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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Tue Feb 27 2024 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST VICINITY... ...SUMMARY... Scattered strong to severe thunderstorms, associated with large hail (some 2 inches diameter), damaging gusts, and a few tornadoes will be possible from late this afternoon into the evening and overnight, from parts of the mid Mississippi Valley to the Ohio Valley and southern Great Lakes. ...Synopsis... A progressive upper trough over the western U.S. this morning is forecast to advance steadily eastward into/across the Plains this afternoon and evening, and then onward toward the Mid and Upper Mississippi Valley overnight. In tandem with the advance of this feature, a strengthening surface cold front currently stretching from the Upper Mississippi Valley to northeastern Colorado will continue plunging southeastward across the Plains through the day. A somewhat ill-defined frontal low will gradually consolidate into this evening over the northern Illinois vicinity, moving northeastward across Lower Michigan overnight. As it does, the trailing cold front will continue to surge southward/southeastward into/across the Midwest/Mid Mississippi Valley/Southern Plains overnight. By 12Z Wednesday, the front should extend from Lake Huron, south across the Middle Ohio Valley, and then southwestward across the Tennessee valley to the Texas Coastal Plain. ...The Midwest vicinity... Ahead of the advancing cold front, southerly low-level flow will continue to advect low-level moisture northward, beneath a low-level inversion/cap evident in morning RAOBs from the southern Plains into the Midwest. Evolution of this gradually moistening but capped low-level airmass will likely be a key determinant with respect to degree of convective evolution -- and the intensity thereof -- late this afternoon/and this evening. Low-level airmass concerns aside, the evolving scenario otherwise remains favorable for severe potential across the Midwest and vicinity. Steep lapse rates are evident above the low-level inversion, and increasingly strong deep-layer flow will accompany the advance of the upper system, and gradual consolidation of the surface frontal low. As such, from a broad dynamic and kinematic perspective, the pattern continues to appear favorable. Thermodynamically, there remain concerns that the boundary layer will remain somewhat cool/stable, relative to the warmer air in the roughly 900 to 800 mb layer. Further, heating/mixing will also result in mixing out, to some degree, of the shallow surface-based moisture returning northward on low-level southerly flow within the developing warm sector. With all that said, 500 to 1000 J/kg mixed-layer CAPE should characterize the boundary layer by late afternoon/early evening, as the front approaches. This will result in isolated to scattered storm development -- initially over the northern Illinois vicinity but later farther south nearer the Ohio Valley -- possibly in a somewhat bimodal manner with a relative minimum in between. Eventually, through mid to late evening, increasingly widespread storms should be expanding across the Midwest/Ohio Valley region, which will then continue eastward across the Upper Ohio Valley and toward the central Appalachians through the end of the period. Given the favorable kinematic environment, at least isolated organized/rotating storms are expected, with some upscale growth into bands possibly occurring overnight and spreading eastward with time. Along with potential for large hail -- locally near 2" in diameter, locally strong/damaging wind gusts are also expect with stronger storms/storm clusters. Additionally, a few tornadoes may also occur, though uncertainties regarding low-level moisture/instability suggest overall tornado potential should remain limited. ..Goss/Broyles.. 02/27/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0300 AM CST Tue Feb 27 2024 Valid 011200Z - 061200Z ...DISCUSSION... Thunderstorm chances will likely continue across the Gulf Coast States/Southeast on Days 4-5/Fri-Sat as a series of weak/low-amplitude upper shortwave troughs migrate across the region. In the low-levels this area will remain under the influence of high pressure and any deeper boundary-layer moisture will remain confined to the immediate coastal areas, with limited inland destabilization. Coupled with weak vertical shear, severe storms are not anticipated. By Days 6-7/Sun-Mon, spread in medium range guidance has increased over the past 24 hours. During this time, an upper trough over the western U.S. is forecast to emerge into the central U.S. However, forecast guidance handles the eastward evolution of the trough very differently. The ECMWF progresses a much lower-amplitude trough eastward across the central Plains to the Upper Midwest, while a secondary, weaker, southern stream shortwave trough moves across TX into the Lower MS Valley. Meanwhile, the GFS maintains its solution of a deeper, more neutral to negatively tilted upper trough traversing the Plains and MS Valley. These differences in the upper pattern have large impacts on surface cyclogenesis, cold front position/timing and quality of low-level moisture return. While some severe potential may develop in this general pattern somewhere from the central/southern Plains to the Mid/Lower MS Valley, uncertainty in most favorable location and timing remains too high to include 15 percent probabilities at this time for the Days 6-7/Sun-Mon time period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0300 AM CST Tue Feb 27 2024 Valid 011200Z - 061200Z ...DISCUSSION... Thunderstorm chances will likely continue across the Gulf Coast States/Southeast on Days 4-5/Fri-Sat as a series of weak/low-amplitude upper shortwave troughs migrate across the region. In the low-levels this area will remain under the influence of high pressure and any deeper boundary-layer moisture will remain confined to the immediate coastal areas, with limited inland destabilization. Coupled with weak vertical shear, severe storms are not anticipated. By Days 6-7/Sun-Mon, spread in medium range guidance has increased over the past 24 hours. During this time, an upper trough over the western U.S. is forecast to emerge into the central U.S. However, forecast guidance handles the eastward evolution of the trough very differently. The ECMWF progresses a much lower-amplitude trough eastward across the central Plains to the Upper Midwest, while a secondary, weaker, southern stream shortwave trough moves across TX into the Lower MS Valley. Meanwhile, the GFS maintains its solution of a deeper, more neutral to negatively tilted upper trough traversing the Plains and MS Valley. These differences in the upper pattern have large impacts on surface cyclogenesis, cold front position/timing and quality of low-level moisture return. While some severe potential may develop in this general pattern somewhere from the central/southern Plains to the Mid/Lower MS Valley, uncertainty in most favorable location and timing remains too high to include 15 percent probabilities at this time for the Days 6-7/Sun-Mon time period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0300 AM CST Tue Feb 27 2024 Valid 011200Z - 061200Z ...DISCUSSION... Thunderstorm chances will likely continue across the Gulf Coast States/Southeast on Days 4-5/Fri-Sat as a series of weak/low-amplitude upper shortwave troughs migrate across the region. In the low-levels this area will remain under the influence of high pressure and any deeper boundary-layer moisture will remain confined to the immediate coastal areas, with limited inland destabilization. Coupled with weak vertical shear, severe storms are not anticipated. By Days 6-7/Sun-Mon, spread in medium range guidance has increased over the past 24 hours. During this time, an upper trough over the western U.S. is forecast to emerge into the central U.S. However, forecast guidance handles the eastward evolution of the trough very differently. The ECMWF progresses a much lower-amplitude trough eastward across the central Plains to the Upper Midwest, while a secondary, weaker, southern stream shortwave trough moves across TX into the Lower MS Valley. Meanwhile, the GFS maintains its solution of a deeper, more neutral to negatively tilted upper trough traversing the Plains and MS Valley. These differences in the upper pattern have large impacts on surface cyclogenesis, cold front position/timing and quality of low-level moisture return. While some severe potential may develop in this general pattern somewhere from the central/southern Plains to the Mid/Lower MS Valley, uncertainty in most favorable location and timing remains too high to include 15 percent probabilities at this time for the Days 6-7/Sun-Mon time period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0300 AM CST Tue Feb 27 2024 Valid 011200Z - 061200Z ...DISCUSSION... Thunderstorm chances will likely continue across the Gulf Coast States/Southeast on Days 4-5/Fri-Sat as a series of weak/low-amplitude upper shortwave troughs migrate across the region. In the low-levels this area will remain under the influence of high pressure and any deeper boundary-layer moisture will remain confined to the immediate coastal areas, with limited inland destabilization. Coupled with weak vertical shear, severe storms are not anticipated. By Days 6-7/Sun-Mon, spread in medium range guidance has increased over the past 24 hours. During this time, an upper trough over the western U.S. is forecast to emerge into the central U.S. However, forecast guidance handles the eastward evolution of the trough very differently. The ECMWF progresses a much lower-amplitude trough eastward across the central Plains to the Upper Midwest, while a secondary, weaker, southern stream shortwave trough moves across TX into the Lower MS Valley. Meanwhile, the GFS maintains its solution of a deeper, more neutral to negatively tilted upper trough traversing the Plains and MS Valley. These differences in the upper pattern have large impacts on surface cyclogenesis, cold front position/timing and quality of low-level moisture return. While some severe potential may develop in this general pattern somewhere from the central/southern Plains to the Mid/Lower MS Valley, uncertainty in most favorable location and timing remains too high to include 15 percent probabilities at this time for the Days 6-7/Sun-Mon time period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0300 AM CST Tue Feb 27 2024 Valid 011200Z - 061200Z ...DISCUSSION... Thunderstorm chances will likely continue across the Gulf Coast States/Southeast on Days 4-5/Fri-Sat as a series of weak/low-amplitude upper shortwave troughs migrate across the region. In the low-levels this area will remain under the influence of high pressure and any deeper boundary-layer moisture will remain confined to the immediate coastal areas, with limited inland destabilization. Coupled with weak vertical shear, severe storms are not anticipated. By Days 6-7/Sun-Mon, spread in medium range guidance has increased over the past 24 hours. During this time, an upper trough over the western U.S. is forecast to emerge into the central U.S. However, forecast guidance handles the eastward evolution of the trough very differently. The ECMWF progresses a much lower-amplitude trough eastward across the central Plains to the Upper Midwest, while a secondary, weaker, southern stream shortwave trough moves across TX into the Lower MS Valley. Meanwhile, the GFS maintains its solution of a deeper, more neutral to negatively tilted upper trough traversing the Plains and MS Valley. These differences in the upper pattern have large impacts on surface cyclogenesis, cold front position/timing and quality of low-level moisture return. While some severe potential may develop in this general pattern somewhere from the central/southern Plains to the Mid/Lower MS Valley, uncertainty in most favorable location and timing remains too high to include 15 percent probabilities at this time for the Days 6-7/Sun-Mon time period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0300 AM CST Tue Feb 27 2024 Valid 011200Z - 061200Z ...DISCUSSION... Thunderstorm chances will likely continue across the Gulf Coast States/Southeast on Days 4-5/Fri-Sat as a series of weak/low-amplitude upper shortwave troughs migrate across the region. In the low-levels this area will remain under the influence of high pressure and any deeper boundary-layer moisture will remain confined to the immediate coastal areas, with limited inland destabilization. Coupled with weak vertical shear, severe storms are not anticipated. By Days 6-7/Sun-Mon, spread in medium range guidance has increased over the past 24 hours. During this time, an upper trough over the western U.S. is forecast to emerge into the central U.S. However, forecast guidance handles the eastward evolution of the trough very differently. The ECMWF progresses a much lower-amplitude trough eastward across the central Plains to the Upper Midwest, while a secondary, weaker, southern stream shortwave trough moves across TX into the Lower MS Valley. Meanwhile, the GFS maintains its solution of a deeper, more neutral to negatively tilted upper trough traversing the Plains and MS Valley. These differences in the upper pattern have large impacts on surface cyclogenesis, cold front position/timing and quality of low-level moisture return. While some severe potential may develop in this general pattern somewhere from the central/southern Plains to the Mid/Lower MS Valley, uncertainty in most favorable location and timing remains too high to include 15 percent probabilities at this time for the Days 6-7/Sun-Mon time period. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper trough over the Central US is forecast to amplify significantly as it moves into the northeast Wednesday. Behind the trough a strong cold front will sweep southeastward ushering in a much colder air mass over the western and central US. Behind the front, strong northerly winds are expected over the Plains along with higher relative humidity, limiting the fire-weather threat. One exception, may be across parts of south TX and the Rio Grande Valley. Winds of 20-25 mph may briefly overlap with humidity below 30% over areas of somewhat receptive fuels. However, this is likely to be brief and widespread fire-weather concerns are not expected. ..Lyons.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper trough over the Central US is forecast to amplify significantly as it moves into the northeast Wednesday. Behind the trough a strong cold front will sweep southeastward ushering in a much colder air mass over the western and central US. Behind the front, strong northerly winds are expected over the Plains along with higher relative humidity, limiting the fire-weather threat. One exception, may be across parts of south TX and the Rio Grande Valley. Winds of 20-25 mph may briefly overlap with humidity below 30% over areas of somewhat receptive fuels. However, this is likely to be brief and widespread fire-weather concerns are not expected. ..Lyons.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper trough over the Central US is forecast to amplify significantly as it moves into the northeast Wednesday. Behind the trough a strong cold front will sweep southeastward ushering in a much colder air mass over the western and central US. Behind the front, strong northerly winds are expected over the Plains along with higher relative humidity, limiting the fire-weather threat. One exception, may be across parts of south TX and the Rio Grande Valley. Winds of 20-25 mph may briefly overlap with humidity below 30% over areas of somewhat receptive fuels. However, this is likely to be brief and widespread fire-weather concerns are not expected. ..Lyons.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper trough over the Central US is forecast to amplify significantly as it moves into the northeast Wednesday. Behind the trough a strong cold front will sweep southeastward ushering in a much colder air mass over the western and central US. Behind the front, strong northerly winds are expected over the Plains along with higher relative humidity, limiting the fire-weather threat. One exception, may be across parts of south TX and the Rio Grande Valley. Winds of 20-25 mph may briefly overlap with humidity below 30% over areas of somewhat receptive fuels. However, this is likely to be brief and widespread fire-weather concerns are not expected. ..Lyons.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper trough over the Central US is forecast to amplify significantly as it moves into the northeast Wednesday. Behind the trough a strong cold front will sweep southeastward ushering in a much colder air mass over the western and central US. Behind the front, strong northerly winds are expected over the Plains along with higher relative humidity, limiting the fire-weather threat. One exception, may be across parts of south TX and the Rio Grande Valley. Winds of 20-25 mph may briefly overlap with humidity below 30% over areas of somewhat receptive fuels. However, this is likely to be brief and widespread fire-weather concerns are not expected. ..Lyons.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Tue Feb 27 2024 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... ...Synopsis... An upper trough over the Central US is forecast to amplify significantly as it moves into the northeast Wednesday. Behind the trough a strong cold front will sweep southeastward ushering in a much colder air mass over the western and central US. Behind the front, strong northerly winds are expected over the Plains along with higher relative humidity, limiting the fire-weather threat. One exception, may be across parts of south TX and the Rio Grande Valley. Winds of 20-25 mph may briefly overlap with humidity below 30% over areas of somewhat receptive fuels. However, this is likely to be brief and widespread fire-weather concerns are not expected. ..Lyons.. 02/27/2024 ...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 0158 AM CST Tue Feb 27 2024 Valid 271200Z - 281200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE TEXAS PANHANDLE AND WESTERN OKLAHOMA... ...Synopsis... Split mid-level flow will gradually consolidate as a Pacific trough merges with an increasingly strong subtropical jet stream over the central CONUS. Very strong westerly flow is expected over the Plains and Midwest, supporting dry and windy conditions. Widespread elevated to critical fire-weather conditions are excepted. ...Southern Plains... As the upper trough begins to move over the Plains, strong low-level flow is expected to develop by mid morning. Westerly winds of 20-25 mph, with gusts of 30-35 mph, are possible across parts of western and central OK and the TX Panhandle. Despite dry downsloping and the unusually warm temperatures, increasing mid and high-level cloud cover may limit diurnal RH minimums to near 20-25%. Still, widespread elevated to near/briefly critical fire-weather conditions appear likely given the increasingly strong wind gusts. Significant fire activity over the preceding days also suggests fuels are more receptive than some guidance indicated. Thus, greater confidence exists for critical conditions across parts of western and central OK and the eastern TX Panhandle where the strongest winds are expected to overlap more receptive fuels, despite marginal humidity. To the east, a pronounced low-level thermal ridge behind a surface trough will support afternoon RH values below 30% with southwest winds of 20-25 mph across the eastern Plains into western MO. While RH values are not overly dry, the strong winds and unusually warm temperatures should allow for widespread elevated to locally critical fire-weather conditions. Fire-weather concerns will begin to diminish later in the evening as a cold front rapidly moves south. Strong gusts may persist behind the front along with a rapid wind shift to north/northwesterly. Cooler temperatures and higher RH behind the front should quickly limit sustained fire-weather concerns through the overnight hours. ..Lyons.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more