Severe Storms

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

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

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

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Mon Mar 18 2024 Valid 181630Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ...SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ...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. ..Weinman/Goss.. 03/18/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CDT Mon Mar 18 2024 Valid 181700Z - 191200Z An Elevated risk area is introduced for portions of southeast Montana, northeast Wyoming, and the far western Dakotas. Although morning guidance has initialized slightly too warm/dry compared to observations, high-resolution runs have captured recent wind speed trends fairly well. These solutions, supported by ensemble probabilities, suggests a reasonably high likelihood of sustained winds near 20 mph across the northern Plains this afternoon as a surface low deepens across southern Canada. Although confidence in reaching critical RH values is low, afternoon RH minimums near 25% appear probable within the downslope flow regime, and given ERC values between the 75-90th percentile, should support at least regional fire weather concerns. Fire weather concerns may extend further east into the central and eastern Dakotas, but confidence in sustained, widespread elevated conditions is more limited due to greater spread in deterministic/ensemble solutions. Morning surface observations in the lee of the VA/NC Appalachians are sampling rather dry conditions with RH values in the 20-30% range. Localized fire weather concerns are probable in the immediate lee of the higher terrain as a frontal surge increases winds to 10-15 mph (gusting upwards of 20 mph) this afternoon. However, confidence in the spatial coverage of this threat is limited away from terrain features. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0130 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern over the US will be dominated by a deep eastern trough with northwesterly mid-level flow across the central US and a cutoff low over the southwest US. A secondary speed max embedded in the large-scale flow should lead to a surface cyclone near the US-Canada border, which may result in a few areas of Elevated conditions across southeastern Montana and northeastern Wyoming. However, these areas are expected to be localized, and fuels have received some moisture in the last week. Elsewhere across the central US, a large anticyclone is expected to keep winds weak. For these reasons, no risk areas are introduced on this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CDT Mon Mar 18 2024 Valid 181700Z - 191200Z An Elevated risk area is introduced for portions of southeast Montana, northeast Wyoming, and the far western Dakotas. Although morning guidance has initialized slightly too warm/dry compared to observations, high-resolution runs have captured recent wind speed trends fairly well. These solutions, supported by ensemble probabilities, suggests a reasonably high likelihood of sustained winds near 20 mph across the northern Plains this afternoon as a surface low deepens across southern Canada. Although confidence in reaching critical RH values is low, afternoon RH minimums near 25% appear probable within the downslope flow regime, and given ERC values between the 75-90th percentile, should support at least regional fire weather concerns. Fire weather concerns may extend further east into the central and eastern Dakotas, but confidence in sustained, widespread elevated conditions is more limited due to greater spread in deterministic/ensemble solutions. Morning surface observations in the lee of the VA/NC Appalachians are sampling rather dry conditions with RH values in the 20-30% range. Localized fire weather concerns are probable in the immediate lee of the higher terrain as a frontal surge increases winds to 10-15 mph (gusting upwards of 20 mph) this afternoon. However, confidence in the spatial coverage of this threat is limited away from terrain features. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0130 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern over the US will be dominated by a deep eastern trough with northwesterly mid-level flow across the central US and a cutoff low over the southwest US. A secondary speed max embedded in the large-scale flow should lead to a surface cyclone near the US-Canada border, which may result in a few areas of Elevated conditions across southeastern Montana and northeastern Wyoming. However, these areas are expected to be localized, and fuels have received some moisture in the last week. Elsewhere across the central US, a large anticyclone is expected to keep winds weak. For these reasons, no risk areas are introduced on this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CDT Mon Mar 18 2024 Valid 181700Z - 191200Z An Elevated risk area is introduced for portions of southeast Montana, northeast Wyoming, and the far western Dakotas. Although morning guidance has initialized slightly too warm/dry compared to observations, high-resolution runs have captured recent wind speed trends fairly well. These solutions, supported by ensemble probabilities, suggests a reasonably high likelihood of sustained winds near 20 mph across the northern Plains this afternoon as a surface low deepens across southern Canada. Although confidence in reaching critical RH values is low, afternoon RH minimums near 25% appear probable within the downslope flow regime, and given ERC values between the 75-90th percentile, should support at least regional fire weather concerns. Fire weather concerns may extend further east into the central and eastern Dakotas, but confidence in sustained, widespread elevated conditions is more limited due to greater spread in deterministic/ensemble solutions. Morning surface observations in the lee of the VA/NC Appalachians are sampling rather dry conditions with RH values in the 20-30% range. Localized fire weather concerns are probable in the immediate lee of the higher terrain as a frontal surge increases winds to 10-15 mph (gusting upwards of 20 mph) this afternoon. However, confidence in the spatial coverage of this threat is limited away from terrain features. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0130 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern over the US will be dominated by a deep eastern trough with northwesterly mid-level flow across the central US and a cutoff low over the southwest US. A secondary speed max embedded in the large-scale flow should lead to a surface cyclone near the US-Canada border, which may result in a few areas of Elevated conditions across southeastern Montana and northeastern Wyoming. However, these areas are expected to be localized, and fuels have received some moisture in the last week. Elsewhere across the central US, a large anticyclone is expected to keep winds weak. For these reasons, no risk areas are introduced on this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CDT Mon Mar 18 2024 Valid 181700Z - 191200Z An Elevated risk area is introduced for portions of southeast Montana, northeast Wyoming, and the far western Dakotas. Although morning guidance has initialized slightly too warm/dry compared to observations, high-resolution runs have captured recent wind speed trends fairly well. These solutions, supported by ensemble probabilities, suggests a reasonably high likelihood of sustained winds near 20 mph across the northern Plains this afternoon as a surface low deepens across southern Canada. Although confidence in reaching critical RH values is low, afternoon RH minimums near 25% appear probable within the downslope flow regime, and given ERC values between the 75-90th percentile, should support at least regional fire weather concerns. Fire weather concerns may extend further east into the central and eastern Dakotas, but confidence in sustained, widespread elevated conditions is more limited due to greater spread in deterministic/ensemble solutions. Morning surface observations in the lee of the VA/NC Appalachians are sampling rather dry conditions with RH values in the 20-30% range. Localized fire weather concerns are probable in the immediate lee of the higher terrain as a frontal surge increases winds to 10-15 mph (gusting upwards of 20 mph) this afternoon. However, confidence in the spatial coverage of this threat is limited away from terrain features. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0130 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern over the US will be dominated by a deep eastern trough with northwesterly mid-level flow across the central US and a cutoff low over the southwest US. A secondary speed max embedded in the large-scale flow should lead to a surface cyclone near the US-Canada border, which may result in a few areas of Elevated conditions across southeastern Montana and northeastern Wyoming. However, these areas are expected to be localized, and fuels have received some moisture in the last week. Elsewhere across the central US, a large anticyclone is expected to keep winds weak. For these reasons, no risk areas are introduced on this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CDT Mon Mar 18 2024 Valid 181700Z - 191200Z An Elevated risk area is introduced for portions of southeast Montana, northeast Wyoming, and the far western Dakotas. Although morning guidance has initialized slightly too warm/dry compared to observations, high-resolution runs have captured recent wind speed trends fairly well. These solutions, supported by ensemble probabilities, suggests a reasonably high likelihood of sustained winds near 20 mph across the northern Plains this afternoon as a surface low deepens across southern Canada. Although confidence in reaching critical RH values is low, afternoon RH minimums near 25% appear probable within the downslope flow regime, and given ERC values between the 75-90th percentile, should support at least regional fire weather concerns. Fire weather concerns may extend further east into the central and eastern Dakotas, but confidence in sustained, widespread elevated conditions is more limited due to greater spread in deterministic/ensemble solutions. Morning surface observations in the lee of the VA/NC Appalachians are sampling rather dry conditions with RH values in the 20-30% range. Localized fire weather concerns are probable in the immediate lee of the higher terrain as a frontal surge increases winds to 10-15 mph (gusting upwards of 20 mph) this afternoon. However, confidence in the spatial coverage of this threat is limited away from terrain features. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0130 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern over the US will be dominated by a deep eastern trough with northwesterly mid-level flow across the central US and a cutoff low over the southwest US. A secondary speed max embedded in the large-scale flow should lead to a surface cyclone near the US-Canada border, which may result in a few areas of Elevated conditions across southeastern Montana and northeastern Wyoming. However, these areas are expected to be localized, and fuels have received some moisture in the last week. Elsewhere across the central US, a large anticyclone is expected to keep winds weak. For these reasons, no risk areas are introduced on this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1033 AM CDT Mon Mar 18 2024 Valid 181700Z - 191200Z An Elevated risk area is introduced for portions of southeast Montana, northeast Wyoming, and the far western Dakotas. Although morning guidance has initialized slightly too warm/dry compared to observations, high-resolution runs have captured recent wind speed trends fairly well. These solutions, supported by ensemble probabilities, suggests a reasonably high likelihood of sustained winds near 20 mph across the northern Plains this afternoon as a surface low deepens across southern Canada. Although confidence in reaching critical RH values is low, afternoon RH minimums near 25% appear probable within the downslope flow regime, and given ERC values between the 75-90th percentile, should support at least regional fire weather concerns. Fire weather concerns may extend further east into the central and eastern Dakotas, but confidence in sustained, widespread elevated conditions is more limited due to greater spread in deterministic/ensemble solutions. Morning surface observations in the lee of the VA/NC Appalachians are sampling rather dry conditions with RH values in the 20-30% range. Localized fire weather concerns are probable in the immediate lee of the higher terrain as a frontal surge increases winds to 10-15 mph (gusting upwards of 20 mph) this afternoon. However, confidence in the spatial coverage of this threat is limited away from terrain features. ..Moore.. 03/18/2024 .PREV DISCUSSION... /ISSUED 0130 AM CDT Mon Mar 18 2024/ ...Synopsis... The mid-level pattern over the US will be dominated by a deep eastern trough with northwesterly mid-level flow across the central US and a cutoff low over the southwest US. A secondary speed max embedded in the large-scale flow should lead to a surface cyclone near the US-Canada border, which may result in a few areas of Elevated conditions across southeastern Montana and northeastern Wyoming. However, these areas are expected to be localized, and fuels have received some moisture in the last week. Elsewhere across the central US, a large anticyclone is expected to keep winds weak. For these reasons, no risk areas are introduced on this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more