Aggregator

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Sun May 18 2025 Valid 181300Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE LOWER MISSISSIPPI VALLEY AND PARTS OF ALABAMA AND GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected later today across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...Central/Southern Plains... Water-vapor imagery this morning shows a potent mid- to upper-level trough over the Four Corners with a couple of downstream MCVs moving east-southeast over AR and AL this morning. A 500-mb speed max (60+ kt) is forecast to move through the base of this trough and eject into the TX Panhandle/southwestern KS late this afternoon and evening as the trough evolves into a negative tilt. Rich low-level moisture was observed at both surface sites and raob sites over the southern Great Plains this morning. Increasing moisture at 850 mb was sampled beneath very steep 700-500 mb lapse rates on the Dodge City raob. Southerly low-level flow is forecast to increase today across the southern-central Great Plains as a composite frontal zone/outflow over OK advances northward as a warm front into southern KS later this afternoon. Models show surface dewpoints rising into the 60s across western KS with lower 70s farther south near the OK/KS border and locales southward along/east of the dryline later this afternoon. Model guidance shows the strongest signal for scattered storm development from parts of the central High Plains southeast into southwest KS later this afternoon/evening as large-scale ascent overspreads the destabilizing moist/unstable sector. Confidence is greatest in scattered supercells developing across western/southwest KS later this afternoon as CINH erodes amidst strong boundary layer heating. A very to extremely unstable airmass with long hodographs will rapidly promote supercell evolution with any sustained/maturing updraft. The LLJ is forecast to intensify during the late afternoon/evening and enlarge the hodographs, supporting tornado potential. The combination of shear/buoyancy will become very favorable for intense supercells capable of large to giant hail (potentially 3-4+ inches in diameter) and strong to intense tornadoes, especially from western OK northward into south-central and western KS. It is within a focused corridor on the northern periphery of the richer moisture over parts of south-central and southwest KS where a potent environment and expected higher storm coverage prompted an upgrade to Moderate Risk. Lower storm coverage is expected farther south across western OK, but a similar environment will exist. Similar to previous forecast thinking, it remains uncertain how much convection will develop along the dry line south of I40, especially across TX. However, minimal inhibition warrants concern, as any updrafts that evolve within a strongly sheared and buoyant air mass should produce at least large hail. Farther north, left-exit region of mid-level jet will encourage a secondary corridor of strong/severe thunderstorms from northeast CO into western NE. Surface low is expected to track across eastern CO into western KS which will maintain a moist/upslope component to boundary layer across this portion of the High Plains. Strong low-level warm advection will assist organized convection as it spreads northeast during the overnight hours. ...AR eastward into GA... A pair of MCVs this morning are aiding in a couple of severe thunderstorm clusters being sustained along a residual frontal zone that serves as the northern periphery of richer low-level moisture. Short-term model guidance has varied considerably in the depiction of these MCS. Nonetheless, the 11 UTC BMX raob showed an very unstable airmass (3300 J/kg MUCAPE) and 65-kt 500 mb flow. Current thinking is both MCSs will pose a risk for mainly damaging gusts through this morning. ..Smith/Marsh.. 05/18/2025 Read more

MD 0853 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CENTRAL ALABAMA AND FAR WEST-CENTRAL GEORGIA
Mesoscale Discussion 0853 NWS Storm Prediction Center Norman OK 0640 AM CDT Sun May 18 2025 Areas affected...Central Alabama and far west-central Georgia Concerning...Severe potential...Watch possible Valid 181140Z - 181245Z Probability of Watch Issuance...40 percent SUMMARY...A thunderstorm cluster moving across central Alabama will pose a threat for isolated large hail and wind damage in the near term. Longer term evolution of this cluster is less certain, but the area will continue to be monitored for potential watch issuance. DISCUSSION...Long-lived cluster of thunderstorms continues to move across central Alabama this morning along the instability gradient. The strongest of these thunderstorms (located across eastern Tuscaloosa County) appears to have increased in intensity over the last hour and has even developed a rear-inflow jet (RIJ) -- suggested by radar reflectivity structure and an increase in rear-to-front wind speeds. This will pose a damaging wind threat in the short term. Additionally, overall reflectivity structure of the thunderstorm complex suggests the development of a mesoscale convective vortex. Should this be the case, an increase in updraft intensity would be expected in the near term owing to increasing convergence and stronger deep-layer shear. MUCAPE is around 1000 J/kg and deep-layer shear around 50 knots across the thunderstorm cluster now, but drops off to around 1000 J/kg and 30-40 knots as the cluster approaches western Georgia. As the thunderstorms move east, the lack of clarity of the MCV evolution and a slightly less favorable environment results in uncertainty as to whether a severe thunderstorm watch will be needed downstream. Conditions will continue to be monitored for potential watch issuance. ..Marsh/Smith.. 05/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FFC...BMX... LAT...LON 33668760 33848657 33438503 32818492 33038744 33668760 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

WW 0285 Status Updates
STATUS FOR WATCH 0285 HAS NOT BEEN ISSUED YET Read more

WW 0285 Status Updates
STATUS FOR WATCH 0285 HAS NOT BEEN ISSUED YET Read more

000
ABPZ20 KNHC 181117
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sun May 18 2025

For the eastern North Pacific...east of 140 degrees west longitude:

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Roberts

MD 0852 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN OKLAHOMA AND ARKANSAS
Mesoscale Discussion 0852 NWS Storm Prediction Center Norman OK 0423 AM CDT Sun May 18 2025 Areas affected...eastern Oklahoma and Arkansas Concerning...Severe potential...Watch possible Valid 180923Z - 181030Z Probability of Watch Issuance...60 percent SUMMARY...Ongoing thunderstorms will move out of existing Severe Thunderstorm Watch #283. Conditions are being monitored to determine if a small downstream watch is needed. DISCUSSION...The ongoing MCS across eastern Oklahoma is moving east-southeast along an instability gradient stretching from northwest Oklahoma into southeast Arkansas. Recent Oklahoma Mesonet peak gusts have reported 58 mph gust in Webbers Falls, OK, and 55 mph gust in Sallisaw, OK, which are slightly down from upstream wind measurements. Despite the recent downward trend in measured wind, the MCS is well developed and organized, has access to more than sufficient instability, and deep-layer shear around 50 knots. The thunderstorms are approaching the eastern edge of Severe Thunderstorm Watch #283 so trends continue to be assessed to determine if a small, downstream Severe Thunderstorm Watch may be necessary over parts of Arkansas. ..Marsh/Smith.. 05/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MEG...LZK...TSA... LAT...LON 34989586 36099501 34839056 33839137 34989586 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

WW 0284 Status Updates
STATUS FOR WATCH 0284 HAS NOT BEEN ISSUED YET Read more

WW 0284 Status Updates
STATUS FOR WATCH 0284 HAS NOT BEEN ISSUED YET Read more

WW 0284 Status Updates
STATUS FOR WATCH 0284 HAS NOT BEEN ISSUED YET Read more

WW 0284 Status Updates
STATUS FOR WATCH 0284 HAS NOT BEEN ISSUED YET Read more

WW 0284 Status Updates
STATUS FOR WATCH 0284 HAS NOT BEEN ISSUED YET Read more

WW 0284 Status Updates
STATUS FOR WATCH 0284 HAS NOT BEEN ISSUED YET Read more