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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0212 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...19z Update... Minimal changes were made to the prior forecast. The latest model guidance has shown increasing humidity and rain chances across much of the High Plains. However, at least a few hours of strong southerly winds (20-25 mph) will likely interact with reasonably dry fuels and RH below 30%. While confidence is not overly high, a few hours of elevated fire-weather conditions are possible before rain and the cold front approach. Dry and breezy conditions are also possible across parts of southwest CO and eastern UT, but fuels here are not receptive. See prior discussion. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Strong deep-layer south-southwesterly flow preceding an amplified large-scale trough over the West will impinge on the central High Plains during the day. Here, a tightening pressure gradient along a pronounced lee trough, and boundary-layer mixing into the strong flow aloft, will favor 20-25 mph sustained southerly surface winds (with higher gusts). These winds should overlap 20-25 percent RH for a few hours, before a cold front and related precipitation overspread the area from the west during the evening. Given receptive fuels across the area, elevated fire-weather conditions are expected during the afternoon (prior to the arrival of precipitation). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Sep 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO NORTHEAST MONTANA... ...SUMMARY... Isolated to scattered severe gusts and hail are possible Tuesday across a large swath of the High Plains region, mainly from late afternoon into the evening. The greater concentrations of severe storms may occur over the central High Plains into northeast Montana. ...Synopsis... A mid/upper cyclone is forecast over the Great Basin Tuesday morning. This system will pivot northeast across the central Rockies and into the northern High Plains through the forecast period. This will bring a belt of strong south/southwesterly deep-layer flow across CO/WY and adjacent portions of the High Plains. A surface low will deepen over MT through the period, with a surface trough extending southward through the central/southern High Plains. A warm front is forecast to extend west to east from southeast MT into north-central SD during the morning. With time, this boundary will lift northward toward the International border during the nighttime hours. As the system deepens and the low-level baroclinic zone over the Plains strengthens, 850-700 mb flow is forecast to markedly increase during the afternoon/evening to 30-50 kt. While deeper boundary-layer moisture is forecast to remain east of the surface trough axis and north of the warm front, steep midlevel lapse rates will support pockets of weak to moderate instability. An arc of thunderstorm activity, with a mix of line segments and discrete cells, are expected to develop in the vicinity of the surface low/warm front south/southeast along the surface trough during the afternoon and evening hours. ...Eastern MT... Strong ascent will overspread the region as the upper trough pivots northeast during the late afternoon/evening. Boundary-layer moisture will be greatest to the north of the warm front across north-central/northeast MT, but capping will likely remain in place. Storm motion will likely result in convection remaining elevated to the cool side of the warm front. Nevertheless, steep midlevel lapse rates and favorable vertical shear (elongated/straight hodographs) will support some risk for large hail. As stronger forcing and sufficient erosion of capping can overlap during the evening, strong to severe wind gusts also will be possible. ...Northern/Central High Plains Vicinity... Convection is expected to develop over the higher terrain of CO/WY during the afternoon. Given strengthening mid/upper flow and weak instability, some locally strong gusts could occur with this initial activity near the core of the upper low over western/central CO. As convection shifts east/northeast through the afternoon and into the evening, strong heating is expected to result in a steep low-level lapse rate environment across the High Plains. While deep boundary-layer moisture will remain further east across the Plains, steep midlevel lapse rates and surface dewpoints in the 50s F will result in a corridor of around 1000-1500 J/kg MLCAPE from far eastern CO into parts of western NE/SD. Strengthening midlevel flow atop a deeply mixed boundary-layer will likely support severe gusts (isolated gusts to 75 mph possible) with linear segments spreading northeast across the central High Plains during the late afternoon/evening. ...Southern High Plains Vicinity... Further south, large-scale ascent will be weaker, with stronger height falls focused north of the region. Nevertheless, low-level convergence along the surface trough and modest instability (up to 1000 J/kg MLCAPE) will support initial thunderstorm development over the higher terrain of south-central CO into north-central NM. Forecast soundings show supercell wind profiles across the adjacent High Plains by afternoon. Midlevel lapse rates will be somewhat modest (around 6.5-7 C/km), but elongated/straight hodographs and plenty of instability through the 700-300 mb layer suggest isolated hail is possible. Steep low-level lapse rates also will support isolated strong to severe gusts. ..Leitman.. 09/16/2024 Read more

000
ABPZ20 KNHC 161729
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Mon Sep 16 2024

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

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

$$
Forecaster Pasch

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Sep 16 2024 Valid 161700Z - 171200Z ...17z Update... The prior forecast remains largely on track with only minor changes. The Elevated area over parts of NV was expanded northward where gusty winds and pockets of low humidity are expected to be slightly more prevalent. Over the central High Plains, recent rainfall and additional storms are likely to temper fuels somewhat. However, strong southerly winds (gusts as high as 30 mph) may still overlap with areas of drier fuels and humidity below 30%. While uncertain in areal extent, some fire-weather risk will continue this afternoon and evening. Otherwise, see the prior discussion for more information. ..Lyons.. 09/16/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Mon Sep 16 2024/ ...Synopsis... Within the base of a deep midlevel cyclone moving eastward across the Great Basin, a related jet streak will overspread the Lower CO River Valley. Here, boundary-layer mixing into the strengthening flow aloft, coupled with a tightening pressure gradient peripheral to an evolving surface cyclone, will favor 20-25 mph sustained southerly surface winds. Despite a gradual increase in moisture/RH, diurnal heating should still support a corridor of around 20 percent RH amid the strong surface winds along the Lower CO River Valley -- favoring elevated fire-weather conditions. Elevated fire-weather conditions are also expected over portions of the central High Plains -- where breezy/gusty southerly surface winds will overlap 20 percent RH near a lee trough during the afternoon. While spotty rainfall during the past 24 hours could limit fuel receptiveness over parts of the area, mostly receptive fuels should still yield some fire-weather risk. Farther east, warm/dry conditions are expected over portions of OH and KY -- along the southwestern periphery of an expansive surface anticyclone. While sustained surface winds around 10 mph should limit the overall fire-weather threat, around 20 percent RH and very dry/receptive fuels will still pose localized fire-weather concerns during the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more