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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 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 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 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 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
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
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
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
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
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 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 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

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

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

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

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

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 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Tue Mar 12 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDDLE MISSISSIPPI VALLEY INTO EASTERN OKLAHOMA...EAST TEXAS...AND THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Strong to severe thunderstorms are possible across a large area from the Middle Mississippi Valley into eastern Oklahoma, East Texas, and the Lower Mississippi Valley on Thursday. ...Synopsis... A surface low is forecast to be over the NE/IA/MO border vicinity early Thursday morning, with a cold front extending southwestward from this low across eastern KS and central OK into the TX Hill Country. An expansive warm sector is expected to be in place east of this cold front, from the Mid MS Valley into the southern Plains and Lower MS Valley early Thursday morning, supported by the previous days' return flow. Showers and thunderstorms may be ongoing in the vicinity of a warm front extending north-northeastward from the surface low, but much of the warm sector is currently expected to be free from any early period storms. This broad warm sector is expected to destabilize throughout the day with two primary corridors of severe thunderstorms potential, one near the surface low from southern IA/northern MO into west-central IL and another farther south from eastern OK and east TX into LA and AR. ...Southern IA/Northern MO/West-Central IL... Upper 50s dewpoints are expected south of the warm front throughout the period. Despite this somewhat modest low-level moisture, moderate to strong buoyancy is still anticipated early in the afternoon as surface temperatures climb into the low 70s, supported by cold mid-level temperatures and resulting steep mid-level lapse rates. Low-level convergence near the surface low and warm front will likely result in convective initiation amid vertical wind profiles that support supercells. There may be a tendency for storms to move north of the warm front over time, but enough residence in the warm sector is anticipated for some storms to reach maturity. Any mature supercells would be capable of all severe hazards, including tornadoes, strong gusts, and very large hail. ...Eastern OK and East TX into LA and AR... Weak surface troughing will likely interact with an increasingly unstable airmass across the region during the afternoon, with convective initiation anticipated around 18Z across southeast OK and northeast TX. Given robust buoyancy and moderate vertical shear, initial development will likely be supercellular and capable of all severe hazards, including very large hail. How the convection evolves after the initial more discrete storms remains uncertain, with some potential for development into more linear structures given the front-parallel deep-layer vertical shear. If upscale growth is realized, the resulting convective line would then push eastward into AR and LA, with some potential for damaging gusts. ..Mosier.. 03/12/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Tue Mar 12 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDDLE MISSISSIPPI VALLEY INTO EASTERN OKLAHOMA...EAST TEXAS...AND THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Strong to severe thunderstorms are possible across a large area from the Middle Mississippi Valley into eastern Oklahoma, East Texas, and the Lower Mississippi Valley on Thursday. ...Synopsis... A surface low is forecast to be over the NE/IA/MO border vicinity early Thursday morning, with a cold front extending southwestward from this low across eastern KS and central OK into the TX Hill Country. An expansive warm sector is expected to be in place east of this cold front, from the Mid MS Valley into the southern Plains and Lower MS Valley early Thursday morning, supported by the previous days' return flow. Showers and thunderstorms may be ongoing in the vicinity of a warm front extending north-northeastward from the surface low, but much of the warm sector is currently expected to be free from any early period storms. This broad warm sector is expected to destabilize throughout the day with two primary corridors of severe thunderstorms potential, one near the surface low from southern IA/northern MO into west-central IL and another farther south from eastern OK and east TX into LA and AR. ...Southern IA/Northern MO/West-Central IL... Upper 50s dewpoints are expected south of the warm front throughout the period. Despite this somewhat modest low-level moisture, moderate to strong buoyancy is still anticipated early in the afternoon as surface temperatures climb into the low 70s, supported by cold mid-level temperatures and resulting steep mid-level lapse rates. Low-level convergence near the surface low and warm front will likely result in convective initiation amid vertical wind profiles that support supercells. There may be a tendency for storms to move north of the warm front over time, but enough residence in the warm sector is anticipated for some storms to reach maturity. Any mature supercells would be capable of all severe hazards, including tornadoes, strong gusts, and very large hail. ...Eastern OK and East TX into LA and AR... Weak surface troughing will likely interact with an increasingly unstable airmass across the region during the afternoon, with convective initiation anticipated around 18Z across southeast OK and northeast TX. Given robust buoyancy and moderate vertical shear, initial development will likely be supercellular and capable of all severe hazards, including very large hail. How the convection evolves after the initial more discrete storms remains uncertain, with some potential for development into more linear structures given the front-parallel deep-layer vertical shear. If upscale growth is realized, the resulting convective line would then push eastward into AR and LA, with some potential for damaging gusts. ..Mosier.. 03/12/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Tue Mar 12 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDDLE MISSISSIPPI VALLEY INTO EASTERN OKLAHOMA...EAST TEXAS...AND THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Strong to severe thunderstorms are possible across a large area from the Middle Mississippi Valley into eastern Oklahoma, East Texas, and the Lower Mississippi Valley on Thursday. ...Synopsis... A surface low is forecast to be over the NE/IA/MO border vicinity early Thursday morning, with a cold front extending southwestward from this low across eastern KS and central OK into the TX Hill Country. An expansive warm sector is expected to be in place east of this cold front, from the Mid MS Valley into the southern Plains and Lower MS Valley early Thursday morning, supported by the previous days' return flow. Showers and thunderstorms may be ongoing in the vicinity of a warm front extending north-northeastward from the surface low, but much of the warm sector is currently expected to be free from any early period storms. This broad warm sector is expected to destabilize throughout the day with two primary corridors of severe thunderstorms potential, one near the surface low from southern IA/northern MO into west-central IL and another farther south from eastern OK and east TX into LA and AR. ...Southern IA/Northern MO/West-Central IL... Upper 50s dewpoints are expected south of the warm front throughout the period. Despite this somewhat modest low-level moisture, moderate to strong buoyancy is still anticipated early in the afternoon as surface temperatures climb into the low 70s, supported by cold mid-level temperatures and resulting steep mid-level lapse rates. Low-level convergence near the surface low and warm front will likely result in convective initiation amid vertical wind profiles that support supercells. There may be a tendency for storms to move north of the warm front over time, but enough residence in the warm sector is anticipated for some storms to reach maturity. Any mature supercells would be capable of all severe hazards, including tornadoes, strong gusts, and very large hail. ...Eastern OK and East TX into LA and AR... Weak surface troughing will likely interact with an increasingly unstable airmass across the region during the afternoon, with convective initiation anticipated around 18Z across southeast OK and northeast TX. Given robust buoyancy and moderate vertical shear, initial development will likely be supercellular and capable of all severe hazards, including very large hail. How the convection evolves after the initial more discrete storms remains uncertain, with some potential for development into more linear structures given the front-parallel deep-layer vertical shear. If upscale growth is realized, the resulting convective line would then push eastward into AR and LA, with some potential for damaging gusts. ..Mosier.. 03/12/2024 Read more