Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Mon Mar 18 2024 Valid 201200Z - 261200Z Fire weather concerns are possible during the middle of the current work week as well as over the weekend, though confidence in this potential is currently too limited to introduce risk probabilities. ...D3/Wednesday - Mid-Atlantic... The upper shortwave trough currently over southern Canada is forecast to propagate to the southeast over the next 48-72 hours, reaching the Atlantic coast by late afternoon D3/Wednesday. This will establish a westerly offshore flow regime from the central/southern Appalachians into the Mid-Atlantic region. With little precipitation anticipated with this system, the combination of breezy downslope winds with an influx of dry air may support regional fire weather concerns. Elevated fire weather conditions are probable, and localized critical conditions are possible in the lee of the higher terrain. However, confidence in regional details remains too limited to introduce highlights. ...D3/Wednesday and D7/Sunday - Southern High Plains... The meandering upper low currently over the Southwest is forecast to migrate into the southern Plains on D3/Wednesday. As this occurs, weak cyclogenesis over the Plains should induce downslope westerly flow off the southern Rockies into parts of eastern NM and southwest TX. This may allow for areas of elevated to critical fire weather conditions, though weak mid-level winds associated with the low-amplitude wave should limit the potential for substantial, widespread fire concerns. Long-range guidance continues to show an upper pattern regime change by the upcoming weekend. Shortwave troughing should become established over the western CONUS by Saturday with some deterministic solutions showing the progression of the upper wave into the Four Corners region by Sunday. This synoptic regime will favor the development of a strong lee cyclone over the central High Plains with an accompanying swath of dry/windy conditions across eastern NM and southwest/west TX behind a sharpening dryline. This is a typical fire weather regime for this region, and critical fire weather conditions are likely if this pattern is realized. However, long-range ensemble analyses show that the timing/progression of the upper wave in deterministic solutions may be too fast compared to most ensemble clusters. Probabilities are withheld for this forecast due to the inherent uncertainty at this time range, but if ensemble/deterministic solutions come into better agreement regarding the timing of the upper wave, risk probabilities will be introduced. ..Moore.. 03/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Mon Mar 18 2024 Valid 201200Z - 261200Z Fire weather concerns are possible during the middle of the current work week as well as over the weekend, though confidence in this potential is currently too limited to introduce risk probabilities. ...D3/Wednesday - Mid-Atlantic... The upper shortwave trough currently over southern Canada is forecast to propagate to the southeast over the next 48-72 hours, reaching the Atlantic coast by late afternoon D3/Wednesday. This will establish a westerly offshore flow regime from the central/southern Appalachians into the Mid-Atlantic region. With little precipitation anticipated with this system, the combination of breezy downslope winds with an influx of dry air may support regional fire weather concerns. Elevated fire weather conditions are probable, and localized critical conditions are possible in the lee of the higher terrain. However, confidence in regional details remains too limited to introduce highlights. ...D3/Wednesday and D7/Sunday - Southern High Plains... The meandering upper low currently over the Southwest is forecast to migrate into the southern Plains on D3/Wednesday. As this occurs, weak cyclogenesis over the Plains should induce downslope westerly flow off the southern Rockies into parts of eastern NM and southwest TX. This may allow for areas of elevated to critical fire weather conditions, though weak mid-level winds associated with the low-amplitude wave should limit the potential for substantial, widespread fire concerns. Long-range guidance continues to show an upper pattern regime change by the upcoming weekend. Shortwave troughing should become established over the western CONUS by Saturday with some deterministic solutions showing the progression of the upper wave into the Four Corners region by Sunday. This synoptic regime will favor the development of a strong lee cyclone over the central High Plains with an accompanying swath of dry/windy conditions across eastern NM and southwest/west TX behind a sharpening dryline. This is a typical fire weather regime for this region, and critical fire weather conditions are likely if this pattern is realized. However, long-range ensemble analyses show that the timing/progression of the upper wave in deterministic solutions may be too fast compared to most ensemble clusters. Probabilities are withheld for this forecast due to the inherent uncertainty at this time range, but if ensemble/deterministic solutions come into better agreement regarding the timing of the upper wave, risk probabilities will be introduced. ..Moore.. 03/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Mon Mar 18 2024 Valid 201200Z - 261200Z Fire weather concerns are possible during the middle of the current work week as well as over the weekend, though confidence in this potential is currently too limited to introduce risk probabilities. ...D3/Wednesday - Mid-Atlantic... The upper shortwave trough currently over southern Canada is forecast to propagate to the southeast over the next 48-72 hours, reaching the Atlantic coast by late afternoon D3/Wednesday. This will establish a westerly offshore flow regime from the central/southern Appalachians into the Mid-Atlantic region. With little precipitation anticipated with this system, the combination of breezy downslope winds with an influx of dry air may support regional fire weather concerns. Elevated fire weather conditions are probable, and localized critical conditions are possible in the lee of the higher terrain. However, confidence in regional details remains too limited to introduce highlights. ...D3/Wednesday and D7/Sunday - Southern High Plains... The meandering upper low currently over the Southwest is forecast to migrate into the southern Plains on D3/Wednesday. As this occurs, weak cyclogenesis over the Plains should induce downslope westerly flow off the southern Rockies into parts of eastern NM and southwest TX. This may allow for areas of elevated to critical fire weather conditions, though weak mid-level winds associated with the low-amplitude wave should limit the potential for substantial, widespread fire concerns. Long-range guidance continues to show an upper pattern regime change by the upcoming weekend. Shortwave troughing should become established over the western CONUS by Saturday with some deterministic solutions showing the progression of the upper wave into the Four Corners region by Sunday. This synoptic regime will favor the development of a strong lee cyclone over the central High Plains with an accompanying swath of dry/windy conditions across eastern NM and southwest/west TX behind a sharpening dryline. This is a typical fire weather regime for this region, and critical fire weather conditions are likely if this pattern is realized. However, long-range ensemble analyses show that the timing/progression of the upper wave in deterministic solutions may be too fast compared to most ensemble clusters. Probabilities are withheld for this forecast due to the inherent uncertainty at this time range, but if ensemble/deterministic solutions come into better agreement regarding the timing of the upper wave, risk probabilities will be introduced. ..Moore.. 03/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0340 PM CDT Mon Mar 18 2024 Valid 201200Z - 261200Z Fire weather concerns are possible during the middle of the current work week as well as over the weekend, though confidence in this potential is currently too limited to introduce risk probabilities. ...D3/Wednesday - Mid-Atlantic... The upper shortwave trough currently over southern Canada is forecast to propagate to the southeast over the next 48-72 hours, reaching the Atlantic coast by late afternoon D3/Wednesday. This will establish a westerly offshore flow regime from the central/southern Appalachians into the Mid-Atlantic region. With little precipitation anticipated with this system, the combination of breezy downslope winds with an influx of dry air may support regional fire weather concerns. Elevated fire weather conditions are probable, and localized critical conditions are possible in the lee of the higher terrain. However, confidence in regional details remains too limited to introduce highlights. ...D3/Wednesday and D7/Sunday - Southern High Plains... The meandering upper low currently over the Southwest is forecast to migrate into the southern Plains on D3/Wednesday. As this occurs, weak cyclogenesis over the Plains should induce downslope westerly flow off the southern Rockies into parts of eastern NM and southwest TX. This may allow for areas of elevated to critical fire weather conditions, though weak mid-level winds associated with the low-amplitude wave should limit the potential for substantial, widespread fire concerns. Long-range guidance continues to show an upper pattern regime change by the upcoming weekend. Shortwave troughing should become established over the western CONUS by Saturday with some deterministic solutions showing the progression of the upper wave into the Four Corners region by Sunday. This synoptic regime will favor the development of a strong lee cyclone over the central High Plains with an accompanying swath of dry/windy conditions across eastern NM and southwest/west TX behind a sharpening dryline. This is a typical fire weather regime for this region, and critical fire weather conditions are likely if this pattern is realized. However, long-range ensemble analyses show that the timing/progression of the upper wave in deterministic solutions may be too fast compared to most ensemble clusters. Probabilities are withheld for this forecast due to the inherent uncertainty at this time range, but if ensemble/deterministic solutions come into better agreement regarding the timing of the upper wave, risk probabilities will be introduced. ..Moore.. 03/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Mon Mar 18 2024 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL FLORIDA AND MUCH OF THE FLORIDA ATLANTIC COAST.... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. Thus far storms have been confined to the east coast of Florida with quick movement over the ocean. However, as the boundary layer continues to warm/deepen thunderstorms will become more likely farther inland. Cumulus have begun to expand along the front across the central Peninsula. In the presence of weak broad-scale ascent, this front will likely be the source for any storms which develop this afternoon. The marginal was trimmed in areas northwest of the front, but otherwise, no changes were necessary. ..Bentley.. 03/18/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Mar 18 2024/ ...Central and eastern Florida Peninsula... Morning water-vapor imagery indicates a shortwave trough over the middle MS Valley digging southward into the base of a larger-scale trough. This evolution will allow a related cold front to continue southward across the central/southern FL Peninsula today. While the FL Peninsula will generally be displaced from the associated midlevel height falls/large-scale ascent, afternoon storm development will be aided by ascent along the shallow frontal zone and diurnal heating of a moist boundary layer amid leftover outflow boundaries from morning convection. The development of 40-50-kt effective shear (characterized by a long/mostly straight hodograph) will support a mix of organized multicells and transient supercells along/ahead of the southward-moving front and mesoscale boundaries over the warm sector. These storms will be aided by relatively steep midlevel lapse rates atop a moist/destabilizing boundary layer. A deep CAPE profile (with moderate surface-based buoyancy) and the aforementioned hodograph will support large hail up to 1.75 inches and locally severe gusts near 60 mph with any sustained/organized storms. Additionally, a brief tornado cannot be entirely ruled out along the east coast, where locally backed flow may contribute to slightly more low-level hodograph curvature. However, veered low-level flow ahead of the front (along with a lack of large-scale ascent) and deep westerly flow may both limit the coverage of organized storms, and convective residence time in the most favorable environment -- warranting the maintenance of the Marginal risk. ...Arizona and southern California... A mid/upper-level low centered over west-central AZ will move slowly westward into southern CA today. On the eastern periphery of this feature, 25-30-kt midlevel southeasterlies combined with cold temperatures aloft/steep midlevel lapse rates could favor a couple strong/loosely organized storms capable of mainly small hail and locally strong gusts. Along the northern and western periphery of the upper low, a stronger belt of midlevel flow (around 45 kt) accompanying a westward-moving impulse will overspread west-central AZ into southern CA this afternoon. Over parts of southern CA (particularly west of the Desert), upper 40s/lower 50s dewpoints beneath the steep lapse rates will contribute to more substantial buoyancy amid 30-40 kt of effective shear. While convective evolution/sustenance is uncertain given offshore/downslope flow across this area, there is a conditional risk of near-severe hail and gusty winds if any longer-lived storms develop. Overall, confidence in this scenario is too low to add unconditional 5-percent hail/wind probabilities with this outlook. Read more

MD 0270 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE CENTRAL AND EASTERN FLORIDA PENINSULA
Mesoscale Discussion 0270 NWS Storm Prediction Center Norman OK 1255 PM CDT Mon Mar 18 2024 Areas affected...Portions of the central and eastern Florida Peninsula Concerning...Severe potential...Watch unlikely Valid 181755Z - 182030Z Probability of Watch Issuance...20 percent SUMMARY...Strong to severe storm potential will gradually increase through the afternoon across portions of the central and eastern FL Peninsula. Primary concerns are isolated large hail and locally damaging gusts. DISCUSSION...Latest day cloud phase satellite imagery indicates a deepening boundary-layer cumulus field developing along/ahead of a diffuse ENE/WSW-oriented cold front draped across central FL this afternoon. Isolated convection is beginning to develop within this cumulus field, as the associated frontal ascent intersects steepening boundary-layer lapse rates and rich moisture (upper 60s/lower 70s surface dewpoints). During the next few hours, the continued ascent and destabilization should support isolated to widely scattered thunderstorms, which will generally spread east-southeastward along the front, with additional isolated development possible along differential heating boundaries into southern FL. The 15Z XMR sounding and more recent ACARS and VWP data are sampling 50-60 kt midlevel west-southwesterly flow, which is contributing to a long/mostly straight hodograph (40-50 kt of effective shear). This, combined with the continued boundary-layer destabilization beneath relatively steep midlevel lapse rates, will support organized multicells and transient/splitting supercells. As this activity spreads eastward into the increasing surface-based instability, the risk of isolated large hail up to 1.75 inches and locally damaging gusts (potentially near 60 mph) will increase. While less likely, a brief tornado cannot be entirely ruled out along the east coast, where surface winds are beginning to back, yielding modest low-level hodograph curvature/low-level streamwise vorticity. Given that large-scale forcing for ascent is weak and surface winds are veered ahead of the front, the overall coverage of severe storms should be limited, and storm intensification may be gradual. Therefore, the severe risk appears too isolated for a watch at this time. ..Weinman/Goss.. 03/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB...TBW...JAX... LAT...LON 26727995 26228000 26078019 26198045 26798095 27368174 27438212 27748246 28148253 28528245 28938224 29328165 29438126 29408095 28998062 28378030 27228003 26727995 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0118 PM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... No forecast changes are needed. Elevated fire weather conditions may emerge through much of the OH River Valley region tomorrow afternoon as a surface trough/weak cold front push through the region. Strong mid-level flow and modestly deep boundary-layer mixing should support 15-25 mph winds with gusts upwards of 30-35 mph. Despite the strong winds, RH values are expected to be relatively mild with ensemble mean values near 30%; however, solutions that typically exhibit deeper mixing suggest RH values may fall as low as 20-25% through parts of the OH Valley (most likely along and south of the OH river to the western slopes of the southern Appalachians). In addition to the uncertainty in the RH forecast, fuel status is mixed across the region with areas that are primarily characterized by finer fuels (grasses and leaves) reporting sufficiently dry fuels to support a fire concern. Dry conditions are expected to persist across NC and VA, but weaker winds should limit overall concerns. No highlights are introduced at this time, but relative humidity and fuel trends will continue to be monitored. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern through the day on Tuesday is expected to be characterized a large trough across the central and eastern US with a decaying cutoff low across the southwestern US. At the surface, this would result in a ridge near the Gulf Coast. Although winds across the northern and central Florida peninsula are currently forecast to be light, relative humidity may be in the 30-40% range. This may result in pockets of elevated fire conditions across this region. However, given the moist fuels and the uncertainty on wind speeds, will not introduce Elevated highlights for now. Elsewhere across the continental US, higher relative humidity is expected to generally keep fire concerns minimal. ...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 0118 PM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... No forecast changes are needed. Elevated fire weather conditions may emerge through much of the OH River Valley region tomorrow afternoon as a surface trough/weak cold front push through the region. Strong mid-level flow and modestly deep boundary-layer mixing should support 15-25 mph winds with gusts upwards of 30-35 mph. Despite the strong winds, RH values are expected to be relatively mild with ensemble mean values near 30%; however, solutions that typically exhibit deeper mixing suggest RH values may fall as low as 20-25% through parts of the OH Valley (most likely along and south of the OH river to the western slopes of the southern Appalachians). In addition to the uncertainty in the RH forecast, fuel status is mixed across the region with areas that are primarily characterized by finer fuels (grasses and leaves) reporting sufficiently dry fuels to support a fire concern. Dry conditions are expected to persist across NC and VA, but weaker winds should limit overall concerns. No highlights are introduced at this time, but relative humidity and fuel trends will continue to be monitored. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern through the day on Tuesday is expected to be characterized a large trough across the central and eastern US with a decaying cutoff low across the southwestern US. At the surface, this would result in a ridge near the Gulf Coast. Although winds across the northern and central Florida peninsula are currently forecast to be light, relative humidity may be in the 30-40% range. This may result in pockets of elevated fire conditions across this region. However, given the moist fuels and the uncertainty on wind speeds, will not introduce Elevated highlights for now. Elsewhere across the continental US, higher relative humidity is expected to generally keep fire concerns minimal. ...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 0118 PM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... No forecast changes are needed. Elevated fire weather conditions may emerge through much of the OH River Valley region tomorrow afternoon as a surface trough/weak cold front push through the region. Strong mid-level flow and modestly deep boundary-layer mixing should support 15-25 mph winds with gusts upwards of 30-35 mph. Despite the strong winds, RH values are expected to be relatively mild with ensemble mean values near 30%; however, solutions that typically exhibit deeper mixing suggest RH values may fall as low as 20-25% through parts of the OH Valley (most likely along and south of the OH river to the western slopes of the southern Appalachians). In addition to the uncertainty in the RH forecast, fuel status is mixed across the region with areas that are primarily characterized by finer fuels (grasses and leaves) reporting sufficiently dry fuels to support a fire concern. Dry conditions are expected to persist across NC and VA, but weaker winds should limit overall concerns. No highlights are introduced at this time, but relative humidity and fuel trends will continue to be monitored. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern through the day on Tuesday is expected to be characterized a large trough across the central and eastern US with a decaying cutoff low across the southwestern US. At the surface, this would result in a ridge near the Gulf Coast. Although winds across the northern and central Florida peninsula are currently forecast to be light, relative humidity may be in the 30-40% range. This may result in pockets of elevated fire conditions across this region. However, given the moist fuels and the uncertainty on wind speeds, will not introduce Elevated highlights for now. Elsewhere across the continental US, higher relative humidity is expected to generally keep fire concerns minimal. ...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 0118 PM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... No forecast changes are needed. Elevated fire weather conditions may emerge through much of the OH River Valley region tomorrow afternoon as a surface trough/weak cold front push through the region. Strong mid-level flow and modestly deep boundary-layer mixing should support 15-25 mph winds with gusts upwards of 30-35 mph. Despite the strong winds, RH values are expected to be relatively mild with ensemble mean values near 30%; however, solutions that typically exhibit deeper mixing suggest RH values may fall as low as 20-25% through parts of the OH Valley (most likely along and south of the OH river to the western slopes of the southern Appalachians). In addition to the uncertainty in the RH forecast, fuel status is mixed across the region with areas that are primarily characterized by finer fuels (grasses and leaves) reporting sufficiently dry fuels to support a fire concern. Dry conditions are expected to persist across NC and VA, but weaker winds should limit overall concerns. No highlights are introduced at this time, but relative humidity and fuel trends will continue to be monitored. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern through the day on Tuesday is expected to be characterized a large trough across the central and eastern US with a decaying cutoff low across the southwestern US. At the surface, this would result in a ridge near the Gulf Coast. Although winds across the northern and central Florida peninsula are currently forecast to be light, relative humidity may be in the 30-40% range. This may result in pockets of elevated fire conditions across this region. However, given the moist fuels and the uncertainty on wind speeds, will not introduce Elevated highlights for now. Elsewhere across the continental US, higher relative humidity is expected to generally keep fire concerns minimal. ...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 0118 PM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... No forecast changes are needed. Elevated fire weather conditions may emerge through much of the OH River Valley region tomorrow afternoon as a surface trough/weak cold front push through the region. Strong mid-level flow and modestly deep boundary-layer mixing should support 15-25 mph winds with gusts upwards of 30-35 mph. Despite the strong winds, RH values are expected to be relatively mild with ensemble mean values near 30%; however, solutions that typically exhibit deeper mixing suggest RH values may fall as low as 20-25% through parts of the OH Valley (most likely along and south of the OH river to the western slopes of the southern Appalachians). In addition to the uncertainty in the RH forecast, fuel status is mixed across the region with areas that are primarily characterized by finer fuels (grasses and leaves) reporting sufficiently dry fuels to support a fire concern. Dry conditions are expected to persist across NC and VA, but weaker winds should limit overall concerns. No highlights are introduced at this time, but relative humidity and fuel trends will continue to be monitored. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern through the day on Tuesday is expected to be characterized a large trough across the central and eastern US with a decaying cutoff low across the southwestern US. At the surface, this would result in a ridge near the Gulf Coast. Although winds across the northern and central Florida peninsula are currently forecast to be light, relative humidity may be in the 30-40% range. This may result in pockets of elevated fire conditions across this region. However, given the moist fuels and the uncertainty on wind speeds, will not introduce Elevated highlights for now. Elsewhere across the continental US, higher relative humidity is expected to generally keep fire concerns minimal. ...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 0118 PM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... No forecast changes are needed. Elevated fire weather conditions may emerge through much of the OH River Valley region tomorrow afternoon as a surface trough/weak cold front push through the region. Strong mid-level flow and modestly deep boundary-layer mixing should support 15-25 mph winds with gusts upwards of 30-35 mph. Despite the strong winds, RH values are expected to be relatively mild with ensemble mean values near 30%; however, solutions that typically exhibit deeper mixing suggest RH values may fall as low as 20-25% through parts of the OH Valley (most likely along and south of the OH river to the western slopes of the southern Appalachians). In addition to the uncertainty in the RH forecast, fuel status is mixed across the region with areas that are primarily characterized by finer fuels (grasses and leaves) reporting sufficiently dry fuels to support a fire concern. Dry conditions are expected to persist across NC and VA, but weaker winds should limit overall concerns. No highlights are introduced at this time, but relative humidity and fuel trends will continue to be monitored. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern through the day on Tuesday is expected to be characterized a large trough across the central and eastern US with a decaying cutoff low across the southwestern US. At the surface, this would result in a ridge near the Gulf Coast. Although winds across the northern and central Florida peninsula are currently forecast to be light, relative humidity may be in the 30-40% range. This may result in pockets of elevated fire conditions across this region. However, given the moist fuels and the uncertainty on wind speeds, will not introduce Elevated highlights for now. Elsewhere across the continental US, higher relative humidity is expected to generally keep fire concerns minimal. ...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 1155 AM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Tuesday through Tuesday night. ...Synopsis... A cut off low will start to slowly drift east across Arizona on Tuesday which will bring scattered thunderstorm activity. Elsewhere in the CONUS, cool and dry/stable conditions are expected. Diurnal thunderstorms are expected near the upper-low across Arizona and vicinity on Tuesday as valley locations warm into the 60s and the mountains warm into the 50s, generating around 500 J/kg MLCAPE. Steep lapse rates amid the cool temperatures aloft will support moderately strong updrafts. However, where these storms are most likely, shear will be very weak. Therefore, no severe thunderstorms are expected. A few thunderstorms are possible along the mountains from southern California into the central Sierra, but once again, shear should remain too weak to support organized thunderstorms and an appreciable threat for severe weather. ..Bentley.. 03/18/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1155 AM CDT Mon Mar 18 2024 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Tuesday through Tuesday night. ...Synopsis... A cut off low will start to slowly drift east across Arizona on Tuesday which will bring scattered thunderstorm activity. Elsewhere in the CONUS, cool and dry/stable conditions are expected. Diurnal thunderstorms are expected near the upper-low across Arizona and vicinity on Tuesday as valley locations warm into the 60s and the mountains warm into the 50s, generating around 500 J/kg MLCAPE. Steep lapse rates amid the cool temperatures aloft will support moderately strong updrafts. However, where these storms are most likely, shear will be very weak. Therefore, no severe thunderstorms are expected. A few thunderstorms are possible along the mountains from southern California into the central Sierra, but once again, shear should remain too weak to support organized thunderstorms and an appreciable threat for severe weather. ..Bentley.. 03/18/2024 Read more