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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0216 AM CDT Thu May 01 2025 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR FAR SOUTH TEXAS AND FROM THE SOUTHEAST TO NEW ENGLAND... ...SUMMARY... Isolated strong to severe storms are possible on Saturday from the Southeast to New England and across far South Texas. ...Synopsis... A mid-level trough will move from the Great Lakes to the Northeast on Saturday. At the surface a cold front will advance across the Appalachians and eventually off the Atlantic Coast and will also extend westward near the Gulf Coast, and into South Texas. High pressure will build into the Midwest in the wake of this cold front. ...East Coast... Scattered thunderstorms are expected to develop along and ahead of a cold front during the afternoon as some destabilization occurs east of the Appalachians. An expansive area of upper 50s to low 60s dewpoints will be present east of the Appalachians on Saturday. Some heating is expected during the afternoon which may lead to weak to potentially moderate instability. Mid-level lapse rates are forecast to be weak with only marginally strong shear. Given this environment, a few multicell storms are possible along and ahead of the eastward advancing cold front. However, more widespread coverage of severe storms is not anticipated at this time. ...Far South Texas... Thunderstorms will likely be ongoing at the beginning of the period along a front as it moves south across Texas. A very moist airmass with steep mid-level lapse rates will be in place with 45 to 50 knots of deep-layer shear. Therefore, organized storms, including the potential for supercells exists during the morning hours Saturday before the front moves into northern Mexico/the Gulf. ..Bentley.. 05/01/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0216 AM CDT Thu May 01 2025 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR FAR SOUTH TEXAS AND FROM THE SOUTHEAST TO NEW ENGLAND... ...SUMMARY... Isolated strong to severe storms are possible on Saturday from the Southeast to New England and across far South Texas. ...Synopsis... A mid-level trough will move from the Great Lakes to the Northeast on Saturday. At the surface a cold front will advance across the Appalachians and eventually off the Atlantic Coast and will also extend westward near the Gulf Coast, and into South Texas. High pressure will build into the Midwest in the wake of this cold front. ...East Coast... Scattered thunderstorms are expected to develop along and ahead of a cold front during the afternoon as some destabilization occurs east of the Appalachians. An expansive area of upper 50s to low 60s dewpoints will be present east of the Appalachians on Saturday. Some heating is expected during the afternoon which may lead to weak to potentially moderate instability. Mid-level lapse rates are forecast to be weak with only marginally strong shear. Given this environment, a few multicell storms are possible along and ahead of the eastward advancing cold front. However, more widespread coverage of severe storms is not anticipated at this time. ...Far South Texas... Thunderstorms will likely be ongoing at the beginning of the period along a front as it moves south across Texas. A very moist airmass with steep mid-level lapse rates will be in place with 45 to 50 knots of deep-layer shear. Therefore, organized storms, including the potential for supercells exists during the morning hours Saturday before the front moves into northern Mexico/the Gulf. ..Bentley.. 05/01/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0216 AM CDT Thu May 01 2025 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR FAR SOUTH TEXAS AND FROM THE SOUTHEAST TO NEW ENGLAND... ...SUMMARY... Isolated strong to severe storms are possible on Saturday from the Southeast to New England and across far South Texas. ...Synopsis... A mid-level trough will move from the Great Lakes to the Northeast on Saturday. At the surface a cold front will advance across the Appalachians and eventually off the Atlantic Coast and will also extend westward near the Gulf Coast, and into South Texas. High pressure will build into the Midwest in the wake of this cold front. ...East Coast... Scattered thunderstorms are expected to develop along and ahead of a cold front during the afternoon as some destabilization occurs east of the Appalachians. An expansive area of upper 50s to low 60s dewpoints will be present east of the Appalachians on Saturday. Some heating is expected during the afternoon which may lead to weak to potentially moderate instability. Mid-level lapse rates are forecast to be weak with only marginally strong shear. Given this environment, a few multicell storms are possible along and ahead of the eastward advancing cold front. However, more widespread coverage of severe storms is not anticipated at this time. ...Far South Texas... Thunderstorms will likely be ongoing at the beginning of the period along a front as it moves south across Texas. A very moist airmass with steep mid-level lapse rates will be in place with 45 to 50 knots of deep-layer shear. Therefore, organized storms, including the potential for supercells exists during the morning hours Saturday before the front moves into northern Mexico/the Gulf. ..Bentley.. 05/01/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0216 AM CDT Thu May 01 2025 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR FAR SOUTH TEXAS AND FROM THE SOUTHEAST TO NEW ENGLAND... ...SUMMARY... Isolated strong to severe storms are possible on Saturday from the Southeast to New England and across far South Texas. ...Synopsis... A mid-level trough will move from the Great Lakes to the Northeast on Saturday. At the surface a cold front will advance across the Appalachians and eventually off the Atlantic Coast and will also extend westward near the Gulf Coast, and into South Texas. High pressure will build into the Midwest in the wake of this cold front. ...East Coast... Scattered thunderstorms are expected to develop along and ahead of a cold front during the afternoon as some destabilization occurs east of the Appalachians. An expansive area of upper 50s to low 60s dewpoints will be present east of the Appalachians on Saturday. Some heating is expected during the afternoon which may lead to weak to potentially moderate instability. Mid-level lapse rates are forecast to be weak with only marginally strong shear. Given this environment, a few multicell storms are possible along and ahead of the eastward advancing cold front. However, more widespread coverage of severe storms is not anticipated at this time. ...Far South Texas... Thunderstorms will likely be ongoing at the beginning of the period along a front as it moves south across Texas. A very moist airmass with steep mid-level lapse rates will be in place with 45 to 50 knots of deep-layer shear. Therefore, organized storms, including the potential for supercells exists during the morning hours Saturday before the front moves into northern Mexico/the Gulf. ..Bentley.. 05/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TRANS PECOS TO EAST-CENTRAL TEXAS... ...SUMMARY... Scattered strong to severe thunderstorms are expected from the Northeast, across the Ohio, Tennessee, and Lower Mississippi Valleys and into Texas on Friday. The greatest threat for large hail will be from the Trans Pecos to East Texas. ...Synopsis... A surface low will move from Ontario into northern Quebec on Friday with a trailing front stalling from the Great Lakes to the Ozarks to West Texas. This front will start to accelerate southeast during the late afternoon/evening as a positively tilted mid-level trough amplifies and moves south across the Plains. Scattered strong to severe storms are forecast along this frontal zone Friday afternoon/evening. ...Trans Pecos to East Texas... Moderate instability is forecast south of a frontal zone across central Texas Friday afternoon. As the mid-level trough advances southward through the Plains, mid-level temperatures will cool and ascent will overspread this frontal zone. Therefore, as the airmass becomes uncapped, scattered thunderstorms should develop along the front. 35 to 40 knots of effective shear should be sufficient for supercells with a primary hazard of large hail. ...Mid Mississippi Valley to the eastern Great Lakes... Scattered thunderstorms are expected along and ahead of the front from Louisiana to western New York on Friday afternoon. The best flow will be across Kentucky and Ohio and into Pennsylvania and New York, but heating/destabilization becomes more questionable that far north. The best overlap of mid-level flow and richer low-level moisture will be across the Mid-Mississippi Valley. However, cloud cover associated with an MCS which is expected to be ongoing at the beginning of the period across Texas and Arkansas will limit heating and thus destabilization. Better instability will be likely where heating can occur to the south of the more extensive cloud cover, but shear/forcing becomes weaker farther south and east. Therefore, within the broad marginal risk from western New York to Louisiana there will likely be one or more corridors with a greater threat for severe storms, but those areas will be mesoscale in nature and highly dependent on Day 1 convection. Therefore, no higher probabilities have been added at this time. ..Bentley.. 05/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TRANS PECOS TO EAST-CENTRAL TEXAS... ...SUMMARY... Scattered strong to severe thunderstorms are expected from the Northeast, across the Ohio, Tennessee, and Lower Mississippi Valleys and into Texas on Friday. The greatest threat for large hail will be from the Trans Pecos to East Texas. ...Synopsis... A surface low will move from Ontario into northern Quebec on Friday with a trailing front stalling from the Great Lakes to the Ozarks to West Texas. This front will start to accelerate southeast during the late afternoon/evening as a positively tilted mid-level trough amplifies and moves south across the Plains. Scattered strong to severe storms are forecast along this frontal zone Friday afternoon/evening. ...Trans Pecos to East Texas... Moderate instability is forecast south of a frontal zone across central Texas Friday afternoon. As the mid-level trough advances southward through the Plains, mid-level temperatures will cool and ascent will overspread this frontal zone. Therefore, as the airmass becomes uncapped, scattered thunderstorms should develop along the front. 35 to 40 knots of effective shear should be sufficient for supercells with a primary hazard of large hail. ...Mid Mississippi Valley to the eastern Great Lakes... Scattered thunderstorms are expected along and ahead of the front from Louisiana to western New York on Friday afternoon. The best flow will be across Kentucky and Ohio and into Pennsylvania and New York, but heating/destabilization becomes more questionable that far north. The best overlap of mid-level flow and richer low-level moisture will be across the Mid-Mississippi Valley. However, cloud cover associated with an MCS which is expected to be ongoing at the beginning of the period across Texas and Arkansas will limit heating and thus destabilization. Better instability will be likely where heating can occur to the south of the more extensive cloud cover, but shear/forcing becomes weaker farther south and east. Therefore, within the broad marginal risk from western New York to Louisiana there will likely be one or more corridors with a greater threat for severe storms, but those areas will be mesoscale in nature and highly dependent on Day 1 convection. Therefore, no higher probabilities have been added at this time. ..Bentley.. 05/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TRANS PECOS TO EAST-CENTRAL TEXAS... ...SUMMARY... Scattered strong to severe thunderstorms are expected from the Northeast, across the Ohio, Tennessee, and Lower Mississippi Valleys and into Texas on Friday. The greatest threat for large hail will be from the Trans Pecos to East Texas. ...Synopsis... A surface low will move from Ontario into northern Quebec on Friday with a trailing front stalling from the Great Lakes to the Ozarks to West Texas. This front will start to accelerate southeast during the late afternoon/evening as a positively tilted mid-level trough amplifies and moves south across the Plains. Scattered strong to severe storms are forecast along this frontal zone Friday afternoon/evening. ...Trans Pecos to East Texas... Moderate instability is forecast south of a frontal zone across central Texas Friday afternoon. As the mid-level trough advances southward through the Plains, mid-level temperatures will cool and ascent will overspread this frontal zone. Therefore, as the airmass becomes uncapped, scattered thunderstorms should develop along the front. 35 to 40 knots of effective shear should be sufficient for supercells with a primary hazard of large hail. ...Mid Mississippi Valley to the eastern Great Lakes... Scattered thunderstorms are expected along and ahead of the front from Louisiana to western New York on Friday afternoon. The best flow will be across Kentucky and Ohio and into Pennsylvania and New York, but heating/destabilization becomes more questionable that far north. The best overlap of mid-level flow and richer low-level moisture will be across the Mid-Mississippi Valley. However, cloud cover associated with an MCS which is expected to be ongoing at the beginning of the period across Texas and Arkansas will limit heating and thus destabilization. Better instability will be likely where heating can occur to the south of the more extensive cloud cover, but shear/forcing becomes weaker farther south and east. Therefore, within the broad marginal risk from western New York to Louisiana there will likely be one or more corridors with a greater threat for severe storms, but those areas will be mesoscale in nature and highly dependent on Day 1 convection. Therefore, no higher probabilities have been added at this time. ..Bentley.. 05/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TRANS PECOS TO EAST-CENTRAL TEXAS... ...SUMMARY... Scattered strong to severe thunderstorms are expected from the Northeast, across the Ohio, Tennessee, and Lower Mississippi Valleys and into Texas on Friday. The greatest threat for large hail will be from the Trans Pecos to East Texas. ...Synopsis... A surface low will move from Ontario into northern Quebec on Friday with a trailing front stalling from the Great Lakes to the Ozarks to West Texas. This front will start to accelerate southeast during the late afternoon/evening as a positively tilted mid-level trough amplifies and moves south across the Plains. Scattered strong to severe storms are forecast along this frontal zone Friday afternoon/evening. ...Trans Pecos to East Texas... Moderate instability is forecast south of a frontal zone across central Texas Friday afternoon. As the mid-level trough advances southward through the Plains, mid-level temperatures will cool and ascent will overspread this frontal zone. Therefore, as the airmass becomes uncapped, scattered thunderstorms should develop along the front. 35 to 40 knots of effective shear should be sufficient for supercells with a primary hazard of large hail. ...Mid Mississippi Valley to the eastern Great Lakes... Scattered thunderstorms are expected along and ahead of the front from Louisiana to western New York on Friday afternoon. The best flow will be across Kentucky and Ohio and into Pennsylvania and New York, but heating/destabilization becomes more questionable that far north. The best overlap of mid-level flow and richer low-level moisture will be across the Mid-Mississippi Valley. However, cloud cover associated with an MCS which is expected to be ongoing at the beginning of the period across Texas and Arkansas will limit heating and thus destabilization. Better instability will be likely where heating can occur to the south of the more extensive cloud cover, but shear/forcing becomes weaker farther south and east. Therefore, within the broad marginal risk from western New York to Louisiana there will likely be one or more corridors with a greater threat for severe storms, but those areas will be mesoscale in nature and highly dependent on Day 1 convection. Therefore, no higher probabilities have been added at this time. ..Bentley.. 05/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF WRN NY...WRN PA...WRN WV...MUCH OF OH...SERN IN...CNTRL AND ERN KY...MIDDLE TN...CNTRL/SRN MS...NRN/CNTRL LA...SRN AR...SRN OK...NRN TX... ...SUMMARY... Lines and/or clusters of strong to severe thunderstorms are likely to impact parts of the Ohio Valley into lower Great Lakes, parts of the lower Mississippi Valley, and the southern Great Plains this afternoon through tonight. ...Discussion... It appears that an amplifying mid/upper flow regime across the northern mid-latitudes of the eastern Pacific into North America will undergo further amplification while continuing to develop inland through this period. This will include a prominent ridge overspreading the Canadian Rockies and northern U.S. intermountain region later today through tonight, perhaps with an embedded high evolving to the east of the Cascades. Downstream, a notable short wave trough is forecast to continue digging to the lee of the northern U.S. Rockies, preceded by a short wave trough which has recently emerged from the Southwest. Models suggest that the lead perturbation will undergo shearing, but it may still provide support for modest deepening of a surface low northeast of the middle Mississippi Valley through lower Great Lakes region by late tonight. To the southwest of this low, conglomerate outflow from extensive convective development of prior days will at least initially precede and obscure any trailing surface front. By 12Z this morning, it appears that the leading edge of this outflow will be in the process of advancing eastward through the lower Ohio Valley, while stalling and weakening across the lower Mississippi Valley through upper Texas coastal plain. It remains a bit unclear the extent to which the surface outflow, residual cloud cover and rain will impact destabilization and convective potential later today. It is possible that this could impact a sizable area centered across parts of the Mid South. ...Ohio Valley into lower Great Lakes... Uncertainty exists concerning the possible influence of convective outflow and cloud cover on destabilization, and spread is evident among the various model output concerning the synoptic evolution. However, broad surface troughing overspreading the region during the day may provide the focus for the highest probabilities of vigorous thunderstorm development. Boundary-layer moistening (including mid 60s F surface dew points) and warming may become sufficient to support mixed-layer CAPE on the order of 1000-2000+ J/kg, in the presence of 30-50 kt south to southwesterly flow in the 850-500 mb layer. This environment may become conducive to organizing lines or clusters of storms, and perhaps a few supercell structures, posing a risk of severe wind and hail, with at least some potential for tornadoes, during the afternoon and evening. ...Lower Mississippi Valley vicinity... Large-scale forcing for ascent to support convective development remains unclear, on top of the possible lingering influence of convective outflow, cloud cover and rain. However, the NAM and Rapid Refresh suggest that a zone of strengthening differential heating may develop across the Ark-La-Tex into lower Mississippi Valley during the day, providing a focus for strong destabilization beneath steep-lapse rates associated with remnant elevated mixed-layer air. Aided by boundary-layer moisture characterized by surface dew points near 70F, large CAPE on the order of 2000-3000+ J/kg is forecast beneath modest westerly mid-level flow. Perhaps aided by lift associated with low-level warm advection, organizing convection posing a risk for large hail and damaging wind gusts appears possible. This may include supercell structures, at least initially, and eventually an upscale growing, east-southeastward propagating cluster. ...Raton Mesa into southern Great Plains Red River vicinity... Models indicate another zone of potentially strong convective development may evolve late this afternoon into tonight, as the boundary layer moistens and heats beneath the northern periphery of a plume of elevated mixed-layer air. It appears that this will advect east/east-southeast of the southern Rockies, near the southern periphery of the mid-level troughing digging to the lee of the northern Rockies. Models suggest that a smaller-scale embedded perturbation may be accompanied by increasing convective development across and east-southeast of the Raton Mesa vicinity by early this evening. Aided by updraft inflow of increasing instability across the Texas Panhandle into areas near/north of the Red River, there appears potential for the evolution of an upscale growing cluster. The 01/00Z NAM, in particular, generates a convective perturbation that would appear to include 70+ kt westerly rear inflow (in the 850-700 mb layer) across Oklahoma by late tonight. Based on other output, this appears an outlier, but the evolution of a convective cluster posing a risk for severe hail and wind appears possible. ..Kerr/Weinman.. 05/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF WRN NY...WRN PA...WRN WV...MUCH OF OH...SERN IN...CNTRL AND ERN KY...MIDDLE TN...CNTRL/SRN MS...NRN/CNTRL LA...SRN AR...SRN OK...NRN TX... ...SUMMARY... Lines and/or clusters of strong to severe thunderstorms are likely to impact parts of the Ohio Valley into lower Great Lakes, parts of the lower Mississippi Valley, and the southern Great Plains this afternoon through tonight. ...Discussion... It appears that an amplifying mid/upper flow regime across the northern mid-latitudes of the eastern Pacific into North America will undergo further amplification while continuing to develop inland through this period. This will include a prominent ridge overspreading the Canadian Rockies and northern U.S. intermountain region later today through tonight, perhaps with an embedded high evolving to the east of the Cascades. Downstream, a notable short wave trough is forecast to continue digging to the lee of the northern U.S. Rockies, preceded by a short wave trough which has recently emerged from the Southwest. Models suggest that the lead perturbation will undergo shearing, but it may still provide support for modest deepening of a surface low northeast of the middle Mississippi Valley through lower Great Lakes region by late tonight. To the southwest of this low, conglomerate outflow from extensive convective development of prior days will at least initially precede and obscure any trailing surface front. By 12Z this morning, it appears that the leading edge of this outflow will be in the process of advancing eastward through the lower Ohio Valley, while stalling and weakening across the lower Mississippi Valley through upper Texas coastal plain. It remains a bit unclear the extent to which the surface outflow, residual cloud cover and rain will impact destabilization and convective potential later today. It is possible that this could impact a sizable area centered across parts of the Mid South. ...Ohio Valley into lower Great Lakes... Uncertainty exists concerning the possible influence of convective outflow and cloud cover on destabilization, and spread is evident among the various model output concerning the synoptic evolution. However, broad surface troughing overspreading the region during the day may provide the focus for the highest probabilities of vigorous thunderstorm development. Boundary-layer moistening (including mid 60s F surface dew points) and warming may become sufficient to support mixed-layer CAPE on the order of 1000-2000+ J/kg, in the presence of 30-50 kt south to southwesterly flow in the 850-500 mb layer. This environment may become conducive to organizing lines or clusters of storms, and perhaps a few supercell structures, posing a risk of severe wind and hail, with at least some potential for tornadoes, during the afternoon and evening. ...Lower Mississippi Valley vicinity... Large-scale forcing for ascent to support convective development remains unclear, on top of the possible lingering influence of convective outflow, cloud cover and rain. However, the NAM and Rapid Refresh suggest that a zone of strengthening differential heating may develop across the Ark-La-Tex into lower Mississippi Valley during the day, providing a focus for strong destabilization beneath steep-lapse rates associated with remnant elevated mixed-layer air. Aided by boundary-layer moisture characterized by surface dew points near 70F, large CAPE on the order of 2000-3000+ J/kg is forecast beneath modest westerly mid-level flow. Perhaps aided by lift associated with low-level warm advection, organizing convection posing a risk for large hail and damaging wind gusts appears possible. This may include supercell structures, at least initially, and eventually an upscale growing, east-southeastward propagating cluster. ...Raton Mesa into southern Great Plains Red River vicinity... Models indicate another zone of potentially strong convective development may evolve late this afternoon into tonight, as the boundary layer moistens and heats beneath the northern periphery of a plume of elevated mixed-layer air. It appears that this will advect east/east-southeast of the southern Rockies, near the southern periphery of the mid-level troughing digging to the lee of the northern Rockies. Models suggest that a smaller-scale embedded perturbation may be accompanied by increasing convective development across and east-southeast of the Raton Mesa vicinity by early this evening. Aided by updraft inflow of increasing instability across the Texas Panhandle into areas near/north of the Red River, there appears potential for the evolution of an upscale growing cluster. The 01/00Z NAM, in particular, generates a convective perturbation that would appear to include 70+ kt westerly rear inflow (in the 850-700 mb layer) across Oklahoma by late tonight. Based on other output, this appears an outlier, but the evolution of a convective cluster posing a risk for severe hail and wind appears possible. ..Kerr/Weinman.. 05/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF WRN NY...WRN PA...WRN WV...MUCH OF OH...SERN IN...CNTRL AND ERN KY...MIDDLE TN...CNTRL/SRN MS...NRN/CNTRL LA...SRN AR...SRN OK...NRN TX... ...SUMMARY... Lines and/or clusters of strong to severe thunderstorms are likely to impact parts of the Ohio Valley into lower Great Lakes, parts of the lower Mississippi Valley, and the southern Great Plains this afternoon through tonight. ...Discussion... It appears that an amplifying mid/upper flow regime across the northern mid-latitudes of the eastern Pacific into North America will undergo further amplification while continuing to develop inland through this period. This will include a prominent ridge overspreading the Canadian Rockies and northern U.S. intermountain region later today through tonight, perhaps with an embedded high evolving to the east of the Cascades. Downstream, a notable short wave trough is forecast to continue digging to the lee of the northern U.S. Rockies, preceded by a short wave trough which has recently emerged from the Southwest. Models suggest that the lead perturbation will undergo shearing, but it may still provide support for modest deepening of a surface low northeast of the middle Mississippi Valley through lower Great Lakes region by late tonight. To the southwest of this low, conglomerate outflow from extensive convective development of prior days will at least initially precede and obscure any trailing surface front. By 12Z this morning, it appears that the leading edge of this outflow will be in the process of advancing eastward through the lower Ohio Valley, while stalling and weakening across the lower Mississippi Valley through upper Texas coastal plain. It remains a bit unclear the extent to which the surface outflow, residual cloud cover and rain will impact destabilization and convective potential later today. It is possible that this could impact a sizable area centered across parts of the Mid South. ...Ohio Valley into lower Great Lakes... Uncertainty exists concerning the possible influence of convective outflow and cloud cover on destabilization, and spread is evident among the various model output concerning the synoptic evolution. However, broad surface troughing overspreading the region during the day may provide the focus for the highest probabilities of vigorous thunderstorm development. Boundary-layer moistening (including mid 60s F surface dew points) and warming may become sufficient to support mixed-layer CAPE on the order of 1000-2000+ J/kg, in the presence of 30-50 kt south to southwesterly flow in the 850-500 mb layer. This environment may become conducive to organizing lines or clusters of storms, and perhaps a few supercell structures, posing a risk of severe wind and hail, with at least some potential for tornadoes, during the afternoon and evening. ...Lower Mississippi Valley vicinity... Large-scale forcing for ascent to support convective development remains unclear, on top of the possible lingering influence of convective outflow, cloud cover and rain. However, the NAM and Rapid Refresh suggest that a zone of strengthening differential heating may develop across the Ark-La-Tex into lower Mississippi Valley during the day, providing a focus for strong destabilization beneath steep-lapse rates associated with remnant elevated mixed-layer air. Aided by boundary-layer moisture characterized by surface dew points near 70F, large CAPE on the order of 2000-3000+ J/kg is forecast beneath modest westerly mid-level flow. Perhaps aided by lift associated with low-level warm advection, organizing convection posing a risk for large hail and damaging wind gusts appears possible. This may include supercell structures, at least initially, and eventually an upscale growing, east-southeastward propagating cluster. ...Raton Mesa into southern Great Plains Red River vicinity... Models indicate another zone of potentially strong convective development may evolve late this afternoon into tonight, as the boundary layer moistens and heats beneath the northern periphery of a plume of elevated mixed-layer air. It appears that this will advect east/east-southeast of the southern Rockies, near the southern periphery of the mid-level troughing digging to the lee of the northern Rockies. Models suggest that a smaller-scale embedded perturbation may be accompanied by increasing convective development across and east-southeast of the Raton Mesa vicinity by early this evening. Aided by updraft inflow of increasing instability across the Texas Panhandle into areas near/north of the Red River, there appears potential for the evolution of an upscale growing cluster. The 01/00Z NAM, in particular, generates a convective perturbation that would appear to include 70+ kt westerly rear inflow (in the 850-700 mb layer) across Oklahoma by late tonight. Based on other output, this appears an outlier, but the evolution of a convective cluster posing a risk for severe hail and wind appears possible. ..Kerr/Weinman.. 05/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF WRN NY...WRN PA...WRN WV...MUCH OF OH...SERN IN...CNTRL AND ERN KY...MIDDLE TN...CNTRL/SRN MS...NRN/CNTRL LA...SRN AR...SRN OK...NRN TX... ...SUMMARY... Lines and/or clusters of strong to severe thunderstorms are likely to impact parts of the Ohio Valley into lower Great Lakes, parts of the lower Mississippi Valley, and the southern Great Plains this afternoon through tonight. ...Discussion... It appears that an amplifying mid/upper flow regime across the northern mid-latitudes of the eastern Pacific into North America will undergo further amplification while continuing to develop inland through this period. This will include a prominent ridge overspreading the Canadian Rockies and northern U.S. intermountain region later today through tonight, perhaps with an embedded high evolving to the east of the Cascades. Downstream, a notable short wave trough is forecast to continue digging to the lee of the northern U.S. Rockies, preceded by a short wave trough which has recently emerged from the Southwest. Models suggest that the lead perturbation will undergo shearing, but it may still provide support for modest deepening of a surface low northeast of the middle Mississippi Valley through lower Great Lakes region by late tonight. To the southwest of this low, conglomerate outflow from extensive convective development of prior days will at least initially precede and obscure any trailing surface front. By 12Z this morning, it appears that the leading edge of this outflow will be in the process of advancing eastward through the lower Ohio Valley, while stalling and weakening across the lower Mississippi Valley through upper Texas coastal plain. It remains a bit unclear the extent to which the surface outflow, residual cloud cover and rain will impact destabilization and convective potential later today. It is possible that this could impact a sizable area centered across parts of the Mid South. ...Ohio Valley into lower Great Lakes... Uncertainty exists concerning the possible influence of convective outflow and cloud cover on destabilization, and spread is evident among the various model output concerning the synoptic evolution. However, broad surface troughing overspreading the region during the day may provide the focus for the highest probabilities of vigorous thunderstorm development. Boundary-layer moistening (including mid 60s F surface dew points) and warming may become sufficient to support mixed-layer CAPE on the order of 1000-2000+ J/kg, in the presence of 30-50 kt south to southwesterly flow in the 850-500 mb layer. This environment may become conducive to organizing lines or clusters of storms, and perhaps a few supercell structures, posing a risk of severe wind and hail, with at least some potential for tornadoes, during the afternoon and evening. ...Lower Mississippi Valley vicinity... Large-scale forcing for ascent to support convective development remains unclear, on top of the possible lingering influence of convective outflow, cloud cover and rain. However, the NAM and Rapid Refresh suggest that a zone of strengthening differential heating may develop across the Ark-La-Tex into lower Mississippi Valley during the day, providing a focus for strong destabilization beneath steep-lapse rates associated with remnant elevated mixed-layer air. Aided by boundary-layer moisture characterized by surface dew points near 70F, large CAPE on the order of 2000-3000+ J/kg is forecast beneath modest westerly mid-level flow. Perhaps aided by lift associated with low-level warm advection, organizing convection posing a risk for large hail and damaging wind gusts appears possible. This may include supercell structures, at least initially, and eventually an upscale growing, east-southeastward propagating cluster. ...Raton Mesa into southern Great Plains Red River vicinity... Models indicate another zone of potentially strong convective development may evolve late this afternoon into tonight, as the boundary layer moistens and heats beneath the northern periphery of a plume of elevated mixed-layer air. It appears that this will advect east/east-southeast of the southern Rockies, near the southern periphery of the mid-level troughing digging to the lee of the northern Rockies. Models suggest that a smaller-scale embedded perturbation may be accompanied by increasing convective development across and east-southeast of the Raton Mesa vicinity by early this evening. Aided by updraft inflow of increasing instability across the Texas Panhandle into areas near/north of the Red River, there appears potential for the evolution of an upscale growing cluster. The 01/00Z NAM, in particular, generates a convective perturbation that would appear to include 70+ kt westerly rear inflow (in the 850-700 mb layer) across Oklahoma by late tonight. Based on other output, this appears an outlier, but the evolution of a convective cluster posing a risk for severe hail and wind appears possible. ..Kerr/Weinman.. 05/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Thu May 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF WRN NY...WRN PA...WRN WV...MUCH OF OH...SERN IN...CNTRL AND ERN KY...MIDDLE TN...CNTRL/SRN MS...NRN/CNTRL LA...SRN AR...SRN OK...NRN TX... ...SUMMARY... Lines and/or clusters of strong to severe thunderstorms are likely to impact parts of the Ohio Valley into lower Great Lakes, parts of the lower Mississippi Valley, and the southern Great Plains this afternoon through tonight. ...Discussion... It appears that an amplifying mid/upper flow regime across the northern mid-latitudes of the eastern Pacific into North America will undergo further amplification while continuing to develop inland through this period. This will include a prominent ridge overspreading the Canadian Rockies and northern U.S. intermountain region later today through tonight, perhaps with an embedded high evolving to the east of the Cascades. Downstream, a notable short wave trough is forecast to continue digging to the lee of the northern U.S. Rockies, preceded by a short wave trough which has recently emerged from the Southwest. Models suggest that the lead perturbation will undergo shearing, but it may still provide support for modest deepening of a surface low northeast of the middle Mississippi Valley through lower Great Lakes region by late tonight. To the southwest of this low, conglomerate outflow from extensive convective development of prior days will at least initially precede and obscure any trailing surface front. By 12Z this morning, it appears that the leading edge of this outflow will be in the process of advancing eastward through the lower Ohio Valley, while stalling and weakening across the lower Mississippi Valley through upper Texas coastal plain. It remains a bit unclear the extent to which the surface outflow, residual cloud cover and rain will impact destabilization and convective potential later today. It is possible that this could impact a sizable area centered across parts of the Mid South. ...Ohio Valley into lower Great Lakes... Uncertainty exists concerning the possible influence of convective outflow and cloud cover on destabilization, and spread is evident among the various model output concerning the synoptic evolution. However, broad surface troughing overspreading the region during the day may provide the focus for the highest probabilities of vigorous thunderstorm development. Boundary-layer moistening (including mid 60s F surface dew points) and warming may become sufficient to support mixed-layer CAPE on the order of 1000-2000+ J/kg, in the presence of 30-50 kt south to southwesterly flow in the 850-500 mb layer. This environment may become conducive to organizing lines or clusters of storms, and perhaps a few supercell structures, posing a risk of severe wind and hail, with at least some potential for tornadoes, during the afternoon and evening. ...Lower Mississippi Valley vicinity... Large-scale forcing for ascent to support convective development remains unclear, on top of the possible lingering influence of convective outflow, cloud cover and rain. However, the NAM and Rapid Refresh suggest that a zone of strengthening differential heating may develop across the Ark-La-Tex into lower Mississippi Valley during the day, providing a focus for strong destabilization beneath steep-lapse rates associated with remnant elevated mixed-layer air. Aided by boundary-layer moisture characterized by surface dew points near 70F, large CAPE on the order of 2000-3000+ J/kg is forecast beneath modest westerly mid-level flow. Perhaps aided by lift associated with low-level warm advection, organizing convection posing a risk for large hail and damaging wind gusts appears possible. This may include supercell structures, at least initially, and eventually an upscale growing, east-southeastward propagating cluster. ...Raton Mesa into southern Great Plains Red River vicinity... Models indicate another zone of potentially strong convective development may evolve late this afternoon into tonight, as the boundary layer moistens and heats beneath the northern periphery of a plume of elevated mixed-layer air. It appears that this will advect east/east-southeast of the southern Rockies, near the southern periphery of the mid-level troughing digging to the lee of the northern Rockies. Models suggest that a smaller-scale embedded perturbation may be accompanied by increasing convective development across and east-southeast of the Raton Mesa vicinity by early this evening. Aided by updraft inflow of increasing instability across the Texas Panhandle into areas near/north of the Red River, there appears potential for the evolution of an upscale growing cluster. The 01/00Z NAM, in particular, generates a convective perturbation that would appear to include 70+ kt westerly rear inflow (in the 850-700 mb layer) across Oklahoma by late tonight. Based on other output, this appears an outlier, but the evolution of a convective cluster posing a risk for severe hail and wind appears possible. ..Kerr/Weinman.. 05/01/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... ...Synopsis... A low-amplitude midlevel trough will move eastward across northern Mexico and the Southwest. As large-scale ascent accompanying this feature overspreads a midlevel moisture plume across the Southwest, widely scattered dry thunderstorms will develop along the higher terrain. However, the overlap of these high-based thunderstorms and dry/receptive fuels appears too limited for Dry Thunderstorm highlights at this time. Elsewhere across the CONUS, a minimal overlap of dry/breezy conditions will limit fire-weather concerns. ..Weinman.. 05/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... ...Synopsis... A low-amplitude midlevel trough will move eastward across northern Mexico and the Southwest. As large-scale ascent accompanying this feature overspreads a midlevel moisture plume across the Southwest, widely scattered dry thunderstorms will develop along the higher terrain. However, the overlap of these high-based thunderstorms and dry/receptive fuels appears too limited for Dry Thunderstorm highlights at this time. Elsewhere across the CONUS, a minimal overlap of dry/breezy conditions will limit fire-weather concerns. ..Weinman.. 05/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... ...Synopsis... A low-amplitude midlevel trough will move eastward across northern Mexico and the Southwest. As large-scale ascent accompanying this feature overspreads a midlevel moisture plume across the Southwest, widely scattered dry thunderstorms will develop along the higher terrain. However, the overlap of these high-based thunderstorms and dry/receptive fuels appears too limited for Dry Thunderstorm highlights at this time. Elsewhere across the CONUS, a minimal overlap of dry/breezy conditions will limit fire-weather concerns. ..Weinman.. 05/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... ...Synopsis... A low-amplitude midlevel trough will move eastward across northern Mexico and the Southwest. As large-scale ascent accompanying this feature overspreads a midlevel moisture plume across the Southwest, widely scattered dry thunderstorms will develop along the higher terrain. However, the overlap of these high-based thunderstorms and dry/receptive fuels appears too limited for Dry Thunderstorm highlights at this time. Elsewhere across the CONUS, a minimal overlap of dry/breezy conditions will limit fire-weather concerns. ..Weinman.. 05/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... ...Synopsis... A low-amplitude midlevel trough will move eastward across northern Mexico and the Southwest. As large-scale ascent accompanying this feature overspreads a midlevel moisture plume across the Southwest, widely scattered dry thunderstorms will develop along the higher terrain. However, the overlap of these high-based thunderstorms and dry/receptive fuels appears too limited for Dry Thunderstorm highlights at this time. Elsewhere across the CONUS, a minimal overlap of dry/breezy conditions will limit fire-weather concerns. ..Weinman.. 05/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Thu May 01 2025 Valid 021200Z - 031200Z ...NO CRITICAL AREAS... ...Synopsis... A low-amplitude midlevel trough will move eastward across northern Mexico and the Southwest. As large-scale ascent accompanying this feature overspreads a midlevel moisture plume across the Southwest, widely scattered dry thunderstorms will develop along the higher terrain. However, the overlap of these high-based thunderstorms and dry/receptive fuels appears too limited for Dry Thunderstorm highlights at this time. Elsewhere across the CONUS, a minimal overlap of dry/breezy conditions will limit fire-weather concerns. ..Weinman.. 05/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0630 CONCERNING SEVERE THUNDERSTORM WATCH 202... FOR CENTRAL/EAST TEXAS
Mesoscale Discussion 0630 NWS Storm Prediction Center Norman OK 1110 PM CDT Wed Apr 30 2025 Areas affected...Central/East Texas Concerning...Severe Thunderstorm Watch 202... Valid 010410Z - 010545Z The severe weather threat for Severe Thunderstorm Watch 202 continues. SUMMARY...Isolated large hail threat continues with convection this evening. Severe threat is expected to gradually wane and a new ww is not currently anticipated. However an EXT could be warranted for an hour or so. DISCUSSION...Southern influence of southern Plains short-wave trough appears to be aiding southwestern flank of elongated MCS. Latest radar data suggests several robust updrafts continue to generate hail, especially over Williamson/Milam County just northeast of Austin. This activity is moving slowly southeast as the primary synoptic boundary sags into this portion of TX. Isolated large hail continues to be the main severe threat with these storms. ..Darrow.. 05/01/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LCH...SHV...HGX...FWD...EWX... LAT...LON 30859738 30869627 31389533 31999465 31739402 30919439 30259614 30319723 30599774 30859738 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more