Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ...Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ..Leitman.. 09/17/2024 Read more

WW 0674 Status Updates
STATUS FOR WATCH 0674 HAS NOT BEEN ISSUED YET Read more

WW 0674 Status Updates
STATUS FOR WATCH 0674 HAS NOT BEEN ISSUED YET Read more

No watches are valid as of Tue Sep 17 18:31:02 UTC 2024.

MD 2077 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR WESTERN AND CENTRAL COLORADO....CENTRAL INTO EASTERN WYOMING
Mesoscale Discussion 2077 NWS Storm Prediction Center Norman OK 1133 AM CDT Tue Sep 17 2024 Areas affected...western and central Colorado....central into eastern Wyoming Concerning...Severe potential...Watch possible Valid 171633Z - 171830Z Probability of Watch Issuance...40 percent SUMMARY...A gradual increase in thunderstorm development appears likely to continue through Noon-2 PM MDT. While stronger storms posing a risk for locally severe wind gusts probably will remain widely scattered in the near term, it is possible this could become more widespread across and east of the Continental Divide this afternoon. DISCUSSION...Downstream of a vigorous short wave trough, now in the process of pivoting northeastward across the Great Basin, scattered thunderstorm development is underway in the presence of weak to modest destabilization. Low-level lapse rates are still in the process of steepening in response to boundary-layer heating and mixing, beneath the leading edge of mid-level cooling. However, downward mixing of 40-50+ kt ambient deep-layer mean flow is already contributing to severe gusts in the widely scattered stronger storms. This is likely to continue through the next few hours, as the mid/upper trough approaches the Wyoming/Colorado Rockies and boundary-layer destabilization progresses. Although the extent of the severe weather potential into and across the Continental Divide through 18-20Z remains a bit unclear, the gradual upscale growth of a consolidating line of storms appears at least possible along/ahead of the leading edge of the mid-level cooling. This may be accompanied by a strengthening surface cold pool accompanied by potential for increasingly widespread strong to severe wind gusts. ..Kerr/Gleason.. 09/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...PUB...BOU...CYS...ABQ...BYZ...RIW...GJT... LAT...LON 45310677 44470587 43470512 40750502 38910497 37430523 36670750 37550837 39730847 40750851 42420854 43510758 45310677 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Tue Sep 17 2024 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Isolated severe wind and hail are possible across a portion of the Great Plains during the late afternoon and evening on Wednesday. ...Great Plains... A stacked cyclone will slowly shift east/northeast from eastern MT to southern SK/MB on Wednesday into early Thursday. At the surface, a dryline will be oriented from the eastern Dakotas into western/central NE, then southward across western KS and into the OK/TX Panhandle vicinity. With time, a cold front will merge with this feature on the northern end across the Dakotas during the nighttime hours. Deep-layer south/southwesterly flow will remain somewhat enhanced across the northern/central Plains toward the Upper Midwest as the mid/upper trough shifts east. Around 30-35 kt effective shear magnitudes are forecast along the extent of the dryline. Meanwhile, surface dewpoints in the 60s will be maintained ahead of the surface boundary in a persistent southerly low-level warm advection regime. Midlevel temperatures are forecast to be somewhat warm, precluding steeper lapse rates. Nevertheless, 1000-2000 J/kg MLCAPE is expected, with the greatest instability expected near/north of the Mid-MO Valley. Weakening convection may be ongoing Wednesday morning in the vicinity of the Mid-MO valley, with areas of cloud cover extending northward into MN. Where stronger heating occurs, low-level convergence along the surface dryline and any remnant outflow boundaries may focus thunderstorm development during the afternoon. Large-scale ascent will be nebulous, with stronger forcing focused near/north of the international border. Instability and shear will decrease with southward extent into KS and the southern Plains. This will limit coverage and intensity of convection to some degree. Nevertheless, isolated strong to severe storms may pose a risk for locally damaging gusts and hail. Additional thunderstorms may develop overnight as the surface cold front overtakes the dryline from the far eastern Dakotas into MN. This activity will be driven by warm advection and likely be elevated. Severe potential currently appears low beyond the 03-06z time frame. ..Leitman.. 09/17/2024 Read more