Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Jun 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... The greatest severe-thunderstorm threat is over parts of the northern/central High Plains this afternoon and evening. Gusts near 80 mph, damaging hail greater than 2.5 inches and a few tornadoes are possible. ...Synopsis... The mid/upper-level pattern will feature a progressive northern stream, with troughs initially located over the inland Pacific Northwest and over the Northeast. A series of phased vorticity maxima extend from the Northeastern trough southwestward across the central/southern Appalachians to parts of MS/LA in recent moisture- channel imagery. This feature should shift eastward to the eastern Carolinas, southern GA and coastal MS by 00Z, becoming stationary tonight across GA and the Gulf Coast east of LA, but moving offshore from NC and SC. The Northwestern trough will move eastward astride the international border, with a closed 500-mb low forming and moving over extreme southern parts of AB/SK tonight. By 12Z tomorrow, the trough should extend from the southern SK low across central MT to southern ID. Though the flow will remain nearly zonal well to its southeast over the central High Plains, height falls are expected to extend as far south as parts of the OK/TX Panhandles. At the surface, the 11Z analysis showed a cold front across western MT, central ID and northern CA, and a warm front from near HVR across east-central MT, western/southern SD and northern NE. Cyclogenesis will continue over MT through the day, shifting eastward. By 00Z, the main low should reach the MT/ND border area roughly between GDV-DIK, with cold front southwestward across northwestern WY, southeastern ID and central NV. A dryline should sharpen over the High Plains through the day, and by 00Z, extend from near the MT/SD line across eastern CO to the western TX Panhandle. The warm front should extend from the low southeastward over the western Dakotas and central parts of NE/KS, becoming diffuse and fragmented farther southeast. A lingering segment of a separate front should be quasistationary and act as a surface trough/convergence zone across southern parts of AL/GA and the central/eastern Carolinas. ...Great Plains... Scattered thunderstorms are expected to develop in multiple episodes over the northern/central Plains, probably leading off with cold-frontal initiation from late morning through afternoon across parts of western/central MT, where large-scale lift will be strongest with the approach of the northwestern trough aloft. This activity -- which may arise from the same vertical-motion field now associated with convection in higher elevations of southwestern MT -- should move generally eastward over the Plains, with upscale organization possible. Severe gusts (some exceeding 70 mph) and sporadic hail (some exceeding 2 inches diameter) will be the main concerns. Subsequent development is expected closer to the surface low, dryline and warm front over the northeastern MT/western Dakotas area this afternoon/evening, also posing a threat for large to very large hail and severe gusts. Tornado potential will be relatively maximized with any discrete or embedded supercell(s) moving into the plume of greatest low-level moisture and backing of surface flow near the low and warm front (east of the dryline). Deep-layer shear should strengthen throughout the day ahead of the cold front, across the central/northern High Plains, while heating gradually weakens MLCINH, and regional lift increases in relation to low-level cyclogenesis. This will combine with a plume of favorable low-level moisture (dewpoints generally in the 60s F by mid/late afternoon) to support a corridor of MLCAPE in the 1000-2000 J/kg range near and just west of the warm front. Effective-shear magnitudes in the 40-55-kt range (strongest on the northern areas) will support supercell potential, with longer hodographs west of the warm front favoring destructive-hail production. One or more storm clusters may evolve and grow upscale into MCS activity this evening, further reinforcing the wind potential, with support from moisture transport and enhanced storm-relative flow of a 40-50-kt LLJ. Convection should be more isolated southward down the dryline and lee trough into the western KS/OK Panhandle region, with deep shear also weakening southward. However, intense surface heating and somewhat high LCL will foster boundary-layer conditions suitable for at least isolated severe gusts and hail. Some clustering and mesobeta-scale cold-pool aggregation may occur to maximize severe-wind potential for a few hours sub-regionally. ...UT and western parts of CO/WY... Widely scattered to scattered thunderstorms are expected to form atop a seasonally moist, well-heated and weakly capped boundary layer this afternoon, offering locally severe gusts, isolated large hail, and a marginal/conditional tornado threat. This activity should develop as height falls spread over the area related to the Northwestern trough, along/ahead of the surface cold front. Diurnal heating will reduce MLCINH substantially, especially in the presence of moisture characterized by 50s F surface dewpoints remaining in many basins/valleys through the heating mixing cycle, while orographic forcing also aids lift locally. That moisture, combined with steep low/middle-level lapse rates, will support MLCAPE of 500-1500 J/kg, atop favorable subcloud thermal profiles to support downdraft accelerations to severe levels. Although environmental flow should be nearly unidirectional through most of the troposphere, terrain-forced backing will enhanced deep shear locally, with effective-shear magnitudes generally in the 25-40-kt range. Mostly multicells and a few supercells are possible. ...Southeast... Widely scattered to scattered thunderstorms should develop this afternoon into early evening, from the NC Coastal Plain southwestward to southern portions of AL/GA. Damaging to isolated severe gusts will be the main concern. Activity should develop most densely near the remnant front/convergence zone as the mid/upper trough closely approaches, as well as along sea-breeze, outflow and differential-heating boundaries south/southeast of the front. Despite weak midlevel lapse rates, a combination of strong diurnal heating and rich low-level moisture (with surface dewpoints commonly in the upper 60s to mid 70s F) should yield MLCAPE in the 1500-2000 J/kg range. Weak low/middle-level flow will limit vertical shear substantially, and convection should be multicellular in nature with some clustering and local cold-pool development possible. Though moist-, subcloud layers nonetheless should be well-mixed, supporting strong/locally severe downdrafts. ..Edwards/Bunting.. 06/27/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Thu Jun 27 2024 Valid 301200Z - 051200Z ...DISCUSSION... ...D4/Sunday: Eastern MT into western ND... A mid/upper-level trough will move eastward from the Northwest toward the northern Rockies on Sunday, with some influence of this trough reaching the northern High Plains by late afternoon into early evening. Low-level moisture return north of a surface low across WY will support moderate destabilization across parts of eastern MT. Scattered storm development will be possible by early evening as the mid/upper trough approaches. Increasing midlevel flow will support initial supercell development, with a threat of large hail. A strengthening nocturnal low-level jet will aid in potential MCS development, which may spread some severe-wind potential into at least western ND Sunday night. ...D4/Sunday: Southern New England into the Mid Atlantic... Depending on the influence of early-day convection and timing of a cold front, some modest destabilization may occur from southern New England into the Mid Atlantic Sunday afternoon. Deep-layer shear would support some storm organization, and strong to locally severe storms will be possible. ...D5/Monday: Central/northern Great Plains... The mid/upper-level trough that moves across the northern Rockies on Sunday is forecast to emerge over the northern/central Great Plains on Sunday. Moderate to locally strong destabilization will be possible near and west of a warm front that is forecast to lift northeastward through the day. Deep-layer shear will increase as midlevel height falls overspread the warm sector, and scattered strong to severe storms may develop in the vicinity of a trailing surface trough/cold front. Supercells will be possible with initial development, with a potential tendency for some clustering/upscale growth with time. A 15% probability area has been included across parts of SD/NE, where confidence is currently greatest in severe-storm development. Some severe threat could also evolve across parts of ND, but there is greater uncertainty with northward extent due to the potential for an early-day MCS. Farther east, guidance varies regarding the potential for destabilization into parts of MN/IA. ...D6/Tuesday: East-central Plains into the upper Midwest... Some severe threat could spread eastward into parts of the east-central Plains and Midwest on Tuesday, in conjunction with the eastward-moving mid/upper-level trough and attendant cold front. However, predictability is currently too low to include probabilities, due to uncertainty regarding trough evolution and the influence of antecedent convection. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 27 2024 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OH INTO WESTERN PA AND NORTHERN WV... ...SUMMARY... Damaging winds and a couple tornadoes are possible across parts of the upper Ohio Valley and Northeast on Saturday. ...Parts of the Ohio Valley and Northeast... A mid/upper-level shortwave trough and related surface low are forecast to move from parts of the upper Midwest into Ontario/Quebec on Saturday, while a trailing shortwave will move southeastward across the upper Great Lakes during the evening. One or more MCVs may move eastward within a belt of westerly midlevel flow from parts of the Midwest/Ohio Valley into the Northeast. A cold front trailing from the primary surface low will move eastward across parts of the Midwest, Ohio Valley, and Great Lakes, and eventually into parts of the Northeast by Sunday morning. Rich low-level moisture is forecast to stream northeastward along/ahead of the cold front, aided by a belt of relatively strong southwesterly 850 mb flow. Midlevel lapse rates are expected to remain weak, but low 70s F dewpoints and modest diurnal heating could support moderate to locally strong buoyancy by mid/late afternoon, though the influence of early-day convection on destabilization remains rather uncertain. Scattered thunderstorms may develop during the afternoon from OH into western PA, with more isolated development possible along the trailing front into the lower OH Valley. Deep-layer shear will be sufficient for organized convection, and a few supercells and/or organized clusters could develop and move eastward during the afternoon into the evening, with a threat of scattered damaging wind. Some tornado threat could also evolve, in the presence of rich moisture and somewhat favorable low-level shear/SRH. A Slight Risk has been added from OH into western PA. Some expansion of this risk area is possible with time, depending on extent of destabilization farther east, and storm coverage farther southwest. ...Ozark Region into the south-central Plains... Strong buoyancy is forecast to develop during the afternoon along the trailing cold front from parts of southern KS/MO into northern OK/AR. Deep-layer flow is expected to be rather weak, but modest veering with height may support effective shear of 20-30 kt near the front. Storm coverage along the front in this region remains somewhat uncertain, but isolated strong to severe storms will be possible, with a threat of localized severe gusts and possibly some hail. A couple stronger storms may also develop within a post-frontal regime across parts of the southern/central High Plains. ..Dean.. 06/27/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 27 2024 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OH INTO WESTERN PA AND NORTHERN WV... ...SUMMARY... Damaging winds and a couple tornadoes are possible across parts of the upper Ohio Valley and Northeast on Saturday. ...Parts of the Ohio Valley and Northeast... A mid/upper-level shortwave trough and related surface low are forecast to move from parts of the upper Midwest into Ontario/Quebec on Saturday, while a trailing shortwave will move southeastward across the upper Great Lakes during the evening. One or more MCVs may move eastward within a belt of westerly midlevel flow from parts of the Midwest/Ohio Valley into the Northeast. A cold front trailing from the primary surface low will move eastward across parts of the Midwest, Ohio Valley, and Great Lakes, and eventually into parts of the Northeast by Sunday morning. Rich low-level moisture is forecast to stream northeastward along/ahead of the cold front, aided by a belt of relatively strong southwesterly 850 mb flow. Midlevel lapse rates are expected to remain weak, but low 70s F dewpoints and modest diurnal heating could support moderate to locally strong buoyancy by mid/late afternoon, though the influence of early-day convection on destabilization remains rather uncertain. Scattered thunderstorms may develop during the afternoon from OH into western PA, with more isolated development possible along the trailing front into the lower OH Valley. Deep-layer shear will be sufficient for organized convection, and a few supercells and/or organized clusters could develop and move eastward during the afternoon into the evening, with a threat of scattered damaging wind. Some tornado threat could also evolve, in the presence of rich moisture and somewhat favorable low-level shear/SRH. A Slight Risk has been added from OH into western PA. Some expansion of this risk area is possible with time, depending on extent of destabilization farther east, and storm coverage farther southwest. ...Ozark Region into the south-central Plains... Strong buoyancy is forecast to develop during the afternoon along the trailing cold front from parts of southern KS/MO into northern OK/AR. Deep-layer flow is expected to be rather weak, but modest veering with height may support effective shear of 20-30 kt near the front. Storm coverage along the front in this region remains somewhat uncertain, but isolated strong to severe storms will be possible, with a threat of localized severe gusts and possibly some hail. A couple stronger storms may also develop within a post-frontal regime across parts of the southern/central High Plains. ..Dean.. 06/27/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 27 2024 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OH INTO WESTERN PA AND NORTHERN WV... ...SUMMARY... Damaging winds and a couple tornadoes are possible across parts of the upper Ohio Valley and Northeast on Saturday. ...Parts of the Ohio Valley and Northeast... A mid/upper-level shortwave trough and related surface low are forecast to move from parts of the upper Midwest into Ontario/Quebec on Saturday, while a trailing shortwave will move southeastward across the upper Great Lakes during the evening. One or more MCVs may move eastward within a belt of westerly midlevel flow from parts of the Midwest/Ohio Valley into the Northeast. A cold front trailing from the primary surface low will move eastward across parts of the Midwest, Ohio Valley, and Great Lakes, and eventually into parts of the Northeast by Sunday morning. Rich low-level moisture is forecast to stream northeastward along/ahead of the cold front, aided by a belt of relatively strong southwesterly 850 mb flow. Midlevel lapse rates are expected to remain weak, but low 70s F dewpoints and modest diurnal heating could support moderate to locally strong buoyancy by mid/late afternoon, though the influence of early-day convection on destabilization remains rather uncertain. Scattered thunderstorms may develop during the afternoon from OH into western PA, with more isolated development possible along the trailing front into the lower OH Valley. Deep-layer shear will be sufficient for organized convection, and a few supercells and/or organized clusters could develop and move eastward during the afternoon into the evening, with a threat of scattered damaging wind. Some tornado threat could also evolve, in the presence of rich moisture and somewhat favorable low-level shear/SRH. A Slight Risk has been added from OH into western PA. Some expansion of this risk area is possible with time, depending on extent of destabilization farther east, and storm coverage farther southwest. ...Ozark Region into the south-central Plains... Strong buoyancy is forecast to develop during the afternoon along the trailing cold front from parts of southern KS/MO into northern OK/AR. Deep-layer flow is expected to be rather weak, but modest veering with height may support effective shear of 20-30 kt near the front. Storm coverage along the front in this region remains somewhat uncertain, but isolated strong to severe storms will be possible, with a threat of localized severe gusts and possibly some hail. A couple stronger storms may also develop within a post-frontal regime across parts of the southern/central High Plains. ..Dean.. 06/27/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 27 2024 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OH INTO WESTERN PA AND NORTHERN WV... ...SUMMARY... Damaging winds and a couple tornadoes are possible across parts of the upper Ohio Valley and Northeast on Saturday. ...Parts of the Ohio Valley and Northeast... A mid/upper-level shortwave trough and related surface low are forecast to move from parts of the upper Midwest into Ontario/Quebec on Saturday, while a trailing shortwave will move southeastward across the upper Great Lakes during the evening. One or more MCVs may move eastward within a belt of westerly midlevel flow from parts of the Midwest/Ohio Valley into the Northeast. A cold front trailing from the primary surface low will move eastward across parts of the Midwest, Ohio Valley, and Great Lakes, and eventually into parts of the Northeast by Sunday morning. Rich low-level moisture is forecast to stream northeastward along/ahead of the cold front, aided by a belt of relatively strong southwesterly 850 mb flow. Midlevel lapse rates are expected to remain weak, but low 70s F dewpoints and modest diurnal heating could support moderate to locally strong buoyancy by mid/late afternoon, though the influence of early-day convection on destabilization remains rather uncertain. Scattered thunderstorms may develop during the afternoon from OH into western PA, with more isolated development possible along the trailing front into the lower OH Valley. Deep-layer shear will be sufficient for organized convection, and a few supercells and/or organized clusters could develop and move eastward during the afternoon into the evening, with a threat of scattered damaging wind. Some tornado threat could also evolve, in the presence of rich moisture and somewhat favorable low-level shear/SRH. A Slight Risk has been added from OH into western PA. Some expansion of this risk area is possible with time, depending on extent of destabilization farther east, and storm coverage farther southwest. ...Ozark Region into the south-central Plains... Strong buoyancy is forecast to develop during the afternoon along the trailing cold front from parts of southern KS/MO into northern OK/AR. Deep-layer flow is expected to be rather weak, but modest veering with height may support effective shear of 20-30 kt near the front. Storm coverage along the front in this region remains somewhat uncertain, but isolated strong to severe storms will be possible, with a threat of localized severe gusts and possibly some hail. A couple stronger storms may also develop within a post-frontal regime across parts of the southern/central High Plains. ..Dean.. 06/27/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 27 2024 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OH INTO WESTERN PA AND NORTHERN WV... ...SUMMARY... Damaging winds and a couple tornadoes are possible across parts of the upper Ohio Valley and Northeast on Saturday. ...Parts of the Ohio Valley and Northeast... A mid/upper-level shortwave trough and related surface low are forecast to move from parts of the upper Midwest into Ontario/Quebec on Saturday, while a trailing shortwave will move southeastward across the upper Great Lakes during the evening. One or more MCVs may move eastward within a belt of westerly midlevel flow from parts of the Midwest/Ohio Valley into the Northeast. A cold front trailing from the primary surface low will move eastward across parts of the Midwest, Ohio Valley, and Great Lakes, and eventually into parts of the Northeast by Sunday morning. Rich low-level moisture is forecast to stream northeastward along/ahead of the cold front, aided by a belt of relatively strong southwesterly 850 mb flow. Midlevel lapse rates are expected to remain weak, but low 70s F dewpoints and modest diurnal heating could support moderate to locally strong buoyancy by mid/late afternoon, though the influence of early-day convection on destabilization remains rather uncertain. Scattered thunderstorms may develop during the afternoon from OH into western PA, with more isolated development possible along the trailing front into the lower OH Valley. Deep-layer shear will be sufficient for organized convection, and a few supercells and/or organized clusters could develop and move eastward during the afternoon into the evening, with a threat of scattered damaging wind. Some tornado threat could also evolve, in the presence of rich moisture and somewhat favorable low-level shear/SRH. A Slight Risk has been added from OH into western PA. Some expansion of this risk area is possible with time, depending on extent of destabilization farther east, and storm coverage farther southwest. ...Ozark Region into the south-central Plains... Strong buoyancy is forecast to develop during the afternoon along the trailing cold front from parts of southern KS/MO into northern OK/AR. Deep-layer flow is expected to be rather weak, but modest veering with height may support effective shear of 20-30 kt near the front. Storm coverage along the front in this region remains somewhat uncertain, but isolated strong to severe storms will be possible, with a threat of localized severe gusts and possibly some hail. A couple stronger storms may also develop within a post-frontal regime across parts of the southern/central High Plains. ..Dean.. 06/27/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0136 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level trough initially within the northern Rockies will eject into the northern/central Plains on Friday. At the surface, a cold front will move into the upper Midwest and push southward into parts of the southern Plains before stalling. ...Central/Southern Wyoming... Strong winds due to the favorable position of the mid-level jet as well as the strong pressure gradient behind the front will promote 15-25 mph winds across the area. RH could fall to 15-20% with perhaps localized 10-15% values by the afternoon. Fuel information and recent fire activity would suggest southeastern Wyoming and nearby vicinity have the driest fuels. Precipitation that occurred Wednesday afternoon/evening along with potential precipitation on Thursday increases uncertainty in how dry fuels will be on Friday. In southwest/south-central Wyoming, fuels are sparse and present fuels do not appear overly dry based on current data. Furthermore, this area could also see some precipitation on Thursday. As impacts of precipitation on fuels become more clear, elevated highlights could be added for southeastern Wyoming. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0136 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level trough initially within the northern Rockies will eject into the northern/central Plains on Friday. At the surface, a cold front will move into the upper Midwest and push southward into parts of the southern Plains before stalling. ...Central/Southern Wyoming... Strong winds due to the favorable position of the mid-level jet as well as the strong pressure gradient behind the front will promote 15-25 mph winds across the area. RH could fall to 15-20% with perhaps localized 10-15% values by the afternoon. Fuel information and recent fire activity would suggest southeastern Wyoming and nearby vicinity have the driest fuels. Precipitation that occurred Wednesday afternoon/evening along with potential precipitation on Thursday increases uncertainty in how dry fuels will be on Friday. In southwest/south-central Wyoming, fuels are sparse and present fuels do not appear overly dry based on current data. Furthermore, this area could also see some precipitation on Thursday. As impacts of precipitation on fuels become more clear, elevated highlights could be added for southeastern Wyoming. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0136 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level trough initially within the northern Rockies will eject into the northern/central Plains on Friday. At the surface, a cold front will move into the upper Midwest and push southward into parts of the southern Plains before stalling. ...Central/Southern Wyoming... Strong winds due to the favorable position of the mid-level jet as well as the strong pressure gradient behind the front will promote 15-25 mph winds across the area. RH could fall to 15-20% with perhaps localized 10-15% values by the afternoon. Fuel information and recent fire activity would suggest southeastern Wyoming and nearby vicinity have the driest fuels. Precipitation that occurred Wednesday afternoon/evening along with potential precipitation on Thursday increases uncertainty in how dry fuels will be on Friday. In southwest/south-central Wyoming, fuels are sparse and present fuels do not appear overly dry based on current data. Furthermore, this area could also see some precipitation on Thursday. As impacts of precipitation on fuels become more clear, elevated highlights could be added for southeastern Wyoming. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0136 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level trough initially within the northern Rockies will eject into the northern/central Plains on Friday. At the surface, a cold front will move into the upper Midwest and push southward into parts of the southern Plains before stalling. ...Central/Southern Wyoming... Strong winds due to the favorable position of the mid-level jet as well as the strong pressure gradient behind the front will promote 15-25 mph winds across the area. RH could fall to 15-20% with perhaps localized 10-15% values by the afternoon. Fuel information and recent fire activity would suggest southeastern Wyoming and nearby vicinity have the driest fuels. Precipitation that occurred Wednesday afternoon/evening along with potential precipitation on Thursday increases uncertainty in how dry fuels will be on Friday. In southwest/south-central Wyoming, fuels are sparse and present fuels do not appear overly dry based on current data. Furthermore, this area could also see some precipitation on Thursday. As impacts of precipitation on fuels become more clear, elevated highlights could be added for southeastern Wyoming. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0136 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level trough initially within the northern Rockies will eject into the northern/central Plains on Friday. At the surface, a cold front will move into the upper Midwest and push southward into parts of the southern Plains before stalling. ...Central/Southern Wyoming... Strong winds due to the favorable position of the mid-level jet as well as the strong pressure gradient behind the front will promote 15-25 mph winds across the area. RH could fall to 15-20% with perhaps localized 10-15% values by the afternoon. Fuel information and recent fire activity would suggest southeastern Wyoming and nearby vicinity have the driest fuels. Precipitation that occurred Wednesday afternoon/evening along with potential precipitation on Thursday increases uncertainty in how dry fuels will be on Friday. In southwest/south-central Wyoming, fuels are sparse and present fuels do not appear overly dry based on current data. Furthermore, this area could also see some precipitation on Thursday. As impacts of precipitation on fuels become more clear, elevated highlights could be added for southeastern Wyoming. ..Wendt.. 06/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0114 AM CDT Thu Jun 27 2024 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST CO...MUCH OF NE/KS/IA...NORTHERN MO...SOUTHERN MN... CORRECTED FOR HAIL GRAPHIC ...SUMMARY... Severe thunderstorms may develop from parts of the central Plains into parts of the upper Midwest and upper Mississippi Valley on Friday. Large hail, damaging wind, and a couple tornadoes will be possible. ...Central/northern Plains into the upper Midwest/Great Lakes... A mid/upper-level trough will move eastward across the northern Great Plains into the upper Great Lakes region on Friday into Friday night. In conjunction with the shortwave, a surface low will move eastward across the Dakotas into MN, with secondary low development possible across the central Plains. A warm front is forecast to move northward across the mid/upper MS Valley, while a cold front will move through the northern/central Plains into MN through the day and into the evening. Elevated convection may be ongoing at the start of the period, within a warm-advection regime. In the wake of the morning convection, moderate to locally strong destabilization will be possible in the vicinity of the cold front and a possible outflow boundary across parts of NE/IA into northeast KS/northwest MO, with somewhat more modest destabilization along the northward extension of the front into parts of MN. Deep-layer shear will be sufficient for organized convection across the region. Storm evolution during the afternoon/evening remains somewhat uncertain, but development of a few supercells and/or stronger clusters will be possible near the front from eastern NE/northeast KS into southern MN/western IA/northwest MO. Hail and damaging winds will be possible with the strongest storms across the warm sector. In addition, some tornado threat may evolve with any sustained supercell, especially from southeast NE/eastern KS into northwest MO/southwest IA, where buoyancy may be maximized, and low-level shear/SRH will be somewhat enhanced into the evening. Farther west, organized storms may also develop near and north of the front across the central High Plains. Initial supercell development will be possible from northeast CO into southwest NE/northwest KS, with a threat of hail and localized severe gusts. Some upscale growth into multiple clusters or a small MCS may occur with time, which could pose at least a localized threat of significant severe gusts. The Slight Risk has been expanded to cover the scenarios described above, though some uncertainty remains regarding storm evolution through the period. ..Dean.. 06/27/2024 Read more