward extent of the higher-magnitude severe risk across Minnesota/Wisconsin later today, although latest 16z data features a recent abatement of those northerly winds. Regardless, intense storm development is anticipated into the afternoon across a broad north/south corridor. A synoptically evident and regional outbreak-favorable setup exists, especially by mid/late May standards, highlighted by a coupled upper jet structure over the Upper Midwest, strengthening deep-layer wind fields, and steady cyclogenesis from the Nebraska/Kansas border vicinity this morning northeastward toward the Minnesota/Wisconsin border tonight. Low-level winds will remain strong diurnally ahead of the primary cyclone, but a noteworthy strengthening of mid-level winds 3-7 km AGL (reference 700mb/500mb) will rapidly occur through the afternoon/evening, which will likely have direct outbreak-relevant influences on initial supercell intensity, QLCS evolution and overall fast east-northeastward storm motions later today. Steepening mid-level lapse rates, noted in upstream 12z observed soundings such as Topeka/Dodge City KS and Springfield MO, will overspread an increasingly moist airmass generally characterized by mid/upper 60s F surface dewpoints, contributing to warm-sector MLCAPE to upwards of 2500-3000 J/kg this afternoon. Scattered to numerous thunderstorms, including scattered fast-moving supercells, are expected to initially form over parts of eastern Nebraska by late morning/midday, and into Iowa and northern/central Missouri this afternoon. This will occur as the cold front impinges on a retreating outflow boundary from the morning storms, and an airmass destabilizing rapidly on both sides of the boundary from a combination of diurnal heating and intense warm advection. Additional, initially semi-discrete, supercellular development is also plausible farther east across Iowa this afternoon in vicinity of modifying outflow/warm front. Sufficient airmass recovery for a surface-based, all-hazards severe threat is expected across most of Iowa and potentially into southern Minnesota as well, spreading into parts of western/northern Illinois and Wisconsin. Several tornadoes, including some strong with EF2+ potential, are expected, along with large, damaging hail and severe downdrafts. This includes the possibility of long-track supercells/tornadoes and swaths of locally intense wind damage. Later tonight, storms should begin to gradually outrun the corridor of favorable surface-based buoyancy in the evening after crossing the Mississippi River, but may remain well-organized in terms of severe-wind threat across Lake Michigan vicinity. ...Ozarks/Oklahoma to south Texas... Isolated to scattered thunderstorms are expected to form from mid afternoon into evening near the front and dryline, offering large to very large hail and locally severe gusts. Hail at least 3 inches in diameter is possible. A tornado or two is not out of the question, especially in northern areas (Ozarks vicinity) under the fringes of the gradient-flow/deep-shear influence from the ejecting shortwave trough, and with high-CAPE storm-scale processes amid favorable deep shear elsewhere. Renewed storm development, potentially severe, could also occur in the predawn hours of Wednesday across Oklahoma near the front. Though capping from an EML will limit convective potential for much of the day, a combination of strong surface heating, rich boundary- layer moisture, and frontal/dryline lift will weaken MLCINH enough by mid/late afternoon to support deep convective development. Upper 60s to low 70s F surface dewpoints should become common beneath a high equilibrium level (deep troposphere) and steep mid-level lapse rates, supporting a corridor of 3000-4000 J/kg MLCAPE (locally higher). Sufficient veering of winds with height, and effective-shear magnitudes in the 45-60 kt range, will support supercell potential. Activity over Texas my weaken within a few hours after sunset as nocturnal boundary-layer cooling re-establishes the strong capping beneath the EML. However, farther north across parts of Arkansas/Missouri, a weaker EML influence may permit activity to persist later and farther east this evening, before weakening. ...Adirondacks region to northern New England... Widely scattered to scattered thunderstorms should develop over portions of the Adirondacks and White Mountains today, and perhaps also move into the area from nearby parts of extreme eastern Ontario and southernmost Quebec. Damaging gusts and isolated severe hail will be possible. A mid/upper-level shortwave trough and embedded MCV -- related to the significantly severe MCS over Kansas two days ago -- is apparent in satellite imagery over Lake Huron. This feature will move eastward toward northern New York/New England and times well with the diurnal-heating cycle there. Activity should form as large-scale DCVA/lift and enhancement of midlevel flow -- preceding the MCV/shortwave trough -- spread atop a destabilized, suitably moist boundary layer, heated to convective temperature over elevated terrain. These processes will erode MLCINH to negligible levels, fostering MLCAPE commonly in the 1000-1500 J/kg range, locally/briefly near 2000 J/kg. Deep shear should remain modest, with effective-shear magnitudes generally 25-35 kt, though enough veering with height in low levels may develop to shape somewhat enlarged hodographs. Multicell and transient supercell modes should predominate, with the severe threat diminishing markedly after sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Tue May 21 2024 Valid 212000Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MUCH OF IOWA...NORTHERN MISSOURI...SOUTHWEST WISCONSIN AND NORTHWEST ILLINOIS... ...SUMMARY... An outbreak of severe thunderstorms, including the potential for strong tornadoes, large hail, and widespread damaging winds, is expected this afternoon through evening, especially across Iowa, Missouri to northern Illinois, southeast Minnesota, and southern Wisconsin. ...20Z Update... A broken line of storms with supercells within continues to get better organized over southwest IA near the surface low, with a possible meso low developing near Red Oak IA as of 1930Z. Low-level shear is very favorable for intense tornadic supercells, with 0-500m SRH over 200 m2/s2 noted on the DMX radar. Pressure falls continue into this region, along with clearing and further destabilization. As such, tornadoes appear imminent across much of IA over the next few hours. Farther south into eastern KS and northern MO, a very unstable air mass has developed here as well, with an impressive 18Z TOP sounding. Steep midlevel lapse rates over 8 C/km with strong deep-layer shear including 50-60 kt speeds around 700 mb will favor downstream supercells producing very large hail with tornado risk. ..Jewell.. 05/21/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Tue May 21 2024/ ...Middle/Lower Missouri Valley and Midwest... As an outbreak precursor, a well-organized cluster of storms across south-central/east-central Iowa mid-late this morning has had a history of producing at least isolated/episodic severe weather since the predawn hours. These storms are focused along/north of an outflow-reinforced warm front that will lift northward through late today into tonight. This will be heavily influenced by a highly dynamic mass response to a northeast-moving mid-level shortwave trough that is readily evident in water vapor imagery over the central High Plains this morning. That said, some short-term uncertainties exist as of 15z observational data, with gusty post-convective northeasterly winds still present across south-central Iowa, which relates to some uncertainty with the northward extent of the higher-magnitude severe risk across Minnesota/Wisconsin later today, although latest 16z data features a recent abatement of those northerly winds. Regardless, intense storm development is anticipated into the afternoon across a broad north/south corridor. A synoptically evident and regional outbreak-favorable setup exists, especially by mid/late May standards, highlighted by a coupled upper jet structure over the Upper Midwest, strengthening deep-layer wind fields, and steady cyclogenesis from the Nebraska/Kansas border vicinity this morning northeastward toward the Minnesota/Wisconsin border tonight. Low-level winds will remain strong diurnally ahead of the primary cyclone, but a noteworthy strengthening of mid-level winds 3-7 km AGL (reference 700mb/500mb) will rapidly occur through the afternoon/evening, which will likely have direct outbreak-relevant influences on initial supercell intensity, QLCS evolution and overall fast east-northeastward storm motions later today. Steepening mid-level lapse rates, noted in upstream 12z observed soundings such as Topeka/Dodge City KS and Springfield MO, will overspread an increasingly moist airmass generally characterized by mid/upper 60s F surface dewpoints, contributing to warm-sector MLCAPE to upwards of 2500-3000 J/kg this afternoon. Scattered to numerous thunderstorms, including scattered fast-moving supercells, are expected to initially form over parts of eastern Nebraska by late morning/midday, and into Iowa and northern/central Missouri this afternoon. This will occur as the cold front impinges on a retreating outflow boundary from the morning storms, and an airmass destabilizing rapidly on both sides of the boundary from a combination of diurnal heating and intense warm advection. Additional, initially semi-discrete, supercellular development is also plausible farther east across Iowa this afternoon in vicinity of modifying outflow/warm front. Sufficient airmass recovery for a surface-based, all-hazards severe threat is expected across most of Iowa and potentially into southern Minnesota as well, spreading into parts of western/northern Illinois and Wisconsin. Several tornadoes, including some strong with EF2+ potential, are expected, along with large, damaging hail and severe downdrafts. This includes the possibility of long-track supercells/tornadoes and swaths of locally intense wind damage. Later tonight, storms should begin to gradually outrun the corridor of favorable surface-based buoyancy in the evening after crossing the Mississippi River, but may remain well-organized in terms of severe-wind threat across Lake Michigan vicinity. ...Ozarks/Oklahoma to south Texas... Isolated to scattered thunderstorms are expected to form from mid afternoon into evening near the front and dryline, offering large to very large hail and locally severe gusts. Hail at least 3 inches in diameter is possible. A tornado or two is not out of the question, especially in northern areas (Ozarks vicinity) under the fringes of the gradient-flow/deep-shear influence from the ejecting shortwave trough, and with high-CAPE storm-scale processes amid favorable deep shear elsewhere. Renewed storm development, potentially severe, could also occur in the predawn hours of Wednesday across Oklahoma near the front. Though capping from an EML will limit convective potential for much of the day, a combination of strong surface heating, rich boundary- layer moisture, and frontal/dryline lift will weaken MLCINH enough by mid/late afternoon to support deep convective development. Upper 60s to low 70s F surface dewpoints should become common beneath a high equilibrium level (deep troposphere) and steep mid-level lapse rates, supporting a corridor of 3000-4000 J/kg MLCAPE (locally higher). Sufficient veering of winds with height, and effective-shear magnitudes in the 45-60 kt range, will support supercell potential. Activity over Texas my weaken within a few hours after sunset as nocturnal boundary-layer cooling re-establishes the strong capping beneath the EML. However, farther north across parts of Arkansas/Missouri, a weaker EML influence may permit activity to persist later and farther east this evening, before weakening. ...Adirondacks region to northern New England... Widely scattered to scattered thunderstorms should develop over portions of the Adirondacks and White Mountains today, and perhaps also move into the area from nearby parts of extreme eastern Ontario and southernmost Quebec. Damaging gusts and isolated severe hail will be possible. A mid/upper-level shortwave trough and embedded MCV -- related to the significantly severe MCS over Kansas two days ago -- is apparent in satellite imagery over Lake Huron. This feature will move eastward toward northern New York/New England and times well with the diurnal-heating cycle there. Activity should form as large-scale DCVA/lift and enhancement of midlevel flow -- preceding the MCV/shortwave trough -- spread atop a destabilized, suitably moist boundary layer, heated to convective temperature over elevated terrain. These processes will erode MLCINH to negligible levels, fostering MLCAPE commonly in the 1000-1500 J/kg range, locally/briefly near 2000 J/kg. Deep shear should remain modest, with effective-shear magnitudes generally 25-35 kt, though enough veering with height in low levels may develop to shape somewhat enlarged hodographs. Multicell and transient supercell modes should predominate, with the severe threat diminishing markedly after sunset. Read more

MD 0873 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHERN WI
Mesoscale Discussion 0873 NWS Storm Prediction Center Norman OK 0115 PM CDT Tue May 21 2024 Areas affected...Southern WI Concerning...Severe potential...Watch possible Valid 211815Z - 211945Z Probability of Watch Issuance...40 percent SUMMARY...Isolated hail and/or damaging gusts are possible. Limited severe coverage will likely preclude the need for a watch in the short term. A greater severe risk is anticipated later this evening as the line of storms moving out of IA moves into the region. DISCUSSION...Surface observations reveal a warm front extends east-to-west across far southern WI, with temperatures in the upper 70s/low 80s south of the boundary and in the mid 60s to low 70s north of it. Dewpoints south of the boundary are in the upper 60s while remaining in the low to mid 60s north of it. Ongoing convective cluster moving across southwest WI has recently shown a strengthening trend, likely a result of increased warm-air advection across the warm front. Given the persistence of the strong low-level flow and increasing low-level moisture, this cluster is forecast to continue quickly northeastward, with some potential for isolated hail and/or damaging gusts as it does. A more isolated storm has developed east of this cluster in Dane County. This storm is very close to the warm front but still looks to be slightly elevated, although the more recent slow, more eastward storm motion may be indicating a trend toward more surface-based character. Recent MKX VAD sampled enough low-level curvature to support some tornado potential if the storm can become surface-based. Otherwise, the primary risk with this storm is large hail. Limited severe coverage will likely preclude the need for a watch, but convective trends are being monitored closely. A greater severe risk is anticipated later this evening as the line of storms moving out of IA moves into the region. ..Mosier/Guyer.. 05/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...MKX...ARX... LAT...LON 42718888 42989012 44149022 44618904 44148788 43108817 42718888 Read more

WW 0278 Status Updates
STATUS FOR WATCH 0278 HAS NOT BEEN ISSUED YET Read more

WW 0278 Status Updates
STATUS FOR WATCH 0278 HAS NOT BEEN ISSUED YET Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM FNB TO 25 SW SLB TO 10 SSE FSD. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-137-141-143-145-155-165-167-212040- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON MONTGOMERY O'BRIEN OSCEOLA PAGE POTTAWATTAMIE SHELBY SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM FNB TO 25 SW SLB TO 10 SSE FSD. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-137-141-143-145-155-165-167-212040- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON MONTGOMERY O'BRIEN OSCEOLA PAGE POTTAWATTAMIE SHELBY SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM FNB TO 25 SW SLB TO 10 SSE FSD. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-137-141-143-145-155-165-167-212040- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON MONTGOMERY O'BRIEN OSCEOLA PAGE POTTAWATTAMIE SHELBY SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM FNB TO 25 SW SLB TO 10 SSE FSD. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-137-141-143-145-155-165-167-212040- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON MONTGOMERY O'BRIEN OSCEOLA PAGE POTTAWATTAMIE SHELBY SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM FNB TO 25 SW SLB TO 10 SSE FSD. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-137-141-143-145-155-165-167-212040- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON MONTGOMERY O'BRIEN OSCEOLA PAGE POTTAWATTAMIE SHELBY SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM FNB TO 25 SW SLB TO 10 SSE FSD. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-137-141-143-145-155-165-167-212040- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON MONTGOMERY O'BRIEN OSCEOLA PAGE POTTAWATTAMIE SHELBY SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 276 TORNADO IA MO NE SD 211610Z - 212200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 276 NWS Storm Prediction Center Norman OK 1110 AM CDT Tue May 21 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Western Iowa Northwest Missouri Eastern Nebraska Southeast South Dakota * Effective this Tuesday morning and afternoon from 1110 AM until 500 PM CDT. * Primary threats include... A few tornadoes and a couple intense tornadoes possible Scattered large hail likely with isolated very large hail events to 3 inches in diameter possible Scattered damaging wind gusts to 70 mph likely SUMMARY...The atmosphere is expected to rapidly become favorable for severe storm development, including the potential for tornadoes, through early/mid-afternoon. The tornado watch area is approximately along and 60 statute miles east and west of a line from 55 miles west northwest of Spencer IA to 25 miles west of Falls City NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 275... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 22035. ...Guyer Read more

MD 0871 CONCERNING SEVERE POTENTIAL...TORNADO WATCH LIKELY FOR CENTRAL/EASTERN IA...SOUTH-CENTRAL/SOUTHEAST MN...FAR SOUTHWEST WI...FAR NORTHWEST IL
Mesoscale Discussion 0871 NWS Storm Prediction Center Norman OK 1232 PM CDT Tue May 21 2024 Areas affected...Central/Eastern IA...South-Central/Southeast MN...Far Southwest WI...Far Northwest IL Concerning...Severe potential...Tornado Watch likely Valid 211732Z - 211930Z Probability of Watch Issuance...95 percent SUMMARY...Environmental conditions are expected to becoming increasingly supportive of a significant severe thunderstorms capable of all severe hazards, including very large hail up to 3" inches, strong gusts to 75 mph, and long-track tornadoes. A Tornado Watch will likely be needed around 18-19Z, and a PDS designation is being considered. DISCUSSION...Recent surface analysis places a low over southeast NE, with an outflow-modified warm front extending east-northeast across southern IA through the IA/IL/WI border vicinity. This warm front is expected to rapidly move northward in response to strong mass response ahead of the approaching shortwave trough, with upper 60s dewpoints likely in place across much of IA and mid 60s possibly reaching southern MN. As this occurs, steep mid-level lapse rates will also advect into the region, resulting strong buoyancy (i.e. MLCAPE 2500-3000 J/kg) by the early afternoon. Wind fields are expected to strengthen during this time frame as well, result in in very long hodographs and fast storm motion. Bunkers right motion for much of the region will be around 50 kt by the early afternoon. The result will be an environment very supportive of significant severe thunderstorms. An initially discrete mode is anticipated, with the fast storm motions allowing storms to stay ahead of the cold front impinging on the region from the west. Any discrete storms will likely obtain supercellular characteristics quickly, with very large hail up to 3" inches, strong gusts to 75 mph, and tornadoes all possible. This includes the possibility of long-lived, long-track supercells capable of strong tornadoes and intense wind damage. Storm interactions with the warm front, as well as the presence of the deepening surface low, suggest the significant severe potential will likely extend into south-central/southeast MI and southwest MN, despite being displaced just north of the better mid-level flow and low-level moisture. Some upscale growth is anticipated as storms continue eastward, with the resulting convective line capable of significant wind gusts around 75 mph. Given the continued strengthening of the low-level flow anticipated, some embedded QLCS circulations are likely as well. All of these factors suggests a significant severe weather event is probable, and a Tornado Watch will likely be needed around 18-19Z. A PDS designation is being considered for this watch. ..Mosier/Guyer.. 05/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MKX...DVN...ARX...MPX...DMX...EAX...FSD...OAX... LAT...LON 40969085 40619167 40579233 40589388 40649446 40959493 41799502 43169492 44119422 44189139 43209038 41869013 40969085 Read more

MD 0872 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTH TEXAS INTO SOUTHEAST OKLAHOMA
Mesoscale Discussion 0872 NWS Storm Prediction Center Norman OK 1245 PM CDT Tue May 21 2024 Areas affected...Portions of North Texas into southeast Oklahoma Concerning...Severe potential...Watch unlikely Valid 211745Z - 211915Z Probability of Watch Issuance...20 percent SUMMARY...Elevated storms will have some potential to intensify and produce large hail. Uncertainty in these storms being maintained make watch issuance fairly uncertain. Convective trends will be monitored. DISCUSSION...Elevated storms have developed in North Texas. These storms are not captured by any CAMs. Based on the 12Z OUN/DFW soundings, this activity is most likely rooted somewhere between 800-700 mb--driven by very modest influence from the approaching shortwave trough in the southern High Plains as well as weak 850 mb warm advection. The primary uncertainty is how long this activity will last as the low-level jet is expected to weaken into the afternoon. Should these storms intensify, the very steep lapse rates, strong elevated buoyancy, and effective shear of 55-60 kts will support supercell structures capable of large hail (1-2 inches). Boundary-layer destabilization still appears it will another few hours. With this activity moving quickly northeast, it is quite uncertain if storms could root near/at the surface. ..Wendt/Guyer.. 05/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SHV...TSA...FWD...OUN... LAT...LON 32759772 32819785 32999788 33549772 34069762 34479735 34679706 35079581 35079495 34749481 34069527 33439652 32759748 32759772 Read more

MD 0870 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR ADIRONDACKS INTO PARTS OF NORTHERN NEW ENGLAND
Mesoscale Discussion 0870 NWS Storm Prediction Center Norman OK 1208 PM CDT Tue May 21 2024 Areas affected...Adirondacks into Parts of northern New England Concerning...Severe potential...Watch unlikely Valid 211708Z - 211915Z Probability of Watch Issuance...20 percent SUMMARY...Damaging winds and isolated marginally severe hail may occur this afternoon. Clustering of storms may lead to locally greater wind damage potential. A watch is not expected. DISCUSSION...Morning observed soundings from CAR/GYX showed mid-level lapse rates approaching 7 C/km. With an approaching MCV/shortwave from Great Lakes region convection last evening, some increase in storm coverage is expected to occur this afternoon. Effective shear will only be modest (25-30 kts), but a few more organized storms/clusters appear possible. Damaging winds and marginally severe hail will be the primary risks with this activity. Should storms cluster, locally greater potential for damaging winds would exist especially where low-level lapse rates have steepened. ..Wendt/Guyer.. 05/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BOX...BTV...ALY...BGM...BUF... LAT...LON 43917528 44287511 44797443 45157281 45177194 45757081 46597008 46466919 45706922 44267036 43497080 42917205 42407362 42457370 42437458 42697513 43057539 43917528 Read more

WW 0276 Status Updates
STATUS REPORT ON WW 276 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 W FNB TO 25 NNW TQE TO 5 N YKN. ..HART..05/21/24 ATTN...WFO...FSD...OAX...EAX... STATUS REPORT FOR WT 276 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-071-085-093-119-129-133-137-141-143-145-149- 155-165-167-193-211940- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON FREMONT HARRISON IDA LYON MILLS MONONA MONTGOMERY O'BRIEN OSCEOLA PAGE PLYMOUTH POTTAWATTAMIE SHELBY SIOUX WOODBURY MOC005-211940- MO . MISSOURI COUNTIES INCLUDED ARE ATCHISON NEC025-043-055-127-147-153-177-211940- Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0115 PM CDT Tue May 21 2024 Valid 221200Z - 231200Z The previous forecast (see below) remains on track, and only minor adjustments were made with this update. ..Weinman.. 05/21/2024 .PREV DISCUSSION... /ISSUED 0222 AM CDT Tue May 21 2024/ ...Synopsis... A broad upper trough will encompass the central and western CONUS Wednesday. The strongest mid-level flow is expected to extend from the Southern Plains through the Upper Midwest and Great Lakes regions, and across the Pacific Northwest near the base of mid-level cyclone. A deeply mixed air mass will remain present over the Desert Southwest, while a cold front dives southward into portions of the Southern and High Plains. Further west across portions of NM and AZ, sustained westerly surface winds near 15 mph are expected where increasingly receptive fuels and single-digit RH will be present. Localized wind speeds may briefly approach or exceed 20 mph across southern NM Wednesday afternoon, but the probability of this occurring for more than 3 hours across a broad region is too low to introduce a Critical area at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more