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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Wed Sep 18 2024 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHEAST NEBRASKA INTO FAR NORTHWEST IOWA...EASTERN SOUTH DAKOTA...AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of producing severe wind gusts and large hail are possible today across parts of the eastern Dakotas and Minnesota into the mid Missouri Valley. A marginal severe threat will also extend southward into parts of the central and southern Plains. ...Northern Plains/Upper Midwest to the Southern High Plains... A closed upper low centered over eastern MT will continue northeastward during the period, reaching southeast SK by early Thursday morning. Upper-level ridging extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward to the Upper Great Lakes. A belt of enhanced southwesterly mid-level flow will extend from southern CA through the central High Plains, while also wrapping cyclonically through the eastern Dakotas and into southern Canada. At the surface, a trough/front extends southward from central ND into SD and western NE, before continuing southwestward over the central/southern High Plains. This boundary may serve as a focus for renewed thunderstorm development later today. A band of elevated convection has generally moved northward from northeast ND and northwest MN into southern MB. In the wake of this activity, cloud cover remains prevalent across much of the warm sector across the northern Plains/Upper Midwest. Still, filtered daytime heating of an adequately moist boundary layer should aid in the development of around 1500-2000 J/kg of MLCAPE by late afternoon. Isolated to scattered thunderstorms may form along/east of the surface trough/front within a favorable zone of 30-40 kt of effective bulk shear. But, better large-scale forcing associated with the upper low over the northern High Plains will tend to remain displaced north and west (in southern Canada). Accordingly, 12Z high-resolution guidance continues to vary regarding storm coverage across the Slight Risk (isolated versus scattered) given the weaker forcing aloft. Even with this continued uncertainty, various NAM/RAP forecast soundings still suggest a somewhat conditional risk for organized storms (mix of multicells and supercells). Severe hail/wind may accompany the stronger storms from late afternoon through early evening, before this activity eventually weakens. Further south into the central/southern Plains, low-levels are forecast to be somewhat drier near the surface trough, with surface dewpoints expected to mostly range in the upper 50s to low 60s by late afternoon with pronounced boundary-layer mixing. Warmer mid-level temperatures and limited large-scale ascent across these regions should temper the overall intensity of any updrafts that can form and be sustained, and resultant intensity/coverage of this convection. Still, some guidance shows locally greater thunderstorm coverage and resulting isolated severe wind threat from the eastern TX Panhandle into far northwest OK and southern KS during the late afternoon/early evening, where low-level lapse rates should be maximized with robust daytime heating. ..Gleason/Moore.. 09/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Wed Sep 18 2024 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHEAST NEBRASKA INTO FAR NORTHWEST IOWA...EASTERN SOUTH DAKOTA...AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of producing severe wind gusts and large hail are possible today across parts of the eastern Dakotas and Minnesota into the mid Missouri Valley. A marginal severe threat will also extend southward into parts of the central and southern Plains. ...Northern Plains/Upper Midwest to the Southern High Plains... A closed upper low centered over eastern MT will continue northeastward during the period, reaching southeast SK by early Thursday morning. Upper-level ridging extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward to the Upper Great Lakes. A belt of enhanced southwesterly mid-level flow will extend from southern CA through the central High Plains, while also wrapping cyclonically through the eastern Dakotas and into southern Canada. At the surface, a trough/front extends southward from central ND into SD and western NE, before continuing southwestward over the central/southern High Plains. This boundary may serve as a focus for renewed thunderstorm development later today. A band of elevated convection has generally moved northward from northeast ND and northwest MN into southern MB. In the wake of this activity, cloud cover remains prevalent across much of the warm sector across the northern Plains/Upper Midwest. Still, filtered daytime heating of an adequately moist boundary layer should aid in the development of around 1500-2000 J/kg of MLCAPE by late afternoon. Isolated to scattered thunderstorms may form along/east of the surface trough/front within a favorable zone of 30-40 kt of effective bulk shear. But, better large-scale forcing associated with the upper low over the northern High Plains will tend to remain displaced north and west (in southern Canada). Accordingly, 12Z high-resolution guidance continues to vary regarding storm coverage across the Slight Risk (isolated versus scattered) given the weaker forcing aloft. Even with this continued uncertainty, various NAM/RAP forecast soundings still suggest a somewhat conditional risk for organized storms (mix of multicells and supercells). Severe hail/wind may accompany the stronger storms from late afternoon through early evening, before this activity eventually weakens. Further south into the central/southern Plains, low-levels are forecast to be somewhat drier near the surface trough, with surface dewpoints expected to mostly range in the upper 50s to low 60s by late afternoon with pronounced boundary-layer mixing. Warmer mid-level temperatures and limited large-scale ascent across these regions should temper the overall intensity of any updrafts that can form and be sustained, and resultant intensity/coverage of this convection. Still, some guidance shows locally greater thunderstorm coverage and resulting isolated severe wind threat from the eastern TX Panhandle into far northwest OK and southern KS during the late afternoon/early evening, where low-level lapse rates should be maximized with robust daytime heating. ..Gleason/Moore.. 09/18/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 1118 AM CDT Wed Sep 18 2024 Valid 181700Z - 191200Z ...NO CRITICAL AREAS... ...17z Update... Morning observations show widespread precipitation greater than 0.1 inches, with pockets as high as 1-1.25 inches, has fallen over much of western SD and western NE in the last 72 hours. While some drier pockets remain, fuel guidance shows a notable decrease in dryness as a result. Meteorological conditions may still support some localized fire-weather concerns with strong southwesterly winds expected behind the surface low this afternoon. However, the strongest winds are likely to remain farther northwest where the heaviest precipitation has fallen. Gusty winds and humidity below 20% may support some drying today, but fuel recovery is expected to be modest such that no areas will be introduced. See the prior discussion for more information. ..Lyons.. 09/18/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Wed Sep 18 2024/ ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ...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 0733 AM CDT Wed Sep 18 2024 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... Water-vapor imagery depicts a mid-level low over southeast MT this morning and this feature will continue northeastward during the period and reach southeastern SK by early Thursday morning. A mid-level ridge extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward into the Upper Great Lakes. A ribbon of stronger southwesterly mid-level flow will extend from southern CA through the central High Plains and wrapping cyclonically through the eastern Dakotas and into southern Canada. In the low levels, a surface trough will be the primary feature of interest with a plume of 60s deg F dewpoints extending northward to the east of the boundary from the southern Great Plains into the Upper Midwest. In wake of early day dissipating shower/thunderstorm activity (e.g., eastern Dakotas, southern KS), heating of an adequately moist boundary layer will result in moderate destabilization by mid afternoon (1500-2500 J/kg SBCAPE). Isolated to scattered thunderstorms are forecast within a zone of 25-40 kt 0-6 km shear. Some model guidance varies on storm coverage across the Slight Risk (isolated vs. scattered) but forecast sounding profiles indicate a risk for organized storms mainly in the form of organized multicells and supercells. Hail/wind may accompany the stronger storms during the late afternoon through the early evening before this activity begins to weaken. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. Warmer mid-level temperatures and limited large-scale ascent than farther north will likely contribute to tempering the overall intensity of the updrafts and resultant severe intensity/coverage. Models suggest perhaps locally higher storm coverage and resulting severe-wind threat from the TX Panhandle north-northeast into far southern KS during the late afternoon/early evening. ..Smith/Mosier.. 09/18/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Wed Sep 18 2024 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... Water-vapor imagery depicts a mid-level low over southeast MT this morning and this feature will continue northeastward during the period and reach southeastern SK by early Thursday morning. A mid-level ridge extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward into the Upper Great Lakes. A ribbon of stronger southwesterly mid-level flow will extend from southern CA through the central High Plains and wrapping cyclonically through the eastern Dakotas and into southern Canada. In the low levels, a surface trough will be the primary feature of interest with a plume of 60s deg F dewpoints extending northward to the east of the boundary from the southern Great Plains into the Upper Midwest. In wake of early day dissipating shower/thunderstorm activity (e.g., eastern Dakotas, southern KS), heating of an adequately moist boundary layer will result in moderate destabilization by mid afternoon (1500-2500 J/kg SBCAPE). Isolated to scattered thunderstorms are forecast within a zone of 25-40 kt 0-6 km shear. Some model guidance varies on storm coverage across the Slight Risk (isolated vs. scattered) but forecast sounding profiles indicate a risk for organized storms mainly in the form of organized multicells and supercells. Hail/wind may accompany the stronger storms during the late afternoon through the early evening before this activity begins to weaken. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. Warmer mid-level temperatures and limited large-scale ascent than farther north will likely contribute to tempering the overall intensity of the updrafts and resultant severe intensity/coverage. Models suggest perhaps locally higher storm coverage and resulting severe-wind threat from the TX Panhandle north-northeast into far southern KS during the late afternoon/early evening. ..Smith/Mosier.. 09/18/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Wed Sep 18 2024 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... Water-vapor imagery depicts a mid-level low over southeast MT this morning and this feature will continue northeastward during the period and reach southeastern SK by early Thursday morning. A mid-level ridge extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward into the Upper Great Lakes. A ribbon of stronger southwesterly mid-level flow will extend from southern CA through the central High Plains and wrapping cyclonically through the eastern Dakotas and into southern Canada. In the low levels, a surface trough will be the primary feature of interest with a plume of 60s deg F dewpoints extending northward to the east of the boundary from the southern Great Plains into the Upper Midwest. In wake of early day dissipating shower/thunderstorm activity (e.g., eastern Dakotas, southern KS), heating of an adequately moist boundary layer will result in moderate destabilization by mid afternoon (1500-2500 J/kg SBCAPE). Isolated to scattered thunderstorms are forecast within a zone of 25-40 kt 0-6 km shear. Some model guidance varies on storm coverage across the Slight Risk (isolated vs. scattered) but forecast sounding profiles indicate a risk for organized storms mainly in the form of organized multicells and supercells. Hail/wind may accompany the stronger storms during the late afternoon through the early evening before this activity begins to weaken. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. Warmer mid-level temperatures and limited large-scale ascent than farther north will likely contribute to tempering the overall intensity of the updrafts and resultant severe intensity/coverage. Models suggest perhaps locally higher storm coverage and resulting severe-wind threat from the TX Panhandle north-northeast into far southern KS during the late afternoon/early evening. ..Smith/Mosier.. 09/18/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Wed Sep 18 2024 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... Water-vapor imagery depicts a mid-level low over southeast MT this morning and this feature will continue northeastward during the period and reach southeastern SK by early Thursday morning. A mid-level ridge extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward into the Upper Great Lakes. A ribbon of stronger southwesterly mid-level flow will extend from southern CA through the central High Plains and wrapping cyclonically through the eastern Dakotas and into southern Canada. In the low levels, a surface trough will be the primary feature of interest with a plume of 60s deg F dewpoints extending northward to the east of the boundary from the southern Great Plains into the Upper Midwest. In wake of early day dissipating shower/thunderstorm activity (e.g., eastern Dakotas, southern KS), heating of an adequately moist boundary layer will result in moderate destabilization by mid afternoon (1500-2500 J/kg SBCAPE). Isolated to scattered thunderstorms are forecast within a zone of 25-40 kt 0-6 km shear. Some model guidance varies on storm coverage across the Slight Risk (isolated vs. scattered) but forecast sounding profiles indicate a risk for organized storms mainly in the form of organized multicells and supercells. Hail/wind may accompany the stronger storms during the late afternoon through the early evening before this activity begins to weaken. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. Warmer mid-level temperatures and limited large-scale ascent than farther north will likely contribute to tempering the overall intensity of the updrafts and resultant severe intensity/coverage. Models suggest perhaps locally higher storm coverage and resulting severe-wind threat from the TX Panhandle north-northeast into far southern KS during the late afternoon/early evening. ..Smith/Mosier.. 09/18/2024 Read more

000
ABPZ20 KNHC 181126
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Wed Sep 18 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Roberts

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Sep 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Lower-end severe potential should return on D4/Saturday in advance of a southern-stream shortwave trough over the Southwest. A mid-level jetlet, with 500-mb winds from 50-60 kts, is progged to eject across NM as the shortwave trough reaches the Four Corners area. A mesoscale corridor of severe storms might develop Saturday afternoon across a part of eastern NM or Far West TX. The expected buoyancy plume should be modest in amplitude and rather confined spatially owing to mid-level temperatures warmer than -3 C at 500 mb across much of TX. This shortwave trough may weaken slightly as it progresses towards the central Great Plains on D5/Sunday. But moderate mid-level southwesterlies may overspread a plume of rich low-level moisture arcing to the west-northwest from the Mid/Lower MS Valley. A mesoscale corridor of focused severe potential could develop in parts of KS/NE to western MO. Predictability for each scenario on D4-5 remains too low to confidently delineate a 15 percent area at these spatiotemporal scales. Larger-scale pattern predictability becomes too low into early next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Sep 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Lower-end severe potential should return on D4/Saturday in advance of a southern-stream shortwave trough over the Southwest. A mid-level jetlet, with 500-mb winds from 50-60 kts, is progged to eject across NM as the shortwave trough reaches the Four Corners area. A mesoscale corridor of severe storms might develop Saturday afternoon across a part of eastern NM or Far West TX. The expected buoyancy plume should be modest in amplitude and rather confined spatially owing to mid-level temperatures warmer than -3 C at 500 mb across much of TX. This shortwave trough may weaken slightly as it progresses towards the central Great Plains on D5/Sunday. But moderate mid-level southwesterlies may overspread a plume of rich low-level moisture arcing to the west-northwest from the Mid/Lower MS Valley. A mesoscale corridor of focused severe potential could develop in parts of KS/NE to western MO. Predictability for each scenario on D4-5 remains too low to confidently delineate a 15 percent area at these spatiotemporal scales. Larger-scale pattern predictability becomes too low into early next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Sep 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Lower-end severe potential should return on D4/Saturday in advance of a southern-stream shortwave trough over the Southwest. A mid-level jetlet, with 500-mb winds from 50-60 kts, is progged to eject across NM as the shortwave trough reaches the Four Corners area. A mesoscale corridor of severe storms might develop Saturday afternoon across a part of eastern NM or Far West TX. The expected buoyancy plume should be modest in amplitude and rather confined spatially owing to mid-level temperatures warmer than -3 C at 500 mb across much of TX. This shortwave trough may weaken slightly as it progresses towards the central Great Plains on D5/Sunday. But moderate mid-level southwesterlies may overspread a plume of rich low-level moisture arcing to the west-northwest from the Mid/Lower MS Valley. A mesoscale corridor of focused severe potential could develop in parts of KS/NE to western MO. Predictability for each scenario on D4-5 remains too low to confidently delineate a 15 percent area at these spatiotemporal scales. Larger-scale pattern predictability becomes too low into early next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Sep 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Lower-end severe potential should return on D4/Saturday in advance of a southern-stream shortwave trough over the Southwest. A mid-level jetlet, with 500-mb winds from 50-60 kts, is progged to eject across NM as the shortwave trough reaches the Four Corners area. A mesoscale corridor of severe storms might develop Saturday afternoon across a part of eastern NM or Far West TX. The expected buoyancy plume should be modest in amplitude and rather confined spatially owing to mid-level temperatures warmer than -3 C at 500 mb across much of TX. This shortwave trough may weaken slightly as it progresses towards the central Great Plains on D5/Sunday. But moderate mid-level southwesterlies may overspread a plume of rich low-level moisture arcing to the west-northwest from the Mid/Lower MS Valley. A mesoscale corridor of focused severe potential could develop in parts of KS/NE to western MO. Predictability for each scenario on D4-5 remains too low to confidently delineate a 15 percent area at these spatiotemporal scales. Larger-scale pattern predictability becomes too low into early next week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Sep 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Lower-end severe potential should return on D4/Saturday in advance of a southern-stream shortwave trough over the Southwest. A mid-level jetlet, with 500-mb winds from 50-60 kts, is progged to eject across NM as the shortwave trough reaches the Four Corners area. A mesoscale corridor of severe storms might develop Saturday afternoon across a part of eastern NM or Far West TX. The expected buoyancy plume should be modest in amplitude and rather confined spatially owing to mid-level temperatures warmer than -3 C at 500 mb across much of TX. This shortwave trough may weaken slightly as it progresses towards the central Great Plains on D5/Sunday. But moderate mid-level southwesterlies may overspread a plume of rich low-level moisture arcing to the west-northwest from the Mid/Lower MS Valley. A mesoscale corridor of focused severe potential could develop in parts of KS/NE to western MO. Predictability for each scenario on D4-5 remains too low to confidently delineate a 15 percent area at these spatiotemporal scales. Larger-scale pattern predictability becomes too low into early next week. Read more