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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0659 AM CST Thu Jan 11 2024 Valid 111300Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE ARKLATEX REGION... ...SUMMARY... Tornadoes, damaging to severe thunderstorm gusts and large hail are possible tonight over the Arklatex region, and nearby parts of southeastern Oklahoma, east Texas, Arkansas, and western/northern Louisiana. ...Synopsis... In mid/upper levels, broadly cyclonic flow will continue over most of the CONUS this period. Within that, the principle influence will be the southern portion of a shortwave trough -- evident in moisture-channel imagery from WY southwestward across UT to the southern Sierra. That southern lobe will dig southeastward across AZ today, reaching central/southern NM, the ELP region, and northern Chihuahua by 00Z. By 12Z tomorrow, this perturbation should become negatively tilted, with an axis from north-central OK to east- central TX. Mass response will be intense, with a compact, cyclonic jet core of 150-160-kt at 250 mb and 110-130 kt at 500 mb by 12Z, over a corridor from central TX to the Mid-South. By then, a 50-70- kt LLJ should develop across parts of LA into the Mid-South region. At the surface, 11Z analysis showed a low over southeastern WI, with strong cold front southwestward over northern MO to central KS, becoming quasistationary to warm across northwestern KS to another low over northeastern CO. The northern low should move eastward and weaken today, while strong cyclogenesis occurs with the southward/ southeastward-shifting CO low. By 00Z, the latter low should be deepening over western OK, with the trailing Arctic cold front surging southward across the southern High Plains, and a Pacific cold front southwestward over far west TX. The fronts will merge through the remainder of the period as the main cyclone elongates along the front, while moving northeastward. By 12Z, the combined cold front should extend from the low-pressure area over MO, across western/central AR and east TX, to the northwestern Gulf shelf waters. A dryline should develop today on the western rim of the moist-advection plume, with the boundary extending from north- central to deep south TX by 00Z. The dryline will be overtaken by the cold front overnight, from north-south. ...Arklatex and vicinity... Scattered thunderstorms are expected to develop by about 6Z over portions of central/north-central TX near I-35, then shift eastward and expand across much of the outlook area into early morning. Activity should produce large hail early, some potentially significant (2+ inches diameter), and pose an increasing threat for damaging wind and at least a few tornadoes. Late tonight into early morning, strong tornadoes may become possible with any supercells crossing the Arklatex region as moisture, instability, lift, and vertical shear all increase in tandem. Large-scale ascent aloft will intensify tonight with the approach of the mid/upper trough, spreading steepening midlevel lapse rates and weakening CINH over the corridor of frontal forcing. From the early development, the convective plume should grow northward as theta-e increases ahead of the frontal segment farther inland, and southward as the front overtakes more of the dryline and impinges on already favorable moisture. Surface dewpoints in the upper 50s to mid 60s F should spread into the Arklatex region just ahead of the front, yielding a corridor of around 500-1000 J/kg MLCAPE, decreasing northward into the Ozarks where return flow still is cool and not as moist, and southward toward the coast where optimal lapse rates/ cooling aloft don't reach. Greater CINH with southward extent also may impede any warm-sector deep-convective development tonight near the coast, with potential increasing northward. Kinematically, strengthening flow aloft not only will yield favorable shear (e.g., 45-55 kt effective-shear vectors), but will have a substantial component across the belt of strongest convective lift associated with the front. This may aid potential for discrete to semi-discrete supercell mode for at least a few hours, despite rapidly intensifying deep-layer lift and quick growth in overall convective coverage late tonight. Hodographs will be favorably enlarged and shaped under the western rim of the strengthening LLJ, with 200-400 J/kg effective SRH being common. In the lowest 1/2 to 1 km, SRH above 200 J/kg also is possible. ..Edwards/Jewell.. 01/11/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0659 AM CST Thu Jan 11 2024 Valid 111300Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE ARKLATEX REGION... ...SUMMARY... Tornadoes, damaging to severe thunderstorm gusts and large hail are possible tonight over the Arklatex region, and nearby parts of southeastern Oklahoma, east Texas, Arkansas, and western/northern Louisiana. ...Synopsis... In mid/upper levels, broadly cyclonic flow will continue over most of the CONUS this period. Within that, the principle influence will be the southern portion of a shortwave trough -- evident in moisture-channel imagery from WY southwestward across UT to the southern Sierra. That southern lobe will dig southeastward across AZ today, reaching central/southern NM, the ELP region, and northern Chihuahua by 00Z. By 12Z tomorrow, this perturbation should become negatively tilted, with an axis from north-central OK to east- central TX. Mass response will be intense, with a compact, cyclonic jet core of 150-160-kt at 250 mb and 110-130 kt at 500 mb by 12Z, over a corridor from central TX to the Mid-South. By then, a 50-70- kt LLJ should develop across parts of LA into the Mid-South region. At the surface, 11Z analysis showed a low over southeastern WI, with strong cold front southwestward over northern MO to central KS, becoming quasistationary to warm across northwestern KS to another low over northeastern CO. The northern low should move eastward and weaken today, while strong cyclogenesis occurs with the southward/ southeastward-shifting CO low. By 00Z, the latter low should be deepening over western OK, with the trailing Arctic cold front surging southward across the southern High Plains, and a Pacific cold front southwestward over far west TX. The fronts will merge through the remainder of the period as the main cyclone elongates along the front, while moving northeastward. By 12Z, the combined cold front should extend from the low-pressure area over MO, across western/central AR and east TX, to the northwestern Gulf shelf waters. A dryline should develop today on the western rim of the moist-advection plume, with the boundary extending from north- central to deep south TX by 00Z. The dryline will be overtaken by the cold front overnight, from north-south. ...Arklatex and vicinity... Scattered thunderstorms are expected to develop by about 6Z over portions of central/north-central TX near I-35, then shift eastward and expand across much of the outlook area into early morning. Activity should produce large hail early, some potentially significant (2+ inches diameter), and pose an increasing threat for damaging wind and at least a few tornadoes. Late tonight into early morning, strong tornadoes may become possible with any supercells crossing the Arklatex region as moisture, instability, lift, and vertical shear all increase in tandem. Large-scale ascent aloft will intensify tonight with the approach of the mid/upper trough, spreading steepening midlevel lapse rates and weakening CINH over the corridor of frontal forcing. From the early development, the convective plume should grow northward as theta-e increases ahead of the frontal segment farther inland, and southward as the front overtakes more of the dryline and impinges on already favorable moisture. Surface dewpoints in the upper 50s to mid 60s F should spread into the Arklatex region just ahead of the front, yielding a corridor of around 500-1000 J/kg MLCAPE, decreasing northward into the Ozarks where return flow still is cool and not as moist, and southward toward the coast where optimal lapse rates/ cooling aloft don't reach. Greater CINH with southward extent also may impede any warm-sector deep-convective development tonight near the coast, with potential increasing northward. Kinematically, strengthening flow aloft not only will yield favorable shear (e.g., 45-55 kt effective-shear vectors), but will have a substantial component across the belt of strongest convective lift associated with the front. This may aid potential for discrete to semi-discrete supercell mode for at least a few hours, despite rapidly intensifying deep-layer lift and quick growth in overall convective coverage late tonight. Hodographs will be favorably enlarged and shaped under the western rim of the strengthening LLJ, with 200-400 J/kg effective SRH being common. In the lowest 1/2 to 1 km, SRH above 200 J/kg also is possible. ..Edwards/Jewell.. 01/11/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0659 AM CST Thu Jan 11 2024 Valid 111300Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE ARKLATEX REGION... ...SUMMARY... Tornadoes, damaging to severe thunderstorm gusts and large hail are possible tonight over the Arklatex region, and nearby parts of southeastern Oklahoma, east Texas, Arkansas, and western/northern Louisiana. ...Synopsis... In mid/upper levels, broadly cyclonic flow will continue over most of the CONUS this period. Within that, the principle influence will be the southern portion of a shortwave trough -- evident in moisture-channel imagery from WY southwestward across UT to the southern Sierra. That southern lobe will dig southeastward across AZ today, reaching central/southern NM, the ELP region, and northern Chihuahua by 00Z. By 12Z tomorrow, this perturbation should become negatively tilted, with an axis from north-central OK to east- central TX. Mass response will be intense, with a compact, cyclonic jet core of 150-160-kt at 250 mb and 110-130 kt at 500 mb by 12Z, over a corridor from central TX to the Mid-South. By then, a 50-70- kt LLJ should develop across parts of LA into the Mid-South region. At the surface, 11Z analysis showed a low over southeastern WI, with strong cold front southwestward over northern MO to central KS, becoming quasistationary to warm across northwestern KS to another low over northeastern CO. The northern low should move eastward and weaken today, while strong cyclogenesis occurs with the southward/ southeastward-shifting CO low. By 00Z, the latter low should be deepening over western OK, with the trailing Arctic cold front surging southward across the southern High Plains, and a Pacific cold front southwestward over far west TX. The fronts will merge through the remainder of the period as the main cyclone elongates along the front, while moving northeastward. By 12Z, the combined cold front should extend from the low-pressure area over MO, across western/central AR and east TX, to the northwestern Gulf shelf waters. A dryline should develop today on the western rim of the moist-advection plume, with the boundary extending from north- central to deep south TX by 00Z. The dryline will be overtaken by the cold front overnight, from north-south. ...Arklatex and vicinity... Scattered thunderstorms are expected to develop by about 6Z over portions of central/north-central TX near I-35, then shift eastward and expand across much of the outlook area into early morning. Activity should produce large hail early, some potentially significant (2+ inches diameter), and pose an increasing threat for damaging wind and at least a few tornadoes. Late tonight into early morning, strong tornadoes may become possible with any supercells crossing the Arklatex region as moisture, instability, lift, and vertical shear all increase in tandem. Large-scale ascent aloft will intensify tonight with the approach of the mid/upper trough, spreading steepening midlevel lapse rates and weakening CINH over the corridor of frontal forcing. From the early development, the convective plume should grow northward as theta-e increases ahead of the frontal segment farther inland, and southward as the front overtakes more of the dryline and impinges on already favorable moisture. Surface dewpoints in the upper 50s to mid 60s F should spread into the Arklatex region just ahead of the front, yielding a corridor of around 500-1000 J/kg MLCAPE, decreasing northward into the Ozarks where return flow still is cool and not as moist, and southward toward the coast where optimal lapse rates/ cooling aloft don't reach. Greater CINH with southward extent also may impede any warm-sector deep-convective development tonight near the coast, with potential increasing northward. Kinematically, strengthening flow aloft not only will yield favorable shear (e.g., 45-55 kt effective-shear vectors), but will have a substantial component across the belt of strongest convective lift associated with the front. This may aid potential for discrete to semi-discrete supercell mode for at least a few hours, despite rapidly intensifying deep-layer lift and quick growth in overall convective coverage late tonight. Hodographs will be favorably enlarged and shaped under the western rim of the strengthening LLJ, with 200-400 J/kg effective SRH being common. In the lowest 1/2 to 1 km, SRH above 200 J/kg also is possible. ..Edwards/Jewell.. 01/11/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0659 AM CST Thu Jan 11 2024 Valid 111300Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE ARKLATEX REGION... ...SUMMARY... Tornadoes, damaging to severe thunderstorm gusts and large hail are possible tonight over the Arklatex region, and nearby parts of southeastern Oklahoma, east Texas, Arkansas, and western/northern Louisiana. ...Synopsis... In mid/upper levels, broadly cyclonic flow will continue over most of the CONUS this period. Within that, the principle influence will be the southern portion of a shortwave trough -- evident in moisture-channel imagery from WY southwestward across UT to the southern Sierra. That southern lobe will dig southeastward across AZ today, reaching central/southern NM, the ELP region, and northern Chihuahua by 00Z. By 12Z tomorrow, this perturbation should become negatively tilted, with an axis from north-central OK to east- central TX. Mass response will be intense, with a compact, cyclonic jet core of 150-160-kt at 250 mb and 110-130 kt at 500 mb by 12Z, over a corridor from central TX to the Mid-South. By then, a 50-70- kt LLJ should develop across parts of LA into the Mid-South region. At the surface, 11Z analysis showed a low over southeastern WI, with strong cold front southwestward over northern MO to central KS, becoming quasistationary to warm across northwestern KS to another low over northeastern CO. The northern low should move eastward and weaken today, while strong cyclogenesis occurs with the southward/ southeastward-shifting CO low. By 00Z, the latter low should be deepening over western OK, with the trailing Arctic cold front surging southward across the southern High Plains, and a Pacific cold front southwestward over far west TX. The fronts will merge through the remainder of the period as the main cyclone elongates along the front, while moving northeastward. By 12Z, the combined cold front should extend from the low-pressure area over MO, across western/central AR and east TX, to the northwestern Gulf shelf waters. A dryline should develop today on the western rim of the moist-advection plume, with the boundary extending from north- central to deep south TX by 00Z. The dryline will be overtaken by the cold front overnight, from north-south. ...Arklatex and vicinity... Scattered thunderstorms are expected to develop by about 6Z over portions of central/north-central TX near I-35, then shift eastward and expand across much of the outlook area into early morning. Activity should produce large hail early, some potentially significant (2+ inches diameter), and pose an increasing threat for damaging wind and at least a few tornadoes. Late tonight into early morning, strong tornadoes may become possible with any supercells crossing the Arklatex region as moisture, instability, lift, and vertical shear all increase in tandem. Large-scale ascent aloft will intensify tonight with the approach of the mid/upper trough, spreading steepening midlevel lapse rates and weakening CINH over the corridor of frontal forcing. From the early development, the convective plume should grow northward as theta-e increases ahead of the frontal segment farther inland, and southward as the front overtakes more of the dryline and impinges on already favorable moisture. Surface dewpoints in the upper 50s to mid 60s F should spread into the Arklatex region just ahead of the front, yielding a corridor of around 500-1000 J/kg MLCAPE, decreasing northward into the Ozarks where return flow still is cool and not as moist, and southward toward the coast where optimal lapse rates/ cooling aloft don't reach. Greater CINH with southward extent also may impede any warm-sector deep-convective development tonight near the coast, with potential increasing northward. Kinematically, strengthening flow aloft not only will yield favorable shear (e.g., 45-55 kt effective-shear vectors), but will have a substantial component across the belt of strongest convective lift associated with the front. This may aid potential for discrete to semi-discrete supercell mode for at least a few hours, despite rapidly intensifying deep-layer lift and quick growth in overall convective coverage late tonight. Hodographs will be favorably enlarged and shaped under the western rim of the strengthening LLJ, with 200-400 J/kg effective SRH being common. In the lowest 1/2 to 1 km, SRH above 200 J/kg also is possible. ..Edwards/Jewell.. 01/11/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0659 AM CST Thu Jan 11 2024 Valid 111300Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE ARKLATEX REGION... ...SUMMARY... Tornadoes, damaging to severe thunderstorm gusts and large hail are possible tonight over the Arklatex region, and nearby parts of southeastern Oklahoma, east Texas, Arkansas, and western/northern Louisiana. ...Synopsis... In mid/upper levels, broadly cyclonic flow will continue over most of the CONUS this period. Within that, the principle influence will be the southern portion of a shortwave trough -- evident in moisture-channel imagery from WY southwestward across UT to the southern Sierra. That southern lobe will dig southeastward across AZ today, reaching central/southern NM, the ELP region, and northern Chihuahua by 00Z. By 12Z tomorrow, this perturbation should become negatively tilted, with an axis from north-central OK to east- central TX. Mass response will be intense, with a compact, cyclonic jet core of 150-160-kt at 250 mb and 110-130 kt at 500 mb by 12Z, over a corridor from central TX to the Mid-South. By then, a 50-70- kt LLJ should develop across parts of LA into the Mid-South region. At the surface, 11Z analysis showed a low over southeastern WI, with strong cold front southwestward over northern MO to central KS, becoming quasistationary to warm across northwestern KS to another low over northeastern CO. The northern low should move eastward and weaken today, while strong cyclogenesis occurs with the southward/ southeastward-shifting CO low. By 00Z, the latter low should be deepening over western OK, with the trailing Arctic cold front surging southward across the southern High Plains, and a Pacific cold front southwestward over far west TX. The fronts will merge through the remainder of the period as the main cyclone elongates along the front, while moving northeastward. By 12Z, the combined cold front should extend from the low-pressure area over MO, across western/central AR and east TX, to the northwestern Gulf shelf waters. A dryline should develop today on the western rim of the moist-advection plume, with the boundary extending from north- central to deep south TX by 00Z. The dryline will be overtaken by the cold front overnight, from north-south. ...Arklatex and vicinity... Scattered thunderstorms are expected to develop by about 6Z over portions of central/north-central TX near I-35, then shift eastward and expand across much of the outlook area into early morning. Activity should produce large hail early, some potentially significant (2+ inches diameter), and pose an increasing threat for damaging wind and at least a few tornadoes. Late tonight into early morning, strong tornadoes may become possible with any supercells crossing the Arklatex region as moisture, instability, lift, and vertical shear all increase in tandem. Large-scale ascent aloft will intensify tonight with the approach of the mid/upper trough, spreading steepening midlevel lapse rates and weakening CINH over the corridor of frontal forcing. From the early development, the convective plume should grow northward as theta-e increases ahead of the frontal segment farther inland, and southward as the front overtakes more of the dryline and impinges on already favorable moisture. Surface dewpoints in the upper 50s to mid 60s F should spread into the Arklatex region just ahead of the front, yielding a corridor of around 500-1000 J/kg MLCAPE, decreasing northward into the Ozarks where return flow still is cool and not as moist, and southward toward the coast where optimal lapse rates/ cooling aloft don't reach. Greater CINH with southward extent also may impede any warm-sector deep-convective development tonight near the coast, with potential increasing northward. Kinematically, strengthening flow aloft not only will yield favorable shear (e.g., 45-55 kt effective-shear vectors), but will have a substantial component across the belt of strongest convective lift associated with the front. This may aid potential for discrete to semi-discrete supercell mode for at least a few hours, despite rapidly intensifying deep-layer lift and quick growth in overall convective coverage late tonight. Hodographs will be favorably enlarged and shaped under the western rim of the strengthening LLJ, with 200-400 J/kg effective SRH being common. In the lowest 1/2 to 1 km, SRH above 200 J/kg also is possible. ..Edwards/Jewell.. 01/11/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Jan 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... A deep remnant mid-level low, near James Bay by the beginning of the period, may deepen some further while redeveloping northward, then westward, into southern Hudson Bay by early next week, within an elongating area of low mid-level heights across much of eastern Canada, the Great Lakes and Northeast. This may linger into the middle to latter portion of next week, when a new mid-level low may form near Newfoundland and Labrador, associated with strong surface cyclogenesis offshore of the northern U.S. Atlantic coast and Canadian Maritimes. It appears that this cyclogenesis will initiate in response to a short wave trough emanating from the Canadian Arctic, before initially digging to the lee of the Canadian/northern U.S. Rockies, downstream of mid-level ridging building inland of the Pacific coast. The track and evolution of this perturbation through residual cyclonic flow across the interior through eastern U.S. remains varied within the model output. However, it currently appears that the initial surface wave development will remain weak, along a stalled remnant frontal zone across the eastern Gulf of Mexico and east/northeast of the Florida Peninsula late next Monday night through Tuesday morning. This currently seems likely to minimize the risk for organized severe thunderstorms. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Jan 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... A deep remnant mid-level low, near James Bay by the beginning of the period, may deepen some further while redeveloping northward, then westward, into southern Hudson Bay by early next week, within an elongating area of low mid-level heights across much of eastern Canada, the Great Lakes and Northeast. This may linger into the middle to latter portion of next week, when a new mid-level low may form near Newfoundland and Labrador, associated with strong surface cyclogenesis offshore of the northern U.S. Atlantic coast and Canadian Maritimes. It appears that this cyclogenesis will initiate in response to a short wave trough emanating from the Canadian Arctic, before initially digging to the lee of the Canadian/northern U.S. Rockies, downstream of mid-level ridging building inland of the Pacific coast. The track and evolution of this perturbation through residual cyclonic flow across the interior through eastern U.S. remains varied within the model output. However, it currently appears that the initial surface wave development will remain weak, along a stalled remnant frontal zone across the eastern Gulf of Mexico and east/northeast of the Florida Peninsula late next Monday night through Tuesday morning. This currently seems likely to minimize the risk for organized severe thunderstorms. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Jan 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... A deep remnant mid-level low, near James Bay by the beginning of the period, may deepen some further while redeveloping northward, then westward, into southern Hudson Bay by early next week, within an elongating area of low mid-level heights across much of eastern Canada, the Great Lakes and Northeast. This may linger into the middle to latter portion of next week, when a new mid-level low may form near Newfoundland and Labrador, associated with strong surface cyclogenesis offshore of the northern U.S. Atlantic coast and Canadian Maritimes. It appears that this cyclogenesis will initiate in response to a short wave trough emanating from the Canadian Arctic, before initially digging to the lee of the Canadian/northern U.S. Rockies, downstream of mid-level ridging building inland of the Pacific coast. The track and evolution of this perturbation through residual cyclonic flow across the interior through eastern U.S. remains varied within the model output. However, it currently appears that the initial surface wave development will remain weak, along a stalled remnant frontal zone across the eastern Gulf of Mexico and east/northeast of the Florida Peninsula late next Monday night through Tuesday morning. This currently seems likely to minimize the risk for organized severe thunderstorms. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Jan 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... A deep remnant mid-level low, near James Bay by the beginning of the period, may deepen some further while redeveloping northward, then westward, into southern Hudson Bay by early next week, within an elongating area of low mid-level heights across much of eastern Canada, the Great Lakes and Northeast. This may linger into the middle to latter portion of next week, when a new mid-level low may form near Newfoundland and Labrador, associated with strong surface cyclogenesis offshore of the northern U.S. Atlantic coast and Canadian Maritimes. It appears that this cyclogenesis will initiate in response to a short wave trough emanating from the Canadian Arctic, before initially digging to the lee of the Canadian/northern U.S. Rockies, downstream of mid-level ridging building inland of the Pacific coast. The track and evolution of this perturbation through residual cyclonic flow across the interior through eastern U.S. remains varied within the model output. However, it currently appears that the initial surface wave development will remain weak, along a stalled remnant frontal zone across the eastern Gulf of Mexico and east/northeast of the Florida Peninsula late next Monday night through Tuesday morning. This currently seems likely to minimize the risk for organized severe thunderstorms. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0320 AM CST Thu Jan 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... A deep remnant mid-level low, near James Bay by the beginning of the period, may deepen some further while redeveloping northward, then westward, into southern Hudson Bay by early next week, within an elongating area of low mid-level heights across much of eastern Canada, the Great Lakes and Northeast. This may linger into the middle to latter portion of next week, when a new mid-level low may form near Newfoundland and Labrador, associated with strong surface cyclogenesis offshore of the northern U.S. Atlantic coast and Canadian Maritimes. It appears that this cyclogenesis will initiate in response to a short wave trough emanating from the Canadian Arctic, before initially digging to the lee of the Canadian/northern U.S. Rockies, downstream of mid-level ridging building inland of the Pacific coast. The track and evolution of this perturbation through residual cyclonic flow across the interior through eastern U.S. remains varied within the model output. However, it currently appears that the initial surface wave development will remain weak, along a stalled remnant frontal zone across the eastern Gulf of Mexico and east/northeast of the Florida Peninsula late next Monday night through Tuesday morning. This currently seems likely to minimize the risk for organized severe thunderstorms. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Thu Jan 11 2024 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across much of the U.S., Saturday through Saturday night. ...Discussion... While the center of a broad, initially intense, surface cyclone is generally forecast to weaken while migrating northeast of the Great Lakes region during this period, models suggest that a remnant mid-level circulation may begin to deepen while turning northward toward James Bay. In their wake, Arctic air, initially banked up across the northern Great Plains into the Rockies, appears likely to surge southeastward through much of the southern Great Plains and lower Mississippi Valley by late Saturday night. This will reinforce a preceding cold front, which is forecast to advance offshore and away from much of the Atlantic Seaboard, while stalling across the southern Florida Peninsula through southeastern Gulf of Mexico. Coupled with low-level warming and moistening, dynamically driven steepening of lapse rates above a cool/stable boundary layer may be contributing to convection capable of producing lightning near southeastern New England coastal areas early in the period. Otherwise, some weak thunderstorm development will remain possible along the stalling front, though this may remain mostly confined to areas near and offshore of the southern Florida coastal waters. ..Kerr.. 01/11/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Thu Jan 11 2024 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across much of the U.S., Saturday through Saturday night. ...Discussion... While the center of a broad, initially intense, surface cyclone is generally forecast to weaken while migrating northeast of the Great Lakes region during this period, models suggest that a remnant mid-level circulation may begin to deepen while turning northward toward James Bay. In their wake, Arctic air, initially banked up across the northern Great Plains into the Rockies, appears likely to surge southeastward through much of the southern Great Plains and lower Mississippi Valley by late Saturday night. This will reinforce a preceding cold front, which is forecast to advance offshore and away from much of the Atlantic Seaboard, while stalling across the southern Florida Peninsula through southeastern Gulf of Mexico. Coupled with low-level warming and moistening, dynamically driven steepening of lapse rates above a cool/stable boundary layer may be contributing to convection capable of producing lightning near southeastern New England coastal areas early in the period. Otherwise, some weak thunderstorm development will remain possible along the stalling front, though this may remain mostly confined to areas near and offshore of the southern Florida coastal waters. ..Kerr.. 01/11/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Thu Jan 11 2024 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across much of the U.S., Saturday through Saturday night. ...Discussion... While the center of a broad, initially intense, surface cyclone is generally forecast to weaken while migrating northeast of the Great Lakes region during this period, models suggest that a remnant mid-level circulation may begin to deepen while turning northward toward James Bay. In their wake, Arctic air, initially banked up across the northern Great Plains into the Rockies, appears likely to surge southeastward through much of the southern Great Plains and lower Mississippi Valley by late Saturday night. This will reinforce a preceding cold front, which is forecast to advance offshore and away from much of the Atlantic Seaboard, while stalling across the southern Florida Peninsula through southeastern Gulf of Mexico. Coupled with low-level warming and moistening, dynamically driven steepening of lapse rates above a cool/stable boundary layer may be contributing to convection capable of producing lightning near southeastern New England coastal areas early in the period. Otherwise, some weak thunderstorm development will remain possible along the stalling front, though this may remain mostly confined to areas near and offshore of the southern Florida coastal waters. ..Kerr.. 01/11/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Thu Jan 11 2024 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across much of the U.S., Saturday through Saturday night. ...Discussion... While the center of a broad, initially intense, surface cyclone is generally forecast to weaken while migrating northeast of the Great Lakes region during this period, models suggest that a remnant mid-level circulation may begin to deepen while turning northward toward James Bay. In their wake, Arctic air, initially banked up across the northern Great Plains into the Rockies, appears likely to surge southeastward through much of the southern Great Plains and lower Mississippi Valley by late Saturday night. This will reinforce a preceding cold front, which is forecast to advance offshore and away from much of the Atlantic Seaboard, while stalling across the southern Florida Peninsula through southeastern Gulf of Mexico. Coupled with low-level warming and moistening, dynamically driven steepening of lapse rates above a cool/stable boundary layer may be contributing to convection capable of producing lightning near southeastern New England coastal areas early in the period. Otherwise, some weak thunderstorm development will remain possible along the stalling front, though this may remain mostly confined to areas near and offshore of the southern Florida coastal waters. ..Kerr.. 01/11/2024 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Thu Jan 11 2024 Valid 131200Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across much of the U.S., Saturday through Saturday night. ...Discussion... While the center of a broad, initially intense, surface cyclone is generally forecast to weaken while migrating northeast of the Great Lakes region during this period, models suggest that a remnant mid-level circulation may begin to deepen while turning northward toward James Bay. In their wake, Arctic air, initially banked up across the northern Great Plains into the Rockies, appears likely to surge southeastward through much of the southern Great Plains and lower Mississippi Valley by late Saturday night. This will reinforce a preceding cold front, which is forecast to advance offshore and away from much of the Atlantic Seaboard, while stalling across the southern Florida Peninsula through southeastern Gulf of Mexico. Coupled with low-level warming and moistening, dynamically driven steepening of lapse rates above a cool/stable boundary layer may be contributing to convection capable of producing lightning near southeastern New England coastal areas early in the period. Otherwise, some weak thunderstorm development will remain possible along the stalling front, though this may remain mostly confined to areas near and offshore of the southern Florida coastal waters. ..Kerr.. 01/11/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Thu Jan 11 2024 Valid 121200Z - 131200Z ...Synopsis... The surface low previously over the southern Plains is forecast to deepen rapidly and lift away into the OH Valley as the parent trough intensifies over the Midwest. In the wake of the trough/low, a cold front will move south over the southern Plains toward the Gulf coast, supporting strong northwesterly winds and dry surface conditions over parts of southwest TX. A few hours of elevated fire-weather conditions are possible before an Arctic front arrives with much colder temperatures. ...Southwest Texas & Rio Grande Valley... Behind the leading cold front, strong northwesterly surface flow is expected across the Rio Grande Valley and Southwest Texas on Friday. Several days of dry/breezy conditions have allowed antecedent fine fuels to dry sufficiently to support fire spread. Winds will be strongest through early afternoon before weakening into the overnight hours as the surface low lifts away to the northeast. A few hours of overlap of the stronger winds with RH values below 20% will promote elevated to locally critical fire weather conditions. ..Lyons.. 01/11/2024 ...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 0150 AM CST Thu Jan 11 2024 Valid 121200Z - 131200Z ...Synopsis... The surface low previously over the southern Plains is forecast to deepen rapidly and lift away into the OH Valley as the parent trough intensifies over the Midwest. In the wake of the trough/low, a cold front will move south over the southern Plains toward the Gulf coast, supporting strong northwesterly winds and dry surface conditions over parts of southwest TX. A few hours of elevated fire-weather conditions are possible before an Arctic front arrives with much colder temperatures. ...Southwest Texas & Rio Grande Valley... Behind the leading cold front, strong northwesterly surface flow is expected across the Rio Grande Valley and Southwest Texas on Friday. Several days of dry/breezy conditions have allowed antecedent fine fuels to dry sufficiently to support fire spread. Winds will be strongest through early afternoon before weakening into the overnight hours as the surface low lifts away to the northeast. A few hours of overlap of the stronger winds with RH values below 20% will promote elevated to locally critical fire weather conditions. ..Lyons.. 01/11/2024 ...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 0150 AM CST Thu Jan 11 2024 Valid 121200Z - 131200Z ...Synopsis... The surface low previously over the southern Plains is forecast to deepen rapidly and lift away into the OH Valley as the parent trough intensifies over the Midwest. In the wake of the trough/low, a cold front will move south over the southern Plains toward the Gulf coast, supporting strong northwesterly winds and dry surface conditions over parts of southwest TX. A few hours of elevated fire-weather conditions are possible before an Arctic front arrives with much colder temperatures. ...Southwest Texas & Rio Grande Valley... Behind the leading cold front, strong northwesterly surface flow is expected across the Rio Grande Valley and Southwest Texas on Friday. Several days of dry/breezy conditions have allowed antecedent fine fuels to dry sufficiently to support fire spread. Winds will be strongest through early afternoon before weakening into the overnight hours as the surface low lifts away to the northeast. A few hours of overlap of the stronger winds with RH values below 20% will promote elevated to locally critical fire weather conditions. ..Lyons.. 01/11/2024 ...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 0150 AM CST Thu Jan 11 2024 Valid 121200Z - 131200Z ...Synopsis... The surface low previously over the southern Plains is forecast to deepen rapidly and lift away into the OH Valley as the parent trough intensifies over the Midwest. In the wake of the trough/low, a cold front will move south over the southern Plains toward the Gulf coast, supporting strong northwesterly winds and dry surface conditions over parts of southwest TX. A few hours of elevated fire-weather conditions are possible before an Arctic front arrives with much colder temperatures. ...Southwest Texas & Rio Grande Valley... Behind the leading cold front, strong northwesterly surface flow is expected across the Rio Grande Valley and Southwest Texas on Friday. Several days of dry/breezy conditions have allowed antecedent fine fuels to dry sufficiently to support fire spread. Winds will be strongest through early afternoon before weakening into the overnight hours as the surface low lifts away to the northeast. A few hours of overlap of the stronger winds with RH values below 20% will promote elevated to locally critical fire weather conditions. ..Lyons.. 01/11/2024 ...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 0150 AM CST Thu Jan 11 2024 Valid 121200Z - 131200Z ...Synopsis... The surface low previously over the southern Plains is forecast to deepen rapidly and lift away into the OH Valley as the parent trough intensifies over the Midwest. In the wake of the trough/low, a cold front will move south over the southern Plains toward the Gulf coast, supporting strong northwesterly winds and dry surface conditions over parts of southwest TX. A few hours of elevated fire-weather conditions are possible before an Arctic front arrives with much colder temperatures. ...Southwest Texas & Rio Grande Valley... Behind the leading cold front, strong northwesterly surface flow is expected across the Rio Grande Valley and Southwest Texas on Friday. Several days of dry/breezy conditions have allowed antecedent fine fuels to dry sufficiently to support fire spread. Winds will be strongest through early afternoon before weakening into the overnight hours as the surface low lifts away to the northeast. A few hours of overlap of the stronger winds with RH values below 20% will promote elevated to locally critical fire weather conditions. ..Lyons.. 01/11/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more