Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Mon Mar 25 2024 Valid 251630Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF NORTHEAST LOUISIANA...SOUTHEAST ARKANSAS...AND CENTRAL MISSISSIPPI.... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...ArkLaMiss Region... Few changes have been made to the ongoing forecast. A large upper trough is present today over the western states, with the primary cold front sagging southward from east TX into western AR. Low-level moisture return has been slow ahead of the front over much of the lower MS Valley due to easterly trajectories. However, mid/upper 60s dewpoints are finally spreading inland into southern LA. This trend will continue through the afternoon with ample moisture expected into the southern half of MS by evening. Increasing moisture and at least broken sunshine should lead to sufficient destabilization for thunderstorm intensification by mid-afternoon along/ahead of the front over central LA. These storms will track northeastward toward central MS by early evening, then into western AL after dark. Forecast soundings suggest poor lapse rates in the lower troposphere which may limit updraft strength and overall severe risk. However, very strong low-level shear will promote supercell/bowing structures. Damaging winds and a few tornadoes (possibly strong) continue to be the concern this afternoon and evening. ...IA/MO/KS... The primary surface low is currently over eastern KS and will track into western IA this afternoon. Visible satellite imagery shows a region of mostly clear skies in the warm sector of the low, leading to steepening low-level lapse rates and marginal CAPE. Most 12z CAM guidance develops a few low-topped showers or perhaps thunderstorms late today along the front as it moves into this area. The most robust cells might produce gusty winds, funnel clouds, or perhaps a tornado for a few hours this afternoon. ..Hart/Thornton.. 03/25/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Mon Mar 25 2024 Valid 251630Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF NORTHEAST LOUISIANA...SOUTHEAST ARKANSAS...AND CENTRAL MISSISSIPPI.... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...ArkLaMiss Region... Few changes have been made to the ongoing forecast. A large upper trough is present today over the western states, with the primary cold front sagging southward from east TX into western AR. Low-level moisture return has been slow ahead of the front over much of the lower MS Valley due to easterly trajectories. However, mid/upper 60s dewpoints are finally spreading inland into southern LA. This trend will continue through the afternoon with ample moisture expected into the southern half of MS by evening. Increasing moisture and at least broken sunshine should lead to sufficient destabilization for thunderstorm intensification by mid-afternoon along/ahead of the front over central LA. These storms will track northeastward toward central MS by early evening, then into western AL after dark. Forecast soundings suggest poor lapse rates in the lower troposphere which may limit updraft strength and overall severe risk. However, very strong low-level shear will promote supercell/bowing structures. Damaging winds and a few tornadoes (possibly strong) continue to be the concern this afternoon and evening. ...IA/MO/KS... The primary surface low is currently over eastern KS and will track into western IA this afternoon. Visible satellite imagery shows a region of mostly clear skies in the warm sector of the low, leading to steepening low-level lapse rates and marginal CAPE. Most 12z CAM guidance develops a few low-topped showers or perhaps thunderstorms late today along the front as it moves into this area. The most robust cells might produce gusty winds, funnel clouds, or perhaps a tornado for a few hours this afternoon. ..Hart/Thornton.. 03/25/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Mon Mar 25 2024 Valid 251630Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF NORTHEAST LOUISIANA...SOUTHEAST ARKANSAS...AND CENTRAL MISSISSIPPI.... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...ArkLaMiss Region... Few changes have been made to the ongoing forecast. A large upper trough is present today over the western states, with the primary cold front sagging southward from east TX into western AR. Low-level moisture return has been slow ahead of the front over much of the lower MS Valley due to easterly trajectories. However, mid/upper 60s dewpoints are finally spreading inland into southern LA. This trend will continue through the afternoon with ample moisture expected into the southern half of MS by evening. Increasing moisture and at least broken sunshine should lead to sufficient destabilization for thunderstorm intensification by mid-afternoon along/ahead of the front over central LA. These storms will track northeastward toward central MS by early evening, then into western AL after dark. Forecast soundings suggest poor lapse rates in the lower troposphere which may limit updraft strength and overall severe risk. However, very strong low-level shear will promote supercell/bowing structures. Damaging winds and a few tornadoes (possibly strong) continue to be the concern this afternoon and evening. ...IA/MO/KS... The primary surface low is currently over eastern KS and will track into western IA this afternoon. Visible satellite imagery shows a region of mostly clear skies in the warm sector of the low, leading to steepening low-level lapse rates and marginal CAPE. Most 12z CAM guidance develops a few low-topped showers or perhaps thunderstorms late today along the front as it moves into this area. The most robust cells might produce gusty winds, funnel clouds, or perhaps a tornado for a few hours this afternoon. ..Hart/Thornton.. 03/25/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Mon Mar 25 2024 Valid 251630Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF NORTHEAST LOUISIANA...SOUTHEAST ARKANSAS...AND CENTRAL MISSISSIPPI.... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...ArkLaMiss Region... Few changes have been made to the ongoing forecast. A large upper trough is present today over the western states, with the primary cold front sagging southward from east TX into western AR. Low-level moisture return has been slow ahead of the front over much of the lower MS Valley due to easterly trajectories. However, mid/upper 60s dewpoints are finally spreading inland into southern LA. This trend will continue through the afternoon with ample moisture expected into the southern half of MS by evening. Increasing moisture and at least broken sunshine should lead to sufficient destabilization for thunderstorm intensification by mid-afternoon along/ahead of the front over central LA. These storms will track northeastward toward central MS by early evening, then into western AL after dark. Forecast soundings suggest poor lapse rates in the lower troposphere which may limit updraft strength and overall severe risk. However, very strong low-level shear will promote supercell/bowing structures. Damaging winds and a few tornadoes (possibly strong) continue to be the concern this afternoon and evening. ...IA/MO/KS... The primary surface low is currently over eastern KS and will track into western IA this afternoon. Visible satellite imagery shows a region of mostly clear skies in the warm sector of the low, leading to steepening low-level lapse rates and marginal CAPE. Most 12z CAM guidance develops a few low-topped showers or perhaps thunderstorms late today along the front as it moves into this area. The most robust cells might produce gusty winds, funnel clouds, or perhaps a tornado for a few hours this afternoon. ..Hart/Thornton.. 03/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Mon Mar 25 2024 Valid 251300Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN LOUISIANA AND SOUTHEASTERN ARKANSAS TO EASTERN MISSISSIPPI... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...Synopsis... In mid/upper levels, a well-developed synoptic trough extends from a cyclone over the central Plains southwestward across far west TX to northwestern mainland MX and central Baja. A series of shortwaves behind the leading/synoptic trough will help to maintain larger- scale cyclonic flow over much of the western/central CONUS and northern MX through the period. However, the 500-mb cyclone should move erratically across KS today into this evening, reaching parts of northwestern MO, IA and southern MN by 12Z tomorrow. To its east and south, a broad, strong fetch of cyclonically curving, roughly southwesterly flow aloft will shift eastward from the Southern Plains across the lower Mississippi, Tennessee and lower Ohio Valleys. At the surface, 11Z analysis showed a low near CNK, with Pacific/ leading cold front having overtaken the dryline and drawn through north-central/south-central TX to easternmost Coahuila. A polar front was drawn from the low across northwestern OK, the southern TX Panhandle and east-central NM. The low should move to west-central IA by 00Z, with leading front reaching eastern parts of MO/AR, northern LA, extreme southeast TX, and the northwestern Gulf. By then, the polar front should extend southward over easternmost parts of KS/OK to north-central TX, the northern Permian Basin region of TX, and southeastern NM. By 12Z, the low should reach northwestern WI, with the fronts essentially merged southward to western KY, and the leading boundary from there across southeastern parts of MS/LA. ...East TX to AL... A swath of precip and embedded convection -- including widely scattered thunderstorms -- is apparent along and ahead of the Pacific front, from portions of central TX into the Ozarks. Much of this activity has exhibited a disorganized, anafrontal character for several hours, as the leading boundary continues to progress slightly rightward of storm motion. Overall severe potential should remain marginal over the next few hours as that general character persists. However, severe potential should ramp up from midday onward across the outlook area amid favorable/strengthening ambient deep shear. Two processes will contribute to increased surface-based convective/severe potential along this boundary from midday into tonight: 1. Some slowing of the boundary and decrease in anafrontal tendencies as it crosses the lower Mississippi River/Delta region, and 2. The foregoing warm sector becomes substantially more buoyant through a combination of warm advection, moist advection and diabatic heating of the boundary layer -- especially from a few counties north of I-20 southward. Forecast soundings reasonably depict a northward-narrowing, triangular wedge of 500-1500 MLCAPE shifting eastward over the region ahead of the main convective line. While much more uncertain, discrete supercell development may occur off the southern/southeastern part of the line, given progged decrease in MLCINH in the free warm sector. The geometry of the height gradient aloft -- around the southern rim of the ejecting cyclone and associated/trailing shortwave trough -- still will maintain a strongly parallel flow component to the primary band of convective forcing, helping to maintain quasi-linear mode. However, given the strength of the deep shear (effective- shear magnitudes of 55-65 kt), and of the low-level shear/hodographs (effective SRH of 250-500 J/kg), the line will encounter in and near the "enhanced" area, tornadoes are probable from associated LEWP/bow formations and embedded mesovortices, as well as any supercells that can mature enough before/during QLCS merger. The parameter space will support significant (EF2+ damage potential) tornadoes as well, though local storm mode/duration will strongly regulate that threat. The QLCS gradually will outpace the favorable inflow-layer thermodynamic regime from north-south, as it moves eastward into AL overnight, but with southern parts still offering a severe threat. ...Lower Missouri Valley region... Widely scattered to scattered thunderstorms should form this afternoon near the surface low and polar front. Isolated, marginally severe hail or gusts may be noted, and a tornado is possible. The airmass between the leading and polar fronts will remain somewhat moist, with surface dewpoints in the 50s F over much of the region. Diabatic heating and warm advection will contribute some low-level destabilization, though its duration and strength will be limited within a narrow corridor northwest of the cloud/precip shield from the aforementioned main convective band. However, large-scale lift preceding the ejecting mid/upper-level low and trough should lead to cold air aloft (e.g., 500-mb temperatures around -19 to -22 deg C), steepening low/middle-level lapse rates and decreasing MLCINH through much of the afternoon. This should support MLCAPE around 500 J/kg, with strong deep/speed shear and potential for vorticity-rich low-level boundaries to augment shear/hodographs locally. Convection should weaken soon after dark. ..Edwards/Wendt.. 03/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Mon Mar 25 2024 Valid 251300Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN LOUISIANA AND SOUTHEASTERN ARKANSAS TO EASTERN MISSISSIPPI... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...Synopsis... In mid/upper levels, a well-developed synoptic trough extends from a cyclone over the central Plains southwestward across far west TX to northwestern mainland MX and central Baja. A series of shortwaves behind the leading/synoptic trough will help to maintain larger- scale cyclonic flow over much of the western/central CONUS and northern MX through the period. However, the 500-mb cyclone should move erratically across KS today into this evening, reaching parts of northwestern MO, IA and southern MN by 12Z tomorrow. To its east and south, a broad, strong fetch of cyclonically curving, roughly southwesterly flow aloft will shift eastward from the Southern Plains across the lower Mississippi, Tennessee and lower Ohio Valleys. At the surface, 11Z analysis showed a low near CNK, with Pacific/ leading cold front having overtaken the dryline and drawn through north-central/south-central TX to easternmost Coahuila. A polar front was drawn from the low across northwestern OK, the southern TX Panhandle and east-central NM. The low should move to west-central IA by 00Z, with leading front reaching eastern parts of MO/AR, northern LA, extreme southeast TX, and the northwestern Gulf. By then, the polar front should extend southward over easternmost parts of KS/OK to north-central TX, the northern Permian Basin region of TX, and southeastern NM. By 12Z, the low should reach northwestern WI, with the fronts essentially merged southward to western KY, and the leading boundary from there across southeastern parts of MS/LA. ...East TX to AL... A swath of precip and embedded convection -- including widely scattered thunderstorms -- is apparent along and ahead of the Pacific front, from portions of central TX into the Ozarks. Much of this activity has exhibited a disorganized, anafrontal character for several hours, as the leading boundary continues to progress slightly rightward of storm motion. Overall severe potential should remain marginal over the next few hours as that general character persists. However, severe potential should ramp up from midday onward across the outlook area amid favorable/strengthening ambient deep shear. Two processes will contribute to increased surface-based convective/severe potential along this boundary from midday into tonight: 1. Some slowing of the boundary and decrease in anafrontal tendencies as it crosses the lower Mississippi River/Delta region, and 2. The foregoing warm sector becomes substantially more buoyant through a combination of warm advection, moist advection and diabatic heating of the boundary layer -- especially from a few counties north of I-20 southward. Forecast soundings reasonably depict a northward-narrowing, triangular wedge of 500-1500 MLCAPE shifting eastward over the region ahead of the main convective line. While much more uncertain, discrete supercell development may occur off the southern/southeastern part of the line, given progged decrease in MLCINH in the free warm sector. The geometry of the height gradient aloft -- around the southern rim of the ejecting cyclone and associated/trailing shortwave trough -- still will maintain a strongly parallel flow component to the primary band of convective forcing, helping to maintain quasi-linear mode. However, given the strength of the deep shear (effective- shear magnitudes of 55-65 kt), and of the low-level shear/hodographs (effective SRH of 250-500 J/kg), the line will encounter in and near the "enhanced" area, tornadoes are probable from associated LEWP/bow formations and embedded mesovortices, as well as any supercells that can mature enough before/during QLCS merger. The parameter space will support significant (EF2+ damage potential) tornadoes as well, though local storm mode/duration will strongly regulate that threat. The QLCS gradually will outpace the favorable inflow-layer thermodynamic regime from north-south, as it moves eastward into AL overnight, but with southern parts still offering a severe threat. ...Lower Missouri Valley region... Widely scattered to scattered thunderstorms should form this afternoon near the surface low and polar front. Isolated, marginally severe hail or gusts may be noted, and a tornado is possible. The airmass between the leading and polar fronts will remain somewhat moist, with surface dewpoints in the 50s F over much of the region. Diabatic heating and warm advection will contribute some low-level destabilization, though its duration and strength will be limited within a narrow corridor northwest of the cloud/precip shield from the aforementioned main convective band. However, large-scale lift preceding the ejecting mid/upper-level low and trough should lead to cold air aloft (e.g., 500-mb temperatures around -19 to -22 deg C), steepening low/middle-level lapse rates and decreasing MLCINH through much of the afternoon. This should support MLCAPE around 500 J/kg, with strong deep/speed shear and potential for vorticity-rich low-level boundaries to augment shear/hodographs locally. Convection should weaken soon after dark. ..Edwards/Wendt.. 03/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Mon Mar 25 2024 Valid 251300Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN LOUISIANA AND SOUTHEASTERN ARKANSAS TO EASTERN MISSISSIPPI... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...Synopsis... In mid/upper levels, a well-developed synoptic trough extends from a cyclone over the central Plains southwestward across far west TX to northwestern mainland MX and central Baja. A series of shortwaves behind the leading/synoptic trough will help to maintain larger- scale cyclonic flow over much of the western/central CONUS and northern MX through the period. However, the 500-mb cyclone should move erratically across KS today into this evening, reaching parts of northwestern MO, IA and southern MN by 12Z tomorrow. To its east and south, a broad, strong fetch of cyclonically curving, roughly southwesterly flow aloft will shift eastward from the Southern Plains across the lower Mississippi, Tennessee and lower Ohio Valleys. At the surface, 11Z analysis showed a low near CNK, with Pacific/ leading cold front having overtaken the dryline and drawn through north-central/south-central TX to easternmost Coahuila. A polar front was drawn from the low across northwestern OK, the southern TX Panhandle and east-central NM. The low should move to west-central IA by 00Z, with leading front reaching eastern parts of MO/AR, northern LA, extreme southeast TX, and the northwestern Gulf. By then, the polar front should extend southward over easternmost parts of KS/OK to north-central TX, the northern Permian Basin region of TX, and southeastern NM. By 12Z, the low should reach northwestern WI, with the fronts essentially merged southward to western KY, and the leading boundary from there across southeastern parts of MS/LA. ...East TX to AL... A swath of precip and embedded convection -- including widely scattered thunderstorms -- is apparent along and ahead of the Pacific front, from portions of central TX into the Ozarks. Much of this activity has exhibited a disorganized, anafrontal character for several hours, as the leading boundary continues to progress slightly rightward of storm motion. Overall severe potential should remain marginal over the next few hours as that general character persists. However, severe potential should ramp up from midday onward across the outlook area amid favorable/strengthening ambient deep shear. Two processes will contribute to increased surface-based convective/severe potential along this boundary from midday into tonight: 1. Some slowing of the boundary and decrease in anafrontal tendencies as it crosses the lower Mississippi River/Delta region, and 2. The foregoing warm sector becomes substantially more buoyant through a combination of warm advection, moist advection and diabatic heating of the boundary layer -- especially from a few counties north of I-20 southward. Forecast soundings reasonably depict a northward-narrowing, triangular wedge of 500-1500 MLCAPE shifting eastward over the region ahead of the main convective line. While much more uncertain, discrete supercell development may occur off the southern/southeastern part of the line, given progged decrease in MLCINH in the free warm sector. The geometry of the height gradient aloft -- around the southern rim of the ejecting cyclone and associated/trailing shortwave trough -- still will maintain a strongly parallel flow component to the primary band of convective forcing, helping to maintain quasi-linear mode. However, given the strength of the deep shear (effective- shear magnitudes of 55-65 kt), and of the low-level shear/hodographs (effective SRH of 250-500 J/kg), the line will encounter in and near the "enhanced" area, tornadoes are probable from associated LEWP/bow formations and embedded mesovortices, as well as any supercells that can mature enough before/during QLCS merger. The parameter space will support significant (EF2+ damage potential) tornadoes as well, though local storm mode/duration will strongly regulate that threat. The QLCS gradually will outpace the favorable inflow-layer thermodynamic regime from north-south, as it moves eastward into AL overnight, but with southern parts still offering a severe threat. ...Lower Missouri Valley region... Widely scattered to scattered thunderstorms should form this afternoon near the surface low and polar front. Isolated, marginally severe hail or gusts may be noted, and a tornado is possible. The airmass between the leading and polar fronts will remain somewhat moist, with surface dewpoints in the 50s F over much of the region. Diabatic heating and warm advection will contribute some low-level destabilization, though its duration and strength will be limited within a narrow corridor northwest of the cloud/precip shield from the aforementioned main convective band. However, large-scale lift preceding the ejecting mid/upper-level low and trough should lead to cold air aloft (e.g., 500-mb temperatures around -19 to -22 deg C), steepening low/middle-level lapse rates and decreasing MLCINH through much of the afternoon. This should support MLCAPE around 500 J/kg, with strong deep/speed shear and potential for vorticity-rich low-level boundaries to augment shear/hodographs locally. Convection should weaken soon after dark. ..Edwards/Wendt.. 03/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Mon Mar 25 2024 Valid 251300Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN LOUISIANA AND SOUTHEASTERN ARKANSAS TO EASTERN MISSISSIPPI... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...Synopsis... In mid/upper levels, a well-developed synoptic trough extends from a cyclone over the central Plains southwestward across far west TX to northwestern mainland MX and central Baja. A series of shortwaves behind the leading/synoptic trough will help to maintain larger- scale cyclonic flow over much of the western/central CONUS and northern MX through the period. However, the 500-mb cyclone should move erratically across KS today into this evening, reaching parts of northwestern MO, IA and southern MN by 12Z tomorrow. To its east and south, a broad, strong fetch of cyclonically curving, roughly southwesterly flow aloft will shift eastward from the Southern Plains across the lower Mississippi, Tennessee and lower Ohio Valleys. At the surface, 11Z analysis showed a low near CNK, with Pacific/ leading cold front having overtaken the dryline and drawn through north-central/south-central TX to easternmost Coahuila. A polar front was drawn from the low across northwestern OK, the southern TX Panhandle and east-central NM. The low should move to west-central IA by 00Z, with leading front reaching eastern parts of MO/AR, northern LA, extreme southeast TX, and the northwestern Gulf. By then, the polar front should extend southward over easternmost parts of KS/OK to north-central TX, the northern Permian Basin region of TX, and southeastern NM. By 12Z, the low should reach northwestern WI, with the fronts essentially merged southward to western KY, and the leading boundary from there across southeastern parts of MS/LA. ...East TX to AL... A swath of precip and embedded convection -- including widely scattered thunderstorms -- is apparent along and ahead of the Pacific front, from portions of central TX into the Ozarks. Much of this activity has exhibited a disorganized, anafrontal character for several hours, as the leading boundary continues to progress slightly rightward of storm motion. Overall severe potential should remain marginal over the next few hours as that general character persists. However, severe potential should ramp up from midday onward across the outlook area amid favorable/strengthening ambient deep shear. Two processes will contribute to increased surface-based convective/severe potential along this boundary from midday into tonight: 1. Some slowing of the boundary and decrease in anafrontal tendencies as it crosses the lower Mississippi River/Delta region, and 2. The foregoing warm sector becomes substantially more buoyant through a combination of warm advection, moist advection and diabatic heating of the boundary layer -- especially from a few counties north of I-20 southward. Forecast soundings reasonably depict a northward-narrowing, triangular wedge of 500-1500 MLCAPE shifting eastward over the region ahead of the main convective line. While much more uncertain, discrete supercell development may occur off the southern/southeastern part of the line, given progged decrease in MLCINH in the free warm sector. The geometry of the height gradient aloft -- around the southern rim of the ejecting cyclone and associated/trailing shortwave trough -- still will maintain a strongly parallel flow component to the primary band of convective forcing, helping to maintain quasi-linear mode. However, given the strength of the deep shear (effective- shear magnitudes of 55-65 kt), and of the low-level shear/hodographs (effective SRH of 250-500 J/kg), the line will encounter in and near the "enhanced" area, tornadoes are probable from associated LEWP/bow formations and embedded mesovortices, as well as any supercells that can mature enough before/during QLCS merger. The parameter space will support significant (EF2+ damage potential) tornadoes as well, though local storm mode/duration will strongly regulate that threat. The QLCS gradually will outpace the favorable inflow-layer thermodynamic regime from north-south, as it moves eastward into AL overnight, but with southern parts still offering a severe threat. ...Lower Missouri Valley region... Widely scattered to scattered thunderstorms should form this afternoon near the surface low and polar front. Isolated, marginally severe hail or gusts may be noted, and a tornado is possible. The airmass between the leading and polar fronts will remain somewhat moist, with surface dewpoints in the 50s F over much of the region. Diabatic heating and warm advection will contribute some low-level destabilization, though its duration and strength will be limited within a narrow corridor northwest of the cloud/precip shield from the aforementioned main convective band. However, large-scale lift preceding the ejecting mid/upper-level low and trough should lead to cold air aloft (e.g., 500-mb temperatures around -19 to -22 deg C), steepening low/middle-level lapse rates and decreasing MLCINH through much of the afternoon. This should support MLCAPE around 500 J/kg, with strong deep/speed shear and potential for vorticity-rich low-level boundaries to augment shear/hodographs locally. Convection should weaken soon after dark. ..Edwards/Wendt.. 03/25/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Mon Mar 25 2024 Valid 251300Z - 261200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN LOUISIANA AND SOUTHEASTERN ARKANSAS TO EASTERN MISSISSIPPI... ...SUMMARY... Tornadoes and damaging thunderstorm gusts are possible today through tonight from east Texas to Alabama. ...Synopsis... In mid/upper levels, a well-developed synoptic trough extends from a cyclone over the central Plains southwestward across far west TX to northwestern mainland MX and central Baja. A series of shortwaves behind the leading/synoptic trough will help to maintain larger- scale cyclonic flow over much of the western/central CONUS and northern MX through the period. However, the 500-mb cyclone should move erratically across KS today into this evening, reaching parts of northwestern MO, IA and southern MN by 12Z tomorrow. To its east and south, a broad, strong fetch of cyclonically curving, roughly southwesterly flow aloft will shift eastward from the Southern Plains across the lower Mississippi, Tennessee and lower Ohio Valleys. At the surface, 11Z analysis showed a low near CNK, with Pacific/ leading cold front having overtaken the dryline and drawn through north-central/south-central TX to easternmost Coahuila. A polar front was drawn from the low across northwestern OK, the southern TX Panhandle and east-central NM. The low should move to west-central IA by 00Z, with leading front reaching eastern parts of MO/AR, northern LA, extreme southeast TX, and the northwestern Gulf. By then, the polar front should extend southward over easternmost parts of KS/OK to north-central TX, the northern Permian Basin region of TX, and southeastern NM. By 12Z, the low should reach northwestern WI, with the fronts essentially merged southward to western KY, and the leading boundary from there across southeastern parts of MS/LA. ...East TX to AL... A swath of precip and embedded convection -- including widely scattered thunderstorms -- is apparent along and ahead of the Pacific front, from portions of central TX into the Ozarks. Much of this activity has exhibited a disorganized, anafrontal character for several hours, as the leading boundary continues to progress slightly rightward of storm motion. Overall severe potential should remain marginal over the next few hours as that general character persists. However, severe potential should ramp up from midday onward across the outlook area amid favorable/strengthening ambient deep shear. Two processes will contribute to increased surface-based convective/severe potential along this boundary from midday into tonight: 1. Some slowing of the boundary and decrease in anafrontal tendencies as it crosses the lower Mississippi River/Delta region, and 2. The foregoing warm sector becomes substantially more buoyant through a combination of warm advection, moist advection and diabatic heating of the boundary layer -- especially from a few counties north of I-20 southward. Forecast soundings reasonably depict a northward-narrowing, triangular wedge of 500-1500 MLCAPE shifting eastward over the region ahead of the main convective line. While much more uncertain, discrete supercell development may occur off the southern/southeastern part of the line, given progged decrease in MLCINH in the free warm sector. The geometry of the height gradient aloft -- around the southern rim of the ejecting cyclone and associated/trailing shortwave trough -- still will maintain a strongly parallel flow component to the primary band of convective forcing, helping to maintain quasi-linear mode. However, given the strength of the deep shear (effective- shear magnitudes of 55-65 kt), and of the low-level shear/hodographs (effective SRH of 250-500 J/kg), the line will encounter in and near the "enhanced" area, tornadoes are probable from associated LEWP/bow formations and embedded mesovortices, as well as any supercells that can mature enough before/during QLCS merger. The parameter space will support significant (EF2+ damage potential) tornadoes as well, though local storm mode/duration will strongly regulate that threat. The QLCS gradually will outpace the favorable inflow-layer thermodynamic regime from north-south, as it moves eastward into AL overnight, but with southern parts still offering a severe threat. ...Lower Missouri Valley region... Widely scattered to scattered thunderstorms should form this afternoon near the surface low and polar front. Isolated, marginally severe hail or gusts may be noted, and a tornado is possible. The airmass between the leading and polar fronts will remain somewhat moist, with surface dewpoints in the 50s F over much of the region. Diabatic heating and warm advection will contribute some low-level destabilization, though its duration and strength will be limited within a narrow corridor northwest of the cloud/precip shield from the aforementioned main convective band. However, large-scale lift preceding the ejecting mid/upper-level low and trough should lead to cold air aloft (e.g., 500-mb temperatures around -19 to -22 deg C), steepening low/middle-level lapse rates and decreasing MLCINH through much of the afternoon. This should support MLCAPE around 500 J/kg, with strong deep/speed shear and potential for vorticity-rich low-level boundaries to augment shear/hodographs locally. Convection should weaken soon after dark. ..Edwards/Wendt.. 03/25/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Mar 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... Isolated/marginal severe potential on Day 4/Thursday should remain confined along and south of a cold front that will advance southeastward across the FL Peninsula through the day. An upper trough over the Southeast should also continue eastward to the western Atlantic by Thursday evening. Enhanced mid-level winds should promote sufficient deep-layer shear to support organized thunderstorms. However, modest instability and veering low-level winds limiting convergence along the front will probably tend to temper the magnitude and coverage of robust convection. Have therefore not included a 15% severe area for Thursday across the central/southern FL Peninsula. Once the cold front clears the East Coast, severe potential appears minimal across the CONUS from Day 5/Friday until at least Day 6/Saturday. Gradual low-level moisture return across the southern/central Plains and lower/mid MS Valley is forecast in this time frame. But, mid/upper-level ridging and capping concerns across these regions should tend to suppress most convection. By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows an upper trough/low moving from the eastern Pacific across the western states. There appears to be a somewhat bimodal distribution in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual ejection of this upper trough across the southern/central Plains. Some guidance shows a more positively tilted and elongated upper trough evolution, which could still support severe potential across the southern/central Plains by early next week. Other solutions show a more compact, neutral to negatively tilted trough ejection. Stronger low-level mass response in this scenario would lead to greater low-level moisture return, related stronger instability east of a dryline, and a potentially better setup for severe convection next Monday. Regardless, predictability remains far too low to add a 15% severe delineation at this extended time frame. But, trends will be monitored. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Mar 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... Isolated/marginal severe potential on Day 4/Thursday should remain confined along and south of a cold front that will advance southeastward across the FL Peninsula through the day. An upper trough over the Southeast should also continue eastward to the western Atlantic by Thursday evening. Enhanced mid-level winds should promote sufficient deep-layer shear to support organized thunderstorms. However, modest instability and veering low-level winds limiting convergence along the front will probably tend to temper the magnitude and coverage of robust convection. Have therefore not included a 15% severe area for Thursday across the central/southern FL Peninsula. Once the cold front clears the East Coast, severe potential appears minimal across the CONUS from Day 5/Friday until at least Day 6/Saturday. Gradual low-level moisture return across the southern/central Plains and lower/mid MS Valley is forecast in this time frame. But, mid/upper-level ridging and capping concerns across these regions should tend to suppress most convection. By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows an upper trough/low moving from the eastern Pacific across the western states. There appears to be a somewhat bimodal distribution in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual ejection of this upper trough across the southern/central Plains. Some guidance shows a more positively tilted and elongated upper trough evolution, which could still support severe potential across the southern/central Plains by early next week. Other solutions show a more compact, neutral to negatively tilted trough ejection. Stronger low-level mass response in this scenario would lead to greater low-level moisture return, related stronger instability east of a dryline, and a potentially better setup for severe convection next Monday. Regardless, predictability remains far too low to add a 15% severe delineation at this extended time frame. But, trends will be monitored. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Mar 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... Isolated/marginal severe potential on Day 4/Thursday should remain confined along and south of a cold front that will advance southeastward across the FL Peninsula through the day. An upper trough over the Southeast should also continue eastward to the western Atlantic by Thursday evening. Enhanced mid-level winds should promote sufficient deep-layer shear to support organized thunderstorms. However, modest instability and veering low-level winds limiting convergence along the front will probably tend to temper the magnitude and coverage of robust convection. Have therefore not included a 15% severe area for Thursday across the central/southern FL Peninsula. Once the cold front clears the East Coast, severe potential appears minimal across the CONUS from Day 5/Friday until at least Day 6/Saturday. Gradual low-level moisture return across the southern/central Plains and lower/mid MS Valley is forecast in this time frame. But, mid/upper-level ridging and capping concerns across these regions should tend to suppress most convection. By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows an upper trough/low moving from the eastern Pacific across the western states. There appears to be a somewhat bimodal distribution in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual ejection of this upper trough across the southern/central Plains. Some guidance shows a more positively tilted and elongated upper trough evolution, which could still support severe potential across the southern/central Plains by early next week. Other solutions show a more compact, neutral to negatively tilted trough ejection. Stronger low-level mass response in this scenario would lead to greater low-level moisture return, related stronger instability east of a dryline, and a potentially better setup for severe convection next Monday. Regardless, predictability remains far too low to add a 15% severe delineation at this extended time frame. But, trends will be monitored. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Mar 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... Isolated/marginal severe potential on Day 4/Thursday should remain confined along and south of a cold front that will advance southeastward across the FL Peninsula through the day. An upper trough over the Southeast should also continue eastward to the western Atlantic by Thursday evening. Enhanced mid-level winds should promote sufficient deep-layer shear to support organized thunderstorms. However, modest instability and veering low-level winds limiting convergence along the front will probably tend to temper the magnitude and coverage of robust convection. Have therefore not included a 15% severe area for Thursday across the central/southern FL Peninsula. Once the cold front clears the East Coast, severe potential appears minimal across the CONUS from Day 5/Friday until at least Day 6/Saturday. Gradual low-level moisture return across the southern/central Plains and lower/mid MS Valley is forecast in this time frame. But, mid/upper-level ridging and capping concerns across these regions should tend to suppress most convection. By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows an upper trough/low moving from the eastern Pacific across the western states. There appears to be a somewhat bimodal distribution in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual ejection of this upper trough across the southern/central Plains. Some guidance shows a more positively tilted and elongated upper trough evolution, which could still support severe potential across the southern/central Plains by early next week. Other solutions show a more compact, neutral to negatively tilted trough ejection. Stronger low-level mass response in this scenario would lead to greater low-level moisture return, related stronger instability east of a dryline, and a potentially better setup for severe convection next Monday. Regardless, predictability remains far too low to add a 15% severe delineation at this extended time frame. But, trends will be monitored. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Mar 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... Isolated/marginal severe potential on Day 4/Thursday should remain confined along and south of a cold front that will advance southeastward across the FL Peninsula through the day. An upper trough over the Southeast should also continue eastward to the western Atlantic by Thursday evening. Enhanced mid-level winds should promote sufficient deep-layer shear to support organized thunderstorms. However, modest instability and veering low-level winds limiting convergence along the front will probably tend to temper the magnitude and coverage of robust convection. Have therefore not included a 15% severe area for Thursday across the central/southern FL Peninsula. Once the cold front clears the East Coast, severe potential appears minimal across the CONUS from Day 5/Friday until at least Day 6/Saturday. Gradual low-level moisture return across the southern/central Plains and lower/mid MS Valley is forecast in this time frame. But, mid/upper-level ridging and capping concerns across these regions should tend to suppress most convection. By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows an upper trough/low moving from the eastern Pacific across the western states. There appears to be a somewhat bimodal distribution in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual ejection of this upper trough across the southern/central Plains. Some guidance shows a more positively tilted and elongated upper trough evolution, which could still support severe potential across the southern/central Plains by early next week. Other solutions show a more compact, neutral to negatively tilted trough ejection. Stronger low-level mass response in this scenario would lead to greater low-level moisture return, related stronger instability east of a dryline, and a potentially better setup for severe convection next Monday. Regardless, predictability remains far too low to add a 15% severe delineation at this extended time frame. But, trends will be monitored. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Mar 25 2024 Valid 281200Z - 021200Z ...DISCUSSION... Isolated/marginal severe potential on Day 4/Thursday should remain confined along and south of a cold front that will advance southeastward across the FL Peninsula through the day. An upper trough over the Southeast should also continue eastward to the western Atlantic by Thursday evening. Enhanced mid-level winds should promote sufficient deep-layer shear to support organized thunderstorms. However, modest instability and veering low-level winds limiting convergence along the front will probably tend to temper the magnitude and coverage of robust convection. Have therefore not included a 15% severe area for Thursday across the central/southern FL Peninsula. Once the cold front clears the East Coast, severe potential appears minimal across the CONUS from Day 5/Friday until at least Day 6/Saturday. Gradual low-level moisture return across the southern/central Plains and lower/mid MS Valley is forecast in this time frame. But, mid/upper-level ridging and capping concerns across these regions should tend to suppress most convection. By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows an upper trough/low moving from the eastern Pacific across the western states. There appears to be a somewhat bimodal distribution in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual ejection of this upper trough across the southern/central Plains. Some guidance shows a more positively tilted and elongated upper trough evolution, which could still support severe potential across the southern/central Plains by early next week. Other solutions show a more compact, neutral to negatively tilted trough ejection. Stronger low-level mass response in this scenario would lead to greater low-level moisture return, related stronger instability east of a dryline, and a potentially better setup for severe convection next Monday. Regardless, predictability remains far too low to add a 15% severe delineation at this extended time frame. But, trends will be monitored. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Mar 25 2024 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely on Wednesday. ...Synopsis and Discussion... A large-scale upper trough, with split mid-level jets, will move slowly eastward across the central/eastern CONUS on Wednesday. Enhanced southwesterly flow aloft will persist over the Southeast, while a cold front stalls across the FL Panhandle, GA, and Carolinas. At least low to mid 60s surface dewpoints should be present along and southeast of the front. But, poor lapse rates and ongoing convection/cloudiness Wednesday morning are expected to hamper robust destabilization. While occasional gusty winds may occur with the strongest thunderstorms that can develop through the afternoon, the overall wind threat appears too limited at this time to include low severe probabilities. There are some indications in various model guidance that convection may develop Wednesday afternoon on the backside of the upper trough across parts of the southern Plains. Typically, this area would be in a subsident regime, with minimal convective potential owing to a lack of low-level moisture/boundary-layer instability. However, in this case, it appears that cold temperatures aloft combined with shallow/residual low-level moisture and daytime heating will provide modest destabilization as the boundary layer becomes well mixed. Weak instability should preclude an organized severe threat, but isolated strong/gusty winds appear possible with any high-based convection that develops. Finally, occasional lightning flashes may occur with low-topped thunderstorms across coastal portions of the Pacific Northwest. This potential should focus mainly in the afternoon and evening time frame, as cold mid-level temperatures and pronounced ascent associated with an approaching upper trough overspread this region. ..Gleason.. 03/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Mar 25 2024 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely on Wednesday. ...Synopsis and Discussion... A large-scale upper trough, with split mid-level jets, will move slowly eastward across the central/eastern CONUS on Wednesday. Enhanced southwesterly flow aloft will persist over the Southeast, while a cold front stalls across the FL Panhandle, GA, and Carolinas. At least low to mid 60s surface dewpoints should be present along and southeast of the front. But, poor lapse rates and ongoing convection/cloudiness Wednesday morning are expected to hamper robust destabilization. While occasional gusty winds may occur with the strongest thunderstorms that can develop through the afternoon, the overall wind threat appears too limited at this time to include low severe probabilities. There are some indications in various model guidance that convection may develop Wednesday afternoon on the backside of the upper trough across parts of the southern Plains. Typically, this area would be in a subsident regime, with minimal convective potential owing to a lack of low-level moisture/boundary-layer instability. However, in this case, it appears that cold temperatures aloft combined with shallow/residual low-level moisture and daytime heating will provide modest destabilization as the boundary layer becomes well mixed. Weak instability should preclude an organized severe threat, but isolated strong/gusty winds appear possible with any high-based convection that develops. Finally, occasional lightning flashes may occur with low-topped thunderstorms across coastal portions of the Pacific Northwest. This potential should focus mainly in the afternoon and evening time frame, as cold mid-level temperatures and pronounced ascent associated with an approaching upper trough overspread this region. ..Gleason.. 03/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Mar 25 2024 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely on Wednesday. ...Synopsis and Discussion... A large-scale upper trough, with split mid-level jets, will move slowly eastward across the central/eastern CONUS on Wednesday. Enhanced southwesterly flow aloft will persist over the Southeast, while a cold front stalls across the FL Panhandle, GA, and Carolinas. At least low to mid 60s surface dewpoints should be present along and southeast of the front. But, poor lapse rates and ongoing convection/cloudiness Wednesday morning are expected to hamper robust destabilization. While occasional gusty winds may occur with the strongest thunderstorms that can develop through the afternoon, the overall wind threat appears too limited at this time to include low severe probabilities. There are some indications in various model guidance that convection may develop Wednesday afternoon on the backside of the upper trough across parts of the southern Plains. Typically, this area would be in a subsident regime, with minimal convective potential owing to a lack of low-level moisture/boundary-layer instability. However, in this case, it appears that cold temperatures aloft combined with shallow/residual low-level moisture and daytime heating will provide modest destabilization as the boundary layer becomes well mixed. Weak instability should preclude an organized severe threat, but isolated strong/gusty winds appear possible with any high-based convection that develops. Finally, occasional lightning flashes may occur with low-topped thunderstorms across coastal portions of the Pacific Northwest. This potential should focus mainly in the afternoon and evening time frame, as cold mid-level temperatures and pronounced ascent associated with an approaching upper trough overspread this region. ..Gleason.. 03/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Mar 25 2024 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely on Wednesday. ...Synopsis and Discussion... A large-scale upper trough, with split mid-level jets, will move slowly eastward across the central/eastern CONUS on Wednesday. Enhanced southwesterly flow aloft will persist over the Southeast, while a cold front stalls across the FL Panhandle, GA, and Carolinas. At least low to mid 60s surface dewpoints should be present along and southeast of the front. But, poor lapse rates and ongoing convection/cloudiness Wednesday morning are expected to hamper robust destabilization. While occasional gusty winds may occur with the strongest thunderstorms that can develop through the afternoon, the overall wind threat appears too limited at this time to include low severe probabilities. There are some indications in various model guidance that convection may develop Wednesday afternoon on the backside of the upper trough across parts of the southern Plains. Typically, this area would be in a subsident regime, with minimal convective potential owing to a lack of low-level moisture/boundary-layer instability. However, in this case, it appears that cold temperatures aloft combined with shallow/residual low-level moisture and daytime heating will provide modest destabilization as the boundary layer becomes well mixed. Weak instability should preclude an organized severe threat, but isolated strong/gusty winds appear possible with any high-based convection that develops. Finally, occasional lightning flashes may occur with low-topped thunderstorms across coastal portions of the Pacific Northwest. This potential should focus mainly in the afternoon and evening time frame, as cold mid-level temperatures and pronounced ascent associated with an approaching upper trough overspread this region. ..Gleason.. 03/25/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Mar 25 2024 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms appear unlikely on Wednesday. ...Synopsis and Discussion... A large-scale upper trough, with split mid-level jets, will move slowly eastward across the central/eastern CONUS on Wednesday. Enhanced southwesterly flow aloft will persist over the Southeast, while a cold front stalls across the FL Panhandle, GA, and Carolinas. At least low to mid 60s surface dewpoints should be present along and southeast of the front. But, poor lapse rates and ongoing convection/cloudiness Wednesday morning are expected to hamper robust destabilization. While occasional gusty winds may occur with the strongest thunderstorms that can develop through the afternoon, the overall wind threat appears too limited at this time to include low severe probabilities. There are some indications in various model guidance that convection may develop Wednesday afternoon on the backside of the upper trough across parts of the southern Plains. Typically, this area would be in a subsident regime, with minimal convective potential owing to a lack of low-level moisture/boundary-layer instability. However, in this case, it appears that cold temperatures aloft combined with shallow/residual low-level moisture and daytime heating will provide modest destabilization as the boundary layer becomes well mixed. Weak instability should preclude an organized severe threat, but isolated strong/gusty winds appear possible with any high-based convection that develops. Finally, occasional lightning flashes may occur with low-topped thunderstorms across coastal portions of the Pacific Northwest. This potential should focus mainly in the afternoon and evening time frame, as cold mid-level temperatures and pronounced ascent associated with an approaching upper trough overspread this region. ..Gleason.. 03/25/2024 Read more