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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jun 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms should occur today across parts of the Upper Mississippi Valley, and over the central High Plains and northern Plains late this afternoon through tonight. Both severe/damaging winds and large hail appear possible. ...Upper Mississippi Valley/Upper Great Lakes... A loosely organized thunderstorm cluster is ongoing late this morning across northern WI into the U.P. of MI. With steep mid-level lapse rates present per the 12Z sounding from GRB, along with sufficient deep-layer shear to support organized updrafts, at least an isolated severe hail/wind risk should continue through the afternoon across this region along and east of a front. In the wake of this activity, large-scale ascent appears nebulous/weak across much of the upper MS Valley. Still, modest forcing associated with low-level warm advection through the day may be enough for additional convection to develop this afternoon along the southward extent of the front across this region. The best chance for this to occur appears to be across parts of northern IA/southern MN and perhaps western WI along and near the surface front, which may try to lift slowly northward through this afternoon/evening. If surface-based thunderstorms can develop across this area, they would pose some threat for severe hail and damaging winds given moderate forecast instability and sufficient deep-layer shear to support updraft organization. However, this scenario remains low confidence, as earlier convection has shunted the surface front well into IA this morning. This boundary is forecast to lift northward as a warm front tonight ahead of an mid/upper-level wave approaching from the northern/central Plains, and mainly a hail threat could persist across parts of MN and vicinity through early Tuesday morning with elevated supercells that may develop in a strengthening low-level warm advection regime. ...Northern/Central Plains... A pronounced upper trough/low over the Northwest will move eastward through the period over the northern/central Rockies and adjacent High Plains. Related surface lee cyclogenesis is expected to further occur through this evening over the central High Plains, focused on the northeast CO, southeast WY, and NE Panhandle vicinity. Multiple rounds and zones of severe thunderstorm potential still appear possible across much of the northern/central Plains this afternoon through tonight. Intense thunderstorm development may occur near the surface triple point in southwest NE and vicinity this afternoon, although the later timing of large-scale ascent associated with the upper trough casts some doubt on surface-based thunderstorm initiation. The presence of steep mid-level lapse rates and rich low-level moisture should aid in the development of moderate to strong instability as daytime heating occurs and as the warm front attempts to lift slowly northward across the central Plains. Deep-layer shear will be strong enough for supercells with associated large hail threat. Isolated very large hail may also occur. Some upscale growth/clustering along and near the front appears possible with time this evening, and a greater threat for severe/damaging winds may eventually be realized. Effective SRH is also forecast to quickly increase late this afternoon into the evening as a southerly low-level jet rapidly strengthens over the northern/central Plains. If any supercell can persist in this time frame, it would pose a threat for a tornado. A somewhat separate area of supercell potential is also evident across northeast WY/southeast MT, where modest low-level moisture return and upslope flow to the Bighorns may promote convective initiation later today as the upper trough continues eastward. Isolated to scattered large hail appears to be the main threat with this convection, if it develops and assuming sufficient instability can materialize. Otherwise, mainly elevated thunderstorms will likely develop and persist late this evening and overnight across a broader portion of the northern Plains. Large hail should be the main threat, although severe/damaging winds may occur with any convection that can remain near/south of the northward-lifting warm front. ...Southern High Plains... Isolated to widely scattered thunderstorms may occur with southward extent along the length of the dryline/lee trough this afternoon across the southern High Plains. Deep-layer shear should remain fairly modest (generally 20-30 kt). Still, any convection that can develop late this afternoon may pose an isolated threat for severe wind gusts and hail through early evening given a moderately to strongly unstable airmass. ...Lower Great Lakes/Upper Ohio River Valley... A remnant convective cluster/MCV over southern Ontario should broadly influence additional thunderstorm development to its east this afternoon across the lower Great Lakes and upper OH Valley regions. Instability is forecast to gradually increase with continued daytime heating and low-level moisture streaming northward. Deep-layer shear should remain generally weak (25 kt or less). Still, steepening low-level lapse rates and a moist/moderately unstable airmass could allow for some stronger pulse-type/occasionally clustering thunderstorms capable of producing localized wind damage this afternoon and early evening. ..Gleason/Lyons.. 06/17/2024 Read more

MD 1300 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN NE
Mesoscale Discussion 1300 NWS Storm Prediction Center Norman OK 0844 AM CDT Mon Jun 17 2024 Areas affected...Eastern NE Concerning...Severe potential...Watch unlikely Valid 171344Z - 171545Z Probability of Watch Issuance...20 percent SUMMARY...Isolated large hail is possible across eastern Nebraska over the next hour or two. Limited severe coverage will likely preclude the need for a watch, but convective trends will be monitored closely. DISCUSSION...Regional radar imagery has shown an increase in thunderstorms along a north-south line from the OFK vicinity southward to around 20 miles southeast of HSI. Surface analysis reveals a warm front across southern NE, with this new development likely a result of warm-air advection across this frontal zone. Moderate elevated buoyancy is in place ahead of this line, with mesoanalysis estimation MUCAPE around 2000 J/kg. This elevated buoyancy will likely persist throughout the remainder of the morning, but the low-level jet is expected to gradually weaken. As a result, the general expectation is that this line will gradually diminish in intensity over the next few hours. Even so, sporadic intensification of the updrafts within this line is possible, with large hail as the primary severe risk. A strong gust or two is also possible given the modest low-level stability. Given the anticipated weakening of these storms, a watch is not currently expected, but convective trends will still be monitored closely. ..Mosier/Gleason.. 06/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...OAX...GID... LAT...LON 40069782 40519818 41629802 42349757 42309629 41239602 40609608 40149668 40069782 Read more

WW 0428 Status Updates
STATUS FOR WATCH 0428 HAS NOT BEEN ISSUED YET Read more

WW 0428 Status Updates
STATUS FOR WATCH 0428 HAS NOT BEEN ISSUED YET Read more

WW 0428 Status Updates
STATUS FOR WATCH 0428 HAS NOT BEEN ISSUED YET Read more

WW 0428 Status Updates
STATUS FOR WATCH 0428 HAS NOT BEEN ISSUED YET Read more

WW 0428 Status Updates
STATUS FOR WATCH 0428 HAS NOT BEEN ISSUED YET Read more

WW 428 SEVERE TSTM MI WI LS 171420Z - 172100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 428 NWS Storm Prediction Center Norman OK 920 AM CDT Mon Jun 17 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of The Western Upper Peninsula of Michigan Northern Wisconsin Lake Superior * Effective this Monday morning and afternoon from 920 AM until 400 PM CDT. * Primary threats include... Isolated damaging wind gusts to 65 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms spreading northeastward this morning and afternoon should continue to pose some threat for severe hail around 1-1.5 inches in diameter, along with severe/damaging winds up to 55-65 mph. The severe thunderstorm watch area is approximately along and 80 statute miles north and south of a line from 20 miles west southwest of Rhinelander WI to 30 miles east of Iron Mountain MI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 427... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Gleason Read more

MD 1299 CONCERNING SEVERE THUNDERSTORM WATCH 427... FOR WESTERN/NORTHERN WISCONSIN TO UPPER MICHIGAN
Mesoscale Discussion 1299 NWS Storm Prediction Center Norman OK 0745 AM CDT Mon Jun 17 2024 Areas affected...Western/northern Wisconsin to Upper Michigan Concerning...Severe Thunderstorm Watch 427... Valid 171245Z - 171415Z The severe weather threat for Severe Thunderstorm Watch 427 continues. SUMMARY...At least isolated severe storms, capable of damaging winds and possibly some hail, will continue to focus across west-central Wisconsin through mid-morning, and may spread into additional parts of central/northern Wisconsin, where an additional Watch could be needed. Severe Thunderstorm Watch 427 continues until 15z. DISCUSSION...A relatively small-scale quasi-linear cluster remains strong/severe this morning as it approaches the I-94 corridor of west-central Wisconsin including the Eau Claire area. This cluster will likely continue northeastward, favoring the instability gradient that extends across southwest/west-central Wisconsin toward northeast Wisconsin and the eastern Upper Peninsula of Michigan. This cluster has a general history of severe-caliber wind gusts in the predawn hours, including a measured 53 kt gust at Rochester Minnesota. An additional Watch could be warranted for portions of central/northern Wisconsin pending short-term convective trends. ..Guyer.. 06/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MQT...GRB...DLH...ARX...MPX... LAT...LON 44519264 46009093 46248773 45648750 44898799 44408943 43959104 44519264 Read more

WW 0427 Status Updates
STATUS REPORT ON WW 427 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NE FOD TO 25 WNW RST TO 30 WSW EAU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1299 ..GUYER..06/17/24 ATTN...WFO...ARX...FSD...DMX...MPX... STATUS REPORT FOR WS 427 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-033-037-067-069-081-089-131-189-191-195-197-171340- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE CERRO GORDO CHICKASAW FLOYD FRANKLIN HANCOCK HOWARD MITCHELL WINNEBAGO WINNESHIEK WORTH WRIGHT MNC039-045-047-049-055-099-109-157-169-171340- MN . MINNESOTA COUNTIES INCLUDED ARE DODGE FILLMORE FREEBORN GOODHUE HOUSTON MOWER OLMSTED WABASHA WINONA WIC011-019-035-053-063-081-091-121-123-171340- Read more

WW 0427 Status Updates
STATUS REPORT ON WW 427 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NE FOD TO 25 WNW RST TO 30 WSW EAU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1299 ..GUYER..06/17/24 ATTN...WFO...ARX...FSD...DMX...MPX... STATUS REPORT FOR WS 427 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-033-037-067-069-081-089-131-189-191-195-197-171340- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE CERRO GORDO CHICKASAW FLOYD FRANKLIN HANCOCK HOWARD MITCHELL WINNEBAGO WINNESHIEK WORTH WRIGHT MNC039-045-047-049-055-099-109-157-169-171340- MN . MINNESOTA COUNTIES INCLUDED ARE DODGE FILLMORE FREEBORN GOODHUE HOUSTON MOWER OLMSTED WABASHA WINONA WIC011-019-035-053-063-081-091-121-123-171340- Read more

WW 0427 Status Updates
STATUS REPORT ON WW 427 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NE FOD TO 25 WNW RST TO 30 WSW EAU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1299 ..GUYER..06/17/24 ATTN...WFO...ARX...FSD...DMX...MPX... STATUS REPORT FOR WS 427 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-033-037-067-069-081-089-131-189-191-195-197-171340- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE CERRO GORDO CHICKASAW FLOYD FRANKLIN HANCOCK HOWARD MITCHELL WINNEBAGO WINNESHIEK WORTH WRIGHT MNC039-045-047-049-055-099-109-157-169-171340- MN . MINNESOTA COUNTIES INCLUDED ARE DODGE FILLMORE FREEBORN GOODHUE HOUSTON MOWER OLMSTED WABASHA WINONA WIC011-019-035-053-063-081-091-121-123-171340- Read more

WW 0427 Status Updates
STATUS REPORT ON WW 427 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NE FOD TO 25 WNW RST TO 30 WSW EAU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1299 ..GUYER..06/17/24 ATTN...WFO...ARX...FSD...DMX...MPX... STATUS REPORT FOR WS 427 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-033-037-067-069-081-089-131-189-191-195-197-171340- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE CERRO GORDO CHICKASAW FLOYD FRANKLIN HANCOCK HOWARD MITCHELL WINNEBAGO WINNESHIEK WORTH WRIGHT MNC039-045-047-049-055-099-109-157-169-171340- MN . MINNESOTA COUNTIES INCLUDED ARE DODGE FILLMORE FREEBORN GOODHUE HOUSTON MOWER OLMSTED WABASHA WINONA WIC011-019-035-053-063-081-091-121-123-171340- Read more

WW 0427 Status Updates
STATUS REPORT ON WW 427 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 NE FOD TO 25 WNW RST TO 30 WSW EAU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1299 ..GUYER..06/17/24 ATTN...WFO...ARX...FSD...DMX...MPX... STATUS REPORT FOR WS 427 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-033-037-067-069-081-089-131-189-191-195-197-171340- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE CERRO GORDO CHICKASAW FLOYD FRANKLIN HANCOCK HOWARD MITCHELL WINNEBAGO WINNESHIEK WORTH WRIGHT MNC039-045-047-049-055-099-109-157-169-171340- MN . MINNESOTA COUNTIES INCLUDED ARE DODGE FILLMORE FREEBORN GOODHUE HOUSTON MOWER OLMSTED WABASHA WINONA WIC011-019-035-053-063-081-091-121-123-171340- Read more