Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Sun Apr 27 2025 Valid 301200Z - 051200Z ...DISCUSSION... ...Day 4/Wednesday - North Central to Northeast Texas... A mid-level trough will eject across the southern Plains on Day 4/Wednesday. Forecast guidance still shows some timing difference which affect the location of the surface low and thus the region of the greatest severe weather threat. However, at this time, the area along and south of the Red River to east-central Texas remains the most likely location to receive some severe weather regardless of the exact solution. Moderate instability and an uncapped environment will support storm development during the day on Wednesday. At this time, it appears widespread convection amid a very moist profile could result in HP storms in close proximity with eventual growth into a MCS. Forecast soundings show favorable low-level shear which would support some tornado threat. However, the aforementioned storm mode concerns could limit this threat despite the favorable wind profile. ...Day 5/Thursday - Mid Mississippi Valley... As a mid-level trough advances from the southern Plains to the Great Lakes on Thursday, a surface low will also develop and continue northeast. The strength and location of this surface low are uncertain at this time due to differing evolution of the mid-level pattern. Warm-sector destabilization also remains highly variable. If a solution such as the GFS solution verifies, then a greater severe weather threat will likely exist across parts of Tennessee and northern AL/MS into parts of the Ohio Valley. However, if the ECMWF instability verifies, the likelihood of widespread severe weather goes down significantly. No probabilities have been added for Day 5 yet, but if details become more clear and favorable, probabilities may eventually be needed. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Sun Apr 27 2025 Valid 301200Z - 051200Z ...DISCUSSION... ...Day 4/Wednesday - North Central to Northeast Texas... A mid-level trough will eject across the southern Plains on Day 4/Wednesday. Forecast guidance still shows some timing difference which affect the location of the surface low and thus the region of the greatest severe weather threat. However, at this time, the area along and south of the Red River to east-central Texas remains the most likely location to receive some severe weather regardless of the exact solution. Moderate instability and an uncapped environment will support storm development during the day on Wednesday. At this time, it appears widespread convection amid a very moist profile could result in HP storms in close proximity with eventual growth into a MCS. Forecast soundings show favorable low-level shear which would support some tornado threat. However, the aforementioned storm mode concerns could limit this threat despite the favorable wind profile. ...Day 5/Thursday - Mid Mississippi Valley... As a mid-level trough advances from the southern Plains to the Great Lakes on Thursday, a surface low will also develop and continue northeast. The strength and location of this surface low are uncertain at this time due to differing evolution of the mid-level pattern. Warm-sector destabilization also remains highly variable. If a solution such as the GFS solution verifies, then a greater severe weather threat will likely exist across parts of Tennessee and northern AL/MS into parts of the Ohio Valley. However, if the ECMWF instability verifies, the likelihood of widespread severe weather goes down significantly. No probabilities have been added for Day 5 yet, but if details become more clear and favorable, probabilities may eventually be needed. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Sun Apr 27 2025 Valid 301200Z - 051200Z ...DISCUSSION... ...Day 4/Wednesday - North Central to Northeast Texas... A mid-level trough will eject across the southern Plains on Day 4/Wednesday. Forecast guidance still shows some timing difference which affect the location of the surface low and thus the region of the greatest severe weather threat. However, at this time, the area along and south of the Red River to east-central Texas remains the most likely location to receive some severe weather regardless of the exact solution. Moderate instability and an uncapped environment will support storm development during the day on Wednesday. At this time, it appears widespread convection amid a very moist profile could result in HP storms in close proximity with eventual growth into a MCS. Forecast soundings show favorable low-level shear which would support some tornado threat. However, the aforementioned storm mode concerns could limit this threat despite the favorable wind profile. ...Day 5/Thursday - Mid Mississippi Valley... As a mid-level trough advances from the southern Plains to the Great Lakes on Thursday, a surface low will also develop and continue northeast. The strength and location of this surface low are uncertain at this time due to differing evolution of the mid-level pattern. Warm-sector destabilization also remains highly variable. If a solution such as the GFS solution verifies, then a greater severe weather threat will likely exist across parts of Tennessee and northern AL/MS into parts of the Ohio Valley. However, if the ECMWF instability verifies, the likelihood of widespread severe weather goes down significantly. No probabilities have been added for Day 5 yet, but if details become more clear and favorable, probabilities may eventually be needed. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Sun Apr 27 2025 Valid 301200Z - 051200Z ...DISCUSSION... ...Day 4/Wednesday - North Central to Northeast Texas... A mid-level trough will eject across the southern Plains on Day 4/Wednesday. Forecast guidance still shows some timing difference which affect the location of the surface low and thus the region of the greatest severe weather threat. However, at this time, the area along and south of the Red River to east-central Texas remains the most likely location to receive some severe weather regardless of the exact solution. Moderate instability and an uncapped environment will support storm development during the day on Wednesday. At this time, it appears widespread convection amid a very moist profile could result in HP storms in close proximity with eventual growth into a MCS. Forecast soundings show favorable low-level shear which would support some tornado threat. However, the aforementioned storm mode concerns could limit this threat despite the favorable wind profile. ...Day 5/Thursday - Mid Mississippi Valley... As a mid-level trough advances from the southern Plains to the Great Lakes on Thursday, a surface low will also develop and continue northeast. The strength and location of this surface low are uncertain at this time due to differing evolution of the mid-level pattern. Warm-sector destabilization also remains highly variable. If a solution such as the GFS solution verifies, then a greater severe weather threat will likely exist across parts of Tennessee and northern AL/MS into parts of the Ohio Valley. However, if the ECMWF instability verifies, the likelihood of widespread severe weather goes down significantly. No probabilities have been added for Day 5 yet, but if details become more clear and favorable, probabilities may eventually be needed. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 AM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN PLAINS TO THE EASTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected along a frontal zone that extends from the southern Plains to the eastern Great Lakes. ...Discussion... A cold front will move through the eastern Great Lakes on Tuesday afternoon and across New York Tuesday evening. Strong instability but weaker shear will be present along the frontal zone in Indiana and Ohio, with stronger flow, but weaker instability across New York. Therefore, strong wind gusts and perhaps an isolated tornado threat will exist across New York and western Pennsylvania with a greater hail threat likely across Ohio and Indiana. Farther west across the Lower Ohio Valley and into the Ozarks, the front will be more stationary. Mid to upper 60s dewpoints will be present south of this front which should allow for moderate to strong instability by Tuesday afternoon. Deep-layer shear is not that strong, but should be sufficient for some multicell clusters and perhaps a supercell or two. Persistent isentropic ascent should support thunderstorm activity in the vicinity of the front, likely across Oklahoma, on Tuesday. South and west of this morning/early afternoon activity is where the best environment should be on Tuesday. Moderate to strong instability is forecast to develop across West Texas and into Northwest Texas Tuesday afternoon. As mid-level flow strengthens ahead of the approaching trough, effective shear will increase through the day. The combination of height falls along the dryline and a strengthening low-level jet near sunset should support supercells capable of large hail and severe wind gusts by late afternoon to evening. ..Bentley.. 04/27/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 AM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN PLAINS TO THE EASTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected along a frontal zone that extends from the southern Plains to the eastern Great Lakes. ...Discussion... A cold front will move through the eastern Great Lakes on Tuesday afternoon and across New York Tuesday evening. Strong instability but weaker shear will be present along the frontal zone in Indiana and Ohio, with stronger flow, but weaker instability across New York. Therefore, strong wind gusts and perhaps an isolated tornado threat will exist across New York and western Pennsylvania with a greater hail threat likely across Ohio and Indiana. Farther west across the Lower Ohio Valley and into the Ozarks, the front will be more stationary. Mid to upper 60s dewpoints will be present south of this front which should allow for moderate to strong instability by Tuesday afternoon. Deep-layer shear is not that strong, but should be sufficient for some multicell clusters and perhaps a supercell or two. Persistent isentropic ascent should support thunderstorm activity in the vicinity of the front, likely across Oklahoma, on Tuesday. South and west of this morning/early afternoon activity is where the best environment should be on Tuesday. Moderate to strong instability is forecast to develop across West Texas and into Northwest Texas Tuesday afternoon. As mid-level flow strengthens ahead of the approaching trough, effective shear will increase through the day. The combination of height falls along the dryline and a strengthening low-level jet near sunset should support supercells capable of large hail and severe wind gusts by late afternoon to evening. ..Bentley.. 04/27/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 AM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN PLAINS TO THE EASTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected along a frontal zone that extends from the southern Plains to the eastern Great Lakes. ...Discussion... A cold front will move through the eastern Great Lakes on Tuesday afternoon and across New York Tuesday evening. Strong instability but weaker shear will be present along the frontal zone in Indiana and Ohio, with stronger flow, but weaker instability across New York. Therefore, strong wind gusts and perhaps an isolated tornado threat will exist across New York and western Pennsylvania with a greater hail threat likely across Ohio and Indiana. Farther west across the Lower Ohio Valley and into the Ozarks, the front will be more stationary. Mid to upper 60s dewpoints will be present south of this front which should allow for moderate to strong instability by Tuesday afternoon. Deep-layer shear is not that strong, but should be sufficient for some multicell clusters and perhaps a supercell or two. Persistent isentropic ascent should support thunderstorm activity in the vicinity of the front, likely across Oklahoma, on Tuesday. South and west of this morning/early afternoon activity is where the best environment should be on Tuesday. Moderate to strong instability is forecast to develop across West Texas and into Northwest Texas Tuesday afternoon. As mid-level flow strengthens ahead of the approaching trough, effective shear will increase through the day. The combination of height falls along the dryline and a strengthening low-level jet near sunset should support supercells capable of large hail and severe wind gusts by late afternoon to evening. ..Bentley.. 04/27/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 AM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN PLAINS TO THE EASTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected along a frontal zone that extends from the southern Plains to the eastern Great Lakes. ...Discussion... A cold front will move through the eastern Great Lakes on Tuesday afternoon and across New York Tuesday evening. Strong instability but weaker shear will be present along the frontal zone in Indiana and Ohio, with stronger flow, but weaker instability across New York. Therefore, strong wind gusts and perhaps an isolated tornado threat will exist across New York and western Pennsylvania with a greater hail threat likely across Ohio and Indiana. Farther west across the Lower Ohio Valley and into the Ozarks, the front will be more stationary. Mid to upper 60s dewpoints will be present south of this front which should allow for moderate to strong instability by Tuesday afternoon. Deep-layer shear is not that strong, but should be sufficient for some multicell clusters and perhaps a supercell or two. Persistent isentropic ascent should support thunderstorm activity in the vicinity of the front, likely across Oklahoma, on Tuesday. South and west of this morning/early afternoon activity is where the best environment should be on Tuesday. Moderate to strong instability is forecast to develop across West Texas and into Northwest Texas Tuesday afternoon. As mid-level flow strengthens ahead of the approaching trough, effective shear will increase through the day. The combination of height falls along the dryline and a strengthening low-level jet near sunset should support supercells capable of large hail and severe wind gusts by late afternoon to evening. ..Bentley.. 04/27/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0109 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...Synopsis... With a mid-level trough translating across the Intermountain West, and a lee cyclone deepening over the central High Plains, strong surface winds and deep boundary layer mixing are forecast across much of the Southwest into the southern High Plains. Critical to Extremely Critical fire-weather conditions are expected across much of southern and central New Mexico, into portions of far West Texas. ...Central/Southern New Mexico into Far West Texas... Widespread 30+ MPH winds and 5-10% relative humidity is anticipated over much of southern, central, and even portions of eastern New Mexico. While dry and windy conditions are anticipated further east of the current highlights, recent wetting rainfall in eastern New Mexico over the last several days will serve to limit the receptiveness of fuels to wildfire ignition and spread. Therefore, Critical and Extremely Critical highlights have been confined to where fuels guidance shows ERCs exceeding the 90th annual percentile, primarily across southern and central New Mexico. ...Eastern Colorado... Elevated highlights have been maintained over eastern Colorado, where dormant/fine fuels are anticipated to be receptive to wildfire ignition and spread with an environment characterized by 10% relative humidity and 15-20 MPH winds. Some recent wetting rainfall has occurred across eastern Colorado, with areas receiving 0.75-2.0 inches of rainfall in the last 48 hours. The Elevated highlights in this update reflect the driest areas receiving little to no rainfall. ..Halbert.. 04/27/2025 ...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 0109 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...Synopsis... With a mid-level trough translating across the Intermountain West, and a lee cyclone deepening over the central High Plains, strong surface winds and deep boundary layer mixing are forecast across much of the Southwest into the southern High Plains. Critical to Extremely Critical fire-weather conditions are expected across much of southern and central New Mexico, into portions of far West Texas. ...Central/Southern New Mexico into Far West Texas... Widespread 30+ MPH winds and 5-10% relative humidity is anticipated over much of southern, central, and even portions of eastern New Mexico. While dry and windy conditions are anticipated further east of the current highlights, recent wetting rainfall in eastern New Mexico over the last several days will serve to limit the receptiveness of fuels to wildfire ignition and spread. Therefore, Critical and Extremely Critical highlights have been confined to where fuels guidance shows ERCs exceeding the 90th annual percentile, primarily across southern and central New Mexico. ...Eastern Colorado... Elevated highlights have been maintained over eastern Colorado, where dormant/fine fuels are anticipated to be receptive to wildfire ignition and spread with an environment characterized by 10% relative humidity and 15-20 MPH winds. Some recent wetting rainfall has occurred across eastern Colorado, with areas receiving 0.75-2.0 inches of rainfall in the last 48 hours. The Elevated highlights in this update reflect the driest areas receiving little to no rainfall. ..Halbert.. 04/27/2025 ...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 0109 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...Synopsis... With a mid-level trough translating across the Intermountain West, and a lee cyclone deepening over the central High Plains, strong surface winds and deep boundary layer mixing are forecast across much of the Southwest into the southern High Plains. Critical to Extremely Critical fire-weather conditions are expected across much of southern and central New Mexico, into portions of far West Texas. ...Central/Southern New Mexico into Far West Texas... Widespread 30+ MPH winds and 5-10% relative humidity is anticipated over much of southern, central, and even portions of eastern New Mexico. While dry and windy conditions are anticipated further east of the current highlights, recent wetting rainfall in eastern New Mexico over the last several days will serve to limit the receptiveness of fuels to wildfire ignition and spread. Therefore, Critical and Extremely Critical highlights have been confined to where fuels guidance shows ERCs exceeding the 90th annual percentile, primarily across southern and central New Mexico. ...Eastern Colorado... Elevated highlights have been maintained over eastern Colorado, where dormant/fine fuels are anticipated to be receptive to wildfire ignition and spread with an environment characterized by 10% relative humidity and 15-20 MPH winds. Some recent wetting rainfall has occurred across eastern Colorado, with areas receiving 0.75-2.0 inches of rainfall in the last 48 hours. The Elevated highlights in this update reflect the driest areas receiving little to no rainfall. ..Halbert.. 04/27/2025 ...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 0109 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEW MEXICO INTO FAR WEST TEXAS... ...Synopsis... With a mid-level trough translating across the Intermountain West, and a lee cyclone deepening over the central High Plains, strong surface winds and deep boundary layer mixing are forecast across much of the Southwest into the southern High Plains. Critical to Extremely Critical fire-weather conditions are expected across much of southern and central New Mexico, into portions of far West Texas. ...Central/Southern New Mexico into Far West Texas... Widespread 30+ MPH winds and 5-10% relative humidity is anticipated over much of southern, central, and even portions of eastern New Mexico. While dry and windy conditions are anticipated further east of the current highlights, recent wetting rainfall in eastern New Mexico over the last several days will serve to limit the receptiveness of fuels to wildfire ignition and spread. Therefore, Critical and Extremely Critical highlights have been confined to where fuels guidance shows ERCs exceeding the 90th annual percentile, primarily across southern and central New Mexico. ...Eastern Colorado... Elevated highlights have been maintained over eastern Colorado, where dormant/fine fuels are anticipated to be receptive to wildfire ignition and spread with an environment characterized by 10% relative humidity and 15-20 MPH winds. Some recent wetting rainfall has occurred across eastern Colorado, with areas receiving 0.75-2.0 inches of rainfall in the last 48 hours. The Elevated highlights in this update reflect the driest areas receiving little to no rainfall. ..Halbert.. 04/27/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL IOWA INTO SOUTHEAST MINNESOTA AND WESTERN WISCONSIN... ...SUMMARY... An outbreak of severe weather remains likely across portions of the Upper Midwest, centered on Monday afternoon and evening. Very large hail, strong tornadoes, and damaging winds are expected. ...Synopsis... A strong (~75 knot) mid-level jet streak will advance from the central Plains to the Upper Midwest on Monday. As this occurs, a surface low will deepen across the Upper Midwest with an eastward advancing dryline to its south and a cold front to the west-southwest. A warm front will extend east of this surface low and move rapidly north through the day, spreading mid 60s dewpoints across much of the Upper Midwest. ...MN/IA/WI... Thunderstorms will likely be ongoing at the beginning of the period north of a warm front across Minnesota and Wisconsin amid moderate isentropic ascent. Isolated large hail will be possible from these storms. A surface low will be located somewhere near eastern South Dakota and will start to advance east during the morning. This surface low is expected to deepen somewhat through the day (perhaps to the low 990s mb range) as it moves toward the Twin Cities. There is a consistent signal for thunderstorms to develop along the cold front as it intersects the surface low/dryline in west-central Minnesota Monday afternoon. After some initial hail threat, these storms will likely become quickly linear along the front with an increasing severe wind threat. Strong low-level shear will also favor some line-embedded tornadoes, particularly if there area any areas within the line which become more favorably oriented to the low-level shear vector. Additional thunderstorms are forecast to develop along the dryline from southern Minnesota to west-central Iowa during the afternoon on Monday. 00Z CAM guidance is not overly bullish with convective development south of the MN/IA border, likely due to relatively weak convergence along the dryline in western Iowa from most high resolution guidance. However, the lack of convection from much of the guidance does not seem realistic considering the overall pattern. ECMWF/GFS/NAM are fairly consistent with a deepening surface low across Minnesota and moderate to strong height falls across the dryline. The southern extent of the previous Day 3 moderate risk corresponds well to the southern extent of the more favorable height falls, and convective precipitation signal from the ECMWF/GFS. Therefore, no adjustments to the southern extent of the moderate risk were deemed necessary. However the moderate risk was expanded slightly westward to account for the expectation for earlier convective initiation (19-21Z) than shown by most guidance. Given very strong effective shear and over 3000 J/kg MLCAPE, expect any supercells which develop to become quickly severe with a threat for all severe weather hazards. As the surface low across Minnesota deepens the low-level jet is also forecast to strengthen across Iowa, Minnesota and Wisconsin. This will elongate low-level hodographs and support an increasing tornado threat during the evening. STP values of 3 to 5 are common across much of the warm sector ahead of anticipated storms with some guidance indicating values of 7 to 10. Therefore, any mature, discrete supercells which can form and maintain within the open warm sector on Monday late afternoon/evening will pose a threat for strong to potentially intense tornadoes. ...Eastern Kansas and northern Missouri to West Texas... Overall forcing will be weaker farther south along the dryline, but subtle height falls across a mostly uncapped warm sector could result in isolated to scattered supercell development Monday afternoon. A secondary area of higher severe weather probabilities may exist from portions of West Texas into southwest Oklahoma where the nocturnally strengthening low-level jet could support scattered supercell development Monday evening. However, weak height rises cast some doubt on storm coverage during the evening, precluding higher probabilities at this time. ..Bentley.. 04/27/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL IOWA INTO SOUTHEAST MINNESOTA AND WESTERN WISCONSIN... ...SUMMARY... An outbreak of severe weather remains likely across portions of the Upper Midwest, centered on Monday afternoon and evening. Very large hail, strong tornadoes, and damaging winds are expected. ...Synopsis... A strong (~75 knot) mid-level jet streak will advance from the central Plains to the Upper Midwest on Monday. As this occurs, a surface low will deepen across the Upper Midwest with an eastward advancing dryline to its south and a cold front to the west-southwest. A warm front will extend east of this surface low and move rapidly north through the day, spreading mid 60s dewpoints across much of the Upper Midwest. ...MN/IA/WI... Thunderstorms will likely be ongoing at the beginning of the period north of a warm front across Minnesota and Wisconsin amid moderate isentropic ascent. Isolated large hail will be possible from these storms. A surface low will be located somewhere near eastern South Dakota and will start to advance east during the morning. This surface low is expected to deepen somewhat through the day (perhaps to the low 990s mb range) as it moves toward the Twin Cities. There is a consistent signal for thunderstorms to develop along the cold front as it intersects the surface low/dryline in west-central Minnesota Monday afternoon. After some initial hail threat, these storms will likely become quickly linear along the front with an increasing severe wind threat. Strong low-level shear will also favor some line-embedded tornadoes, particularly if there area any areas within the line which become more favorably oriented to the low-level shear vector. Additional thunderstorms are forecast to develop along the dryline from southern Minnesota to west-central Iowa during the afternoon on Monday. 00Z CAM guidance is not overly bullish with convective development south of the MN/IA border, likely due to relatively weak convergence along the dryline in western Iowa from most high resolution guidance. However, the lack of convection from much of the guidance does not seem realistic considering the overall pattern. ECMWF/GFS/NAM are fairly consistent with a deepening surface low across Minnesota and moderate to strong height falls across the dryline. The southern extent of the previous Day 3 moderate risk corresponds well to the southern extent of the more favorable height falls, and convective precipitation signal from the ECMWF/GFS. Therefore, no adjustments to the southern extent of the moderate risk were deemed necessary. However the moderate risk was expanded slightly westward to account for the expectation for earlier convective initiation (19-21Z) than shown by most guidance. Given very strong effective shear and over 3000 J/kg MLCAPE, expect any supercells which develop to become quickly severe with a threat for all severe weather hazards. As the surface low across Minnesota deepens the low-level jet is also forecast to strengthen across Iowa, Minnesota and Wisconsin. This will elongate low-level hodographs and support an increasing tornado threat during the evening. STP values of 3 to 5 are common across much of the warm sector ahead of anticipated storms with some guidance indicating values of 7 to 10. Therefore, any mature, discrete supercells which can form and maintain within the open warm sector on Monday late afternoon/evening will pose a threat for strong to potentially intense tornadoes. ...Eastern Kansas and northern Missouri to West Texas... Overall forcing will be weaker farther south along the dryline, but subtle height falls across a mostly uncapped warm sector could result in isolated to scattered supercell development Monday afternoon. A secondary area of higher severe weather probabilities may exist from portions of West Texas into southwest Oklahoma where the nocturnally strengthening low-level jet could support scattered supercell development Monday evening. However, weak height rises cast some doubt on storm coverage during the evening, precluding higher probabilities at this time. ..Bentley.. 04/27/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL IOWA INTO SOUTHEAST MINNESOTA AND WESTERN WISCONSIN... ...SUMMARY... An outbreak of severe weather remains likely across portions of the Upper Midwest, centered on Monday afternoon and evening. Very large hail, strong tornadoes, and damaging winds are expected. ...Synopsis... A strong (~75 knot) mid-level jet streak will advance from the central Plains to the Upper Midwest on Monday. As this occurs, a surface low will deepen across the Upper Midwest with an eastward advancing dryline to its south and a cold front to the west-southwest. A warm front will extend east of this surface low and move rapidly north through the day, spreading mid 60s dewpoints across much of the Upper Midwest. ...MN/IA/WI... Thunderstorms will likely be ongoing at the beginning of the period north of a warm front across Minnesota and Wisconsin amid moderate isentropic ascent. Isolated large hail will be possible from these storms. A surface low will be located somewhere near eastern South Dakota and will start to advance east during the morning. This surface low is expected to deepen somewhat through the day (perhaps to the low 990s mb range) as it moves toward the Twin Cities. There is a consistent signal for thunderstorms to develop along the cold front as it intersects the surface low/dryline in west-central Minnesota Monday afternoon. After some initial hail threat, these storms will likely become quickly linear along the front with an increasing severe wind threat. Strong low-level shear will also favor some line-embedded tornadoes, particularly if there area any areas within the line which become more favorably oriented to the low-level shear vector. Additional thunderstorms are forecast to develop along the dryline from southern Minnesota to west-central Iowa during the afternoon on Monday. 00Z CAM guidance is not overly bullish with convective development south of the MN/IA border, likely due to relatively weak convergence along the dryline in western Iowa from most high resolution guidance. However, the lack of convection from much of the guidance does not seem realistic considering the overall pattern. ECMWF/GFS/NAM are fairly consistent with a deepening surface low across Minnesota and moderate to strong height falls across the dryline. The southern extent of the previous Day 3 moderate risk corresponds well to the southern extent of the more favorable height falls, and convective precipitation signal from the ECMWF/GFS. Therefore, no adjustments to the southern extent of the moderate risk were deemed necessary. However the moderate risk was expanded slightly westward to account for the expectation for earlier convective initiation (19-21Z) than shown by most guidance. Given very strong effective shear and over 3000 J/kg MLCAPE, expect any supercells which develop to become quickly severe with a threat for all severe weather hazards. As the surface low across Minnesota deepens the low-level jet is also forecast to strengthen across Iowa, Minnesota and Wisconsin. This will elongate low-level hodographs and support an increasing tornado threat during the evening. STP values of 3 to 5 are common across much of the warm sector ahead of anticipated storms with some guidance indicating values of 7 to 10. Therefore, any mature, discrete supercells which can form and maintain within the open warm sector on Monday late afternoon/evening will pose a threat for strong to potentially intense tornadoes. ...Eastern Kansas and northern Missouri to West Texas... Overall forcing will be weaker farther south along the dryline, but subtle height falls across a mostly uncapped warm sector could result in isolated to scattered supercell development Monday afternoon. A secondary area of higher severe weather probabilities may exist from portions of West Texas into southwest Oklahoma where the nocturnally strengthening low-level jet could support scattered supercell development Monday evening. However, weak height rises cast some doubt on storm coverage during the evening, precluding higher probabilities at this time. ..Bentley.. 04/27/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM CENTRAL IOWA INTO SOUTHEAST MINNESOTA AND WESTERN WISCONSIN... ...SUMMARY... An outbreak of severe weather remains likely across portions of the Upper Midwest, centered on Monday afternoon and evening. Very large hail, strong tornadoes, and damaging winds are expected. ...Synopsis... A strong (~75 knot) mid-level jet streak will advance from the central Plains to the Upper Midwest on Monday. As this occurs, a surface low will deepen across the Upper Midwest with an eastward advancing dryline to its south and a cold front to the west-southwest. A warm front will extend east of this surface low and move rapidly north through the day, spreading mid 60s dewpoints across much of the Upper Midwest. ...MN/IA/WI... Thunderstorms will likely be ongoing at the beginning of the period north of a warm front across Minnesota and Wisconsin amid moderate isentropic ascent. Isolated large hail will be possible from these storms. A surface low will be located somewhere near eastern South Dakota and will start to advance east during the morning. This surface low is expected to deepen somewhat through the day (perhaps to the low 990s mb range) as it moves toward the Twin Cities. There is a consistent signal for thunderstorms to develop along the cold front as it intersects the surface low/dryline in west-central Minnesota Monday afternoon. After some initial hail threat, these storms will likely become quickly linear along the front with an increasing severe wind threat. Strong low-level shear will also favor some line-embedded tornadoes, particularly if there area any areas within the line which become more favorably oriented to the low-level shear vector. Additional thunderstorms are forecast to develop along the dryline from southern Minnesota to west-central Iowa during the afternoon on Monday. 00Z CAM guidance is not overly bullish with convective development south of the MN/IA border, likely due to relatively weak convergence along the dryline in western Iowa from most high resolution guidance. However, the lack of convection from much of the guidance does not seem realistic considering the overall pattern. ECMWF/GFS/NAM are fairly consistent with a deepening surface low across Minnesota and moderate to strong height falls across the dryline. The southern extent of the previous Day 3 moderate risk corresponds well to the southern extent of the more favorable height falls, and convective precipitation signal from the ECMWF/GFS. Therefore, no adjustments to the southern extent of the moderate risk were deemed necessary. However the moderate risk was expanded slightly westward to account for the expectation for earlier convective initiation (19-21Z) than shown by most guidance. Given very strong effective shear and over 3000 J/kg MLCAPE, expect any supercells which develop to become quickly severe with a threat for all severe weather hazards. As the surface low across Minnesota deepens the low-level jet is also forecast to strengthen across Iowa, Minnesota and Wisconsin. This will elongate low-level hodographs and support an increasing tornado threat during the evening. STP values of 3 to 5 are common across much of the warm sector ahead of anticipated storms with some guidance indicating values of 7 to 10. Therefore, any mature, discrete supercells which can form and maintain within the open warm sector on Monday late afternoon/evening will pose a threat for strong to potentially intense tornadoes. ...Eastern Kansas and northern Missouri to West Texas... Overall forcing will be weaker farther south along the dryline, but subtle height falls across a mostly uncapped warm sector could result in isolated to scattered supercell development Monday afternoon. A secondary area of higher severe weather probabilities may exist from portions of West Texas into southwest Oklahoma where the nocturnally strengthening low-level jet could support scattered supercell development Monday evening. However, weak height rises cast some doubt on storm coverage during the evening, precluding higher probabilities at this time. ..Bentley.. 04/27/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible on Sunday evening into early morning Monday across parts of the Great Plains. Large hail, severe gusts, and a few tornadoes are all possible. ...Synopsis... A deep mid/upper-level trough will move eastward across the western CONUS today. A strong jet will move through the base of the trough and begin to impinge on the central/southern Great Plains by evening. The primary surface low will deepen through the day over the central High Plains and move northeast across NE/SD late tonight. A secondary surface low is expected to develop near/west of the Black Hills during the afternoon. A lee trough/dryline will extend southward into the southern High Plains. Relatively rich low-level moisture will initially be confined to the southern Plains this morning, but will stream quickly northward later today and tonight in advance of the surface lows and dryline. ...Northern Great Plains... Large-scale ascent is expected to increase by evening across the northern Great Plains vicinity, in association with the approaching mid/upper-level trough and jet that will overspread the region. Richer low-level moisture will remain mostly south of this region through much of the day, but steep midlevel lapse rates, moderate buoyancy, and increasing deep-layer shear will support development of a few supercells by evening with a threat of hail and damaging winds. The longevity of any surface-based storms is uncertain and could be limited, but some tornado threat could evolve with any supercells that can persist into the evening, as low-level moisture and shear continue to increase. Some clustering and upscale growth will be possible later tonight, with a threat for hail and damaging wind potentially spreading eastward across the Dakotas into MN before the end of the period. ...Central/southern High Plains... Conditionally, the warm-sector environment across the central and southern High Plains will become quite favorable for organized convection, with strong instability developing by late afternoon in conjunction with strengthening low-level and deep-layer shear. However, despite diminishing MLCINH from afternoon into early evening near the dryline, there is only an inconsistent and relatively limited signal for initiation. One area of potential development will be from west-central NE into northwest KS, in the vicinity of the primary surface low. Guidance also has a somewhat stronger signal for development into parts of the southern High Plains, where strong heating/mixing may result in more favorable low-level convergence on the dryline. There is a relative minimum in signal for storm development from west-central/southwest KS toward the OK Panhandle, but any supercell that develops within this region would be within an increasingly volatile environment during the evening, and pose an all-hazards severe threat. Given the very favorable environment and at least some potential for isolated supercell development by early evening in the vicinity of the dryline, the Slight Risk has been expanded southward for the conditional all-hazards threat. It remains possible that portions of the Slight Risk may see little or no storm development. ..Dean/Halbert.. 04/27/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible on Sunday evening into early morning Monday across parts of the Great Plains. Large hail, severe gusts, and a few tornadoes are all possible. ...Synopsis... A deep mid/upper-level trough will move eastward across the western CONUS today. A strong jet will move through the base of the trough and begin to impinge on the central/southern Great Plains by evening. The primary surface low will deepen through the day over the central High Plains and move northeast across NE/SD late tonight. A secondary surface low is expected to develop near/west of the Black Hills during the afternoon. A lee trough/dryline will extend southward into the southern High Plains. Relatively rich low-level moisture will initially be confined to the southern Plains this morning, but will stream quickly northward later today and tonight in advance of the surface lows and dryline. ...Northern Great Plains... Large-scale ascent is expected to increase by evening across the northern Great Plains vicinity, in association with the approaching mid/upper-level trough and jet that will overspread the region. Richer low-level moisture will remain mostly south of this region through much of the day, but steep midlevel lapse rates, moderate buoyancy, and increasing deep-layer shear will support development of a few supercells by evening with a threat of hail and damaging winds. The longevity of any surface-based storms is uncertain and could be limited, but some tornado threat could evolve with any supercells that can persist into the evening, as low-level moisture and shear continue to increase. Some clustering and upscale growth will be possible later tonight, with a threat for hail and damaging wind potentially spreading eastward across the Dakotas into MN before the end of the period. ...Central/southern High Plains... Conditionally, the warm-sector environment across the central and southern High Plains will become quite favorable for organized convection, with strong instability developing by late afternoon in conjunction with strengthening low-level and deep-layer shear. However, despite diminishing MLCINH from afternoon into early evening near the dryline, there is only an inconsistent and relatively limited signal for initiation. One area of potential development will be from west-central NE into northwest KS, in the vicinity of the primary surface low. Guidance also has a somewhat stronger signal for development into parts of the southern High Plains, where strong heating/mixing may result in more favorable low-level convergence on the dryline. There is a relative minimum in signal for storm development from west-central/southwest KS toward the OK Panhandle, but any supercell that develops within this region would be within an increasingly volatile environment during the evening, and pose an all-hazards severe threat. Given the very favorable environment and at least some potential for isolated supercell development by early evening in the vicinity of the dryline, the Slight Risk has been expanded southward for the conditional all-hazards threat. It remains possible that portions of the Slight Risk may see little or no storm development. ..Dean/Halbert.. 04/27/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible on Sunday evening into early morning Monday across parts of the Great Plains. Large hail, severe gusts, and a few tornadoes are all possible. ...Synopsis... A deep mid/upper-level trough will move eastward across the western CONUS today. A strong jet will move through the base of the trough and begin to impinge on the central/southern Great Plains by evening. The primary surface low will deepen through the day over the central High Plains and move northeast across NE/SD late tonight. A secondary surface low is expected to develop near/west of the Black Hills during the afternoon. A lee trough/dryline will extend southward into the southern High Plains. Relatively rich low-level moisture will initially be confined to the southern Plains this morning, but will stream quickly northward later today and tonight in advance of the surface lows and dryline. ...Northern Great Plains... Large-scale ascent is expected to increase by evening across the northern Great Plains vicinity, in association with the approaching mid/upper-level trough and jet that will overspread the region. Richer low-level moisture will remain mostly south of this region through much of the day, but steep midlevel lapse rates, moderate buoyancy, and increasing deep-layer shear will support development of a few supercells by evening with a threat of hail and damaging winds. The longevity of any surface-based storms is uncertain and could be limited, but some tornado threat could evolve with any supercells that can persist into the evening, as low-level moisture and shear continue to increase. Some clustering and upscale growth will be possible later tonight, with a threat for hail and damaging wind potentially spreading eastward across the Dakotas into MN before the end of the period. ...Central/southern High Plains... Conditionally, the warm-sector environment across the central and southern High Plains will become quite favorable for organized convection, with strong instability developing by late afternoon in conjunction with strengthening low-level and deep-layer shear. However, despite diminishing MLCINH from afternoon into early evening near the dryline, there is only an inconsistent and relatively limited signal for initiation. One area of potential development will be from west-central NE into northwest KS, in the vicinity of the primary surface low. Guidance also has a somewhat stronger signal for development into parts of the southern High Plains, where strong heating/mixing may result in more favorable low-level convergence on the dryline. There is a relative minimum in signal for storm development from west-central/southwest KS toward the OK Panhandle, but any supercell that develops within this region would be within an increasingly volatile environment during the evening, and pose an all-hazards severe threat. Given the very favorable environment and at least some potential for isolated supercell development by early evening in the vicinity of the dryline, the Slight Risk has been expanded southward for the conditional all-hazards threat. It remains possible that portions of the Slight Risk may see little or no storm development. ..Dean/Halbert.. 04/27/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Sun Apr 27 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible on Sunday evening into early morning Monday across parts of the Great Plains. Large hail, severe gusts, and a few tornadoes are all possible. ...Synopsis... A deep mid/upper-level trough will move eastward across the western CONUS today. A strong jet will move through the base of the trough and begin to impinge on the central/southern Great Plains by evening. The primary surface low will deepen through the day over the central High Plains and move northeast across NE/SD late tonight. A secondary surface low is expected to develop near/west of the Black Hills during the afternoon. A lee trough/dryline will extend southward into the southern High Plains. Relatively rich low-level moisture will initially be confined to the southern Plains this morning, but will stream quickly northward later today and tonight in advance of the surface lows and dryline. ...Northern Great Plains... Large-scale ascent is expected to increase by evening across the northern Great Plains vicinity, in association with the approaching mid/upper-level trough and jet that will overspread the region. Richer low-level moisture will remain mostly south of this region through much of the day, but steep midlevel lapse rates, moderate buoyancy, and increasing deep-layer shear will support development of a few supercells by evening with a threat of hail and damaging winds. The longevity of any surface-based storms is uncertain and could be limited, but some tornado threat could evolve with any supercells that can persist into the evening, as low-level moisture and shear continue to increase. Some clustering and upscale growth will be possible later tonight, with a threat for hail and damaging wind potentially spreading eastward across the Dakotas into MN before the end of the period. ...Central/southern High Plains... Conditionally, the warm-sector environment across the central and southern High Plains will become quite favorable for organized convection, with strong instability developing by late afternoon in conjunction with strengthening low-level and deep-layer shear. However, despite diminishing MLCINH from afternoon into early evening near the dryline, there is only an inconsistent and relatively limited signal for initiation. One area of potential development will be from west-central NE into northwest KS, in the vicinity of the primary surface low. Guidance also has a somewhat stronger signal for development into parts of the southern High Plains, where strong heating/mixing may result in more favorable low-level convergence on the dryline. There is a relative minimum in signal for storm development from west-central/southwest KS toward the OK Panhandle, but any supercell that develops within this region would be within an increasingly volatile environment during the evening, and pose an all-hazards severe threat. Given the very favorable environment and at least some potential for isolated supercell development by early evening in the vicinity of the dryline, the Slight Risk has been expanded southward for the conditional all-hazards threat. It remains possible that portions of the Slight Risk may see little or no storm development. ..Dean/Halbert.. 04/27/2025 Read more