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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Thu May 02 2024 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF NORTHWEST TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest into central Texas. ...TX... Morning surface analysis shows a cold front sagging southward across the TX Panhandle and northwest OK, with a dryline extending southward across west TX. Ample low-level moisture is present to the east of the dryline, where a combination of strong afternoon heating and very steep mid-level lapse rates will yield MLCAPE values around 4000 J/kg. Deep layer flow is not particularly strong, but given the impressive thermodynamic environment, the setup should support scattered slow-moving supercells capable of very large hail and damaging winds. Have upped hail probabilities in parts of this region. The cluster of storms may grow upscale after dark, building southeastward into central TX. ...OK into Western Great Lakes... A cold front extends from northwest OK into IA. A large shield of prefrontal precipitation is affecting parts of northern MO and eastern IA. Along and south of the front/cloud shield, areas of strong heating will occur this afternoon. Most CAM solutions suggest multiple clusters of thunderstorms will form in this differential heating zone, with a risk of a few strong/severe cells capable of gusty/damaging winds and hail. Confidence in a more organized severe threat is not sufficient to add a SLGT risk at this time. ..Hart/Barnes/Lyons.. 05/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Thu May 02 2024 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF NORTHWEST TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest into central Texas. ...TX... Morning surface analysis shows a cold front sagging southward across the TX Panhandle and northwest OK, with a dryline extending southward across west TX. Ample low-level moisture is present to the east of the dryline, where a combination of strong afternoon heating and very steep mid-level lapse rates will yield MLCAPE values around 4000 J/kg. Deep layer flow is not particularly strong, but given the impressive thermodynamic environment, the setup should support scattered slow-moving supercells capable of very large hail and damaging winds. Have upped hail probabilities in parts of this region. The cluster of storms may grow upscale after dark, building southeastward into central TX. ...OK into Western Great Lakes... A cold front extends from northwest OK into IA. A large shield of prefrontal precipitation is affecting parts of northern MO and eastern IA. Along and south of the front/cloud shield, areas of strong heating will occur this afternoon. Most CAM solutions suggest multiple clusters of thunderstorms will form in this differential heating zone, with a risk of a few strong/severe cells capable of gusty/damaging winds and hail. Confidence in a more organized severe threat is not sufficient to add a SLGT risk at this time. ..Hart/Barnes/Lyons.. 05/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Thu May 02 2024 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF NORTHWEST TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest into central Texas. ...TX... Morning surface analysis shows a cold front sagging southward across the TX Panhandle and northwest OK, with a dryline extending southward across west TX. Ample low-level moisture is present to the east of the dryline, where a combination of strong afternoon heating and very steep mid-level lapse rates will yield MLCAPE values around 4000 J/kg. Deep layer flow is not particularly strong, but given the impressive thermodynamic environment, the setup should support scattered slow-moving supercells capable of very large hail and damaging winds. Have upped hail probabilities in parts of this region. The cluster of storms may grow upscale after dark, building southeastward into central TX. ...OK into Western Great Lakes... A cold front extends from northwest OK into IA. A large shield of prefrontal precipitation is affecting parts of northern MO and eastern IA. Along and south of the front/cloud shield, areas of strong heating will occur this afternoon. Most CAM solutions suggest multiple clusters of thunderstorms will form in this differential heating zone, with a risk of a few strong/severe cells capable of gusty/damaging winds and hail. Confidence in a more organized severe threat is not sufficient to add a SLGT risk at this time. ..Hart/Barnes/Lyons.. 05/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Thu May 02 2024 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF NORTHWEST TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest into central Texas. ...TX... Morning surface analysis shows a cold front sagging southward across the TX Panhandle and northwest OK, with a dryline extending southward across west TX. Ample low-level moisture is present to the east of the dryline, where a combination of strong afternoon heating and very steep mid-level lapse rates will yield MLCAPE values around 4000 J/kg. Deep layer flow is not particularly strong, but given the impressive thermodynamic environment, the setup should support scattered slow-moving supercells capable of very large hail and damaging winds. Have upped hail probabilities in parts of this region. The cluster of storms may grow upscale after dark, building southeastward into central TX. ...OK into Western Great Lakes... A cold front extends from northwest OK into IA. A large shield of prefrontal precipitation is affecting parts of northern MO and eastern IA. Along and south of the front/cloud shield, areas of strong heating will occur this afternoon. Most CAM solutions suggest multiple clusters of thunderstorms will form in this differential heating zone, with a risk of a few strong/severe cells capable of gusty/damaging winds and hail. Confidence in a more organized severe threat is not sufficient to add a SLGT risk at this time. ..Hart/Barnes/Lyons.. 05/02/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1105 AM CDT Thu May 02 2024 Valid 021630Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF NORTHWEST TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest into central Texas. ...TX... Morning surface analysis shows a cold front sagging southward across the TX Panhandle and northwest OK, with a dryline extending southward across west TX. Ample low-level moisture is present to the east of the dryline, where a combination of strong afternoon heating and very steep mid-level lapse rates will yield MLCAPE values around 4000 J/kg. Deep layer flow is not particularly strong, but given the impressive thermodynamic environment, the setup should support scattered slow-moving supercells capable of very large hail and damaging winds. Have upped hail probabilities in parts of this region. The cluster of storms may grow upscale after dark, building southeastward into central TX. ...OK into Western Great Lakes... A cold front extends from northwest OK into IA. A large shield of prefrontal precipitation is affecting parts of northern MO and eastern IA. Along and south of the front/cloud shield, areas of strong heating will occur this afternoon. Most CAM solutions suggest multiple clusters of thunderstorms will form in this differential heating zone, with a risk of a few strong/severe cells capable of gusty/damaging winds and hail. Confidence in a more organized severe threat is not sufficient to add a SLGT risk at this time. ..Hart/Barnes/Lyons.. 05/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Thu May 02 2024 Valid 021300Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NORTHWEST...NORTH-CENTRAL AND CENTRAL TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest, north-central and central Texas, where large to very large hail, severe gusts and a couple tornadoes are possible. ...Synopsis... In mid/upper levels, a complex cyclone -- now over southern SK and eastern MT -- is forecast to move slowly and erratically eastward stride the international border, orbited by several shortwaves/ vorticity lobes. The most influential of those perturbations is apparent in moisture-channel imagery over eastern WY to northwestern CO. This feature is forecast to strengthen and pivot to the central/eastern Dakotas by 00Z, then across MN to northern WI and western Lake Superior around 2Z tomorrow. Meanwhile, broad west- southwest to southwest flow in mid/upper levels -- with mainly convectively augmented/modified embedded perturbations -- will cover the central/southern Plains States. MCVs are evident over western IA, central OK and southeast TX. These should move across the Mississippi Valley this afternoon/evening, toward the Upper Great Lakes, Ohio Valley and Tennessee Valley, respectively. At the surface, 11Z analysis showed a low near STJ, with cold front across northeastern to south-central KS, the northern/western TX Panhandle, and north-central NM. A dryline was drawn over the Llano Estacado near the TX/NM line, southward into the western Big Bend region. By 00Z, the low should reach western WI, with cold front over northern IL, central MO, southeastern KS, central/southwestern OK, to a weak low over west-central TX. The eastward-mixing dryline will be overtaken by the cold front from north-south, with a 00Z position from the southern low southward near DRT. By 12Z, the cold front should reach the northeastern IN/northwestern OH region, extending southwestward to near a PAH-LIT-DAL line, then as a stationary to warm front west-northwestward to central NM. ...Southern Plains to western Gulf Coast... A large area of precip and embedded areas of thunderstorms is moving eastward across eastern OK, northeast/east TX, and western LA, anchored by some strong thunderstorm clusters in the southeast TX/southwestern LA area. Isolated, marginally severe hail and/or gusts may occur for a few more hours. Behind that activity, an outflow boundary extends across south- central TX, the Hill Country and Concho Valley regions, to the Permian Basin. Northward-directed warm/moist advection and theta-e recovery will occur today over west-central/northwest TX east of the dryline, before being intercepted by the cold front over the northwest TX/southwestern OK region this afternoon. Farther northeast over most of OK, severe potential will be more isolated and conditional near the front, given the presence of partially modified MCS-outflow air instead of a relatively undisturbed Gulf boundary layer. Isolated to scattered thunderstorms are expected to develop near the dryline and along the front this afternoon, with the most favorable parameter space, greatest low-level convergence, and densest convective concentration for severe potential being in and near the "slight" area. The northern rim of the residual outflow boundary will diffuse and move into this region as well, providing a potential low-level vorticity source that may help to offset some flow weaknesses aloft in terms of supporting supercell organization. 30-40 kt effective-shear magnitudes are possible. Forecast soundings reasonably indicate modest low-level flow supporting nearly straight hodographs with both left- and right-moving cells possible. Strong lapse rates -- generally 7.5 to 8 deg C from surface through 400 mb -- and mid/upper 60s F dewpoints, will support a plume of 3000-4500 J/kg MLCAPE over much of northwest, west-central and south-central/ southwest TX ahead of the dryline. Large to very large hail is the greatest concern, though storm-scale processes and boundary interactions may favor a tornado threat as well. Upscale aggregation of some of this convection is possible, increasing the severe-gust potential for at least a few hours into this evening and tonight. ...Midwest... A band of initial convection is crossing portions of IA and northwestern MO, ahead of the surface cold front. As this activity moves eastward into weakly destabilizing parts of IL/WI/northern MO through the day, some intensification may occur, resulting in isolated damaging gusts and marginally severe hail from the strongest segments. Behind this activity and along/ahead of the cold front, modest destabilization (from warm advection and limited insolation) will occur, supporting isolated to widely scattered afternoon thunderstorm development along the front, and additional risk of gusts/hail near severe limits. Favorable deep shear (effective-shear magnitudes around 40-50 kt) will spread over the area. However, limited instability is expected, with modest deep- layer lapse rates and trajectories from convectively processed source regions, keeping MLCAPE generally in the 500-1000 J/kg range in a narrow prefrontal corridor. Activity should weaken in the evening as it moves into a more-stable airmass. ..Edwards/Leitman.. 05/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Thu May 02 2024 Valid 021300Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NORTHWEST...NORTH-CENTRAL AND CENTRAL TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest, north-central and central Texas, where large to very large hail, severe gusts and a couple tornadoes are possible. ...Synopsis... In mid/upper levels, a complex cyclone -- now over southern SK and eastern MT -- is forecast to move slowly and erratically eastward stride the international border, orbited by several shortwaves/ vorticity lobes. The most influential of those perturbations is apparent in moisture-channel imagery over eastern WY to northwestern CO. This feature is forecast to strengthen and pivot to the central/eastern Dakotas by 00Z, then across MN to northern WI and western Lake Superior around 2Z tomorrow. Meanwhile, broad west- southwest to southwest flow in mid/upper levels -- with mainly convectively augmented/modified embedded perturbations -- will cover the central/southern Plains States. MCVs are evident over western IA, central OK and southeast TX. These should move across the Mississippi Valley this afternoon/evening, toward the Upper Great Lakes, Ohio Valley and Tennessee Valley, respectively. At the surface, 11Z analysis showed a low near STJ, with cold front across northeastern to south-central KS, the northern/western TX Panhandle, and north-central NM. A dryline was drawn over the Llano Estacado near the TX/NM line, southward into the western Big Bend region. By 00Z, the low should reach western WI, with cold front over northern IL, central MO, southeastern KS, central/southwestern OK, to a weak low over west-central TX. The eastward-mixing dryline will be overtaken by the cold front from north-south, with a 00Z position from the southern low southward near DRT. By 12Z, the cold front should reach the northeastern IN/northwestern OH region, extending southwestward to near a PAH-LIT-DAL line, then as a stationary to warm front west-northwestward to central NM. ...Southern Plains to western Gulf Coast... A large area of precip and embedded areas of thunderstorms is moving eastward across eastern OK, northeast/east TX, and western LA, anchored by some strong thunderstorm clusters in the southeast TX/southwestern LA area. Isolated, marginally severe hail and/or gusts may occur for a few more hours. Behind that activity, an outflow boundary extends across south- central TX, the Hill Country and Concho Valley regions, to the Permian Basin. Northward-directed warm/moist advection and theta-e recovery will occur today over west-central/northwest TX east of the dryline, before being intercepted by the cold front over the northwest TX/southwestern OK region this afternoon. Farther northeast over most of OK, severe potential will be more isolated and conditional near the front, given the presence of partially modified MCS-outflow air instead of a relatively undisturbed Gulf boundary layer. Isolated to scattered thunderstorms are expected to develop near the dryline and along the front this afternoon, with the most favorable parameter space, greatest low-level convergence, and densest convective concentration for severe potential being in and near the "slight" area. The northern rim of the residual outflow boundary will diffuse and move into this region as well, providing a potential low-level vorticity source that may help to offset some flow weaknesses aloft in terms of supporting supercell organization. 30-40 kt effective-shear magnitudes are possible. Forecast soundings reasonably indicate modest low-level flow supporting nearly straight hodographs with both left- and right-moving cells possible. Strong lapse rates -- generally 7.5 to 8 deg C from surface through 400 mb -- and mid/upper 60s F dewpoints, will support a plume of 3000-4500 J/kg MLCAPE over much of northwest, west-central and south-central/ southwest TX ahead of the dryline. Large to very large hail is the greatest concern, though storm-scale processes and boundary interactions may favor a tornado threat as well. Upscale aggregation of some of this convection is possible, increasing the severe-gust potential for at least a few hours into this evening and tonight. ...Midwest... A band of initial convection is crossing portions of IA and northwestern MO, ahead of the surface cold front. As this activity moves eastward into weakly destabilizing parts of IL/WI/northern MO through the day, some intensification may occur, resulting in isolated damaging gusts and marginally severe hail from the strongest segments. Behind this activity and along/ahead of the cold front, modest destabilization (from warm advection and limited insolation) will occur, supporting isolated to widely scattered afternoon thunderstorm development along the front, and additional risk of gusts/hail near severe limits. Favorable deep shear (effective-shear magnitudes around 40-50 kt) will spread over the area. However, limited instability is expected, with modest deep- layer lapse rates and trajectories from convectively processed source regions, keeping MLCAPE generally in the 500-1000 J/kg range in a narrow prefrontal corridor. Activity should weaken in the evening as it moves into a more-stable airmass. ..Edwards/Leitman.. 05/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Thu May 02 2024 Valid 021300Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NORTHWEST...NORTH-CENTRAL AND CENTRAL TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest, north-central and central Texas, where large to very large hail, severe gusts and a couple tornadoes are possible. ...Synopsis... In mid/upper levels, a complex cyclone -- now over southern SK and eastern MT -- is forecast to move slowly and erratically eastward stride the international border, orbited by several shortwaves/ vorticity lobes. The most influential of those perturbations is apparent in moisture-channel imagery over eastern WY to northwestern CO. This feature is forecast to strengthen and pivot to the central/eastern Dakotas by 00Z, then across MN to northern WI and western Lake Superior around 2Z tomorrow. Meanwhile, broad west- southwest to southwest flow in mid/upper levels -- with mainly convectively augmented/modified embedded perturbations -- will cover the central/southern Plains States. MCVs are evident over western IA, central OK and southeast TX. These should move across the Mississippi Valley this afternoon/evening, toward the Upper Great Lakes, Ohio Valley and Tennessee Valley, respectively. At the surface, 11Z analysis showed a low near STJ, with cold front across northeastern to south-central KS, the northern/western TX Panhandle, and north-central NM. A dryline was drawn over the Llano Estacado near the TX/NM line, southward into the western Big Bend region. By 00Z, the low should reach western WI, with cold front over northern IL, central MO, southeastern KS, central/southwestern OK, to a weak low over west-central TX. The eastward-mixing dryline will be overtaken by the cold front from north-south, with a 00Z position from the southern low southward near DRT. By 12Z, the cold front should reach the northeastern IN/northwestern OH region, extending southwestward to near a PAH-LIT-DAL line, then as a stationary to warm front west-northwestward to central NM. ...Southern Plains to western Gulf Coast... A large area of precip and embedded areas of thunderstorms is moving eastward across eastern OK, northeast/east TX, and western LA, anchored by some strong thunderstorm clusters in the southeast TX/southwestern LA area. Isolated, marginally severe hail and/or gusts may occur for a few more hours. Behind that activity, an outflow boundary extends across south- central TX, the Hill Country and Concho Valley regions, to the Permian Basin. Northward-directed warm/moist advection and theta-e recovery will occur today over west-central/northwest TX east of the dryline, before being intercepted by the cold front over the northwest TX/southwestern OK region this afternoon. Farther northeast over most of OK, severe potential will be more isolated and conditional near the front, given the presence of partially modified MCS-outflow air instead of a relatively undisturbed Gulf boundary layer. Isolated to scattered thunderstorms are expected to develop near the dryline and along the front this afternoon, with the most favorable parameter space, greatest low-level convergence, and densest convective concentration for severe potential being in and near the "slight" area. The northern rim of the residual outflow boundary will diffuse and move into this region as well, providing a potential low-level vorticity source that may help to offset some flow weaknesses aloft in terms of supporting supercell organization. 30-40 kt effective-shear magnitudes are possible. Forecast soundings reasonably indicate modest low-level flow supporting nearly straight hodographs with both left- and right-moving cells possible. Strong lapse rates -- generally 7.5 to 8 deg C from surface through 400 mb -- and mid/upper 60s F dewpoints, will support a plume of 3000-4500 J/kg MLCAPE over much of northwest, west-central and south-central/ southwest TX ahead of the dryline. Large to very large hail is the greatest concern, though storm-scale processes and boundary interactions may favor a tornado threat as well. Upscale aggregation of some of this convection is possible, increasing the severe-gust potential for at least a few hours into this evening and tonight. ...Midwest... A band of initial convection is crossing portions of IA and northwestern MO, ahead of the surface cold front. As this activity moves eastward into weakly destabilizing parts of IL/WI/northern MO through the day, some intensification may occur, resulting in isolated damaging gusts and marginally severe hail from the strongest segments. Behind this activity and along/ahead of the cold front, modest destabilization (from warm advection and limited insolation) will occur, supporting isolated to widely scattered afternoon thunderstorm development along the front, and additional risk of gusts/hail near severe limits. Favorable deep shear (effective-shear magnitudes around 40-50 kt) will spread over the area. However, limited instability is expected, with modest deep- layer lapse rates and trajectories from convectively processed source regions, keeping MLCAPE generally in the 500-1000 J/kg range in a narrow prefrontal corridor. Activity should weaken in the evening as it moves into a more-stable airmass. ..Edwards/Leitman.. 05/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Thu May 02 2024 Valid 021300Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NORTHWEST...NORTH-CENTRAL AND CENTRAL TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest, north-central and central Texas, where large to very large hail, severe gusts and a couple tornadoes are possible. ...Synopsis... In mid/upper levels, a complex cyclone -- now over southern SK and eastern MT -- is forecast to move slowly and erratically eastward stride the international border, orbited by several shortwaves/ vorticity lobes. The most influential of those perturbations is apparent in moisture-channel imagery over eastern WY to northwestern CO. This feature is forecast to strengthen and pivot to the central/eastern Dakotas by 00Z, then across MN to northern WI and western Lake Superior around 2Z tomorrow. Meanwhile, broad west- southwest to southwest flow in mid/upper levels -- with mainly convectively augmented/modified embedded perturbations -- will cover the central/southern Plains States. MCVs are evident over western IA, central OK and southeast TX. These should move across the Mississippi Valley this afternoon/evening, toward the Upper Great Lakes, Ohio Valley and Tennessee Valley, respectively. At the surface, 11Z analysis showed a low near STJ, with cold front across northeastern to south-central KS, the northern/western TX Panhandle, and north-central NM. A dryline was drawn over the Llano Estacado near the TX/NM line, southward into the western Big Bend region. By 00Z, the low should reach western WI, with cold front over northern IL, central MO, southeastern KS, central/southwestern OK, to a weak low over west-central TX. The eastward-mixing dryline will be overtaken by the cold front from north-south, with a 00Z position from the southern low southward near DRT. By 12Z, the cold front should reach the northeastern IN/northwestern OH region, extending southwestward to near a PAH-LIT-DAL line, then as a stationary to warm front west-northwestward to central NM. ...Southern Plains to western Gulf Coast... A large area of precip and embedded areas of thunderstorms is moving eastward across eastern OK, northeast/east TX, and western LA, anchored by some strong thunderstorm clusters in the southeast TX/southwestern LA area. Isolated, marginally severe hail and/or gusts may occur for a few more hours. Behind that activity, an outflow boundary extends across south- central TX, the Hill Country and Concho Valley regions, to the Permian Basin. Northward-directed warm/moist advection and theta-e recovery will occur today over west-central/northwest TX east of the dryline, before being intercepted by the cold front over the northwest TX/southwestern OK region this afternoon. Farther northeast over most of OK, severe potential will be more isolated and conditional near the front, given the presence of partially modified MCS-outflow air instead of a relatively undisturbed Gulf boundary layer. Isolated to scattered thunderstorms are expected to develop near the dryline and along the front this afternoon, with the most favorable parameter space, greatest low-level convergence, and densest convective concentration for severe potential being in and near the "slight" area. The northern rim of the residual outflow boundary will diffuse and move into this region as well, providing a potential low-level vorticity source that may help to offset some flow weaknesses aloft in terms of supporting supercell organization. 30-40 kt effective-shear magnitudes are possible. Forecast soundings reasonably indicate modest low-level flow supporting nearly straight hodographs with both left- and right-moving cells possible. Strong lapse rates -- generally 7.5 to 8 deg C from surface through 400 mb -- and mid/upper 60s F dewpoints, will support a plume of 3000-4500 J/kg MLCAPE over much of northwest, west-central and south-central/ southwest TX ahead of the dryline. Large to very large hail is the greatest concern, though storm-scale processes and boundary interactions may favor a tornado threat as well. Upscale aggregation of some of this convection is possible, increasing the severe-gust potential for at least a few hours into this evening and tonight. ...Midwest... A band of initial convection is crossing portions of IA and northwestern MO, ahead of the surface cold front. As this activity moves eastward into weakly destabilizing parts of IL/WI/northern MO through the day, some intensification may occur, resulting in isolated damaging gusts and marginally severe hail from the strongest segments. Behind this activity and along/ahead of the cold front, modest destabilization (from warm advection and limited insolation) will occur, supporting isolated to widely scattered afternoon thunderstorm development along the front, and additional risk of gusts/hail near severe limits. Favorable deep shear (effective-shear magnitudes around 40-50 kt) will spread over the area. However, limited instability is expected, with modest deep- layer lapse rates and trajectories from convectively processed source regions, keeping MLCAPE generally in the 500-1000 J/kg range in a narrow prefrontal corridor. Activity should weaken in the evening as it moves into a more-stable airmass. ..Edwards/Leitman.. 05/02/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Thu May 02 2024 Valid 021300Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NORTHWEST...NORTH-CENTRAL AND CENTRAL TEXAS... ...SUMMARY... Strong to severe thunderstorms will be possible today from parts of the Upper Midwest to the southern Plains. The greatest potential appears to be over parts of northwest, north-central and central Texas, where large to very large hail, severe gusts and a couple tornadoes are possible. ...Synopsis... In mid/upper levels, a complex cyclone -- now over southern SK and eastern MT -- is forecast to move slowly and erratically eastward stride the international border, orbited by several shortwaves/ vorticity lobes. The most influential of those perturbations is apparent in moisture-channel imagery over eastern WY to northwestern CO. This feature is forecast to strengthen and pivot to the central/eastern Dakotas by 00Z, then across MN to northern WI and western Lake Superior around 2Z tomorrow. Meanwhile, broad west- southwest to southwest flow in mid/upper levels -- with mainly convectively augmented/modified embedded perturbations -- will cover the central/southern Plains States. MCVs are evident over western IA, central OK and southeast TX. These should move across the Mississippi Valley this afternoon/evening, toward the Upper Great Lakes, Ohio Valley and Tennessee Valley, respectively. At the surface, 11Z analysis showed a low near STJ, with cold front across northeastern to south-central KS, the northern/western TX Panhandle, and north-central NM. A dryline was drawn over the Llano Estacado near the TX/NM line, southward into the western Big Bend region. By 00Z, the low should reach western WI, with cold front over northern IL, central MO, southeastern KS, central/southwestern OK, to a weak low over west-central TX. The eastward-mixing dryline will be overtaken by the cold front from north-south, with a 00Z position from the southern low southward near DRT. By 12Z, the cold front should reach the northeastern IN/northwestern OH region, extending southwestward to near a PAH-LIT-DAL line, then as a stationary to warm front west-northwestward to central NM. ...Southern Plains to western Gulf Coast... A large area of precip and embedded areas of thunderstorms is moving eastward across eastern OK, northeast/east TX, and western LA, anchored by some strong thunderstorm clusters in the southeast TX/southwestern LA area. Isolated, marginally severe hail and/or gusts may occur for a few more hours. Behind that activity, an outflow boundary extends across south- central TX, the Hill Country and Concho Valley regions, to the Permian Basin. Northward-directed warm/moist advection and theta-e recovery will occur today over west-central/northwest TX east of the dryline, before being intercepted by the cold front over the northwest TX/southwestern OK region this afternoon. Farther northeast over most of OK, severe potential will be more isolated and conditional near the front, given the presence of partially modified MCS-outflow air instead of a relatively undisturbed Gulf boundary layer. Isolated to scattered thunderstorms are expected to develop near the dryline and along the front this afternoon, with the most favorable parameter space, greatest low-level convergence, and densest convective concentration for severe potential being in and near the "slight" area. The northern rim of the residual outflow boundary will diffuse and move into this region as well, providing a potential low-level vorticity source that may help to offset some flow weaknesses aloft in terms of supporting supercell organization. 30-40 kt effective-shear magnitudes are possible. Forecast soundings reasonably indicate modest low-level flow supporting nearly straight hodographs with both left- and right-moving cells possible. Strong lapse rates -- generally 7.5 to 8 deg C from surface through 400 mb -- and mid/upper 60s F dewpoints, will support a plume of 3000-4500 J/kg MLCAPE over much of northwest, west-central and south-central/ southwest TX ahead of the dryline. Large to very large hail is the greatest concern, though storm-scale processes and boundary interactions may favor a tornado threat as well. Upscale aggregation of some of this convection is possible, increasing the severe-gust potential for at least a few hours into this evening and tonight. ...Midwest... A band of initial convection is crossing portions of IA and northwestern MO, ahead of the surface cold front. As this activity moves eastward into weakly destabilizing parts of IL/WI/northern MO through the day, some intensification may occur, resulting in isolated damaging gusts and marginally severe hail from the strongest segments. Behind this activity and along/ahead of the cold front, modest destabilization (from warm advection and limited insolation) will occur, supporting isolated to widely scattered afternoon thunderstorm development along the front, and additional risk of gusts/hail near severe limits. Favorable deep shear (effective-shear magnitudes around 40-50 kt) will spread over the area. However, limited instability is expected, with modest deep- layer lapse rates and trajectories from convectively processed source regions, keeping MLCAPE generally in the 500-1000 J/kg range in a narrow prefrontal corridor. Activity should weaken in the evening as it moves into a more-stable airmass. ..Edwards/Leitman.. 05/02/2024 Read more

MD 0603 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST TEXAS INTO SOUTHWEST LOUISIANA
Mesoscale Discussion 0603 NWS Storm Prediction Center Norman OK 0554 AM CDT Thu May 02 2024 Areas affected...southeast Texas into southwest Louisiana Concerning...Severe potential...Watch unlikely Valid 021054Z - 021230Z Probability of Watch Issuance...20 percent SUMMARY...Strong thunderstorms may locally produce gusty winds or hail to near 1 inch over the next couple of hours. DISCUSSION...Isolated thunderstorms will continue shifting east/southeast the next few hours. A 30-40 kt southerly low-level jet and embedded, convectively induced MCV is likely aiding in continued thunderstorm organization amid moderate instability (MLCAPE 1500-2000 J/kg). Sporadic, locally strong gusts are possible, in additional to hail to near 1 inch, before storms move offshore over the next couple of hours. Given the marginal nature of the severe threat, and limited spatial/temporal extent of the threat, a watch is not expected. ..Leitman/Edwards.. 05/02/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LCH...HGX... LAT...LON 29919546 30179604 30349616 30649604 30969575 31019543 30889419 30699327 30469286 30239269 29569291 29369357 29469431 29919546 Read more

MD 0602 CONCERNING SEVERE THUNDERSTORM WATCH 176... FOR PORTIONS OF SOUTHEAST NE...NORTHEAST KS AND ADJACENT PORTIONS OF IA/MO
Mesoscale Discussion 0602 NWS Storm Prediction Center Norman OK 0238 AM CDT Thu May 02 2024 Areas affected...portions of southeast NE...northeast KS and adjacent portions of IA/MO Concerning...Severe Thunderstorm Watch 176... Valid 020738Z - 020845Z The severe weather threat for Severe Thunderstorm Watch 176 continues. SUMMARY...Locally strong gusts are possible in the short term across southeast Nebraska into northeast Kansas. Overall severe potential is expected to diminish with time/extent over the next 1-2 hours. DISCUSSION...A leading thunderstorm cluster across southeast NE/far northeast KS will continue to pose a risk for locally strong gusts over the next hour. This activity is moving into an airmass with dewpoints in the upper 40s F and rapidly weakening instability. The expectation is that convection will begin to weaken with time/eastward extent over the next 1-2 hours. As such, a downstream watch is not expected into southwest IA/northwest MO. Additional convective lines/clusters further west over north-central KS are behind outflow from eastern convection. This activity is not expected to pose much severe risk, through gusts to 45 mph are possible. ..Leitman.. 05/02/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...OAX...TOP...GID... LAT...LON 40869717 41179595 40849538 40289511 39719531 39529605 39309724 39399775 39939778 40689745 40869717 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0316 AM CDT Thu May 02 2024 Valid 051200Z - 101200Z ...DISCUSSION... A large upper trough with a strong embedded shortwave will develop across the western CONUS on Sunday/D4, with an 80 kt 500 mb speed max forecast over CO and NM by 12Z Monday. This trough will progressively become negatively tilted, moving quickly across the central and northern Plains during the day on Monday/D5. Even with the leading wave moving northeast, height falls will persist as far south as northern TX as a secondary speed max noses into CO/NM through Tuesday/D6 morning. Although model differences exist regarding the timing of the strong lead wave, the combination of a deepening surface low, strong large-scale ascent and moderate to strong instability will support scattered to perhaps widespread severe storms on Monday. Low-level moisture return will increase Sunday/D4 night as a southerly low-level jet develops. During the day on Monday/D5, models show low to mid 60s F dewpoints as far north as I-80 in NE/IA, with upper 60s to lower 70s F from OK into TX. The end result will be 2000 to perhaps 3000 J/kg MUCAPE across the warm sector, with strengthening shear. The strong wind fields and progressive nature of trough will lead to an eastward expansion of steep low-level lapse rates across most of NE, KS, and into central OK by late afternoon, aiding surface-based storms including supercells, tornadoes, particularly damaging winds and very large hail. If slower solutions such as the ECMWF verify, the severe risk could last well into the evening across eastern KS, OK, and western MO. Given the aforementioned timing and positioning differences with the parent trough and cold front/dryline, will maintain a broad 15% risk area, with upgrades in later outlooks as predictability increases. For the Tuesday/D6 through Thursday/D8 period, significant severe weather potential is likely primarily from parts of TX, OK, and AR, and eventually LA and MS as strengthening zonal flow will be possible across the region. A moist and unstable air mass beneath such a flow regime (moderate west/southwest flow with subtle disturbances) would lead to an eastward expansion of the EML, with not only a tornado risk but very large hail. Additional severe outlooks are likely as these details become more predictable. Read more