SPC Mar 12, 2024 1730 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Tue Mar 12 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms capable of large to very large hail and a tornado or two are possible across the Lower Missouri Valley from Wednesday afternoon through Wednesday night. ...Synopsis... A large-scale upper trough will amplify over the Interior West during the period with a downstream ridge over the MS Valley shifting east into the OH Valley/Appalachians. A shortwave trough is forecast to eject northeast from the Sangre de Cristos into the lower MO Valley through the mid evening. A belt of stronger mid to upper-level southwesterly flow will overspread the TX Panhandle and OK during the afternoon and eventually nose into the lower MO Valley overnight. In the low levels, a cyclone over the KS vicinity during much of the day 2 period will feature a warm front advancing north through portions of the lower MO Valley and a dryline extending southward into OK and north TX. ...KS and NE eastward into the mid MS Valley... Strong low-level moisture advection into the region will occur as surface dewpoints are forecast to rise into the 50s deg F. Large-scale ascent attendant to the approaching shortwave trough coupled with low-level convergence near the surface low and warm front are expected to provide the lift needed for convective initiation. Storm coverage prior to sunset remains uncertain but thunderstorm coverage will likely increase during the evening near the warm front over northern KS eastward into the northern half of MO during the evening into the overnight. Steep mid-level lapse rates and strong deep-layer shear will support a storm environment in which the stronger storms will be capable of large to very large hail. If moisture quality is locally higher near the warm frontal zone and a supercellular mode is maintained, a tornado risk could develop due to enlarged hodographs. Storm coverage will likely increase into the overnight as warm-air advection strengthens in tandem with a LLJ. Primarily elevated storms capable of a large-hail threat may extend as far east as northeast MO into west-central IL. ...OK and north TX... Greater uncertainty on thunderstorm development will exist southward along the dryline and into eastern portions of OK and perhaps north TX beginning late Wednesday afternoon into Wednesday night. Model guidance varies considerably on the magnitude of low-level moisture with NAM exhibiting a more moisture-rich setup compared to model ensembles (HREF, SREF) and considerably drier solutions like the 15z RAP and latest GFS. Forecaster experience with these early season moisture return setups suggest a median to slightly drier solution is most probable. Moisture is the primary and likely consequential ingredient that will dictate severe thunderstorm risk across this corridor late Wednesday afternoon into the evening. With those concerns stated, cool mid-level temperatures in the -16 to -17 deg C range will result in steep lapse rates and contribute to moderate buoyancy (MLCAPE 1000-2000 J/kg). Clockwise-curved and elongated hodographs would favor supercells if a sustained storm can root in the boundary layer. Given the low probability (currently depicted in ensemble CAM guidance) for storm development, will maintain a categorical 1 (Marginal) risk. ..Smith.. 03/12/2024 Read more

SPC Mar 12, 2024 1730 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Tue Mar 12 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms capable of large to very large hail and a tornado or two are possible across the Lower Missouri Valley from Wednesday afternoon through Wednesday night. ...Synopsis... A large-scale upper trough will amplify over the Interior West during the period with a downstream ridge over the MS Valley shifting east into the OH Valley/Appalachians. A shortwave trough is forecast to eject northeast from the Sangre de Cristos into the lower MO Valley through the mid evening. A belt of stronger mid to upper-level southwesterly flow will overspread the TX Panhandle and OK during the afternoon and eventually nose into the lower MO Valley overnight. In the low levels, a cyclone over the KS vicinity during much of the day 2 period will feature a warm front advancing north through portions of the lower MO Valley and a dryline extending southward into OK and north TX. ...KS and NE eastward into the mid MS Valley... Strong low-level moisture advection into the region will occur as surface dewpoints are forecast to rise into the 50s deg F. Large-scale ascent attendant to the approaching shortwave trough coupled with low-level convergence near the surface low and warm front are expected to provide the lift needed for convective initiation. Storm coverage prior to sunset remains uncertain but thunderstorm coverage will likely increase during the evening near the warm front over northern KS eastward into the northern half of MO during the evening into the overnight. Steep mid-level lapse rates and strong deep-layer shear will support a storm environment in which the stronger storms will be capable of large to very large hail. If moisture quality is locally higher near the warm frontal zone and a supercellular mode is maintained, a tornado risk could develop due to enlarged hodographs. Storm coverage will likely increase into the overnight as warm-air advection strengthens in tandem with a LLJ. Primarily elevated storms capable of a large-hail threat may extend as far east as northeast MO into west-central IL. ...OK and north TX... Greater uncertainty on thunderstorm development will exist southward along the dryline and into eastern portions of OK and perhaps north TX beginning late Wednesday afternoon into Wednesday night. Model guidance varies considerably on the magnitude of low-level moisture with NAM exhibiting a more moisture-rich setup compared to model ensembles (HREF, SREF) and considerably drier solutions like the 15z RAP and latest GFS. Forecaster experience with these early season moisture return setups suggest a median to slightly drier solution is most probable. Moisture is the primary and likely consequential ingredient that will dictate severe thunderstorm risk across this corridor late Wednesday afternoon into the evening. With those concerns stated, cool mid-level temperatures in the -16 to -17 deg C range will result in steep lapse rates and contribute to moderate buoyancy (MLCAPE 1000-2000 J/kg). Clockwise-curved and elongated hodographs would favor supercells if a sustained storm can root in the boundary layer. Given the low probability (currently depicted in ensemble CAM guidance) for storm development, will maintain a categorical 1 (Marginal) risk. ..Smith.. 03/12/2024 Read more

SPC Mar 12, 2024 1730 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Tue Mar 12 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms capable of large to very large hail and a tornado or two are possible across the Lower Missouri Valley from Wednesday afternoon through Wednesday night. ...Synopsis... A large-scale upper trough will amplify over the Interior West during the period with a downstream ridge over the MS Valley shifting east into the OH Valley/Appalachians. A shortwave trough is forecast to eject northeast from the Sangre de Cristos into the lower MO Valley through the mid evening. A belt of stronger mid to upper-level southwesterly flow will overspread the TX Panhandle and OK during the afternoon and eventually nose into the lower MO Valley overnight. In the low levels, a cyclone over the KS vicinity during much of the day 2 period will feature a warm front advancing north through portions of the lower MO Valley and a dryline extending southward into OK and north TX. ...KS and NE eastward into the mid MS Valley... Strong low-level moisture advection into the region will occur as surface dewpoints are forecast to rise into the 50s deg F. Large-scale ascent attendant to the approaching shortwave trough coupled with low-level convergence near the surface low and warm front are expected to provide the lift needed for convective initiation. Storm coverage prior to sunset remains uncertain but thunderstorm coverage will likely increase during the evening near the warm front over northern KS eastward into the northern half of MO during the evening into the overnight. Steep mid-level lapse rates and strong deep-layer shear will support a storm environment in which the stronger storms will be capable of large to very large hail. If moisture quality is locally higher near the warm frontal zone and a supercellular mode is maintained, a tornado risk could develop due to enlarged hodographs. Storm coverage will likely increase into the overnight as warm-air advection strengthens in tandem with a LLJ. Primarily elevated storms capable of a large-hail threat may extend as far east as northeast MO into west-central IL. ...OK and north TX... Greater uncertainty on thunderstorm development will exist southward along the dryline and into eastern portions of OK and perhaps north TX beginning late Wednesday afternoon into Wednesday night. Model guidance varies considerably on the magnitude of low-level moisture with NAM exhibiting a more moisture-rich setup compared to model ensembles (HREF, SREF) and considerably drier solutions like the 15z RAP and latest GFS. Forecaster experience with these early season moisture return setups suggest a median to slightly drier solution is most probable. Moisture is the primary and likely consequential ingredient that will dictate severe thunderstorm risk across this corridor late Wednesday afternoon into the evening. With those concerns stated, cool mid-level temperatures in the -16 to -17 deg C range will result in steep lapse rates and contribute to moderate buoyancy (MLCAPE 1000-2000 J/kg). Clockwise-curved and elongated hodographs would favor supercells if a sustained storm can root in the boundary layer. Given the low probability (currently depicted in ensemble CAM guidance) for storm development, will maintain a categorical 1 (Marginal) risk. ..Smith.. 03/12/2024 Read more

SPC Mar 12, 2024 1730 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Tue Mar 12 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms capable of large to very large hail and a tornado or two are possible across the Lower Missouri Valley from Wednesday afternoon through Wednesday night. ...Synopsis... A large-scale upper trough will amplify over the Interior West during the period with a downstream ridge over the MS Valley shifting east into the OH Valley/Appalachians. A shortwave trough is forecast to eject northeast from the Sangre de Cristos into the lower MO Valley through the mid evening. A belt of stronger mid to upper-level southwesterly flow will overspread the TX Panhandle and OK during the afternoon and eventually nose into the lower MO Valley overnight. In the low levels, a cyclone over the KS vicinity during much of the day 2 period will feature a warm front advancing north through portions of the lower MO Valley and a dryline extending southward into OK and north TX. ...KS and NE eastward into the mid MS Valley... Strong low-level moisture advection into the region will occur as surface dewpoints are forecast to rise into the 50s deg F. Large-scale ascent attendant to the approaching shortwave trough coupled with low-level convergence near the surface low and warm front are expected to provide the lift needed for convective initiation. Storm coverage prior to sunset remains uncertain but thunderstorm coverage will likely increase during the evening near the warm front over northern KS eastward into the northern half of MO during the evening into the overnight. Steep mid-level lapse rates and strong deep-layer shear will support a storm environment in which the stronger storms will be capable of large to very large hail. If moisture quality is locally higher near the warm frontal zone and a supercellular mode is maintained, a tornado risk could develop due to enlarged hodographs. Storm coverage will likely increase into the overnight as warm-air advection strengthens in tandem with a LLJ. Primarily elevated storms capable of a large-hail threat may extend as far east as northeast MO into west-central IL. ...OK and north TX... Greater uncertainty on thunderstorm development will exist southward along the dryline and into eastern portions of OK and perhaps north TX beginning late Wednesday afternoon into Wednesday night. Model guidance varies considerably on the magnitude of low-level moisture with NAM exhibiting a more moisture-rich setup compared to model ensembles (HREF, SREF) and considerably drier solutions like the 15z RAP and latest GFS. Forecaster experience with these early season moisture return setups suggest a median to slightly drier solution is most probable. Moisture is the primary and likely consequential ingredient that will dictate severe thunderstorm risk across this corridor late Wednesday afternoon into the evening. With those concerns stated, cool mid-level temperatures in the -16 to -17 deg C range will result in steep lapse rates and contribute to moderate buoyancy (MLCAPE 1000-2000 J/kg). Clockwise-curved and elongated hodographs would favor supercells if a sustained storm can root in the boundary layer. Given the low probability (currently depicted in ensemble CAM guidance) for storm development, will maintain a categorical 1 (Marginal) risk. ..Smith.. 03/12/2024 Read more

SPC Mar 12, 2024 1730 UTC Day 2 Convective Outlook

1 year 5 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Tue Mar 12 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms capable of large to very large hail and a tornado or two are possible across the Lower Missouri Valley from Wednesday afternoon through Wednesday night. ...Synopsis... A large-scale upper trough will amplify over the Interior West during the period with a downstream ridge over the MS Valley shifting east into the OH Valley/Appalachians. A shortwave trough is forecast to eject northeast from the Sangre de Cristos into the lower MO Valley through the mid evening. A belt of stronger mid to upper-level southwesterly flow will overspread the TX Panhandle and OK during the afternoon and eventually nose into the lower MO Valley overnight. In the low levels, a cyclone over the KS vicinity during much of the day 2 period will feature a warm front advancing north through portions of the lower MO Valley and a dryline extending southward into OK and north TX. ...KS and NE eastward into the mid MS Valley... Strong low-level moisture advection into the region will occur as surface dewpoints are forecast to rise into the 50s deg F. Large-scale ascent attendant to the approaching shortwave trough coupled with low-level convergence near the surface low and warm front are expected to provide the lift needed for convective initiation. Storm coverage prior to sunset remains uncertain but thunderstorm coverage will likely increase during the evening near the warm front over northern KS eastward into the northern half of MO during the evening into the overnight. Steep mid-level lapse rates and strong deep-layer shear will support a storm environment in which the stronger storms will be capable of large to very large hail. If moisture quality is locally higher near the warm frontal zone and a supercellular mode is maintained, a tornado risk could develop due to enlarged hodographs. Storm coverage will likely increase into the overnight as warm-air advection strengthens in tandem with a LLJ. Primarily elevated storms capable of a large-hail threat may extend as far east as northeast MO into west-central IL. ...OK and north TX... Greater uncertainty on thunderstorm development will exist southward along the dryline and into eastern portions of OK and perhaps north TX beginning late Wednesday afternoon into Wednesday night. Model guidance varies considerably on the magnitude of low-level moisture with NAM exhibiting a more moisture-rich setup compared to model ensembles (HREF, SREF) and considerably drier solutions like the 15z RAP and latest GFS. Forecaster experience with these early season moisture return setups suggest a median to slightly drier solution is most probable. Moisture is the primary and likely consequential ingredient that will dictate severe thunderstorm risk across this corridor late Wednesday afternoon into the evening. With those concerns stated, cool mid-level temperatures in the -16 to -17 deg C range will result in steep lapse rates and contribute to moderate buoyancy (MLCAPE 1000-2000 J/kg). Clockwise-curved and elongated hodographs would favor supercells if a sustained storm can root in the boundary layer. Given the low probability (currently depicted in ensemble CAM guidance) for storm development, will maintain a categorical 1 (Marginal) risk. ..Smith.. 03/12/2024 Read more

SPC Mar 12, 2024 1630 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Tue Mar 12 2024 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL PLAINS/OZARKS... ...SUMMARY... Isolated severe thunderstorms are possible late this afternoon and evening from eastern Kansas/northeast Oklahoma and the western Ozarks to northern Missouri. ...Eastern Kansas/Northeast Oklahoma and Missouri... A low-amplitude shortwave trough over the south-central Plains this morning will continue eastward, crossing the Ozarks this evening and reaching the lower Ohio River Valley by Wednesday morning. This shortwave trough will generally overlie an increasing, but immature/only modestly moist (50s F surface dewpoints) warm sector, to the east of a southwest/northeast-oriented dryline across the southern Plains toward the Ozarks/lower Missouri Valley. Isolated to widely scattered thunderstorms are possible over the region late this afternoon, and more so this evening, with a marginal large-hail and locally damaging-wind risk where storms develop. The most probable area for such development is expected across far eastern Kansas into Missouri, potentially beginning by around 530pm-6pm CDT. More uncertainty regarding storm development exists with south-southwestward extent across northeast/east-central Oklahoma. Little if any development through late afternoon/early evening may be the most probable outcome within this corridor across Oklahoma, but various forecast soundings (including 12z NAM, which admittedly may be a bit overly moist and under-mixed) suggest some plausibility to very isolated convective development preceding the mid-level trough. Farther north, thunderstorm development is most probable this evening on the north edge of the modestly moist warm sector across central/northern Missouri, near a weak/modestly delineated warm front. Increasing elevated buoyancy (750-1000 J/kg MUCAPE) and steadily steepening lapse rates will be favorable for potentially severe hail (and even strong winds). However, weak effective shear (attributable to a 3-6km AGL flow weakness) should limit the magnitude and overall extent/duration of the large hail risk with northward extent (roughly north of 38N latitude including the I-70 vicinity). ..Guyer/Lyons.. 03/12/2024 Read more

SPC Mar 12, 2024 1630 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Tue Mar 12 2024 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL PLAINS/OZARKS... ...SUMMARY... Isolated severe thunderstorms are possible late this afternoon and evening from eastern Kansas/northeast Oklahoma and the western Ozarks to northern Missouri. ...Eastern Kansas/Northeast Oklahoma and Missouri... A low-amplitude shortwave trough over the south-central Plains this morning will continue eastward, crossing the Ozarks this evening and reaching the lower Ohio River Valley by Wednesday morning. This shortwave trough will generally overlie an increasing, but immature/only modestly moist (50s F surface dewpoints) warm sector, to the east of a southwest/northeast-oriented dryline across the southern Plains toward the Ozarks/lower Missouri Valley. Isolated to widely scattered thunderstorms are possible over the region late this afternoon, and more so this evening, with a marginal large-hail and locally damaging-wind risk where storms develop. The most probable area for such development is expected across far eastern Kansas into Missouri, potentially beginning by around 530pm-6pm CDT. More uncertainty regarding storm development exists with south-southwestward extent across northeast/east-central Oklahoma. Little if any development through late afternoon/early evening may be the most probable outcome within this corridor across Oklahoma, but various forecast soundings (including 12z NAM, which admittedly may be a bit overly moist and under-mixed) suggest some plausibility to very isolated convective development preceding the mid-level trough. Farther north, thunderstorm development is most probable this evening on the north edge of the modestly moist warm sector across central/northern Missouri, near a weak/modestly delineated warm front. Increasing elevated buoyancy (750-1000 J/kg MUCAPE) and steadily steepening lapse rates will be favorable for potentially severe hail (and even strong winds). However, weak effective shear (attributable to a 3-6km AGL flow weakness) should limit the magnitude and overall extent/duration of the large hail risk with northward extent (roughly north of 38N latitude including the I-70 vicinity). ..Guyer/Lyons.. 03/12/2024 Read more

SPC Mar 12, 2024 1630 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Tue Mar 12 2024 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL PLAINS/OZARKS... ...SUMMARY... Isolated severe thunderstorms are possible late this afternoon and evening from eastern Kansas/northeast Oklahoma and the western Ozarks to northern Missouri. ...Eastern Kansas/Northeast Oklahoma and Missouri... A low-amplitude shortwave trough over the south-central Plains this morning will continue eastward, crossing the Ozarks this evening and reaching the lower Ohio River Valley by Wednesday morning. This shortwave trough will generally overlie an increasing, but immature/only modestly moist (50s F surface dewpoints) warm sector, to the east of a southwest/northeast-oriented dryline across the southern Plains toward the Ozarks/lower Missouri Valley. Isolated to widely scattered thunderstorms are possible over the region late this afternoon, and more so this evening, with a marginal large-hail and locally damaging-wind risk where storms develop. The most probable area for such development is expected across far eastern Kansas into Missouri, potentially beginning by around 530pm-6pm CDT. More uncertainty regarding storm development exists with south-southwestward extent across northeast/east-central Oklahoma. Little if any development through late afternoon/early evening may be the most probable outcome within this corridor across Oklahoma, but various forecast soundings (including 12z NAM, which admittedly may be a bit overly moist and under-mixed) suggest some plausibility to very isolated convective development preceding the mid-level trough. Farther north, thunderstorm development is most probable this evening on the north edge of the modestly moist warm sector across central/northern Missouri, near a weak/modestly delineated warm front. Increasing elevated buoyancy (750-1000 J/kg MUCAPE) and steadily steepening lapse rates will be favorable for potentially severe hail (and even strong winds). However, weak effective shear (attributable to a 3-6km AGL flow weakness) should limit the magnitude and overall extent/duration of the large hail risk with northward extent (roughly north of 38N latitude including the I-70 vicinity). ..Guyer/Lyons.. 03/12/2024 Read more

SPC Mar 12, 2024 1630 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Tue Mar 12 2024 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL PLAINS/OZARKS... ...SUMMARY... Isolated severe thunderstorms are possible late this afternoon and evening from eastern Kansas/northeast Oklahoma and the western Ozarks to northern Missouri. ...Eastern Kansas/Northeast Oklahoma and Missouri... A low-amplitude shortwave trough over the south-central Plains this morning will continue eastward, crossing the Ozarks this evening and reaching the lower Ohio River Valley by Wednesday morning. This shortwave trough will generally overlie an increasing, but immature/only modestly moist (50s F surface dewpoints) warm sector, to the east of a southwest/northeast-oriented dryline across the southern Plains toward the Ozarks/lower Missouri Valley. Isolated to widely scattered thunderstorms are possible over the region late this afternoon, and more so this evening, with a marginal large-hail and locally damaging-wind risk where storms develop. The most probable area for such development is expected across far eastern Kansas into Missouri, potentially beginning by around 530pm-6pm CDT. More uncertainty regarding storm development exists with south-southwestward extent across northeast/east-central Oklahoma. Little if any development through late afternoon/early evening may be the most probable outcome within this corridor across Oklahoma, but various forecast soundings (including 12z NAM, which admittedly may be a bit overly moist and under-mixed) suggest some plausibility to very isolated convective development preceding the mid-level trough. Farther north, thunderstorm development is most probable this evening on the north edge of the modestly moist warm sector across central/northern Missouri, near a weak/modestly delineated warm front. Increasing elevated buoyancy (750-1000 J/kg MUCAPE) and steadily steepening lapse rates will be favorable for potentially severe hail (and even strong winds). However, weak effective shear (attributable to a 3-6km AGL flow weakness) should limit the magnitude and overall extent/duration of the large hail risk with northward extent (roughly north of 38N latitude including the I-70 vicinity). ..Guyer/Lyons.. 03/12/2024 Read more

SPC Mar 12, 2024 1630 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Tue Mar 12 2024 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL PLAINS/OZARKS... ...SUMMARY... Isolated severe thunderstorms are possible late this afternoon and evening from eastern Kansas/northeast Oklahoma and the western Ozarks to northern Missouri. ...Eastern Kansas/Northeast Oklahoma and Missouri... A low-amplitude shortwave trough over the south-central Plains this morning will continue eastward, crossing the Ozarks this evening and reaching the lower Ohio River Valley by Wednesday morning. This shortwave trough will generally overlie an increasing, but immature/only modestly moist (50s F surface dewpoints) warm sector, to the east of a southwest/northeast-oriented dryline across the southern Plains toward the Ozarks/lower Missouri Valley. Isolated to widely scattered thunderstorms are possible over the region late this afternoon, and more so this evening, with a marginal large-hail and locally damaging-wind risk where storms develop. The most probable area for such development is expected across far eastern Kansas into Missouri, potentially beginning by around 530pm-6pm CDT. More uncertainty regarding storm development exists with south-southwestward extent across northeast/east-central Oklahoma. Little if any development through late afternoon/early evening may be the most probable outcome within this corridor across Oklahoma, but various forecast soundings (including 12z NAM, which admittedly may be a bit overly moist and under-mixed) suggest some plausibility to very isolated convective development preceding the mid-level trough. Farther north, thunderstorm development is most probable this evening on the north edge of the modestly moist warm sector across central/northern Missouri, near a weak/modestly delineated warm front. Increasing elevated buoyancy (750-1000 J/kg MUCAPE) and steadily steepening lapse rates will be favorable for potentially severe hail (and even strong winds). However, weak effective shear (attributable to a 3-6km AGL flow weakness) should limit the magnitude and overall extent/duration of the large hail risk with northward extent (roughly north of 38N latitude including the I-70 vicinity). ..Guyer/Lyons.. 03/12/2024 Read more

SPC Day 1 Fire Weather Outlook

1 year 5 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Tue Mar 12 2024 Valid 121700Z - 131200Z Expanded the Elevated delineation slightly east across northwest Texas and southwest Oklahoma where slightly farther east mixing of the dryline is expected than previously forecast. Otherwise, the forecast remains on track. See previous forecast discussion below for additional details. ..Bentley.. 03/12/2024 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Mar 12 2024/ ...Synopsis... A surface cyclone is expected to develop across the central Plains Tuesday afternoon, with increasing south to southwesterly flow across much of the central and southern Plains. Gradual moisture return will begin across central Texas into central Oklahoma. A broad area of Elevated fire weather risk is expected across portions of the central and southern Plains behind a surface dryline located across west Texas/western Oklahoma into central Kansas. The driest conditions are expected across eastern New Mexico into western Texas, where relative humidity reductions to 10-15 percent will coincide with sustained winds around 10-15 mph (locally as high as 20 mph). Further north into western Oklahoma and western/central Kansas, relative humidity reductions to 15-25 percent will be possible amid sustained winds 10-15 mph. Closer to the surface low across central Kansas, stronger sustained winds will be possible with relative humidity around 20-25 percent. A period of near Critical to Critical meteorological conditions may be possible briefly within this region. Overall, fuels within this region do not support a Critical delineation and as such an Elevated delineation was maintained. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year 5 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Tue Mar 12 2024 Valid 121700Z - 131200Z Expanded the Elevated delineation slightly east across northwest Texas and southwest Oklahoma where slightly farther east mixing of the dryline is expected than previously forecast. Otherwise, the forecast remains on track. See previous forecast discussion below for additional details. ..Bentley.. 03/12/2024 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Mar 12 2024/ ...Synopsis... A surface cyclone is expected to develop across the central Plains Tuesday afternoon, with increasing south to southwesterly flow across much of the central and southern Plains. Gradual moisture return will begin across central Texas into central Oklahoma. A broad area of Elevated fire weather risk is expected across portions of the central and southern Plains behind a surface dryline located across west Texas/western Oklahoma into central Kansas. The driest conditions are expected across eastern New Mexico into western Texas, where relative humidity reductions to 10-15 percent will coincide with sustained winds around 10-15 mph (locally as high as 20 mph). Further north into western Oklahoma and western/central Kansas, relative humidity reductions to 15-25 percent will be possible amid sustained winds 10-15 mph. Closer to the surface low across central Kansas, stronger sustained winds will be possible with relative humidity around 20-25 percent. A period of near Critical to Critical meteorological conditions may be possible briefly within this region. Overall, fuels within this region do not support a Critical delineation and as such an Elevated delineation was maintained. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year 5 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Tue Mar 12 2024 Valid 121700Z - 131200Z Expanded the Elevated delineation slightly east across northwest Texas and southwest Oklahoma where slightly farther east mixing of the dryline is expected than previously forecast. Otherwise, the forecast remains on track. See previous forecast discussion below for additional details. ..Bentley.. 03/12/2024 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Mar 12 2024/ ...Synopsis... A surface cyclone is expected to develop across the central Plains Tuesday afternoon, with increasing south to southwesterly flow across much of the central and southern Plains. Gradual moisture return will begin across central Texas into central Oklahoma. A broad area of Elevated fire weather risk is expected across portions of the central and southern Plains behind a surface dryline located across west Texas/western Oklahoma into central Kansas. The driest conditions are expected across eastern New Mexico into western Texas, where relative humidity reductions to 10-15 percent will coincide with sustained winds around 10-15 mph (locally as high as 20 mph). Further north into western Oklahoma and western/central Kansas, relative humidity reductions to 15-25 percent will be possible amid sustained winds 10-15 mph. Closer to the surface low across central Kansas, stronger sustained winds will be possible with relative humidity around 20-25 percent. A period of near Critical to Critical meteorological conditions may be possible briefly within this region. Overall, fuels within this region do not support a Critical delineation and as such an Elevated delineation was maintained. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year 5 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Tue Mar 12 2024 Valid 121700Z - 131200Z Expanded the Elevated delineation slightly east across northwest Texas and southwest Oklahoma where slightly farther east mixing of the dryline is expected than previously forecast. Otherwise, the forecast remains on track. See previous forecast discussion below for additional details. ..Bentley.. 03/12/2024 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Mar 12 2024/ ...Synopsis... A surface cyclone is expected to develop across the central Plains Tuesday afternoon, with increasing south to southwesterly flow across much of the central and southern Plains. Gradual moisture return will begin across central Texas into central Oklahoma. A broad area of Elevated fire weather risk is expected across portions of the central and southern Plains behind a surface dryline located across west Texas/western Oklahoma into central Kansas. The driest conditions are expected across eastern New Mexico into western Texas, where relative humidity reductions to 10-15 percent will coincide with sustained winds around 10-15 mph (locally as high as 20 mph). Further north into western Oklahoma and western/central Kansas, relative humidity reductions to 15-25 percent will be possible amid sustained winds 10-15 mph. Closer to the surface low across central Kansas, stronger sustained winds will be possible with relative humidity around 20-25 percent. A period of near Critical to Critical meteorological conditions may be possible briefly within this region. Overall, fuels within this region do not support a Critical delineation and as such an Elevated delineation was maintained. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year 5 months ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Tue Mar 12 2024 Valid 121700Z - 131200Z Expanded the Elevated delineation slightly east across northwest Texas and southwest Oklahoma where slightly farther east mixing of the dryline is expected than previously forecast. Otherwise, the forecast remains on track. See previous forecast discussion below for additional details. ..Bentley.. 03/12/2024 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Mar 12 2024/ ...Synopsis... A surface cyclone is expected to develop across the central Plains Tuesday afternoon, with increasing south to southwesterly flow across much of the central and southern Plains. Gradual moisture return will begin across central Texas into central Oklahoma. A broad area of Elevated fire weather risk is expected across portions of the central and southern Plains behind a surface dryline located across west Texas/western Oklahoma into central Kansas. The driest conditions are expected across eastern New Mexico into western Texas, where relative humidity reductions to 10-15 percent will coincide with sustained winds around 10-15 mph (locally as high as 20 mph). Further north into western Oklahoma and western/central Kansas, relative humidity reductions to 15-25 percent will be possible amid sustained winds 10-15 mph. Closer to the surface low across central Kansas, stronger sustained winds will be possible with relative humidity around 20-25 percent. A period of near Critical to Critical meteorological conditions may be possible briefly within this region. Overall, fuels within this region do not support a Critical delineation and as such an Elevated delineation was maintained. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Mar 12, 2024 1300 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0731 AM CDT Tue Mar 12 2024 Valid 121300Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE WESTERN OZARKS/EASTERN KANSAS REGION TO NORTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible this afternoon and evening from the western Ozarks/eastern Kansas region to northern Missouri. ...Synopsis... The period begins with a progressive, fairly low-amplitude mid/ upper-level pattern over most of the CONUS. However, a trough now over the West Coast vicinity will strengthen as it moves inland and reaches ID, NV and the lower Colorado River Valley by 12Z tomorrow. This will spread a large field of height falls and generally difluent mid/upper flow across the Great Basin, Intermountain West and Rockies tonight, reaching the High Plains by the end of the period. A broad area of low-end, isolated thunderstorm potential exists ahead of the trough in the West. Ahead of these developments, a preceding shortwave trough -- apparent in moisture-channel imagery over eastern parts of WY/CO/NM -- will move eastward over the central Plains today. This perturbation should reach southeasternmost NE, extreme eastern KS and northeasternmost OK by 00Z, then cross the lower Ohio Valley around 12Z. At the surface, 11Z analysis showed a weak frontal-wave low over west-central KS, south of the associated cyclonic circulation center nearer the KS/NE border. The cyclone center and pressure low should consolidate better today as the frontal wave shifts eastward. By 00Z, the surface low should reach northwestern MO, with trailing trough/weak cold front to northwestern OK, the northern TX Panhandle, and southeastern CO. The low should drift eastward over northern MO through tonight, as the trailing front/trough stall over western OK and the eastern TX Panhandle, then begin shifting north again in a regime of lee cyclogenesis preceding the main western CONUS trough. A dryline -- now analyzed over Coahuila and parts of west TX from about MAF southward, should become better defined today from west-central TX to northeastern OK and extreme eastern KS (near the cold front) as moist advection continues across central TX, eastern OK, and the western Ozark Plateau. ...Ozarks/eastern KS to western/northern MO... Isolated to widely scattered thunderstorms are possible over the outlook area late this afternoon and/or this evening, with a marginal large-hail and damaging-wind threat. The western part of the outlook area is intended more for any late-afternoon development (conditional), with evening activity somewhat more certain over eastern parts. Moisture return will be quite immature across the region, but still potentially sufficient for thunderstorm development, with surface dewpoints generally reaching the mid 40s to low 50s F, east of the dryline and south of the warm front. Cooling aloft and steepening of low/middle-level lapse rates will occur this afternoon as DCVA increases and low-level warm advection continues ahead of the favorably timed shortwave trough. Boundary-layer theta-e advection and diabatic surface heating should boost buoyancy and reduce MLCINH throughout the afternoon, resulting in a narrow plume of about 800-1300 J/kg MLCAPE, atop a well-mixed boundary layer. Daytime initiation, should it occur, would be between the surface moist axis, warm front, and dryline/cold front. Though low-level shear is expected to be favorable for supercells, midlevel winds (generally 400-700 mb) are expected to weaken with northward extent, closer to where low-level forcing is strongest, near the low and frontal triple point. This will reduce effective- shear magnitudes from around 40-50 kt in southern areas (Ozarks vicinity) to less than 30 kt near and north of I-70. Though convection may persist longer in that corridor this evening due to greater instability aloft, and support from the LLJ, its increasingly elevated inflow layer, messier mode and lack of greater moisture will temper severe potential. ..Edwards/Dean.. 03/12/2024 Read more

SPC Mar 12, 2024 1300 UTC Day 1 Convective Outlook

1 year 5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0731 AM CDT Tue Mar 12 2024 Valid 121300Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE WESTERN OZARKS/EASTERN KANSAS REGION TO NORTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible this afternoon and evening from the western Ozarks/eastern Kansas region to northern Missouri. ...Synopsis... The period begins with a progressive, fairly low-amplitude mid/ upper-level pattern over most of the CONUS. However, a trough now over the West Coast vicinity will strengthen as it moves inland and reaches ID, NV and the lower Colorado River Valley by 12Z tomorrow. This will spread a large field of height falls and generally difluent mid/upper flow across the Great Basin, Intermountain West and Rockies tonight, reaching the High Plains by the end of the period. A broad area of low-end, isolated thunderstorm potential exists ahead of the trough in the West. Ahead of these developments, a preceding shortwave trough -- apparent in moisture-channel imagery over eastern parts of WY/CO/NM -- will move eastward over the central Plains today. This perturbation should reach southeasternmost NE, extreme eastern KS and northeasternmost OK by 00Z, then cross the lower Ohio Valley around 12Z. At the surface, 11Z analysis showed a weak frontal-wave low over west-central KS, south of the associated cyclonic circulation center nearer the KS/NE border. The cyclone center and pressure low should consolidate better today as the frontal wave shifts eastward. By 00Z, the surface low should reach northwestern MO, with trailing trough/weak cold front to northwestern OK, the northern TX Panhandle, and southeastern CO. The low should drift eastward over northern MO through tonight, as the trailing front/trough stall over western OK and the eastern TX Panhandle, then begin shifting north again in a regime of lee cyclogenesis preceding the main western CONUS trough. A dryline -- now analyzed over Coahuila and parts of west TX from about MAF southward, should become better defined today from west-central TX to northeastern OK and extreme eastern KS (near the cold front) as moist advection continues across central TX, eastern OK, and the western Ozark Plateau. ...Ozarks/eastern KS to western/northern MO... Isolated to widely scattered thunderstorms are possible over the outlook area late this afternoon and/or this evening, with a marginal large-hail and damaging-wind threat. The western part of the outlook area is intended more for any late-afternoon development (conditional), with evening activity somewhat more certain over eastern parts. Moisture return will be quite immature across the region, but still potentially sufficient for thunderstorm development, with surface dewpoints generally reaching the mid 40s to low 50s F, east of the dryline and south of the warm front. Cooling aloft and steepening of low/middle-level lapse rates will occur this afternoon as DCVA increases and low-level warm advection continues ahead of the favorably timed shortwave trough. Boundary-layer theta-e advection and diabatic surface heating should boost buoyancy and reduce MLCINH throughout the afternoon, resulting in a narrow plume of about 800-1300 J/kg MLCAPE, atop a well-mixed boundary layer. Daytime initiation, should it occur, would be between the surface moist axis, warm front, and dryline/cold front. Though low-level shear is expected to be favorable for supercells, midlevel winds (generally 400-700 mb) are expected to weaken with northward extent, closer to where low-level forcing is strongest, near the low and frontal triple point. This will reduce effective- shear magnitudes from around 40-50 kt in southern areas (Ozarks vicinity) to less than 30 kt near and north of I-70. Though convection may persist longer in that corridor this evening due to greater instability aloft, and support from the LLJ, its increasingly elevated inflow layer, messier mode and lack of greater moisture will temper severe potential. ..Edwards/Dean.. 03/12/2024 Read more

SPC Mar 12, 2024 Day 4-8 Severe Weather Outlook

1 year 5 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0348 AM CDT Tue Mar 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Multi-model consensus suggests a mature upper low will be over the Lower CO River Valley/western AZ Friday morning, with moderate westerly/southwesterly flow aloft extending from this low across the southern Plains and Mid-South/Mid MS Valley. More confluent upper flow is expected across the eastern CONUS. Thunderstorms are expected on D4/Friday from the southern Plains and MS Valley into the Southeast as a slow-moving cold front interacts with a modestly buoyant airmass. A few stronger storms are possible, but current expectation is for a largely anafrontal storm structure to limit severe potential. There may be enough residual low-level moisture and buoyancy along the weakening frontal zone for more thunderstorms from the TX Coastal Plains into the Southeast on D5/Saturday and D6/Sunday, but conditions do not look favorable for anything more than a localized severe potential. The southern-stream upper low is forecast to remain largely in place through the weekend and into early next week. At the same time, upper troughing is forecast to gradually deepen across eastern Canada and much of the eastern CONUS. This evolution should result in predominantly dry and stable conditions across the CONUS on D7/Monday and D8/Tuesday. Read more

SPC Mar 12, 2024 Day 4-8 Severe Weather Outlook

1 year 5 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0348 AM CDT Tue Mar 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Multi-model consensus suggests a mature upper low will be over the Lower CO River Valley/western AZ Friday morning, with moderate westerly/southwesterly flow aloft extending from this low across the southern Plains and Mid-South/Mid MS Valley. More confluent upper flow is expected across the eastern CONUS. Thunderstorms are expected on D4/Friday from the southern Plains and MS Valley into the Southeast as a slow-moving cold front interacts with a modestly buoyant airmass. A few stronger storms are possible, but current expectation is for a largely anafrontal storm structure to limit severe potential. There may be enough residual low-level moisture and buoyancy along the weakening frontal zone for more thunderstorms from the TX Coastal Plains into the Southeast on D5/Saturday and D6/Sunday, but conditions do not look favorable for anything more than a localized severe potential. The southern-stream upper low is forecast to remain largely in place through the weekend and into early next week. At the same time, upper troughing is forecast to gradually deepen across eastern Canada and much of the eastern CONUS. This evolution should result in predominantly dry and stable conditions across the CONUS on D7/Monday and D8/Tuesday. Read more

SPC Mar 12, 2024 Day 4-8 Severe Weather Outlook

1 year 5 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0348 AM CDT Tue Mar 12 2024 Valid 151200Z - 201200Z ...DISCUSSION... Multi-model consensus suggests a mature upper low will be over the Lower CO River Valley/western AZ Friday morning, with moderate westerly/southwesterly flow aloft extending from this low across the southern Plains and Mid-South/Mid MS Valley. More confluent upper flow is expected across the eastern CONUS. Thunderstorms are expected on D4/Friday from the southern Plains and MS Valley into the Southeast as a slow-moving cold front interacts with a modestly buoyant airmass. A few stronger storms are possible, but current expectation is for a largely anafrontal storm structure to limit severe potential. There may be enough residual low-level moisture and buoyancy along the weakening frontal zone for more thunderstorms from the TX Coastal Plains into the Southeast on D5/Saturday and D6/Sunday, but conditions do not look favorable for anything more than a localized severe potential. The southern-stream upper low is forecast to remain largely in place through the weekend and into early next week. At the same time, upper troughing is forecast to gradually deepen across eastern Canada and much of the eastern CONUS. This evolution should result in predominantly dry and stable conditions across the CONUS on D7/Monday and D8/Tuesday. Read more