Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CDT Wed Mar 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY THROUGH FRIDAY NIGHT NEAR THE NORTHEASTERN GULF COAST AND ACROSS PARTS OF SOUTHERN FLORIDA AND THE FLORIDA KEYS... ...SUMMARY... One or two clusters of strong thunderstorms may impact portions of southern Florida and the Keys Friday into Friday evening, accompanied by at least some risk for damaging winds and a tornado or two. More isolated strong to severe thunderstorm development may impact northeastern Gulf coastal areas into Friday night. ...Synopsis... It appears that blocking centered over the northeastern Pacific will generally persist through this period, but guidance continues to indicate at least some weakening, as a more progressive regime gradually develops across the central toward eastern mid-latitude Pacific. There remains variability within and among the model output concerning the extent of this weakening, and the eastward acceleration of an associated mid-level low toward the northern U.S. Pacific coast. This may have at least some impact on downstream synoptic developments within the broadly confluent split flow across North America. In the higher-latitude branch, one significant occluding cyclone is forecast to continue migrating northeast and east of the Canadian Maritimes. An elongating upstream cyclonic circulation may become quasi-stationary near the southwestern shores of Hudson Bay, with a series of lower amplitude perturbations digging to its west through south, across the international border. In lower levels, the leading edge of another significant cold intrusion is forecast to nose as far south as the Texas Panhandle and Red River vicinity, and as far east as the lower Great Lakes and Ohio Valley by 12Z Saturday. In lower latitudes, mid-level troughing is still forecast to progress slowly across and east of the lower Mississippi Valley and north central Gulf of Mexico. One smaller-scale perturbation may emerge from its base and become increasingly sheared across and to the east of the southern Appalachians, while another digs across the northwestern through north central Gulf of Mexico by late Friday night. Models continue to differ concerning these features, and the larger-scale troughing will be preceded by a subtropical perturbation which is likely to be in the process of progressing into and across the Florida peninsula by early Friday. It does appear that a broad area of deepening surface low pressure will develop northeastward across much of the eastern Gulf and South Atlantic Coast states. However, sizable spread is evident within the model output concerning sub-synoptic through convective-scale developments across the Southeast, Gulf of Mexico and offshore Atlantic. ...Southeast... Even with the aforementioned uncertainties, it does appear that an initially dry/potentially cool low-level environment, across much of the Florida peninsula through eastern Gulf Coast region, will tend to maintain generally stable conditions inland of coastal areas as initial convection supported by warm advection overspreads it. However, based on various model output, including some convection-allowing guidance, there appears potential for at least one initially organized convective cluster to overspread the Florida Keys/southern Florida peninsula vicinity, coincident with a warm front off the southeastern Gulf of Mexico early Friday. Given sufficient boundary-layer destabilization in the presence of strong deep-layer shear, this may be accompanied by a risk for damaging wind gusts and perhaps a tornado or two. Thereafter, it appears that widespread convective development, perhaps including organizing clusters, may continue along trailing convective outflow gradually advancing across and east-southeast of the southeastern Gulf of Mexico through early Saturday. Convective potential to the north of this outflow remains unclear. However, models do indicate that substantive boundary-layer destabilization is possible across much of the northeastern Gulf of Mexico by late Friday night, ahead of a weak southeastward advancing cold front. Still ahead of the mid-level troughing axis, this environment may support additional scattered strong thunderstorm development which might spread inland across coastal areas before weakening. ..Kerr.. 03/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CDT Wed Mar 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY THROUGH FRIDAY NIGHT NEAR THE NORTHEASTERN GULF COAST AND ACROSS PARTS OF SOUTHERN FLORIDA AND THE FLORIDA KEYS... ...SUMMARY... One or two clusters of strong thunderstorms may impact portions of southern Florida and the Keys Friday into Friday evening, accompanied by at least some risk for damaging winds and a tornado or two. More isolated strong to severe thunderstorm development may impact northeastern Gulf coastal areas into Friday night. ...Synopsis... It appears that blocking centered over the northeastern Pacific will generally persist through this period, but guidance continues to indicate at least some weakening, as a more progressive regime gradually develops across the central toward eastern mid-latitude Pacific. There remains variability within and among the model output concerning the extent of this weakening, and the eastward acceleration of an associated mid-level low toward the northern U.S. Pacific coast. This may have at least some impact on downstream synoptic developments within the broadly confluent split flow across North America. In the higher-latitude branch, one significant occluding cyclone is forecast to continue migrating northeast and east of the Canadian Maritimes. An elongating upstream cyclonic circulation may become quasi-stationary near the southwestern shores of Hudson Bay, with a series of lower amplitude perturbations digging to its west through south, across the international border. In lower levels, the leading edge of another significant cold intrusion is forecast to nose as far south as the Texas Panhandle and Red River vicinity, and as far east as the lower Great Lakes and Ohio Valley by 12Z Saturday. In lower latitudes, mid-level troughing is still forecast to progress slowly across and east of the lower Mississippi Valley and north central Gulf of Mexico. One smaller-scale perturbation may emerge from its base and become increasingly sheared across and to the east of the southern Appalachians, while another digs across the northwestern through north central Gulf of Mexico by late Friday night. Models continue to differ concerning these features, and the larger-scale troughing will be preceded by a subtropical perturbation which is likely to be in the process of progressing into and across the Florida peninsula by early Friday. It does appear that a broad area of deepening surface low pressure will develop northeastward across much of the eastern Gulf and South Atlantic Coast states. However, sizable spread is evident within the model output concerning sub-synoptic through convective-scale developments across the Southeast, Gulf of Mexico and offshore Atlantic. ...Southeast... Even with the aforementioned uncertainties, it does appear that an initially dry/potentially cool low-level environment, across much of the Florida peninsula through eastern Gulf Coast region, will tend to maintain generally stable conditions inland of coastal areas as initial convection supported by warm advection overspreads it. However, based on various model output, including some convection-allowing guidance, there appears potential for at least one initially organized convective cluster to overspread the Florida Keys/southern Florida peninsula vicinity, coincident with a warm front off the southeastern Gulf of Mexico early Friday. Given sufficient boundary-layer destabilization in the presence of strong deep-layer shear, this may be accompanied by a risk for damaging wind gusts and perhaps a tornado or two. Thereafter, it appears that widespread convective development, perhaps including organizing clusters, may continue along trailing convective outflow gradually advancing across and east-southeast of the southeastern Gulf of Mexico through early Saturday. Convective potential to the north of this outflow remains unclear. However, models do indicate that substantive boundary-layer destabilization is possible across much of the northeastern Gulf of Mexico by late Friday night, ahead of a weak southeastward advancing cold front. Still ahead of the mid-level troughing axis, this environment may support additional scattered strong thunderstorm development which might spread inland across coastal areas before weakening. ..Kerr.. 03/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CDT Wed Mar 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY THROUGH FRIDAY NIGHT NEAR THE NORTHEASTERN GULF COAST AND ACROSS PARTS OF SOUTHERN FLORIDA AND THE FLORIDA KEYS... ...SUMMARY... One or two clusters of strong thunderstorms may impact portions of southern Florida and the Keys Friday into Friday evening, accompanied by at least some risk for damaging winds and a tornado or two. More isolated strong to severe thunderstorm development may impact northeastern Gulf coastal areas into Friday night. ...Synopsis... It appears that blocking centered over the northeastern Pacific will generally persist through this period, but guidance continues to indicate at least some weakening, as a more progressive regime gradually develops across the central toward eastern mid-latitude Pacific. There remains variability within and among the model output concerning the extent of this weakening, and the eastward acceleration of an associated mid-level low toward the northern U.S. Pacific coast. This may have at least some impact on downstream synoptic developments within the broadly confluent split flow across North America. In the higher-latitude branch, one significant occluding cyclone is forecast to continue migrating northeast and east of the Canadian Maritimes. An elongating upstream cyclonic circulation may become quasi-stationary near the southwestern shores of Hudson Bay, with a series of lower amplitude perturbations digging to its west through south, across the international border. In lower levels, the leading edge of another significant cold intrusion is forecast to nose as far south as the Texas Panhandle and Red River vicinity, and as far east as the lower Great Lakes and Ohio Valley by 12Z Saturday. In lower latitudes, mid-level troughing is still forecast to progress slowly across and east of the lower Mississippi Valley and north central Gulf of Mexico. One smaller-scale perturbation may emerge from its base and become increasingly sheared across and to the east of the southern Appalachians, while another digs across the northwestern through north central Gulf of Mexico by late Friday night. Models continue to differ concerning these features, and the larger-scale troughing will be preceded by a subtropical perturbation which is likely to be in the process of progressing into and across the Florida peninsula by early Friday. It does appear that a broad area of deepening surface low pressure will develop northeastward across much of the eastern Gulf and South Atlantic Coast states. However, sizable spread is evident within the model output concerning sub-synoptic through convective-scale developments across the Southeast, Gulf of Mexico and offshore Atlantic. ...Southeast... Even with the aforementioned uncertainties, it does appear that an initially dry/potentially cool low-level environment, across much of the Florida peninsula through eastern Gulf Coast region, will tend to maintain generally stable conditions inland of coastal areas as initial convection supported by warm advection overspreads it. However, based on various model output, including some convection-allowing guidance, there appears potential for at least one initially organized convective cluster to overspread the Florida Keys/southern Florida peninsula vicinity, coincident with a warm front off the southeastern Gulf of Mexico early Friday. Given sufficient boundary-layer destabilization in the presence of strong deep-layer shear, this may be accompanied by a risk for damaging wind gusts and perhaps a tornado or two. Thereafter, it appears that widespread convective development, perhaps including organizing clusters, may continue along trailing convective outflow gradually advancing across and east-southeast of the southeastern Gulf of Mexico through early Saturday. Convective potential to the north of this outflow remains unclear. However, models do indicate that substantive boundary-layer destabilization is possible across much of the northeastern Gulf of Mexico by late Friday night, ahead of a weak southeastward advancing cold front. Still ahead of the mid-level troughing axis, this environment may support additional scattered strong thunderstorm development which might spread inland across coastal areas before weakening. ..Kerr.. 03/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CDT Wed Mar 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY THROUGH FRIDAY NIGHT NEAR THE NORTHEASTERN GULF COAST AND ACROSS PARTS OF SOUTHERN FLORIDA AND THE FLORIDA KEYS... ...SUMMARY... One or two clusters of strong thunderstorms may impact portions of southern Florida and the Keys Friday into Friday evening, accompanied by at least some risk for damaging winds and a tornado or two. More isolated strong to severe thunderstorm development may impact northeastern Gulf coastal areas into Friday night. ...Synopsis... It appears that blocking centered over the northeastern Pacific will generally persist through this period, but guidance continues to indicate at least some weakening, as a more progressive regime gradually develops across the central toward eastern mid-latitude Pacific. There remains variability within and among the model output concerning the extent of this weakening, and the eastward acceleration of an associated mid-level low toward the northern U.S. Pacific coast. This may have at least some impact on downstream synoptic developments within the broadly confluent split flow across North America. In the higher-latitude branch, one significant occluding cyclone is forecast to continue migrating northeast and east of the Canadian Maritimes. An elongating upstream cyclonic circulation may become quasi-stationary near the southwestern shores of Hudson Bay, with a series of lower amplitude perturbations digging to its west through south, across the international border. In lower levels, the leading edge of another significant cold intrusion is forecast to nose as far south as the Texas Panhandle and Red River vicinity, and as far east as the lower Great Lakes and Ohio Valley by 12Z Saturday. In lower latitudes, mid-level troughing is still forecast to progress slowly across and east of the lower Mississippi Valley and north central Gulf of Mexico. One smaller-scale perturbation may emerge from its base and become increasingly sheared across and to the east of the southern Appalachians, while another digs across the northwestern through north central Gulf of Mexico by late Friday night. Models continue to differ concerning these features, and the larger-scale troughing will be preceded by a subtropical perturbation which is likely to be in the process of progressing into and across the Florida peninsula by early Friday. It does appear that a broad area of deepening surface low pressure will develop northeastward across much of the eastern Gulf and South Atlantic Coast states. However, sizable spread is evident within the model output concerning sub-synoptic through convective-scale developments across the Southeast, Gulf of Mexico and offshore Atlantic. ...Southeast... Even with the aforementioned uncertainties, it does appear that an initially dry/potentially cool low-level environment, across much of the Florida peninsula through eastern Gulf Coast region, will tend to maintain generally stable conditions inland of coastal areas as initial convection supported by warm advection overspreads it. However, based on various model output, including some convection-allowing guidance, there appears potential for at least one initially organized convective cluster to overspread the Florida Keys/southern Florida peninsula vicinity, coincident with a warm front off the southeastern Gulf of Mexico early Friday. Given sufficient boundary-layer destabilization in the presence of strong deep-layer shear, this may be accompanied by a risk for damaging wind gusts and perhaps a tornado or two. Thereafter, it appears that widespread convective development, perhaps including organizing clusters, may continue along trailing convective outflow gradually advancing across and east-southeast of the southeastern Gulf of Mexico through early Saturday. Convective potential to the north of this outflow remains unclear. However, models do indicate that substantive boundary-layer destabilization is possible across much of the northeastern Gulf of Mexico by late Friday night, ahead of a weak southeastward advancing cold front. Still ahead of the mid-level troughing axis, this environment may support additional scattered strong thunderstorm development which might spread inland across coastal areas before weakening. ..Kerr.. 03/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CDT Wed Mar 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY THROUGH FRIDAY NIGHT NEAR THE NORTHEASTERN GULF COAST AND ACROSS PARTS OF SOUTHERN FLORIDA AND THE FLORIDA KEYS... ...SUMMARY... One or two clusters of strong thunderstorms may impact portions of southern Florida and the Keys Friday into Friday evening, accompanied by at least some risk for damaging winds and a tornado or two. More isolated strong to severe thunderstorm development may impact northeastern Gulf coastal areas into Friday night. ...Synopsis... It appears that blocking centered over the northeastern Pacific will generally persist through this period, but guidance continues to indicate at least some weakening, as a more progressive regime gradually develops across the central toward eastern mid-latitude Pacific. There remains variability within and among the model output concerning the extent of this weakening, and the eastward acceleration of an associated mid-level low toward the northern U.S. Pacific coast. This may have at least some impact on downstream synoptic developments within the broadly confluent split flow across North America. In the higher-latitude branch, one significant occluding cyclone is forecast to continue migrating northeast and east of the Canadian Maritimes. An elongating upstream cyclonic circulation may become quasi-stationary near the southwestern shores of Hudson Bay, with a series of lower amplitude perturbations digging to its west through south, across the international border. In lower levels, the leading edge of another significant cold intrusion is forecast to nose as far south as the Texas Panhandle and Red River vicinity, and as far east as the lower Great Lakes and Ohio Valley by 12Z Saturday. In lower latitudes, mid-level troughing is still forecast to progress slowly across and east of the lower Mississippi Valley and north central Gulf of Mexico. One smaller-scale perturbation may emerge from its base and become increasingly sheared across and to the east of the southern Appalachians, while another digs across the northwestern through north central Gulf of Mexico by late Friday night. Models continue to differ concerning these features, and the larger-scale troughing will be preceded by a subtropical perturbation which is likely to be in the process of progressing into and across the Florida peninsula by early Friday. It does appear that a broad area of deepening surface low pressure will develop northeastward across much of the eastern Gulf and South Atlantic Coast states. However, sizable spread is evident within the model output concerning sub-synoptic through convective-scale developments across the Southeast, Gulf of Mexico and offshore Atlantic. ...Southeast... Even with the aforementioned uncertainties, it does appear that an initially dry/potentially cool low-level environment, across much of the Florida peninsula through eastern Gulf Coast region, will tend to maintain generally stable conditions inland of coastal areas as initial convection supported by warm advection overspreads it. However, based on various model output, including some convection-allowing guidance, there appears potential for at least one initially organized convective cluster to overspread the Florida Keys/southern Florida peninsula vicinity, coincident with a warm front off the southeastern Gulf of Mexico early Friday. Given sufficient boundary-layer destabilization in the presence of strong deep-layer shear, this may be accompanied by a risk for damaging wind gusts and perhaps a tornado or two. Thereafter, it appears that widespread convective development, perhaps including organizing clusters, may continue along trailing convective outflow gradually advancing across and east-southeast of the southeastern Gulf of Mexico through early Saturday. Convective potential to the north of this outflow remains unclear. However, models do indicate that substantive boundary-layer destabilization is possible across much of the northeastern Gulf of Mexico by late Friday night, ahead of a weak southeastward advancing cold front. Still ahead of the mid-level troughing axis, this environment may support additional scattered strong thunderstorm development which might spread inland across coastal areas before weakening. ..Kerr.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS AND FAR SOUTHWEST LOUISIANA... ...SUMMARY... Isolated severe thunderstorms producing large hail and strong wind gusts are possible from parts of far southwest Louisiana and the Texas Coastal Plain northwestward into central and north Texas. ...Southern Plains/Sabine River Valley... An upper-level trough will move eastward across northern Mexico today, as an associated surface low develops and moves northeastward along the Texas coast. A moist airmass, with surface dewpoints in the mid to upper 60s F, will be located along the lower to middle Texas Coast. The moist axis will extend northwestward into central and north Texas. Moderate instability appears most likely to develop from the lower to middle Texas coast inland about 50 statute miles. However, weak instability sufficient for strong updrafts should develop across most of the moist airmass by afternoon. Thunderstorms will likely be ongoing at the start of the period, with a cluster of convection moving northeastward from near Corpus Christi to the Houston vicinity during the morning and early afternoon. Additional storms are forecast to develop further northwest along and near the moist axis during the afternoon across parts central and north Texas. A second round of storms may impact the Texas Coastal Plain during the evening. Ahead of the approaching system, deep-layer shear is expected to increase across the Texas Coastal Plain during the day. RAP forecast soundings near Victoria increase 0-6 km shear from 35 knots at 12Z to near 50 knots by 20Z. This increase in deep-layer shear will likely correspond to an increase in the potential for supercells. The thermodynamic environment over the Texas Coastal Plain is forecast to be favorable for large hail, with 700-500 mb lapse rates in the 7 to 7.5 C/Km range, and 500 mb temperatures around -13 to -15C. Supercells that form will have the greatest threat for large hail. The wind-damage threat is more uncertain, and should depend upon the dominant storm mode. In spite of a low-level temperature inversion evident in the forecast soundings, isolated wind damage may occur, especially if a more persistent line segment can become organized. A marginal tornado threat could also develop if a supercell becomes dominant with that threat extending into far southwest Louisiana, where low-level shear will be strong in the afternoon. Further northwest into parts of central and north Texas, weak destabilization is expected by afternoon as surface temperatures warm. An upper-level low will move into northwest Texas, where a cold pocket aloft will create steep mid-level lapse rates. As scattered thunderstorms increase in coverage during the afternoon, hail will be possible within the stronger cores. The threat is expected to be strongly tied with surface heating. ..Broyles/Flournoy.. 03/21/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Thu Mar 21 2024 Valid 211200Z - 221200Z ...Synopsis... Mostly zonal mid-level flow will pervade the contiguous U.S. during the day today. Associated surface cyclone development in the lee of the Rockies could support Elevated fire-weather conditions this afternoon in southeastern WY and the western NE Panhandle. Dry and windy conditions are also possible across West TX, but any elevated conditions are expected to be more localized. ...Southeastern WY and the western NE Panhandle... A surface cyclone is expected to quickly deepen throughout the day today in the lee of the Laramie Mountains in the NE Panhandle and vicinity. The associated strengthening wind field will support dry, downsloping conditions across the region. By peak heating, widespread relative humidity reductions to 20-25 percent are possible alongside sustained winds of around 15-25 mph. Current guidance suggests a steadily drying fuelscape -- particularly for 1-10-h fuels -- that would support fire spread in the Elevated area. ...West TX... Modest, westerly flow is forecast in West TX this afternoon in the wake of an ejecting mid-level shortwave trough. This will yield strengthening surface wind speeds, likely peaking around 15-20 mph by mid-afternoon. This may contribute to some elevated fire-weather conditions, but the overall threat will be tempered by humidity reductions around 25-30 percent and some recent wetting precipitation moving through the region. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0758 PM CDT Wed Mar 20 2024 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHWEST TEXAS AND WESTERN OKLAHOMA...AND ALONG PARTS OF THE TEXAS COASTAL PLAIN... ...SUMMARY... Isolated, marginally severe storms will be possible this evening across parts of western Oklahoma and northwest Texas. Hail will be possible late in the period across parts of the Texas Coastal Plain. ...Western Oklahoma/Northwest Texas... The latest surface analysis shows a 1008 mb low over the eastern Texas Panhandle, with a quasi-stationary boundary extending eastward from the low into western and central Oklahoma. This boundary will be a focus for convective development this evening. Although a weak cap is in place across the southern Plains, large-scale ascent and low-level convergence may be enough to support new isolated thunderstorm development. RAP forecast soundings near and south of the boundary in the southeast Texas Panhandle and western Oklahoma this evening have MUCAPE near 500 J/kg, effective shear of 35 to 40 knots, and 700-500 mb lapse rates around 7 C/km. This may be sufficient for marginally severe hail this evening. ...Texas Coastal Plain... As an upper-level trough approaches from the west tonight, low-level moisture advection will begin across the Texas Coastal Plain. Surface dewpoints are expected to increase into the mid 60s F across much of the Texas Coastal Plain by late in the period. This will contribute to the development of moderate instability, mainly from Corpus Christi southward. In response to increasing low-level flow, scattered thunderstorms are forecast to begin around 09Z, with a gradual increase in convective coverage taking place over the last few hours of the period. RAP forecast soundings near Corpus Christi at this time have MUCAPE near 1500 J/kg and 60 knots of deep-layer shear. This, along with 700-500 mb lapse rates of 7 to 7.5 C/km, will make isolated large hail a possibility with the stronger rotating storms. A few strong gusts could also occur. ..Broyles.. 03/21/2024 Read more