SPC Dec 5, 2023 1300 UTC Day 1 Convective Outlook

1 year 9 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Tue Dec 05 2023 Valid 051300Z - 061200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm areas are not expected through early Wednesday morning. ...Synopsis/Discussion... In mid/upper levels, a progressive and fairly well-amplified synoptic pattern will carry through the period, led by a strong trough moving across the eastern CONUS, and ridging over the Rockies and High Plains. A strong shortwave trough -- apparent in moisture- channel imagery over portions of WI/IL/MO -- will move eastward across the Appalachians tonight and through the larger-scale trough. Smaller shortwaves will move from northwestern ON across the Upper Great Lakes, and separately, southeastward rapidly from the northern Plains to the Ozarks and portions of the Southeast. Late this afternoon into evening, enough cooling aloft and residual low-level moisture will be in place to support around 100 J/kg MUCAPE ahead of the leading perturbation, in a corridor from southern OH to eastern TN. However, forecast soundings suggest buoyancy will remain below an optimal icing layer for lightning, though a rogue strike or two cannot be ruled out. Otherwise, a long-fetch, warm-advection conveyor ahead of the next Pacific trough will settle southward down the Northwest Coast, reaching northwesternmost CA around the end of the period. Lapse rates in this plume should remain too weak to support areas of thunderstorms. ..Edwards/Kerr.. 12/05/2023 Read more

SPC Dec 5, 2023 1300 UTC Day 1 Convective Outlook

1 year 9 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Tue Dec 05 2023 Valid 051300Z - 061200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm areas are not expected through early Wednesday morning. ...Synopsis/Discussion... In mid/upper levels, a progressive and fairly well-amplified synoptic pattern will carry through the period, led by a strong trough moving across the eastern CONUS, and ridging over the Rockies and High Plains. A strong shortwave trough -- apparent in moisture- channel imagery over portions of WI/IL/MO -- will move eastward across the Appalachians tonight and through the larger-scale trough. Smaller shortwaves will move from northwestern ON across the Upper Great Lakes, and separately, southeastward rapidly from the northern Plains to the Ozarks and portions of the Southeast. Late this afternoon into evening, enough cooling aloft and residual low-level moisture will be in place to support around 100 J/kg MUCAPE ahead of the leading perturbation, in a corridor from southern OH to eastern TN. However, forecast soundings suggest buoyancy will remain below an optimal icing layer for lightning, though a rogue strike or two cannot be ruled out. Otherwise, a long-fetch, warm-advection conveyor ahead of the next Pacific trough will settle southward down the Northwest Coast, reaching northwesternmost CA around the end of the period. Lapse rates in this plume should remain too weak to support areas of thunderstorms. ..Edwards/Kerr.. 12/05/2023 Read more

SPC Dec 5, 2023 1300 UTC Day 1 Convective Outlook

1 year 9 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Tue Dec 05 2023 Valid 051300Z - 061200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm areas are not expected through early Wednesday morning. ...Synopsis/Discussion... In mid/upper levels, a progressive and fairly well-amplified synoptic pattern will carry through the period, led by a strong trough moving across the eastern CONUS, and ridging over the Rockies and High Plains. A strong shortwave trough -- apparent in moisture- channel imagery over portions of WI/IL/MO -- will move eastward across the Appalachians tonight and through the larger-scale trough. Smaller shortwaves will move from northwestern ON across the Upper Great Lakes, and separately, southeastward rapidly from the northern Plains to the Ozarks and portions of the Southeast. Late this afternoon into evening, enough cooling aloft and residual low-level moisture will be in place to support around 100 J/kg MUCAPE ahead of the leading perturbation, in a corridor from southern OH to eastern TN. However, forecast soundings suggest buoyancy will remain below an optimal icing layer for lightning, though a rogue strike or two cannot be ruled out. Otherwise, a long-fetch, warm-advection conveyor ahead of the next Pacific trough will settle southward down the Northwest Coast, reaching northwesternmost CA around the end of the period. Lapse rates in this plume should remain too weak to support areas of thunderstorms. ..Edwards/Kerr.. 12/05/2023 Read more

SPC Dec 5, 2023 1300 UTC Day 1 Convective Outlook

1 year 9 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Tue Dec 05 2023 Valid 051300Z - 061200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm areas are not expected through early Wednesday morning. ...Synopsis/Discussion... In mid/upper levels, a progressive and fairly well-amplified synoptic pattern will carry through the period, led by a strong trough moving across the eastern CONUS, and ridging over the Rockies and High Plains. A strong shortwave trough -- apparent in moisture- channel imagery over portions of WI/IL/MO -- will move eastward across the Appalachians tonight and through the larger-scale trough. Smaller shortwaves will move from northwestern ON across the Upper Great Lakes, and separately, southeastward rapidly from the northern Plains to the Ozarks and portions of the Southeast. Late this afternoon into evening, enough cooling aloft and residual low-level moisture will be in place to support around 100 J/kg MUCAPE ahead of the leading perturbation, in a corridor from southern OH to eastern TN. However, forecast soundings suggest buoyancy will remain below an optimal icing layer for lightning, though a rogue strike or two cannot be ruled out. Otherwise, a long-fetch, warm-advection conveyor ahead of the next Pacific trough will settle southward down the Northwest Coast, reaching northwesternmost CA around the end of the period. Lapse rates in this plume should remain too weak to support areas of thunderstorms. ..Edwards/Kerr.. 12/05/2023 Read more

SPC Dec 5, 2023 Day 4-8 Severe Weather Outlook

1 year 9 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CST Tue Dec 05 2023 Valid 081200Z - 131200Z ...DISCUSSION... ...Ozarks/East TX to the Lower OH Valley/Deep South... The amplifying shortwave trough in the Great Basin vicinity at the start of D4 should become highly amplified over the central states and roughly centered across much of the MS Valley near 12Z/Sun. This scenario is widely supported by the 00Z ECMWF/GEFS ensemble means and deterministic ECMWF/UKMET/CMC runs. Poleward moisture transport from the western Gulf will displace an initially modified CP air mass with low-level warm theta-e advection becoming pronounced on D4/Fri night. This should result in mainly elevated thunderstorms within the strengthening warm conveyor near the developing surface cyclone in the Ozarks vicinity. A low-probability severe threat is apparent in this region south-southwest towards the Ark-La-Tex. Greater severe-weather potential should develop on D5/Sat during the day as mid to upper-level southwesterlies strengthen across the warm sector and instability is boosted by diurnal surface heating, centered on east TX towards the Ark-La-Miss. Convection will likely become widespread by afternoon. The potential for extensive overturning lowers confidence in the degree of north/east extent of the severe threat away from the highlighted 15 percent area. As such, a broad low-probability severe threat should be implied to the north/east from the Lower OH Valley to the Deep South. ...Southeast to Mid-Atlantic States... Potential exists for robust cyclogenesis to peak in the late D5 to D6 time frame on Sun across parts of the Midwest to Great Lakes. The 00Z deterministic ECMWF is particularly intense as the highly amplified upper trough across the MS Valley becomes negatively tilted over the East on D6/Sun. However, ensemble spread within the ECMWF/GEFS appears quite large regarding synoptic details, and this is coupled with a high likelihood of a thermodynamically limited warm sector given weak mid-level lapse rates and negligible to meager buoyancy. But with at least conditional potential for extreme low-level wind fields to potentially overlap upper 50s to mid 60s surface dew points, low severe probabilities appear warranted. Read more

SPC Dec 5, 2023 Day 4-8 Severe Weather Outlook

1 year 9 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CST Tue Dec 05 2023 Valid 081200Z - 131200Z ...DISCUSSION... ...Ozarks/East TX to the Lower OH Valley/Deep South... The amplifying shortwave trough in the Great Basin vicinity at the start of D4 should become highly amplified over the central states and roughly centered across much of the MS Valley near 12Z/Sun. This scenario is widely supported by the 00Z ECMWF/GEFS ensemble means and deterministic ECMWF/UKMET/CMC runs. Poleward moisture transport from the western Gulf will displace an initially modified CP air mass with low-level warm theta-e advection becoming pronounced on D4/Fri night. This should result in mainly elevated thunderstorms within the strengthening warm conveyor near the developing surface cyclone in the Ozarks vicinity. A low-probability severe threat is apparent in this region south-southwest towards the Ark-La-Tex. Greater severe-weather potential should develop on D5/Sat during the day as mid to upper-level southwesterlies strengthen across the warm sector and instability is boosted by diurnal surface heating, centered on east TX towards the Ark-La-Miss. Convection will likely become widespread by afternoon. The potential for extensive overturning lowers confidence in the degree of north/east extent of the severe threat away from the highlighted 15 percent area. As such, a broad low-probability severe threat should be implied to the north/east from the Lower OH Valley to the Deep South. ...Southeast to Mid-Atlantic States... Potential exists for robust cyclogenesis to peak in the late D5 to D6 time frame on Sun across parts of the Midwest to Great Lakes. The 00Z deterministic ECMWF is particularly intense as the highly amplified upper trough across the MS Valley becomes negatively tilted over the East on D6/Sun. However, ensemble spread within the ECMWF/GEFS appears quite large regarding synoptic details, and this is coupled with a high likelihood of a thermodynamically limited warm sector given weak mid-level lapse rates and negligible to meager buoyancy. But with at least conditional potential for extreme low-level wind fields to potentially overlap upper 50s to mid 60s surface dew points, low severe probabilities appear warranted. Read more

SPC Dec 5, 2023 Day 4-8 Severe Weather Outlook

1 year 9 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CST Tue Dec 05 2023 Valid 081200Z - 131200Z ...DISCUSSION... ...Ozarks/East TX to the Lower OH Valley/Deep South... The amplifying shortwave trough in the Great Basin vicinity at the start of D4 should become highly amplified over the central states and roughly centered across much of the MS Valley near 12Z/Sun. This scenario is widely supported by the 00Z ECMWF/GEFS ensemble means and deterministic ECMWF/UKMET/CMC runs. Poleward moisture transport from the western Gulf will displace an initially modified CP air mass with low-level warm theta-e advection becoming pronounced on D4/Fri night. This should result in mainly elevated thunderstorms within the strengthening warm conveyor near the developing surface cyclone in the Ozarks vicinity. A low-probability severe threat is apparent in this region south-southwest towards the Ark-La-Tex. Greater severe-weather potential should develop on D5/Sat during the day as mid to upper-level southwesterlies strengthen across the warm sector and instability is boosted by diurnal surface heating, centered on east TX towards the Ark-La-Miss. Convection will likely become widespread by afternoon. The potential for extensive overturning lowers confidence in the degree of north/east extent of the severe threat away from the highlighted 15 percent area. As such, a broad low-probability severe threat should be implied to the north/east from the Lower OH Valley to the Deep South. ...Southeast to Mid-Atlantic States... Potential exists for robust cyclogenesis to peak in the late D5 to D6 time frame on Sun across parts of the Midwest to Great Lakes. The 00Z deterministic ECMWF is particularly intense as the highly amplified upper trough across the MS Valley becomes negatively tilted over the East on D6/Sun. However, ensemble spread within the ECMWF/GEFS appears quite large regarding synoptic details, and this is coupled with a high likelihood of a thermodynamically limited warm sector given weak mid-level lapse rates and negligible to meager buoyancy. But with at least conditional potential for extreme low-level wind fields to potentially overlap upper 50s to mid 60s surface dew points, low severe probabilities appear warranted. Read more

SPC Dec 5, 2023 Day 4-8 Severe Weather Outlook

1 year 9 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CST Tue Dec 05 2023 Valid 081200Z - 131200Z ...DISCUSSION... ...Ozarks/East TX to the Lower OH Valley/Deep South... The amplifying shortwave trough in the Great Basin vicinity at the start of D4 should become highly amplified over the central states and roughly centered across much of the MS Valley near 12Z/Sun. This scenario is widely supported by the 00Z ECMWF/GEFS ensemble means and deterministic ECMWF/UKMET/CMC runs. Poleward moisture transport from the western Gulf will displace an initially modified CP air mass with low-level warm theta-e advection becoming pronounced on D4/Fri night. This should result in mainly elevated thunderstorms within the strengthening warm conveyor near the developing surface cyclone in the Ozarks vicinity. A low-probability severe threat is apparent in this region south-southwest towards the Ark-La-Tex. Greater severe-weather potential should develop on D5/Sat during the day as mid to upper-level southwesterlies strengthen across the warm sector and instability is boosted by diurnal surface heating, centered on east TX towards the Ark-La-Miss. Convection will likely become widespread by afternoon. The potential for extensive overturning lowers confidence in the degree of north/east extent of the severe threat away from the highlighted 15 percent area. As such, a broad low-probability severe threat should be implied to the north/east from the Lower OH Valley to the Deep South. ...Southeast to Mid-Atlantic States... Potential exists for robust cyclogenesis to peak in the late D5 to D6 time frame on Sun across parts of the Midwest to Great Lakes. The 00Z deterministic ECMWF is particularly intense as the highly amplified upper trough across the MS Valley becomes negatively tilted over the East on D6/Sun. However, ensemble spread within the ECMWF/GEFS appears quite large regarding synoptic details, and this is coupled with a high likelihood of a thermodynamically limited warm sector given weak mid-level lapse rates and negligible to meager buoyancy. But with at least conditional potential for extreme low-level wind fields to potentially overlap upper 50s to mid 60s surface dew points, low severe probabilities appear warranted. Read more

SPC Dec 5, 2023 Day 4-8 Severe Weather Outlook

1 year 9 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CST Tue Dec 05 2023 Valid 081200Z - 131200Z ...DISCUSSION... ...Ozarks/East TX to the Lower OH Valley/Deep South... The amplifying shortwave trough in the Great Basin vicinity at the start of D4 should become highly amplified over the central states and roughly centered across much of the MS Valley near 12Z/Sun. This scenario is widely supported by the 00Z ECMWF/GEFS ensemble means and deterministic ECMWF/UKMET/CMC runs. Poleward moisture transport from the western Gulf will displace an initially modified CP air mass with low-level warm theta-e advection becoming pronounced on D4/Fri night. This should result in mainly elevated thunderstorms within the strengthening warm conveyor near the developing surface cyclone in the Ozarks vicinity. A low-probability severe threat is apparent in this region south-southwest towards the Ark-La-Tex. Greater severe-weather potential should develop on D5/Sat during the day as mid to upper-level southwesterlies strengthen across the warm sector and instability is boosted by diurnal surface heating, centered on east TX towards the Ark-La-Miss. Convection will likely become widespread by afternoon. The potential for extensive overturning lowers confidence in the degree of north/east extent of the severe threat away from the highlighted 15 percent area. As such, a broad low-probability severe threat should be implied to the north/east from the Lower OH Valley to the Deep South. ...Southeast to Mid-Atlantic States... Potential exists for robust cyclogenesis to peak in the late D5 to D6 time frame on Sun across parts of the Midwest to Great Lakes. The 00Z deterministic ECMWF is particularly intense as the highly amplified upper trough across the MS Valley becomes negatively tilted over the East on D6/Sun. However, ensemble spread within the ECMWF/GEFS appears quite large regarding synoptic details, and this is coupled with a high likelihood of a thermodynamically limited warm sector given weak mid-level lapse rates and negligible to meager buoyancy. But with at least conditional potential for extreme low-level wind fields to potentially overlap upper 50s to mid 60s surface dew points, low severe probabilities appear warranted. Read more

SPC Dec 5, 2023 0830 UTC Day 3 Severe Thunderstorm Outlook

1 year 9 months ago
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0121 AM CST Tue Dec 05 2023 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Discussion... Thunderstorm potential will be negligible across much of the CONUS on Thursday. The lone exception will be over the Pacific Northwest, where sporadic lightning flashes are possible, mainly during the first half of the period near the coast. The next in a series of shortwave troughs will impinge on the Pacific Northwest coast on Thursday, before digging towards the northern Great Basin by Thursday night. Already steep 700-500 mb lapse rates in the wake of a trough passage on D2/Wednesday, will steepen further between 8 to 8.5 C/km as cold 500-mb temperatures from -30 to -35 C become common. This should compensate for gradually decreasing boundary-layer moisture with low 40s surface dew points holding along the coast through Thursday afternoon. Scant surface-based buoyancy is anticipated with multiple rounds of scattered low-topped convection. Similar to D2, sporadic lightning flashes will be possible, although focused somewhat farther north along the OR/WA coast and mainly in the morning to afternoon. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0830 UTC Day 3 Severe Thunderstorm Outlook

1 year 9 months ago
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0121 AM CST Tue Dec 05 2023 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Discussion... Thunderstorm potential will be negligible across much of the CONUS on Thursday. The lone exception will be over the Pacific Northwest, where sporadic lightning flashes are possible, mainly during the first half of the period near the coast. The next in a series of shortwave troughs will impinge on the Pacific Northwest coast on Thursday, before digging towards the northern Great Basin by Thursday night. Already steep 700-500 mb lapse rates in the wake of a trough passage on D2/Wednesday, will steepen further between 8 to 8.5 C/km as cold 500-mb temperatures from -30 to -35 C become common. This should compensate for gradually decreasing boundary-layer moisture with low 40s surface dew points holding along the coast through Thursday afternoon. Scant surface-based buoyancy is anticipated with multiple rounds of scattered low-topped convection. Similar to D2, sporadic lightning flashes will be possible, although focused somewhat farther north along the OR/WA coast and mainly in the morning to afternoon. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0830 UTC Day 3 Severe Thunderstorm Outlook

1 year 9 months ago
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0121 AM CST Tue Dec 05 2023 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Discussion... Thunderstorm potential will be negligible across much of the CONUS on Thursday. The lone exception will be over the Pacific Northwest, where sporadic lightning flashes are possible, mainly during the first half of the period near the coast. The next in a series of shortwave troughs will impinge on the Pacific Northwest coast on Thursday, before digging towards the northern Great Basin by Thursday night. Already steep 700-500 mb lapse rates in the wake of a trough passage on D2/Wednesday, will steepen further between 8 to 8.5 C/km as cold 500-mb temperatures from -30 to -35 C become common. This should compensate for gradually decreasing boundary-layer moisture with low 40s surface dew points holding along the coast through Thursday afternoon. Scant surface-based buoyancy is anticipated with multiple rounds of scattered low-topped convection. Similar to D2, sporadic lightning flashes will be possible, although focused somewhat farther north along the OR/WA coast and mainly in the morning to afternoon. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0830 UTC Day 3 Severe Thunderstorm Outlook

1 year 9 months ago
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0121 AM CST Tue Dec 05 2023 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Discussion... Thunderstorm potential will be negligible across much of the CONUS on Thursday. The lone exception will be over the Pacific Northwest, where sporadic lightning flashes are possible, mainly during the first half of the period near the coast. The next in a series of shortwave troughs will impinge on the Pacific Northwest coast on Thursday, before digging towards the northern Great Basin by Thursday night. Already steep 700-500 mb lapse rates in the wake of a trough passage on D2/Wednesday, will steepen further between 8 to 8.5 C/km as cold 500-mb temperatures from -30 to -35 C become common. This should compensate for gradually decreasing boundary-layer moisture with low 40s surface dew points holding along the coast through Thursday afternoon. Scant surface-based buoyancy is anticipated with multiple rounds of scattered low-topped convection. Similar to D2, sporadic lightning flashes will be possible, although focused somewhat farther north along the OR/WA coast and mainly in the morning to afternoon. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0700 UTC Day 2 Convective Outlook

1 year 9 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1142 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Discussion... Thunderstorm potential will remain negligible across much of the CONUS. Sporadic lightning flashes are possible over a portion of northern CA to coastal OR, mainly during the late afternoon and evening on Wednesday. A shortwave trough over the northeast Pacific will move inland across northern CA and the Northwest. In the wake of trough passage, cooler mid-level temperatures amid an expanding plume of steep lapse rates will overspread much of the Pacific Northwest. As this occurs, scant surface-based buoyancy should develop along coastal OR into a portion of northern CA towards late afternoon. 00Z HREF guidance suggests scattered low-topped convection will become common in this time frame, with the deepest convection capable of producing sporadic lightning flashes. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0700 UTC Day 2 Convective Outlook

1 year 9 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1142 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Discussion... Thunderstorm potential will remain negligible across much of the CONUS. Sporadic lightning flashes are possible over a portion of northern CA to coastal OR, mainly during the late afternoon and evening on Wednesday. A shortwave trough over the northeast Pacific will move inland across northern CA and the Northwest. In the wake of trough passage, cooler mid-level temperatures amid an expanding plume of steep lapse rates will overspread much of the Pacific Northwest. As this occurs, scant surface-based buoyancy should develop along coastal OR into a portion of northern CA towards late afternoon. 00Z HREF guidance suggests scattered low-topped convection will become common in this time frame, with the deepest convection capable of producing sporadic lightning flashes. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0700 UTC Day 2 Convective Outlook

1 year 9 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1142 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Discussion... Thunderstorm potential will remain negligible across much of the CONUS. Sporadic lightning flashes are possible over a portion of northern CA to coastal OR, mainly during the late afternoon and evening on Wednesday. A shortwave trough over the northeast Pacific will move inland across northern CA and the Northwest. In the wake of trough passage, cooler mid-level temperatures amid an expanding plume of steep lapse rates will overspread much of the Pacific Northwest. As this occurs, scant surface-based buoyancy should develop along coastal OR into a portion of northern CA towards late afternoon. 00Z HREF guidance suggests scattered low-topped convection will become common in this time frame, with the deepest convection capable of producing sporadic lightning flashes. ..Grams.. 12/05/2023 Read more

SPC Dec 5, 2023 0700 UTC Day 2 Convective Outlook

1 year 9 months ago
SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1142 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Discussion... Thunderstorm potential will remain negligible across much of the CONUS. Sporadic lightning flashes are possible over a portion of northern CA to coastal OR, mainly during the late afternoon and evening on Wednesday. A shortwave trough over the northeast Pacific will move inland across northern CA and the Northwest. In the wake of trough passage, cooler mid-level temperatures amid an expanding plume of steep lapse rates will overspread much of the Pacific Northwest. As this occurs, scant surface-based buoyancy should develop along coastal OR into a portion of northern CA towards late afternoon. 00Z HREF guidance suggests scattered low-topped convection will become common in this time frame, with the deepest convection capable of producing sporadic lightning flashes. ..Grams.. 12/05/2023 Read more

SPC Day 2 Fire Weather Outlook

1 year 9 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1122 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO CRITICAL AREAS... ...Synopsis... The upper-level ridge will continue to shift eastward into the Missouri/Mississippi Valley regions on Wednesday. A trough will begin to develop into the West once again, but will be relatively ill-defined initially. At the surface, a combination of a modestly intensifying surface high in the Southeast and broad surface low pressure in the northern Rockies southward into the High Plains will increase the pressure gradient within parts of the Plains. Gusty south/southwest winds are possible from the southern High Plains into the central Plains and parts of the Upper Midwest. Temperatures should remain rather cool farther north and keep RH elevated. Warmer temperatures are expected farther south and within areas of stronger downslope winds. Pockets of locally elevated fire weather are possible in the southern High Plains and perhaps parts of southeast Wyoming should sufficiently dry fine fuels exist. ..Wendt.. 12/05/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

1 year 9 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1122 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO CRITICAL AREAS... ...Synopsis... The upper-level ridge will continue to shift eastward into the Missouri/Mississippi Valley regions on Wednesday. A trough will begin to develop into the West once again, but will be relatively ill-defined initially. At the surface, a combination of a modestly intensifying surface high in the Southeast and broad surface low pressure in the northern Rockies southward into the High Plains will increase the pressure gradient within parts of the Plains. Gusty south/southwest winds are possible from the southern High Plains into the central Plains and parts of the Upper Midwest. Temperatures should remain rather cool farther north and keep RH elevated. Warmer temperatures are expected farther south and within areas of stronger downslope winds. Pockets of locally elevated fire weather are possible in the southern High Plains and perhaps parts of southeast Wyoming should sufficiently dry fine fuels exist. ..Wendt.. 12/05/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

1 year 9 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1122 PM CST Mon Dec 04 2023 Valid 061200Z - 071200Z ...NO CRITICAL AREAS... ...Synopsis... The upper-level ridge will continue to shift eastward into the Missouri/Mississippi Valley regions on Wednesday. A trough will begin to develop into the West once again, but will be relatively ill-defined initially. At the surface, a combination of a modestly intensifying surface high in the Southeast and broad surface low pressure in the northern Rockies southward into the High Plains will increase the pressure gradient within parts of the Plains. Gusty south/southwest winds are possible from the southern High Plains into the central Plains and parts of the Upper Midwest. Temperatures should remain rather cool farther north and keep RH elevated. Warmer temperatures are expected farther south and within areas of stronger downslope winds. Pockets of locally elevated fire weather are possible in the southern High Plains and perhaps parts of southeast Wyoming should sufficiently dry fine fuels exist. ..Wendt.. 12/05/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more