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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 15 2024 Valid 151300Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN MID-ATLANTIC... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Great Plains, beginning mainly this evening and continuing overnight. Several tornadoes, large to very large hail, and damaging wind gusts all appear possible. Strong tornadoes may occur this evening across parts of Kansas and Nebraska. ...Synopsis... A large, closed upper cyclone is present over the Great Basin this morning. This feature will track eastward across the central Rockies, eventually ejecting over the southern/central Plains tonight. A strong mid/upper-level jet attendant to this upper cyclone will overspread much of the southern/central Plains through this evening. Pronounced large-scale ascent preceding the upper-level trough/low will encourage additional deepening of a surface low over the central High Plains though the day. Moisture will continue streaming northward through the period in tandem with a warm front and persistent low-level warm/moist advection. This warm front should be located across NE and perhaps into far southern SD by late this evening, as the primary surface low consolidates over the NE Panhandle. A dryline is forecast to mix eastward across the southern/central High Plains through peak afternoon heating, before retreating westward this evening across parts of the TX/OK Panhandles and western KS. ...Northern/Central Plains (Kansas/Nebraska/South Dakota)... A cap and the late timing of large-scale ascent associated with the ejecting upper cyclone will likely inhibit convective development across the northern/central Plains through at least late afternoon. Still, low-level moisture will gradually increase through the day, with surface dewpoints of at least upper 50s to low 60s becoming common by early this evening across the warm sector. Steep mid-level lapse rates and cooling thermal profiles aloft are expected to contribute to substantial MLCAPE by the peak of the diurnal heating cycle, with values likely ranging around 2000-3000 J/kg. With gradually strengthening mid/upper-level flow anticipated, deep-layer shear should also become sufficiently strong to support a mix of supercells and multicells across this region. Convective initiation should be delayed across much of KS/NE/SD until around 00Z as a southerly low-level jet rapidly strengthens to 50-60 kt. Very large hail (around 2-3 inches in diameter) will be a threat with any supercells that can form along/near the warm front, or southward along the length of the dryline into western KS. Low-level hodographs are forecast to become enlarged/curved in the 00-06Z time frame tonight, and the threat for tornadoes is likewise expected to increase with any supercells that can persist and remain at least semi-discrete. Confidence has increased in a more concentrated corridor of tornado potential across parts of western/central KS into central NE, where supercells appear most likely in very favorable thermodynamic and kinematic parameter space. Given the forecast strength of the low-level shear, strong tornadoes appear possible this evening/tonight across this area. Severe/damaging winds will also be possible as convection attempts to grow upscale into one or more clusters overnight. Even with nocturnal cooling, these severe/damaging winds may persist given the ample reservoir of buoyancy available. ...Southern Plains (Oklahoma/Texas)... The overall coverage and severity of convection across the southern Plains is somewhat more uncertain compared to locations farther north across the central Plains. This uncertainty is largely tied to the influence of a sub-tropical mid/upper-level jet that will move over the southern Plains through the period, along with associated mid/upper-level cloudiness. These clouds may tend to limit daytime heating to some extent along the length of the dryline. Even so, attempts at robust convective development will probably occur across parts of northwest TX by late this afternoon. If this activity can be sustained, then supercells appear likely given ample (50-60 kt) deep-layer shear. Isolated large to very large hail will probably be the main threat with this convection as it moves towards north-central TX. But, occasional severe/damaging winds and perhaps a couple of tornadoes may also occur through the early evening. Most guidance indicates any supercells which develop will weaken with eastward extent as they encounter increasing MLCIN, and become increasingly displaced from the better large-scale ascent with the upper trough/low ejecting over the central Plains. A highly conditional severe threat remains apparent across OK late this afternoon and evening, with a favorable parameter space to support supercells capable of producing all severe hazards. But, much of OK may have a relative minimum in convective activity until late tonight as a Pacific cold front overtakes the dryline. ...Mid-Atlantic to the Mid Mississippi Valley... The glancing influence and modest ascent with an upper trough across the Northeast and eastern Canada will overspread parts of the Mid-Atlantic by early afternoon. Weak low-level convergence along a sagging cold front should be sufficient to support isolated to scattered thunderstorm development through the afternoon and evening from parts of the mid MS Valley into the OH Valley, central Appalachians, and southern Mid-Atlantic. Ahead of the front across the Mid-Atlantic, generally low 50s surface dewpoints and steepened mid-level lapse rates will foster around 1000-1500 J/kg of MLCAPE with moderately enhanced westerly mid/upper-level flow. Deep-layer shear across this region appears strong enough to support supercells with an associated threat for large hail. Damaging wind gusts may also occur with multicell clusters that attempt to form as they track generally east-southeastward through the evening hours. With weaker deep-layer shear across the mid MS and OH Valleys, convection should be somewhat less organized while still posing an isolated threat for hail/wind. The overall severe threat should gradually diminish through late evening with the loss of diurnal heating. ..Gleason/Grams.. 04/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 15 2024 Valid 151300Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN MID-ATLANTIC... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Great Plains, beginning mainly this evening and continuing overnight. Several tornadoes, large to very large hail, and damaging wind gusts all appear possible. Strong tornadoes may occur this evening across parts of Kansas and Nebraska. ...Synopsis... A large, closed upper cyclone is present over the Great Basin this morning. This feature will track eastward across the central Rockies, eventually ejecting over the southern/central Plains tonight. A strong mid/upper-level jet attendant to this upper cyclone will overspread much of the southern/central Plains through this evening. Pronounced large-scale ascent preceding the upper-level trough/low will encourage additional deepening of a surface low over the central High Plains though the day. Moisture will continue streaming northward through the period in tandem with a warm front and persistent low-level warm/moist advection. This warm front should be located across NE and perhaps into far southern SD by late this evening, as the primary surface low consolidates over the NE Panhandle. A dryline is forecast to mix eastward across the southern/central High Plains through peak afternoon heating, before retreating westward this evening across parts of the TX/OK Panhandles and western KS. ...Northern/Central Plains (Kansas/Nebraska/South Dakota)... A cap and the late timing of large-scale ascent associated with the ejecting upper cyclone will likely inhibit convective development across the northern/central Plains through at least late afternoon. Still, low-level moisture will gradually increase through the day, with surface dewpoints of at least upper 50s to low 60s becoming common by early this evening across the warm sector. Steep mid-level lapse rates and cooling thermal profiles aloft are expected to contribute to substantial MLCAPE by the peak of the diurnal heating cycle, with values likely ranging around 2000-3000 J/kg. With gradually strengthening mid/upper-level flow anticipated, deep-layer shear should also become sufficiently strong to support a mix of supercells and multicells across this region. Convective initiation should be delayed across much of KS/NE/SD until around 00Z as a southerly low-level jet rapidly strengthens to 50-60 kt. Very large hail (around 2-3 inches in diameter) will be a threat with any supercells that can form along/near the warm front, or southward along the length of the dryline into western KS. Low-level hodographs are forecast to become enlarged/curved in the 00-06Z time frame tonight, and the threat for tornadoes is likewise expected to increase with any supercells that can persist and remain at least semi-discrete. Confidence has increased in a more concentrated corridor of tornado potential across parts of western/central KS into central NE, where supercells appear most likely in very favorable thermodynamic and kinematic parameter space. Given the forecast strength of the low-level shear, strong tornadoes appear possible this evening/tonight across this area. Severe/damaging winds will also be possible as convection attempts to grow upscale into one or more clusters overnight. Even with nocturnal cooling, these severe/damaging winds may persist given the ample reservoir of buoyancy available. ...Southern Plains (Oklahoma/Texas)... The overall coverage and severity of convection across the southern Plains is somewhat more uncertain compared to locations farther north across the central Plains. This uncertainty is largely tied to the influence of a sub-tropical mid/upper-level jet that will move over the southern Plains through the period, along with associated mid/upper-level cloudiness. These clouds may tend to limit daytime heating to some extent along the length of the dryline. Even so, attempts at robust convective development will probably occur across parts of northwest TX by late this afternoon. If this activity can be sustained, then supercells appear likely given ample (50-60 kt) deep-layer shear. Isolated large to very large hail will probably be the main threat with this convection as it moves towards north-central TX. But, occasional severe/damaging winds and perhaps a couple of tornadoes may also occur through the early evening. Most guidance indicates any supercells which develop will weaken with eastward extent as they encounter increasing MLCIN, and become increasingly displaced from the better large-scale ascent with the upper trough/low ejecting over the central Plains. A highly conditional severe threat remains apparent across OK late this afternoon and evening, with a favorable parameter space to support supercells capable of producing all severe hazards. But, much of OK may have a relative minimum in convective activity until late tonight as a Pacific cold front overtakes the dryline. ...Mid-Atlantic to the Mid Mississippi Valley... The glancing influence and modest ascent with an upper trough across the Northeast and eastern Canada will overspread parts of the Mid-Atlantic by early afternoon. Weak low-level convergence along a sagging cold front should be sufficient to support isolated to scattered thunderstorm development through the afternoon and evening from parts of the mid MS Valley into the OH Valley, central Appalachians, and southern Mid-Atlantic. Ahead of the front across the Mid-Atlantic, generally low 50s surface dewpoints and steepened mid-level lapse rates will foster around 1000-1500 J/kg of MLCAPE with moderately enhanced westerly mid/upper-level flow. Deep-layer shear across this region appears strong enough to support supercells with an associated threat for large hail. Damaging wind gusts may also occur with multicell clusters that attempt to form as they track generally east-southeastward through the evening hours. With weaker deep-layer shear across the mid MS and OH Valleys, convection should be somewhat less organized while still posing an isolated threat for hail/wind. The overall severe threat should gradually diminish through late evening with the loss of diurnal heating. ..Gleason/Grams.. 04/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 15 2024 Valid 151300Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN MID-ATLANTIC... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Great Plains, beginning mainly this evening and continuing overnight. Several tornadoes, large to very large hail, and damaging wind gusts all appear possible. Strong tornadoes may occur this evening across parts of Kansas and Nebraska. ...Synopsis... A large, closed upper cyclone is present over the Great Basin this morning. This feature will track eastward across the central Rockies, eventually ejecting over the southern/central Plains tonight. A strong mid/upper-level jet attendant to this upper cyclone will overspread much of the southern/central Plains through this evening. Pronounced large-scale ascent preceding the upper-level trough/low will encourage additional deepening of a surface low over the central High Plains though the day. Moisture will continue streaming northward through the period in tandem with a warm front and persistent low-level warm/moist advection. This warm front should be located across NE and perhaps into far southern SD by late this evening, as the primary surface low consolidates over the NE Panhandle. A dryline is forecast to mix eastward across the southern/central High Plains through peak afternoon heating, before retreating westward this evening across parts of the TX/OK Panhandles and western KS. ...Northern/Central Plains (Kansas/Nebraska/South Dakota)... A cap and the late timing of large-scale ascent associated with the ejecting upper cyclone will likely inhibit convective development across the northern/central Plains through at least late afternoon. Still, low-level moisture will gradually increase through the day, with surface dewpoints of at least upper 50s to low 60s becoming common by early this evening across the warm sector. Steep mid-level lapse rates and cooling thermal profiles aloft are expected to contribute to substantial MLCAPE by the peak of the diurnal heating cycle, with values likely ranging around 2000-3000 J/kg. With gradually strengthening mid/upper-level flow anticipated, deep-layer shear should also become sufficiently strong to support a mix of supercells and multicells across this region. Convective initiation should be delayed across much of KS/NE/SD until around 00Z as a southerly low-level jet rapidly strengthens to 50-60 kt. Very large hail (around 2-3 inches in diameter) will be a threat with any supercells that can form along/near the warm front, or southward along the length of the dryline into western KS. Low-level hodographs are forecast to become enlarged/curved in the 00-06Z time frame tonight, and the threat for tornadoes is likewise expected to increase with any supercells that can persist and remain at least semi-discrete. Confidence has increased in a more concentrated corridor of tornado potential across parts of western/central KS into central NE, where supercells appear most likely in very favorable thermodynamic and kinematic parameter space. Given the forecast strength of the low-level shear, strong tornadoes appear possible this evening/tonight across this area. Severe/damaging winds will also be possible as convection attempts to grow upscale into one or more clusters overnight. Even with nocturnal cooling, these severe/damaging winds may persist given the ample reservoir of buoyancy available. ...Southern Plains (Oklahoma/Texas)... The overall coverage and severity of convection across the southern Plains is somewhat more uncertain compared to locations farther north across the central Plains. This uncertainty is largely tied to the influence of a sub-tropical mid/upper-level jet that will move over the southern Plains through the period, along with associated mid/upper-level cloudiness. These clouds may tend to limit daytime heating to some extent along the length of the dryline. Even so, attempts at robust convective development will probably occur across parts of northwest TX by late this afternoon. If this activity can be sustained, then supercells appear likely given ample (50-60 kt) deep-layer shear. Isolated large to very large hail will probably be the main threat with this convection as it moves towards north-central TX. But, occasional severe/damaging winds and perhaps a couple of tornadoes may also occur through the early evening. Most guidance indicates any supercells which develop will weaken with eastward extent as they encounter increasing MLCIN, and become increasingly displaced from the better large-scale ascent with the upper trough/low ejecting over the central Plains. A highly conditional severe threat remains apparent across OK late this afternoon and evening, with a favorable parameter space to support supercells capable of producing all severe hazards. But, much of OK may have a relative minimum in convective activity until late tonight as a Pacific cold front overtakes the dryline. ...Mid-Atlantic to the Mid Mississippi Valley... The glancing influence and modest ascent with an upper trough across the Northeast and eastern Canada will overspread parts of the Mid-Atlantic by early afternoon. Weak low-level convergence along a sagging cold front should be sufficient to support isolated to scattered thunderstorm development through the afternoon and evening from parts of the mid MS Valley into the OH Valley, central Appalachians, and southern Mid-Atlantic. Ahead of the front across the Mid-Atlantic, generally low 50s surface dewpoints and steepened mid-level lapse rates will foster around 1000-1500 J/kg of MLCAPE with moderately enhanced westerly mid/upper-level flow. Deep-layer shear across this region appears strong enough to support supercells with an associated threat for large hail. Damaging wind gusts may also occur with multicell clusters that attempt to form as they track generally east-southeastward through the evening hours. With weaker deep-layer shear across the mid MS and OH Valleys, convection should be somewhat less organized while still posing an isolated threat for hail/wind. The overall severe threat should gradually diminish through late evening with the loss of diurnal heating. ..Gleason/Grams.. 04/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Apr 15 2024 Valid 151300Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN MID-ATLANTIC... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Great Plains, beginning mainly this evening and continuing overnight. Several tornadoes, large to very large hail, and damaging wind gusts all appear possible. Strong tornadoes may occur this evening across parts of Kansas and Nebraska. ...Synopsis... A large, closed upper cyclone is present over the Great Basin this morning. This feature will track eastward across the central Rockies, eventually ejecting over the southern/central Plains tonight. A strong mid/upper-level jet attendant to this upper cyclone will overspread much of the southern/central Plains through this evening. Pronounced large-scale ascent preceding the upper-level trough/low will encourage additional deepening of a surface low over the central High Plains though the day. Moisture will continue streaming northward through the period in tandem with a warm front and persistent low-level warm/moist advection. This warm front should be located across NE and perhaps into far southern SD by late this evening, as the primary surface low consolidates over the NE Panhandle. A dryline is forecast to mix eastward across the southern/central High Plains through peak afternoon heating, before retreating westward this evening across parts of the TX/OK Panhandles and western KS. ...Northern/Central Plains (Kansas/Nebraska/South Dakota)... A cap and the late timing of large-scale ascent associated with the ejecting upper cyclone will likely inhibit convective development across the northern/central Plains through at least late afternoon. Still, low-level moisture will gradually increase through the day, with surface dewpoints of at least upper 50s to low 60s becoming common by early this evening across the warm sector. Steep mid-level lapse rates and cooling thermal profiles aloft are expected to contribute to substantial MLCAPE by the peak of the diurnal heating cycle, with values likely ranging around 2000-3000 J/kg. With gradually strengthening mid/upper-level flow anticipated, deep-layer shear should also become sufficiently strong to support a mix of supercells and multicells across this region. Convective initiation should be delayed across much of KS/NE/SD until around 00Z as a southerly low-level jet rapidly strengthens to 50-60 kt. Very large hail (around 2-3 inches in diameter) will be a threat with any supercells that can form along/near the warm front, or southward along the length of the dryline into western KS. Low-level hodographs are forecast to become enlarged/curved in the 00-06Z time frame tonight, and the threat for tornadoes is likewise expected to increase with any supercells that can persist and remain at least semi-discrete. Confidence has increased in a more concentrated corridor of tornado potential across parts of western/central KS into central NE, where supercells appear most likely in very favorable thermodynamic and kinematic parameter space. Given the forecast strength of the low-level shear, strong tornadoes appear possible this evening/tonight across this area. Severe/damaging winds will also be possible as convection attempts to grow upscale into one or more clusters overnight. Even with nocturnal cooling, these severe/damaging winds may persist given the ample reservoir of buoyancy available. ...Southern Plains (Oklahoma/Texas)... The overall coverage and severity of convection across the southern Plains is somewhat more uncertain compared to locations farther north across the central Plains. This uncertainty is largely tied to the influence of a sub-tropical mid/upper-level jet that will move over the southern Plains through the period, along with associated mid/upper-level cloudiness. These clouds may tend to limit daytime heating to some extent along the length of the dryline. Even so, attempts at robust convective development will probably occur across parts of northwest TX by late this afternoon. If this activity can be sustained, then supercells appear likely given ample (50-60 kt) deep-layer shear. Isolated large to very large hail will probably be the main threat with this convection as it moves towards north-central TX. But, occasional severe/damaging winds and perhaps a couple of tornadoes may also occur through the early evening. Most guidance indicates any supercells which develop will weaken with eastward extent as they encounter increasing MLCIN, and become increasingly displaced from the better large-scale ascent with the upper trough/low ejecting over the central Plains. A highly conditional severe threat remains apparent across OK late this afternoon and evening, with a favorable parameter space to support supercells capable of producing all severe hazards. But, much of OK may have a relative minimum in convective activity until late tonight as a Pacific cold front overtakes the dryline. ...Mid-Atlantic to the Mid Mississippi Valley... The glancing influence and modest ascent with an upper trough across the Northeast and eastern Canada will overspread parts of the Mid-Atlantic by early afternoon. Weak low-level convergence along a sagging cold front should be sufficient to support isolated to scattered thunderstorm development through the afternoon and evening from parts of the mid MS Valley into the OH Valley, central Appalachians, and southern Mid-Atlantic. Ahead of the front across the Mid-Atlantic, generally low 50s surface dewpoints and steepened mid-level lapse rates will foster around 1000-1500 J/kg of MLCAPE with moderately enhanced westerly mid/upper-level flow. Deep-layer shear across this region appears strong enough to support supercells with an associated threat for large hail. Damaging wind gusts may also occur with multicell clusters that attempt to form as they track generally east-southeastward through the evening hours. With weaker deep-layer shear across the mid MS and OH Valleys, convection should be somewhat less organized while still posing an isolated threat for hail/wind. The overall severe threat should gradually diminish through late evening with the loss of diurnal heating. ..Gleason/Grams.. 04/15/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Mon Apr 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... Isolated to scattered large hail and isolated severe wind gusts are evident on D4/Thursday from the Ozark Plateau into central TX. Low probability severe may persist into D5-6, mainly across parts of TX, with severe potential appearing negligible around D7-8. A northern-stream mid/upper trough should shift east from the Northwest into the Upper Midwest on D4. A more piecemeal eastward evolution is progged into the weekend amid multiple embedded impulses. The southern stream is expected to remain relatively weak and quasi-zonal, although there are indications of lower-amplitude impulses migrating through the flow. The best potential for severe appears focused on D4. Both the 00Z NAM/ECMWF hint at elevated convection developing across the central Great Plains late D3 on Thursday morning within a strengthening low-level warm theta-e advection regime south of the trough shifting into the Upper Midwest. Robust diabatic heating is expected in the warm-moist sector over the southern Great Plains, with the largest buoyancy so far this week ahead of the dryline in TX. As surface ridging noses down the High Plains, a lee cyclone will be forced east-southeast into OK as a developing frontal wave. Above-average agreement exists across guidance with surface-based convective development along both the southwest/northeast-oriented baroclinic zone and dryline. Primary uncertainty with southern extent is the degree of deep-layer shear as wind profiles appear weak to modest over most of the larger buoyancy plume. Have delineated a 15 percent area where potential for a few supercells and multicell clusters is evident on Thursday afternoon, with an implied lower severe probability extending farther southwest through much of central TX. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Mon Apr 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... Isolated to scattered large hail and isolated severe wind gusts are evident on D4/Thursday from the Ozark Plateau into central TX. Low probability severe may persist into D5-6, mainly across parts of TX, with severe potential appearing negligible around D7-8. A northern-stream mid/upper trough should shift east from the Northwest into the Upper Midwest on D4. A more piecemeal eastward evolution is progged into the weekend amid multiple embedded impulses. The southern stream is expected to remain relatively weak and quasi-zonal, although there are indications of lower-amplitude impulses migrating through the flow. The best potential for severe appears focused on D4. Both the 00Z NAM/ECMWF hint at elevated convection developing across the central Great Plains late D3 on Thursday morning within a strengthening low-level warm theta-e advection regime south of the trough shifting into the Upper Midwest. Robust diabatic heating is expected in the warm-moist sector over the southern Great Plains, with the largest buoyancy so far this week ahead of the dryline in TX. As surface ridging noses down the High Plains, a lee cyclone will be forced east-southeast into OK as a developing frontal wave. Above-average agreement exists across guidance with surface-based convective development along both the southwest/northeast-oriented baroclinic zone and dryline. Primary uncertainty with southern extent is the degree of deep-layer shear as wind profiles appear weak to modest over most of the larger buoyancy plume. Have delineated a 15 percent area where potential for a few supercells and multicell clusters is evident on Thursday afternoon, with an implied lower severe probability extending farther southwest through much of central TX. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Mon Apr 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... Isolated to scattered large hail and isolated severe wind gusts are evident on D4/Thursday from the Ozark Plateau into central TX. Low probability severe may persist into D5-6, mainly across parts of TX, with severe potential appearing negligible around D7-8. A northern-stream mid/upper trough should shift east from the Northwest into the Upper Midwest on D4. A more piecemeal eastward evolution is progged into the weekend amid multiple embedded impulses. The southern stream is expected to remain relatively weak and quasi-zonal, although there are indications of lower-amplitude impulses migrating through the flow. The best potential for severe appears focused on D4. Both the 00Z NAM/ECMWF hint at elevated convection developing across the central Great Plains late D3 on Thursday morning within a strengthening low-level warm theta-e advection regime south of the trough shifting into the Upper Midwest. Robust diabatic heating is expected in the warm-moist sector over the southern Great Plains, with the largest buoyancy so far this week ahead of the dryline in TX. As surface ridging noses down the High Plains, a lee cyclone will be forced east-southeast into OK as a developing frontal wave. Above-average agreement exists across guidance with surface-based convective development along both the southwest/northeast-oriented baroclinic zone and dryline. Primary uncertainty with southern extent is the degree of deep-layer shear as wind profiles appear weak to modest over most of the larger buoyancy plume. Have delineated a 15 percent area where potential for a few supercells and multicell clusters is evident on Thursday afternoon, with an implied lower severe probability extending farther southwest through much of central TX. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Mon Apr 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... Isolated to scattered large hail and isolated severe wind gusts are evident on D4/Thursday from the Ozark Plateau into central TX. Low probability severe may persist into D5-6, mainly across parts of TX, with severe potential appearing negligible around D7-8. A northern-stream mid/upper trough should shift east from the Northwest into the Upper Midwest on D4. A more piecemeal eastward evolution is progged into the weekend amid multiple embedded impulses. The southern stream is expected to remain relatively weak and quasi-zonal, although there are indications of lower-amplitude impulses migrating through the flow. The best potential for severe appears focused on D4. Both the 00Z NAM/ECMWF hint at elevated convection developing across the central Great Plains late D3 on Thursday morning within a strengthening low-level warm theta-e advection regime south of the trough shifting into the Upper Midwest. Robust diabatic heating is expected in the warm-moist sector over the southern Great Plains, with the largest buoyancy so far this week ahead of the dryline in TX. As surface ridging noses down the High Plains, a lee cyclone will be forced east-southeast into OK as a developing frontal wave. Above-average agreement exists across guidance with surface-based convective development along both the southwest/northeast-oriented baroclinic zone and dryline. Primary uncertainty with southern extent is the degree of deep-layer shear as wind profiles appear weak to modest over most of the larger buoyancy plume. Have delineated a 15 percent area where potential for a few supercells and multicell clusters is evident on Thursday afternoon, with an implied lower severe probability extending farther southwest through much of central TX. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0345 AM CDT Mon Apr 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... Isolated to scattered large hail and isolated severe wind gusts are evident on D4/Thursday from the Ozark Plateau into central TX. Low probability severe may persist into D5-6, mainly across parts of TX, with severe potential appearing negligible around D7-8. A northern-stream mid/upper trough should shift east from the Northwest into the Upper Midwest on D4. A more piecemeal eastward evolution is progged into the weekend amid multiple embedded impulses. The southern stream is expected to remain relatively weak and quasi-zonal, although there are indications of lower-amplitude impulses migrating through the flow. The best potential for severe appears focused on D4. Both the 00Z NAM/ECMWF hint at elevated convection developing across the central Great Plains late D3 on Thursday morning within a strengthening low-level warm theta-e advection regime south of the trough shifting into the Upper Midwest. Robust diabatic heating is expected in the warm-moist sector over the southern Great Plains, with the largest buoyancy so far this week ahead of the dryline in TX. As surface ridging noses down the High Plains, a lee cyclone will be forced east-southeast into OK as a developing frontal wave. Above-average agreement exists across guidance with surface-based convective development along both the southwest/northeast-oriented baroclinic zone and dryline. Primary uncertainty with southern extent is the degree of deep-layer shear as wind profiles appear weak to modest over most of the larger buoyancy plume. Have delineated a 15 percent area where potential for a few supercells and multicell clusters is evident on Thursday afternoon, with an implied lower severe probability extending farther southwest through much of central TX. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Apr 15 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE LOWER OH VALLEY TO MID-SOUTH... ...SUMMARY... Scattered severe thunderstorms are possible on Wednesday afternoon to early evening across parts of the Lower to Central Ohio Valley into the Mid-South. ...Parts of the Midwest to Mid-South... Occluding surface cyclone in the northeast IA vicinity on Wednesday morning will further dampen as it tracks towards Lower MI. Despite weakening tropospheric flow fields, favorable low to deep-layer shear profiles should persist into early evening. The northeast lobe of the warm-moist sector emanating from the western Gulf should spread across at least the Lower OH Valley. While some low-level warm theta-e advection-driven convection may be ongoing at 12Z Wednesday, overall signals have been for less convection impacting the buoyancy plume compared to prior forecasts. As such, potential for greater daytime destabilization is apparent, with a moderate MLCAPE field from 1000-2000 J/kg likely. Most guidance suggests early afternoon convective initiation will occur along the cold front trailing south-southwest from the occluding cyclone. A mix of all severe hazards appears possible with both supercells and multicell clusters. Greatest convective concentration is expected near/north of the Lower to Central Ohio Valley. The buoyancy plume should be more confined within this corridor and eventually pinch off as overturning occurs. With further diminishing of flow fields into the evening, the severe threat will wane after dusk. ..Grams.. 04/15/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Apr 15 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE LOWER OH VALLEY TO MID-SOUTH... ...SUMMARY... Scattered severe thunderstorms are possible on Wednesday afternoon to early evening across parts of the Lower to Central Ohio Valley into the Mid-South. ...Parts of the Midwest to Mid-South... Occluding surface cyclone in the northeast IA vicinity on Wednesday morning will further dampen as it tracks towards Lower MI. Despite weakening tropospheric flow fields, favorable low to deep-layer shear profiles should persist into early evening. The northeast lobe of the warm-moist sector emanating from the western Gulf should spread across at least the Lower OH Valley. While some low-level warm theta-e advection-driven convection may be ongoing at 12Z Wednesday, overall signals have been for less convection impacting the buoyancy plume compared to prior forecasts. As such, potential for greater daytime destabilization is apparent, with a moderate MLCAPE field from 1000-2000 J/kg likely. Most guidance suggests early afternoon convective initiation will occur along the cold front trailing south-southwest from the occluding cyclone. A mix of all severe hazards appears possible with both supercells and multicell clusters. Greatest convective concentration is expected near/north of the Lower to Central Ohio Valley. The buoyancy plume should be more confined within this corridor and eventually pinch off as overturning occurs. With further diminishing of flow fields into the evening, the severe threat will wane after dusk. ..Grams.. 04/15/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Apr 15 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE LOWER OH VALLEY TO MID-SOUTH... ...SUMMARY... Scattered severe thunderstorms are possible on Wednesday afternoon to early evening across parts of the Lower to Central Ohio Valley into the Mid-South. ...Parts of the Midwest to Mid-South... Occluding surface cyclone in the northeast IA vicinity on Wednesday morning will further dampen as it tracks towards Lower MI. Despite weakening tropospheric flow fields, favorable low to deep-layer shear profiles should persist into early evening. The northeast lobe of the warm-moist sector emanating from the western Gulf should spread across at least the Lower OH Valley. While some low-level warm theta-e advection-driven convection may be ongoing at 12Z Wednesday, overall signals have been for less convection impacting the buoyancy plume compared to prior forecasts. As such, potential for greater daytime destabilization is apparent, with a moderate MLCAPE field from 1000-2000 J/kg likely. Most guidance suggests early afternoon convective initiation will occur along the cold front trailing south-southwest from the occluding cyclone. A mix of all severe hazards appears possible with both supercells and multicell clusters. Greatest convective concentration is expected near/north of the Lower to Central Ohio Valley. The buoyancy plume should be more confined within this corridor and eventually pinch off as overturning occurs. With further diminishing of flow fields into the evening, the severe threat will wane after dusk. ..Grams.. 04/15/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Mon Apr 15 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE LOWER OH VALLEY TO MID-SOUTH... ...SUMMARY... Scattered severe thunderstorms are possible on Wednesday afternoon to early evening across parts of the Lower to Central Ohio Valley into the Mid-South. ...Parts of the Midwest to Mid-South... Occluding surface cyclone in the northeast IA vicinity on Wednesday morning will further dampen as it tracks towards Lower MI. Despite weakening tropospheric flow fields, favorable low to deep-layer shear profiles should persist into early evening. The northeast lobe of the warm-moist sector emanating from the western Gulf should spread across at least the Lower OH Valley. While some low-level warm theta-e advection-driven convection may be ongoing at 12Z Wednesday, overall signals have been for less convection impacting the buoyancy plume compared to prior forecasts. As such, potential for greater daytime destabilization is apparent, with a moderate MLCAPE field from 1000-2000 J/kg likely. Most guidance suggests early afternoon convective initiation will occur along the cold front trailing south-southwest from the occluding cyclone. A mix of all severe hazards appears possible with both supercells and multicell clusters. Greatest convective concentration is expected near/north of the Lower to Central Ohio Valley. The buoyancy plume should be more confined within this corridor and eventually pinch off as overturning occurs. With further diminishing of flow fields into the evening, the severe threat will wane after dusk. ..Grams.. 04/15/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0204 AM CDT Mon Apr 15 2024 Valid 161200Z - 171200Z ...Synopsis... As the upper low ejects eastward over the Plains and into the Midwest, strong flow aloft will gradually weaken from west to east. The associated surface low and trailing front/dryline will move eastward as a secondary cold front moves in from the north. Gusty winds and low humidity will remain possible over parts of the southern and central Plains. However, the duration and coverage of critical conditions is uncertain. ...Southern High Plains to the Texas Big Bend... As the strong upper low lifts away to the northeast early D2/Tuesday, winds aloft will slowly diminish across the southern High Plains through the day. Still, downslope west/northwesterly flow will favor dry and warm surface conditions over much of eastern NM and west TX. Surface wind gusts of 15-20 mph are expected through part of the day along with RH below 20%. While not overly robust, a few hours of elevated to locally critical fire-weather conditions still appear likely given widespread dry fuels. Localized fire-weather conditions may also briefly develop farther east into portions of central/eastern KS Tuesday afternoon. Gusty winds and lower humidity will remain possible, ahead of the secondary cold front moving south. However, the limited duration and uncertainty on precipitation from the previous day suggest this threat will be brief and localized. ..Lyons.. 04/15/2024 ...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 0204 AM CDT Mon Apr 15 2024 Valid 161200Z - 171200Z ...Synopsis... As the upper low ejects eastward over the Plains and into the Midwest, strong flow aloft will gradually weaken from west to east. The associated surface low and trailing front/dryline will move eastward as a secondary cold front moves in from the north. Gusty winds and low humidity will remain possible over parts of the southern and central Plains. However, the duration and coverage of critical conditions is uncertain. ...Southern High Plains to the Texas Big Bend... As the strong upper low lifts away to the northeast early D2/Tuesday, winds aloft will slowly diminish across the southern High Plains through the day. Still, downslope west/northwesterly flow will favor dry and warm surface conditions over much of eastern NM and west TX. Surface wind gusts of 15-20 mph are expected through part of the day along with RH below 20%. While not overly robust, a few hours of elevated to locally critical fire-weather conditions still appear likely given widespread dry fuels. Localized fire-weather conditions may also briefly develop farther east into portions of central/eastern KS Tuesday afternoon. Gusty winds and lower humidity will remain possible, ahead of the secondary cold front moving south. However, the limited duration and uncertainty on precipitation from the previous day suggest this threat will be brief and localized. ..Lyons.. 04/15/2024 ...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 0204 AM CDT Mon Apr 15 2024 Valid 161200Z - 171200Z ...Synopsis... As the upper low ejects eastward over the Plains and into the Midwest, strong flow aloft will gradually weaken from west to east. The associated surface low and trailing front/dryline will move eastward as a secondary cold front moves in from the north. Gusty winds and low humidity will remain possible over parts of the southern and central Plains. However, the duration and coverage of critical conditions is uncertain. ...Southern High Plains to the Texas Big Bend... As the strong upper low lifts away to the northeast early D2/Tuesday, winds aloft will slowly diminish across the southern High Plains through the day. Still, downslope west/northwesterly flow will favor dry and warm surface conditions over much of eastern NM and west TX. Surface wind gusts of 15-20 mph are expected through part of the day along with RH below 20%. While not overly robust, a few hours of elevated to locally critical fire-weather conditions still appear likely given widespread dry fuels. Localized fire-weather conditions may also briefly develop farther east into portions of central/eastern KS Tuesday afternoon. Gusty winds and lower humidity will remain possible, ahead of the secondary cold front moving south. However, the limited duration and uncertainty on precipitation from the previous day suggest this threat will be brief and localized. ..Lyons.. 04/15/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon Apr 15 2024 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE SOUTHERN AND CENTRAL HIGH PLAINS... ...Synopsis... An upper low and strong jet streak are forecast to intensify and eject eastward over the Great Plains today and tonight. A lee low should rapidly deepen over central High Plains with surface pressure falls and the strong flow aloft bolstering strong surface winds over much of the Plains. Hot and dry surface conditions atop drying fuels will allow for widespread critical and localized extremely critical fire-weather conditions. ...Southern and central High Plains... As the main upper low phases with the subtropical jet, 70+ kt mid-level flow will shift eastward and cross the Rockies late in the afternoon and evening. The rapidly deepening lee low will force strong west/southwest flow downslope over the High Plains behind a dryline forecast to mix near 100 degrees west. Sustained surface winds of 25-40 mph are possible behind the dryline given the strong pressure falls and enhanced momentum transfer from increasing flow aloft. Minimum RH values are also expected to be critically low, falling to 10-15% over much of the High Plains. Widespread dry and receptive fuels, combined with strong wind gusts and very dry surface conditions, will support ubiquitous high-end critical fire-weather concerns from eastern CO and western KS, into parts of the Panhandles, and eastern NM/west TX. Localized extremely critical conditions also appear possible as strong winds continue to increase into the late afternoon and evening hours. The most likely corridors for localized extreme conditions will exist from southeastern CO into parts of western KS and the northwestern Panhandles, and across parts of the southwest TX. Here, the overlap of the strongest flow aloft and single digit RH is possible for a few hours late in the afternoon. Uncertainty on the duration of extreme conditions remains too large to introduce any Extremely Critical areas. Considerable uncertainty also exists on the positioning of the dryline and the amount of mid and high-level cloud cover. Will maintain a broader Elevated area to capture the potential for more brief fire-weather conditions should the dryline mix farther east. ...Missouri Valley... Locally elevated fire weather conditions are possible in parts of northwestern Iowa into southeast South Dakota this afternoon. Dry air ahead of the warm front and gusty winds will increase prior to precipitation arriving during the evening/overnight. With these dry/windy conditions occurring primarily over marginally dry fuels and over a limited duration, the threat is likely to remain localized. ..Lyons.. 04/15/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon Apr 15 2024 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE SOUTHERN AND CENTRAL HIGH PLAINS... ...Synopsis... An upper low and strong jet streak are forecast to intensify and eject eastward over the Great Plains today and tonight. A lee low should rapidly deepen over central High Plains with surface pressure falls and the strong flow aloft bolstering strong surface winds over much of the Plains. Hot and dry surface conditions atop drying fuels will allow for widespread critical and localized extremely critical fire-weather conditions. ...Southern and central High Plains... As the main upper low phases with the subtropical jet, 70+ kt mid-level flow will shift eastward and cross the Rockies late in the afternoon and evening. The rapidly deepening lee low will force strong west/southwest flow downslope over the High Plains behind a dryline forecast to mix near 100 degrees west. Sustained surface winds of 25-40 mph are possible behind the dryline given the strong pressure falls and enhanced momentum transfer from increasing flow aloft. Minimum RH values are also expected to be critically low, falling to 10-15% over much of the High Plains. Widespread dry and receptive fuels, combined with strong wind gusts and very dry surface conditions, will support ubiquitous high-end critical fire-weather concerns from eastern CO and western KS, into parts of the Panhandles, and eastern NM/west TX. Localized extremely critical conditions also appear possible as strong winds continue to increase into the late afternoon and evening hours. The most likely corridors for localized extreme conditions will exist from southeastern CO into parts of western KS and the northwestern Panhandles, and across parts of the southwest TX. Here, the overlap of the strongest flow aloft and single digit RH is possible for a few hours late in the afternoon. Uncertainty on the duration of extreme conditions remains too large to introduce any Extremely Critical areas. Considerable uncertainty also exists on the positioning of the dryline and the amount of mid and high-level cloud cover. Will maintain a broader Elevated area to capture the potential for more brief fire-weather conditions should the dryline mix farther east. ...Missouri Valley... Locally elevated fire weather conditions are possible in parts of northwestern Iowa into southeast South Dakota this afternoon. Dry air ahead of the warm front and gusty winds will increase prior to precipitation arriving during the evening/overnight. With these dry/windy conditions occurring primarily over marginally dry fuels and over a limited duration, the threat is likely to remain localized. ..Lyons.. 04/15/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon Apr 15 2024 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE SOUTHERN AND CENTRAL HIGH PLAINS... ...Synopsis... An upper low and strong jet streak are forecast to intensify and eject eastward over the Great Plains today and tonight. A lee low should rapidly deepen over central High Plains with surface pressure falls and the strong flow aloft bolstering strong surface winds over much of the Plains. Hot and dry surface conditions atop drying fuels will allow for widespread critical and localized extremely critical fire-weather conditions. ...Southern and central High Plains... As the main upper low phases with the subtropical jet, 70+ kt mid-level flow will shift eastward and cross the Rockies late in the afternoon and evening. The rapidly deepening lee low will force strong west/southwest flow downslope over the High Plains behind a dryline forecast to mix near 100 degrees west. Sustained surface winds of 25-40 mph are possible behind the dryline given the strong pressure falls and enhanced momentum transfer from increasing flow aloft. Minimum RH values are also expected to be critically low, falling to 10-15% over much of the High Plains. Widespread dry and receptive fuels, combined with strong wind gusts and very dry surface conditions, will support ubiquitous high-end critical fire-weather concerns from eastern CO and western KS, into parts of the Panhandles, and eastern NM/west TX. Localized extremely critical conditions also appear possible as strong winds continue to increase into the late afternoon and evening hours. The most likely corridors for localized extreme conditions will exist from southeastern CO into parts of western KS and the northwestern Panhandles, and across parts of the southwest TX. Here, the overlap of the strongest flow aloft and single digit RH is possible for a few hours late in the afternoon. Uncertainty on the duration of extreme conditions remains too large to introduce any Extremely Critical areas. Considerable uncertainty also exists on the positioning of the dryline and the amount of mid and high-level cloud cover. Will maintain a broader Elevated area to capture the potential for more brief fire-weather conditions should the dryline mix farther east. ...Missouri Valley... Locally elevated fire weather conditions are possible in parts of northwestern Iowa into southeast South Dakota this afternoon. Dry air ahead of the warm front and gusty winds will increase prior to precipitation arriving during the evening/overnight. With these dry/windy conditions occurring primarily over marginally dry fuels and over a limited duration, the threat is likely to remain localized. ..Lyons.. 04/15/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon Apr 15 2024 Valid 151200Z - 161200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE SOUTHERN AND CENTRAL HIGH PLAINS... ...Synopsis... An upper low and strong jet streak are forecast to intensify and eject eastward over the Great Plains today and tonight. A lee low should rapidly deepen over central High Plains with surface pressure falls and the strong flow aloft bolstering strong surface winds over much of the Plains. Hot and dry surface conditions atop drying fuels will allow for widespread critical and localized extremely critical fire-weather conditions. ...Southern and central High Plains... As the main upper low phases with the subtropical jet, 70+ kt mid-level flow will shift eastward and cross the Rockies late in the afternoon and evening. The rapidly deepening lee low will force strong west/southwest flow downslope over the High Plains behind a dryline forecast to mix near 100 degrees west. Sustained surface winds of 25-40 mph are possible behind the dryline given the strong pressure falls and enhanced momentum transfer from increasing flow aloft. Minimum RH values are also expected to be critically low, falling to 10-15% over much of the High Plains. Widespread dry and receptive fuels, combined with strong wind gusts and very dry surface conditions, will support ubiquitous high-end critical fire-weather concerns from eastern CO and western KS, into parts of the Panhandles, and eastern NM/west TX. Localized extremely critical conditions also appear possible as strong winds continue to increase into the late afternoon and evening hours. The most likely corridors for localized extreme conditions will exist from southeastern CO into parts of western KS and the northwestern Panhandles, and across parts of the southwest TX. Here, the overlap of the strongest flow aloft and single digit RH is possible for a few hours late in the afternoon. Uncertainty on the duration of extreme conditions remains too large to introduce any Extremely Critical areas. Considerable uncertainty also exists on the positioning of the dryline and the amount of mid and high-level cloud cover. Will maintain a broader Elevated area to capture the potential for more brief fire-weather conditions should the dryline mix farther east. ...Missouri Valley... Locally elevated fire weather conditions are possible in parts of northwestern Iowa into southeast South Dakota this afternoon. Dry air ahead of the warm front and gusty winds will increase prior to precipitation arriving during the evening/overnight. With these dry/windy conditions occurring primarily over marginally dry fuels and over a limited duration, the threat is likely to remain localized. ..Lyons.. 04/15/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more