Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Sep 19 2024 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST AND ALSO THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible in the late afternoon Friday in parts of Illinois, Indiana, and southwest Lower Michigan. Isolated strong to severe storms are also possible across parts of the south-central Plains. ...Midwest... A low-amplitude shortwave trough will pass across the Upper to central Great Lakes during the first half of the period. This will outpace a cold front that trails from a cyclone shifting northeast in MB, yielding a largely weakening to stalling front by Friday evening. Most guidance suggests at least isolated thunderstorms should form within a low-level warm conveyor ahead of the front, generally focused on a moderate buoyancy plume emanating northeast from parts of MO/AR. A fast westerly upper jet will further impinge on this portion of the front as well, favorably timed with peak boundary-layer heating. A few marginally severe storms may develop within this regime. Despite weak mid-level lapse rates, elongation of the mid to upper hodograph should support a threat for 1-1.5 inch hail, along with strong to marginally severe gusts from 45-60 mph. These threats should diminish quickly after sunset. ...Southern KS/northern OK vicinity... A mid/upper-level shortwave trough is forecast to move slowly eastward across the Southwest on Friday. Farther east, a surface boundary initially draped from the lower MO Valley into southern KS/northern OK is forecast to lift northward as a warm front. Large-scale ascent across much of the Plains may remain relatively limited, outside of low-level warm advection near/north of the front. However, relatively strong heating along the western/northern periphery of returning low-level moisture could support thunderstorm development during the afternoon somewhere in the vicinity of southwest KS/northwest OK. Effective shear of 30-40 kt will support potential for somewhat organized convection. Strong to localized severe gusts may be the most likely hazard, but hail cannot be ruled out if any more discrete storms can move into an environment of greater moisture/instability. ...New Mexico... Scattered thunderstorms will be possible across much of NM on Friday, in closer proximity to the approaching shortwave trough. While deep-layer shear will be rather strong, generally weak midlevel lapse rates and buoyancy may tend to limit the potential for more robust storms. If confidence increases regarding sufficient heating/destabilization, then severe probabilities may eventually be needed for parts of the region. ...Central Plains into the lower MO Valley... Guidance continues to vary regarding the potential for robust elevated convection Friday night into Saturday morning, within a low-level warm advection regime. Increasing elevated buoyancy and sufficient mid/upper-level flow could support a few stronger storms with hail potential, but confidence in sufficient coverage and a favored region for this potential is too low for probabilities at this time. ..Dean.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Thu Sep 19 2024 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO EASTERN KANSAS...WESTERN MISSOURI...AND FAR NORTHEAST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are possible this afternoon and evening across central/eastern Minnesota, Iowa, and western Wisconsin. A couple of tornadoes, large hail, and damaging winds may occur across this region. Farther south, an area of locally severe wind gusts and hail may also develop over parts of eastern Kansas, southwest Missouri, and northeast Oklahoma. ...Minnesota/Wisconsin/Iowa... Widely spaced and mainly elevated thunderstorms ongoing late this morning across parts of IA into eastern MN and western WI should continue to diminish in coverage over the next couple of hours. In their wake, daytime heating of a seasonably moist low-level airmass (surface dewpoints generally in the 60s) and somewhat steep mid-level lapse rates will contribute to at least moderate instability by mid afternoon along/ahead of a cold front extending north to south from western MN into eastern NE and western IA. An upper low over northern ND and southeast SK/southwest MB will continue to advance slowly northeastward across south-central Canada through the period. A belt of 35-50 kt mid-level west-southwesterly winds on the southern periphery of the upper low will spread eastward from the northern Plains into the Upper Midwest through this evening. A veering/strengthening wind profile with height through mid levels will support around 30-40 kt of deep-layer shear across the warm sector. This shear will be sufficient for organized thunderstorms, including the potential for a few supercells. Current expectations are that scattered thunderstorms will develop by mid to late afternoon across central/eastern MN into northern/central IA along or just ahead of the eastward-advancing cold front. A rather favorable thermodynamic environment will foster robust updrafts, and any initial supercells should pose a threat for large to very large hail (around 1.5-2.5 inches in diameter). But, a fairly quick transition to more linear structures should occur given the presence of the cold front, with a potentially greater damaging wind threat evolving with eastward extent through the evening before convection eventually weakens. South-southwesterly low-level flow and related shear ahead of the front is not forecast to be overly strong by most guidance this afternoon. But, some threat for a couple of tornadoes remains apparent, especially with any sustained supercells across east-central/southern MN into northern IA late this afternoon/early evening. ...Eastern Kansas into Missouri and Northeast Oklahoma... An upper ridge, with rather warm mid-level temperatures, will remain centered over the southern Plains today. The surface cold front is forecast to continue moving east-southeastward across the mid MO Valley and central Plains through late this afternoon. A surface trough extending southward from this front across the southern High Plains should also mix eastward through peak daytime heating. Given weak large-scale ascent and rather warm mid-level temperatures across this area, there is still a fair amount of uncertainty regarding how many additional thunderstorms will develop later today, notwithstanding the ongoing (mainly elevated) convection over eastern KS and far northwest MO. Still, other surface-based thunderstorms may develop later this afternoon along/near the front/dryline intersection in south-central KS/north-central OK, and along the cold front in eastern KS. While low/mid-level flow should remain fairly modest, steepened low-level lapse rates and moderate instability should support a risk for mainly severe/damaging downdrafts as convection spreads east-southeastward into western MO and northeast OK through this evening. ..Gleason/Moore.. 09/19/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1047 AM CDT Thu Sep 19 2024 Valid 191700Z - 201200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes or additions made. ..Squitieri.. 09/19/2024 .PREV DISCUSSION... /ISSUED 0120 AM CDT Thu Sep 19 2024/ ...Synopsis... In the wake of a midlevel low tracking northeastward across Manitoba, strong post-frontal winds will overspread the northern Plains. While these winds may overlap pockets of 25-35 percent RH, cool surface temperatures/marginal RH and recent rainfall should limit the fire-weather threat. Elsewhere, an expansive surface high centered over the western CONUS will limit surface winds and the overall fire-weather risk. ...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 1047 AM CDT Thu Sep 19 2024 Valid 191700Z - 201200Z ...NO CRITICAL AREAS... The previous forecast remains on track, with no changes or additions made. ..Squitieri.. 09/19/2024 .PREV DISCUSSION... /ISSUED 0120 AM CDT Thu Sep 19 2024/ ...Synopsis... In the wake of a midlevel low tracking northeastward across Manitoba, strong post-frontal winds will overspread the northern Plains. While these winds may overlap pockets of 25-35 percent RH, cool surface temperatures/marginal RH and recent rainfall should limit the fire-weather threat. Elsewhere, an expansive surface high centered over the western CONUS will limit surface winds and the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more