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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0356 PM CST Mon Feb 19 2024 Valid 211200Z - 271200Z Periods of dry and windy conditions will be possible through the extended period D3/Wednesday through D4/Thursday and potentially D8/Monday, with some drying of fuels anticipated across the southern High Plains (especially on D3/Wednesday). On D3/Wednesday, the Pacific trough will move inland across the western US, with enhanced flow aloft overspreading the southern Rockies. As a result, lee cyclogenesis will favor strong westerly surface winds and low RH across the southern High Plains. Recent fuel analysis indicates that fuels across eastern New Mexico will support inclusion of 40 percent probabilities on Wednesday where afternoon relative humidity reductions to 15-20 percent will overlap sustained winds 20-30 mph. Fuels remain around the 50th percentile but as further drying occurs are expected to support some risk of increased fire potential. Dry and windy conditions will extend into the Texas Panhandle, southwest Texas, and far eastern Texas. Fuels within this region have received more recent rain and snowfall and remain less receptive to fire spread. Poor recovery is likely overnight D3/Wednesday - D4/Thursday across southwestern and far western Texas, with breezy post frontal northwesterly flow overlapping elevated to critical relative humidity again Thursday afternoon. The best overlap of windy/dry conditions will overlap unreceptive fuels across southwest Texas precluding the need for probabilities at this time. An upper-level ridge will build in across the western US with downstream troughing across the east D4-Friday through D7-Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. Late D7/Sunday into D8/Monday an upper-level low will begin to phase with the Polar jet stream and move eastward, with a belt of enhanced westerly flow aloft overspreading the Rockies and potential for lee trough development. This pattern will favor a return of windy/dry westerly downslope flow into the central/southern Plains. ..Thornton.. 02/19/2024 ...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 0356 PM CST Mon Feb 19 2024 Valid 211200Z - 271200Z Periods of dry and windy conditions will be possible through the extended period D3/Wednesday through D4/Thursday and potentially D8/Monday, with some drying of fuels anticipated across the southern High Plains (especially on D3/Wednesday). On D3/Wednesday, the Pacific trough will move inland across the western US, with enhanced flow aloft overspreading the southern Rockies. As a result, lee cyclogenesis will favor strong westerly surface winds and low RH across the southern High Plains. Recent fuel analysis indicates that fuels across eastern New Mexico will support inclusion of 40 percent probabilities on Wednesday where afternoon relative humidity reductions to 15-20 percent will overlap sustained winds 20-30 mph. Fuels remain around the 50th percentile but as further drying occurs are expected to support some risk of increased fire potential. Dry and windy conditions will extend into the Texas Panhandle, southwest Texas, and far eastern Texas. Fuels within this region have received more recent rain and snowfall and remain less receptive to fire spread. Poor recovery is likely overnight D3/Wednesday - D4/Thursday across southwestern and far western Texas, with breezy post frontal northwesterly flow overlapping elevated to critical relative humidity again Thursday afternoon. The best overlap of windy/dry conditions will overlap unreceptive fuels across southwest Texas precluding the need for probabilities at this time. An upper-level ridge will build in across the western US with downstream troughing across the east D4-Friday through D7-Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. Late D7/Sunday into D8/Monday an upper-level low will begin to phase with the Polar jet stream and move eastward, with a belt of enhanced westerly flow aloft overspreading the Rockies and potential for lee trough development. This pattern will favor a return of windy/dry westerly downslope flow into the central/southern Plains. ..Thornton.. 02/19/2024 ...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 0356 PM CST Mon Feb 19 2024 Valid 211200Z - 271200Z Periods of dry and windy conditions will be possible through the extended period D3/Wednesday through D4/Thursday and potentially D8/Monday, with some drying of fuels anticipated across the southern High Plains (especially on D3/Wednesday). On D3/Wednesday, the Pacific trough will move inland across the western US, with enhanced flow aloft overspreading the southern Rockies. As a result, lee cyclogenesis will favor strong westerly surface winds and low RH across the southern High Plains. Recent fuel analysis indicates that fuels across eastern New Mexico will support inclusion of 40 percent probabilities on Wednesday where afternoon relative humidity reductions to 15-20 percent will overlap sustained winds 20-30 mph. Fuels remain around the 50th percentile but as further drying occurs are expected to support some risk of increased fire potential. Dry and windy conditions will extend into the Texas Panhandle, southwest Texas, and far eastern Texas. Fuels within this region have received more recent rain and snowfall and remain less receptive to fire spread. Poor recovery is likely overnight D3/Wednesday - D4/Thursday across southwestern and far western Texas, with breezy post frontal northwesterly flow overlapping elevated to critical relative humidity again Thursday afternoon. The best overlap of windy/dry conditions will overlap unreceptive fuels across southwest Texas precluding the need for probabilities at this time. An upper-level ridge will build in across the western US with downstream troughing across the east D4-Friday through D7-Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. Late D7/Sunday into D8/Monday an upper-level low will begin to phase with the Polar jet stream and move eastward, with a belt of enhanced westerly flow aloft overspreading the Rockies and potential for lee trough development. This pattern will favor a return of windy/dry westerly downslope flow into the central/southern Plains. ..Thornton.. 02/19/2024 ...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 0356 PM CST Mon Feb 19 2024 Valid 211200Z - 271200Z Periods of dry and windy conditions will be possible through the extended period D3/Wednesday through D4/Thursday and potentially D8/Monday, with some drying of fuels anticipated across the southern High Plains (especially on D3/Wednesday). On D3/Wednesday, the Pacific trough will move inland across the western US, with enhanced flow aloft overspreading the southern Rockies. As a result, lee cyclogenesis will favor strong westerly surface winds and low RH across the southern High Plains. Recent fuel analysis indicates that fuels across eastern New Mexico will support inclusion of 40 percent probabilities on Wednesday where afternoon relative humidity reductions to 15-20 percent will overlap sustained winds 20-30 mph. Fuels remain around the 50th percentile but as further drying occurs are expected to support some risk of increased fire potential. Dry and windy conditions will extend into the Texas Panhandle, southwest Texas, and far eastern Texas. Fuels within this region have received more recent rain and snowfall and remain less receptive to fire spread. Poor recovery is likely overnight D3/Wednesday - D4/Thursday across southwestern and far western Texas, with breezy post frontal northwesterly flow overlapping elevated to critical relative humidity again Thursday afternoon. The best overlap of windy/dry conditions will overlap unreceptive fuels across southwest Texas precluding the need for probabilities at this time. An upper-level ridge will build in across the western US with downstream troughing across the east D4-Friday through D7-Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. Late D7/Sunday into D8/Monday an upper-level low will begin to phase with the Polar jet stream and move eastward, with a belt of enhanced westerly flow aloft overspreading the Rockies and potential for lee trough development. This pattern will favor a return of windy/dry westerly downslope flow into the central/southern Plains. ..Thornton.. 02/19/2024 ...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 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Mon Feb 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EVENING ACROSS INTERIOR NORTHERN CALIFORNIA... ...SUMMARY... A couple of strong storms may impact parts of the Sacramento Valley by late this afternoon, and perhaps pose at least some risk for producing a tornado or two. ...20Z Update... There has been some adjustment to the outlook, mainly to account for the progression of the synoptic/sub-synoptic features and ongoing trends concerning instability. The occluding offshore cyclone (roughly centered near or northeast of 40N/130W at 19Z) is in the process of gradually weakening. Stronger mid-level height falls are also weakening, and spreading northeast/east of the southern Cascades and northern Sierra Nevada. However, flow appears to remain moderately strong and southerly (near or above 40 kt) around 850 mb across much of the Sacramento Valley, and this is contributing sizable clockwise-curved low-level hodographs, as insolation contributes to at least weak boundary-layer destabilization beneath modestly cold mid-level temperatures. It is not clear that forcing for ascent will support more than one or two boundary-layer based storms over the Sacramento Valley late this afternoon and evening, but the environment still appears conditionally conducive to a low-topped supercell with the potential to produce a brief tornado or two. ..Kerr.. 02/19/2024 .PREV DISCUSSION... /ISSUED 1021 AM CST Mon Feb 19 2024/ ...Synopsis... A pronounced mid-level trough and associated surface low continue to impinge on the West Coast, supporting a continued northward transport of moisture over California into southern portions of the Pacific Northwest. 12Z observed soundings for sites along the California coast already show cooler mid-level temperatures overspreading inland, suggesting that marginal buoyancy should already be present across central into northern CA. With time, insolation will support locally higher amounts of buoyancy amid a highly sheared environment to support low-topped but organized thunderstorms capable of producing severe hazards over portions of central into northern CA this afternoon. ...Portions of central into northern CA... Low-level warm-air advection has encouraged surface temperatures to warm into the mid 50s F across southern portions of the Sacramento Valley prior to diurnal heating. By afternoon, 52-54 F surface dewpoints beneath 7.5+ C/km mid-level lapse rates will boost tall but thin SBCAPE to the 500-750 J/kg range. The BBX VAD currently depicts a sizable, curved low-level hodograph, with over 300 m2/s2 of 0-3 km SRH, and these favorable low-level shear trends are expected to persist through the day as the surface low continues to meander just offshore. Modifying RAP forecast soundings suggest that surface dewpoints need to rise at least into the 53-54F range to support efficient ingesting of SRH for tornadogenesis. It is unclear how widespread 53-54 F dewpoints will become by afternoon, with the tornado threat more conditional on these dewpoints being realized. Nonetheless, a couple of low-topped supercells are possible this afternoon, likely accompanied by at least a marginal severe hail/wind threat. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 0151 PM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/19/2024 .PREV DISCUSSION... /ISSUED 0108 AM CST Mon Feb 19 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for Tuesday, though regional concerns may emerge across portions of eastern New Mexico and west Texas. The upper ridge currently across the Great Basin/Four Corners is forecast to shift east to the southern Rockies by Tuesday afternoon. While the approach of the ridge will suppress the development of a strong lee trough, increasing zonal flow over the terrain will promote breezy westerly downslope winds. Latest ensemble guidance suggests sustained winds around 20 mph may gust up to 30 mph in the lee of more prominent terrain features. These winds, coupled with diurnal RH reductions into the low 20s, may support pockets of elevated fire weather conditions. This potential appears most likely to occur across eastern NM in the lee of the Sangre De Cristo and Sandia Manzano mountains where terrain influences will support breezier winds. Drier/windier solutions hint that these conditions may extend as far east as west TX, but a dry bias has been noted over the past 24 hours in recent RAP/HRRR runs, which casts uncertainty onto the likelihood of observing elevated fire weather conditions of appreciable extent and duration. Furthermore, fuels across much of the southern High Plains remain only marginally dry, with ERC values near or below the 50th percentile for most locations. ...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 1117 AM CST Mon Feb 19 2024 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Widely scattered, generally weak, thunderstorm activity is possible Tuesday into Tuesday night across parts of Pacific Coast states into Great Basin, with little risk for severe weather. ...Discussion... Models indicate that an initially broad and deep cyclone will undergo substantive further weakening later today through late Tuesday night, while migrating northward offshore of the Pacific coast, toward the Vancouver Island/coastal Washington vicinity. Upstream, a significant short wave trough is forecast to gradually split to the southeast of the Aleutians, with the more vigorous southern perturbation beginning to dig through the mid-latitude eastern Pacific. As this occurs, a weak downstream mid-level high may attempt to form near the northern British Columbia coast, while remnant mid-level troughing in the branch of westerlies across the southern mid- and subtropical latitudes begins to progress inland of the Pacific coast. Farther east, large-scale mid-level ridging appears likely to shift across and east of the southern Rockies and northern Mexican plateau, while downstream troughing shifts offshore of the southern Atlantic Seaboard. This regime may undergo some further amplification, with perhaps renewed surface cyclogenesis commencing across the southwestern Atlantic by the end of the period. Low-level cooling and drying in the wake of the lead mid-level troughing has stabilized much of the Gulf of Mexico. While models do suggest that modest modification may commence in at least a narrow corridor across the western Gulf of Mexico into northwestern Gulf coastal areas, it appears that the moistening boundary-layer will remain shallow, and strongly capped by warm eastward advecting lower/mid-tropospheric air. Across the Pacific coast into the Great Basin, ongoing low/mid-level moistening, coupled with continuing cooling aloft through the day Tuesday, may contribute to sufficient destabilization with daytime heating to support widely scattered convection capable of producing lightning. However, latest model output generally suggests that the higher probabilities for thunderstorm development will be focused near the mid-level cold core offshore the southern California/northern Baja coast, before approaching coastal areas late Tuesday night. ..Kerr.. 02/19/2024 Read more