Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0401 AM CDT Sun Apr 07 2024 Valid 101200Z - 151200Z ...DISCUSSION... An active severe weather pattern across the South should persist through mid-week. ...D4-5... Primary feature of interest will be a southern-stream shortwave trough over the west TX vicinity at 12Z Wednesday. Non-GFS/GEFS guidance continues to indicate a slower eastward progression through Thursday. This shortwave impulse should phase into a broader upper trough being carved out as a northern-stream wave digs into the Upper Midwest to Midwest. This will yield substantial flow amplification through the troposphere, mainly late Wednesday into Thursday across the East. However, the overall thermodynamic environment should become increasingly limited. Widespread convection is expected to be ongoing across the central Gulf Coast States early Wednesday within a stout low-level warm theta-e advection regime. This will undoubtedly hamper downstream destabilization to the northeast on D4. But on the southern flank of this convective plume, strong low-level shear will foster some tornado/wind risk. Guidance such as the 00Z ECMWF and UKMET do indicate appreciable diurnal destabilization in its wake over at least the Sabine Valley to Ark-La-Miss vicinity just ahead of the surface cyclone track. The 00Z ECMWF ensemble still indicates a fair degree of spread on where the cyclone should be by Wednesday evening, from LA to the Mid-South. As such, have maintained a relatively broad 15% area, especially given the intensifying flow fields supporting tornado/wind potential persisting into Wednesday night. Lower-level winds should become very strong by Thursday morning yielding a high shear-low CAPE environment across at least a part of the Southeast into Thursday afternoon. This region appears to have the best chance of adequate boundary-layer heating to support at least a damaging wind threat before the convective band shifts off the South Atlantic Coast. Still, strong to very strong low-level flow will also exist farther north into the Upper OH Valley and Mid-Atlantic States where a lower-probability area-of-interest remains evident for D5. ...D6-8... In the wake of the amplified upper trough departing the East, severe potential should be low for a couple days. Air mass modification should ensue towards next weekend from the western Gulf northward across the Great Plains. Indications of the next shortwave trough ejecting eastward in the West may increase severe potential into a portion of the Plains towards D8. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0401 AM CDT Sun Apr 07 2024 Valid 101200Z - 151200Z ...DISCUSSION... An active severe weather pattern across the South should persist through mid-week. ...D4-5... Primary feature of interest will be a southern-stream shortwave trough over the west TX vicinity at 12Z Wednesday. Non-GFS/GEFS guidance continues to indicate a slower eastward progression through Thursday. This shortwave impulse should phase into a broader upper trough being carved out as a northern-stream wave digs into the Upper Midwest to Midwest. This will yield substantial flow amplification through the troposphere, mainly late Wednesday into Thursday across the East. However, the overall thermodynamic environment should become increasingly limited. Widespread convection is expected to be ongoing across the central Gulf Coast States early Wednesday within a stout low-level warm theta-e advection regime. This will undoubtedly hamper downstream destabilization to the northeast on D4. But on the southern flank of this convective plume, strong low-level shear will foster some tornado/wind risk. Guidance such as the 00Z ECMWF and UKMET do indicate appreciable diurnal destabilization in its wake over at least the Sabine Valley to Ark-La-Miss vicinity just ahead of the surface cyclone track. The 00Z ECMWF ensemble still indicates a fair degree of spread on where the cyclone should be by Wednesday evening, from LA to the Mid-South. As such, have maintained a relatively broad 15% area, especially given the intensifying flow fields supporting tornado/wind potential persisting into Wednesday night. Lower-level winds should become very strong by Thursday morning yielding a high shear-low CAPE environment across at least a part of the Southeast into Thursday afternoon. This region appears to have the best chance of adequate boundary-layer heating to support at least a damaging wind threat before the convective band shifts off the South Atlantic Coast. Still, strong to very strong low-level flow will also exist farther north into the Upper OH Valley and Mid-Atlantic States where a lower-probability area-of-interest remains evident for D5. ...D6-8... In the wake of the amplified upper trough departing the East, severe potential should be low for a couple days. Air mass modification should ensue towards next weekend from the western Gulf northward across the Great Plains. Indications of the next shortwave trough ejecting eastward in the West may increase severe potential into a portion of the Plains towards D8. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun Apr 07 2024 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST TX TO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are probable on Tuesday across most of Texas to the Red and Lower Mississippi River Valleys. A few tornadoes, significant large hail, and damaging winds are possible. ...Synopsis... A shortwave trough centered near the AZ/NM/northwest Mexico border area at 12Z Tuesday will likely move gradually eastward into west TX by early Wednesday. Two separate mid-level speed maxes, one curling through the base of the trough and another farther east closer to the northwest Gulf Coast will gradually translate eastward. Primary surface cyclone should become established over the Lower Rio Grande Valley beneath the eastern jet, and eventually drift along a portion of the TX Gulf Coast. ...TX/LA vicinity... Several rounds of deep convection are expected across a large portion of TX towards the Ark-La-Tex and Lower MS Valley vicinity during the period. Greater severe weather probabilities may be needed in later outlooks as mesoscale convective details become more clear. For now, have highlighted a broad cat 2-SLGT risk with an embedded significant severe area. Overall convective evolution appears to be messy. Primary convective coverage during the day will likely be tied to the persistent low-level warm theta-e advection regime, with regenerative periods of convection continuing through the period. Upper-level winds are progged to be weaker relative to D2-Monday, suggesting that cluster/MCS modes will likely dominate. Nevertheless, a feed of steep mid-level lapse rates will be maintained in convectively undisturbed areas and strong deep-layer shear will persist for embedded supercells. Favorable low-level shear should largely remain focused across the northwest Gulf into the Ark-La-Miss. With signals for robust surface heating in parts of south-southeast TX in the afternoon, the greatest tornado potential may exist into east-southeast TX and far western LA on Tuesday evening. Farther west, convection tied closer to the mid-level shortwave trough and surface trough/dryline should redevelop Tuesday afternoon in west TX. This activity should persist and/or separately develop into central TX Tuesday night. A mix of significant large hail and severe wind gusts should be the primary hazards within this regime. ..Grams.. 04/07/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun Apr 07 2024 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST TX TO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are probable on Tuesday across most of Texas to the Red and Lower Mississippi River Valleys. A few tornadoes, significant large hail, and damaging winds are possible. ...Synopsis... A shortwave trough centered near the AZ/NM/northwest Mexico border area at 12Z Tuesday will likely move gradually eastward into west TX by early Wednesday. Two separate mid-level speed maxes, one curling through the base of the trough and another farther east closer to the northwest Gulf Coast will gradually translate eastward. Primary surface cyclone should become established over the Lower Rio Grande Valley beneath the eastern jet, and eventually drift along a portion of the TX Gulf Coast. ...TX/LA vicinity... Several rounds of deep convection are expected across a large portion of TX towards the Ark-La-Tex and Lower MS Valley vicinity during the period. Greater severe weather probabilities may be needed in later outlooks as mesoscale convective details become more clear. For now, have highlighted a broad cat 2-SLGT risk with an embedded significant severe area. Overall convective evolution appears to be messy. Primary convective coverage during the day will likely be tied to the persistent low-level warm theta-e advection regime, with regenerative periods of convection continuing through the period. Upper-level winds are progged to be weaker relative to D2-Monday, suggesting that cluster/MCS modes will likely dominate. Nevertheless, a feed of steep mid-level lapse rates will be maintained in convectively undisturbed areas and strong deep-layer shear will persist for embedded supercells. Favorable low-level shear should largely remain focused across the northwest Gulf into the Ark-La-Miss. With signals for robust surface heating in parts of south-southeast TX in the afternoon, the greatest tornado potential may exist into east-southeast TX and far western LA on Tuesday evening. Farther west, convection tied closer to the mid-level shortwave trough and surface trough/dryline should redevelop Tuesday afternoon in west TX. This activity should persist and/or separately develop into central TX Tuesday night. A mix of significant large hail and severe wind gusts should be the primary hazards within this regime. ..Grams.. 04/07/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun Apr 07 2024 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST TX TO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are probable on Tuesday across most of Texas to the Red and Lower Mississippi River Valleys. A few tornadoes, significant large hail, and damaging winds are possible. ...Synopsis... A shortwave trough centered near the AZ/NM/northwest Mexico border area at 12Z Tuesday will likely move gradually eastward into west TX by early Wednesday. Two separate mid-level speed maxes, one curling through the base of the trough and another farther east closer to the northwest Gulf Coast will gradually translate eastward. Primary surface cyclone should become established over the Lower Rio Grande Valley beneath the eastern jet, and eventually drift along a portion of the TX Gulf Coast. ...TX/LA vicinity... Several rounds of deep convection are expected across a large portion of TX towards the Ark-La-Tex and Lower MS Valley vicinity during the period. Greater severe weather probabilities may be needed in later outlooks as mesoscale convective details become more clear. For now, have highlighted a broad cat 2-SLGT risk with an embedded significant severe area. Overall convective evolution appears to be messy. Primary convective coverage during the day will likely be tied to the persistent low-level warm theta-e advection regime, with regenerative periods of convection continuing through the period. Upper-level winds are progged to be weaker relative to D2-Monday, suggesting that cluster/MCS modes will likely dominate. Nevertheless, a feed of steep mid-level lapse rates will be maintained in convectively undisturbed areas and strong deep-layer shear will persist for embedded supercells. Favorable low-level shear should largely remain focused across the northwest Gulf into the Ark-La-Miss. With signals for robust surface heating in parts of south-southeast TX in the afternoon, the greatest tornado potential may exist into east-southeast TX and far western LA on Tuesday evening. Farther west, convection tied closer to the mid-level shortwave trough and surface trough/dryline should redevelop Tuesday afternoon in west TX. This activity should persist and/or separately develop into central TX Tuesday night. A mix of significant large hail and severe wind gusts should be the primary hazards within this regime. ..Grams.. 04/07/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun Apr 07 2024 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST TX TO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe thunderstorms are probable on Tuesday across most of Texas to the Red and Lower Mississippi River Valleys. A few tornadoes, significant large hail, and damaging winds are possible. ...Synopsis... A shortwave trough centered near the AZ/NM/northwest Mexico border area at 12Z Tuesday will likely move gradually eastward into west TX by early Wednesday. Two separate mid-level speed maxes, one curling through the base of the trough and another farther east closer to the northwest Gulf Coast will gradually translate eastward. Primary surface cyclone should become established over the Lower Rio Grande Valley beneath the eastern jet, and eventually drift along a portion of the TX Gulf Coast. ...TX/LA vicinity... Several rounds of deep convection are expected across a large portion of TX towards the Ark-La-Tex and Lower MS Valley vicinity during the period. Greater severe weather probabilities may be needed in later outlooks as mesoscale convective details become more clear. For now, have highlighted a broad cat 2-SLGT risk with an embedded significant severe area. Overall convective evolution appears to be messy. Primary convective coverage during the day will likely be tied to the persistent low-level warm theta-e advection regime, with regenerative periods of convection continuing through the period. Upper-level winds are progged to be weaker relative to D2-Monday, suggesting that cluster/MCS modes will likely dominate. Nevertheless, a feed of steep mid-level lapse rates will be maintained in convectively undisturbed areas and strong deep-layer shear will persist for embedded supercells. Favorable low-level shear should largely remain focused across the northwest Gulf into the Ark-La-Miss. With signals for robust surface heating in parts of south-southeast TX in the afternoon, the greatest tornado potential may exist into east-southeast TX and far western LA on Tuesday evening. Farther west, convection tied closer to the mid-level shortwave trough and surface trough/dryline should redevelop Tuesday afternoon in west TX. This activity should persist and/or separately develop into central TX Tuesday night. A mix of significant large hail and severe wind gusts should be the primary hazards within this regime. ..Grams.. 04/07/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0121 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST NEW MEXICO INTO WEST TEXAS... ...Synopsis... On Monday, a mid-level trough will amplify across the Southwest into northern Mexico. Moderate mid-level flow ahead of this trough will overspread the southern High Plains. Given the environment in this region will be deeply mixed, some of this stronger mid-level flow should reach the surface with 20+ mph sustained surface winds expected amid single digit relative humidity. Critically dry fuels in this region will support a large fire threat given the meteorological conditions. ..Bentley.. 04/07/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0121 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST NEW MEXICO INTO WEST TEXAS... ...Synopsis... On Monday, a mid-level trough will amplify across the Southwest into northern Mexico. Moderate mid-level flow ahead of this trough will overspread the southern High Plains. Given the environment in this region will be deeply mixed, some of this stronger mid-level flow should reach the surface with 20+ mph sustained surface winds expected amid single digit relative humidity. Critically dry fuels in this region will support a large fire threat given the meteorological conditions. ..Bentley.. 04/07/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0121 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST NEW MEXICO INTO WEST TEXAS... ...Synopsis... On Monday, a mid-level trough will amplify across the Southwest into northern Mexico. Moderate mid-level flow ahead of this trough will overspread the southern High Plains. Given the environment in this region will be deeply mixed, some of this stronger mid-level flow should reach the surface with 20+ mph sustained surface winds expected amid single digit relative humidity. Critically dry fuels in this region will support a large fire threat given the meteorological conditions. ..Bentley.. 04/07/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0121 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST NEW MEXICO INTO WEST TEXAS... ...Synopsis... On Monday, a mid-level trough will amplify across the Southwest into northern Mexico. Moderate mid-level flow ahead of this trough will overspread the southern High Plains. Given the environment in this region will be deeply mixed, some of this stronger mid-level flow should reach the surface with 20+ mph sustained surface winds expected amid single digit relative humidity. Critically dry fuels in this region will support a large fire threat given the meteorological conditions. ..Bentley.. 04/07/2024 ...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 0120 AM CDT Sun Apr 07 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO INTO WEST TEXAS... ...Synopsis... A strong surface low across central Nebraska will weaken as it moves east today. Despite the weakening, a strong pressure gradient is expected across much of the Plains and into the southern High Plains. In addition, a deeply mixed atmosphere is expected beneath strong mid-level flow. Therefore, 20 to 25 mph winds are expected with relative humidity in the single digits. An extended period of dry and windy conditions in the southern High Plains has dried fuels substantially in this region. As a result, large fires will be possible today. ..Bentley.. 04/07/2024 ...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 0120 AM CDT Sun Apr 07 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO INTO WEST TEXAS... ...Synopsis... A strong surface low across central Nebraska will weaken as it moves east today. Despite the weakening, a strong pressure gradient is expected across much of the Plains and into the southern High Plains. In addition, a deeply mixed atmosphere is expected beneath strong mid-level flow. Therefore, 20 to 25 mph winds are expected with relative humidity in the single digits. An extended period of dry and windy conditions in the southern High Plains has dried fuels substantially in this region. As a result, large fires will be possible today. ..Bentley.. 04/07/2024 ...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 0120 AM CDT Sun Apr 07 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO INTO WEST TEXAS... ...Synopsis... A strong surface low across central Nebraska will weaken as it moves east today. Despite the weakening, a strong pressure gradient is expected across much of the Plains and into the southern High Plains. In addition, a deeply mixed atmosphere is expected beneath strong mid-level flow. Therefore, 20 to 25 mph winds are expected with relative humidity in the single digits. An extended period of dry and windy conditions in the southern High Plains has dried fuels substantially in this region. As a result, large fires will be possible today. ..Bentley.. 04/07/2024 ...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 0120 AM CDT Sun Apr 07 2024 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO INTO WEST TEXAS... ...Synopsis... A strong surface low across central Nebraska will weaken as it moves east today. Despite the weakening, a strong pressure gradient is expected across much of the Plains and into the southern High Plains. In addition, a deeply mixed atmosphere is expected beneath strong mid-level flow. Therefore, 20 to 25 mph winds are expected with relative humidity in the single digits. An extended period of dry and windy conditions in the southern High Plains has dried fuels substantially in this region. As a result, large fires will be possible today. ..Bentley.. 04/07/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS... ...SUMMARY... Multiple rounds of severe thunderstorms should develop from early afternoon Monday through Tuesday morning across a large portion of Texas, into south Oklahoma, southwest Arkansas, and west Louisiana. A few tornadoes, scattered large to very large hail, and isolated severe wind gusts will be possible. ...Synopsis... A mid/upper low will drift east-northeast across the Upper Midwest while a separate shortwave trough digs over the Southwest before pivoting along the border with northwest Mexico. Low-level warm theta-e advection will persist across much of the South-Central States through the period. The primary low-level jet will be centered from the northwest Gulf across east TX into the Ark-La-Tex and Ark-La-Miss. Mid-level height falls attendant to the Southwest trough will increase across the west TX vicinity in the early morning Tuesday. ...Southern Great Plains... Strengthening low-level warm theta-e advection from the northwest Gulf should yield increasing thunderstorm coverage by early afternoon, along the northeast periphery of an intensifying elevated mixed layer across west/central TX. Guidance does differ with how far west and south this initial convection will develop into central TX, but a favorable environment for at least a few supercells should evolve from near the I-35 corridor across a portion of east TX. The impinging of steep mid-level lapse rates and very fast upper-level flow will foster an elongated hodograph within the largest portion of the buoyancy profile. This will support a threat for very large hail, generally favored along the southwest part of the overall convective plume as a cluster convective mode dominates with northern extent. Low-level hodograph curvature will also be sufficient for a tornado threat, especially towards early evening as winds slowly increase. Separate areas of convective development should be focused closer to the dryline in west TX and its intersection with the effective warm front/surface trough into southwest OK during the evening, and in another round during the early morning Tuesday. Convective development is most probable in the early evening over the northwest TX to southwest OK vicinity, with less confidence southward in west TX. This development will be high based initially along the fringe of the moisture return. Outflow-dominated supercells will be capable of producing large to very large hail and isolated severe gusts. MUCAPE values within the warm-moist sector that remains convectively undisturbed should build through the period as mid-level lapse rates become very steep (around 9 C/km) across west TX and moist advection continues to surge west-northwest. Guidance differs on the degree of overnight development as mid-level height falls increase late. The 00Z ECMWF remains consistent with prior runs in developing convection across west TX by 12Z Tuesday, which now has support of the 00Z HRW-FV3. The strongly sheared and very steep lapse rate environment will yield a primary threat of very large hail in any sustained supercells. ..Grams.. 04/07/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS... ...SUMMARY... Multiple rounds of severe thunderstorms should develop from early afternoon Monday through Tuesday morning across a large portion of Texas, into south Oklahoma, southwest Arkansas, and west Louisiana. A few tornadoes, scattered large to very large hail, and isolated severe wind gusts will be possible. ...Synopsis... A mid/upper low will drift east-northeast across the Upper Midwest while a separate shortwave trough digs over the Southwest before pivoting along the border with northwest Mexico. Low-level warm theta-e advection will persist across much of the South-Central States through the period. The primary low-level jet will be centered from the northwest Gulf across east TX into the Ark-La-Tex and Ark-La-Miss. Mid-level height falls attendant to the Southwest trough will increase across the west TX vicinity in the early morning Tuesday. ...Southern Great Plains... Strengthening low-level warm theta-e advection from the northwest Gulf should yield increasing thunderstorm coverage by early afternoon, along the northeast periphery of an intensifying elevated mixed layer across west/central TX. Guidance does differ with how far west and south this initial convection will develop into central TX, but a favorable environment for at least a few supercells should evolve from near the I-35 corridor across a portion of east TX. The impinging of steep mid-level lapse rates and very fast upper-level flow will foster an elongated hodograph within the largest portion of the buoyancy profile. This will support a threat for very large hail, generally favored along the southwest part of the overall convective plume as a cluster convective mode dominates with northern extent. Low-level hodograph curvature will also be sufficient for a tornado threat, especially towards early evening as winds slowly increase. Separate areas of convective development should be focused closer to the dryline in west TX and its intersection with the effective warm front/surface trough into southwest OK during the evening, and in another round during the early morning Tuesday. Convective development is most probable in the early evening over the northwest TX to southwest OK vicinity, with less confidence southward in west TX. This development will be high based initially along the fringe of the moisture return. Outflow-dominated supercells will be capable of producing large to very large hail and isolated severe gusts. MUCAPE values within the warm-moist sector that remains convectively undisturbed should build through the period as mid-level lapse rates become very steep (around 9 C/km) across west TX and moist advection continues to surge west-northwest. Guidance differs on the degree of overnight development as mid-level height falls increase late. The 00Z ECMWF remains consistent with prior runs in developing convection across west TX by 12Z Tuesday, which now has support of the 00Z HRW-FV3. The strongly sheared and very steep lapse rate environment will yield a primary threat of very large hail in any sustained supercells. ..Grams.. 04/07/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS... ...SUMMARY... Multiple rounds of severe thunderstorms should develop from early afternoon Monday through Tuesday morning across a large portion of Texas, into south Oklahoma, southwest Arkansas, and west Louisiana. A few tornadoes, scattered large to very large hail, and isolated severe wind gusts will be possible. ...Synopsis... A mid/upper low will drift east-northeast across the Upper Midwest while a separate shortwave trough digs over the Southwest before pivoting along the border with northwest Mexico. Low-level warm theta-e advection will persist across much of the South-Central States through the period. The primary low-level jet will be centered from the northwest Gulf across east TX into the Ark-La-Tex and Ark-La-Miss. Mid-level height falls attendant to the Southwest trough will increase across the west TX vicinity in the early morning Tuesday. ...Southern Great Plains... Strengthening low-level warm theta-e advection from the northwest Gulf should yield increasing thunderstorm coverage by early afternoon, along the northeast periphery of an intensifying elevated mixed layer across west/central TX. Guidance does differ with how far west and south this initial convection will develop into central TX, but a favorable environment for at least a few supercells should evolve from near the I-35 corridor across a portion of east TX. The impinging of steep mid-level lapse rates and very fast upper-level flow will foster an elongated hodograph within the largest portion of the buoyancy profile. This will support a threat for very large hail, generally favored along the southwest part of the overall convective plume as a cluster convective mode dominates with northern extent. Low-level hodograph curvature will also be sufficient for a tornado threat, especially towards early evening as winds slowly increase. Separate areas of convective development should be focused closer to the dryline in west TX and its intersection with the effective warm front/surface trough into southwest OK during the evening, and in another round during the early morning Tuesday. Convective development is most probable in the early evening over the northwest TX to southwest OK vicinity, with less confidence southward in west TX. This development will be high based initially along the fringe of the moisture return. Outflow-dominated supercells will be capable of producing large to very large hail and isolated severe gusts. MUCAPE values within the warm-moist sector that remains convectively undisturbed should build through the period as mid-level lapse rates become very steep (around 9 C/km) across west TX and moist advection continues to surge west-northwest. Guidance differs on the degree of overnight development as mid-level height falls increase late. The 00Z ECMWF remains consistent with prior runs in developing convection across west TX by 12Z Tuesday, which now has support of the 00Z HRW-FV3. The strongly sheared and very steep lapse rate environment will yield a primary threat of very large hail in any sustained supercells. ..Grams.. 04/07/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sun Apr 07 2024 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE SOUTHERN GREAT PLAINS... ...SUMMARY... Multiple rounds of severe thunderstorms should develop from early afternoon Monday through Tuesday morning across a large portion of Texas, into south Oklahoma, southwest Arkansas, and west Louisiana. A few tornadoes, scattered large to very large hail, and isolated severe wind gusts will be possible. ...Synopsis... A mid/upper low will drift east-northeast across the Upper Midwest while a separate shortwave trough digs over the Southwest before pivoting along the border with northwest Mexico. Low-level warm theta-e advection will persist across much of the South-Central States through the period. The primary low-level jet will be centered from the northwest Gulf across east TX into the Ark-La-Tex and Ark-La-Miss. Mid-level height falls attendant to the Southwest trough will increase across the west TX vicinity in the early morning Tuesday. ...Southern Great Plains... Strengthening low-level warm theta-e advection from the northwest Gulf should yield increasing thunderstorm coverage by early afternoon, along the northeast periphery of an intensifying elevated mixed layer across west/central TX. Guidance does differ with how far west and south this initial convection will develop into central TX, but a favorable environment for at least a few supercells should evolve from near the I-35 corridor across a portion of east TX. The impinging of steep mid-level lapse rates and very fast upper-level flow will foster an elongated hodograph within the largest portion of the buoyancy profile. This will support a threat for very large hail, generally favored along the southwest part of the overall convective plume as a cluster convective mode dominates with northern extent. Low-level hodograph curvature will also be sufficient for a tornado threat, especially towards early evening as winds slowly increase. Separate areas of convective development should be focused closer to the dryline in west TX and its intersection with the effective warm front/surface trough into southwest OK during the evening, and in another round during the early morning Tuesday. Convective development is most probable in the early evening over the northwest TX to southwest OK vicinity, with less confidence southward in west TX. This development will be high based initially along the fringe of the moisture return. Outflow-dominated supercells will be capable of producing large to very large hail and isolated severe gusts. MUCAPE values within the warm-moist sector that remains convectively undisturbed should build through the period as mid-level lapse rates become very steep (around 9 C/km) across west TX and moist advection continues to surge west-northwest. Guidance differs on the degree of overnight development as mid-level height falls increase late. The 00Z ECMWF remains consistent with prior runs in developing convection across west TX by 12Z Tuesday, which now has support of the 00Z HRW-FV3. The strongly sheared and very steep lapse rate environment will yield a primary threat of very large hail in any sustained supercells. ..Grams.. 04/07/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Sun Apr 07 2024 Valid 071200Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF FAR EAST TEXAS INTO THE LOWER/MID MISSISSIPPI VALLEY... ...SUMMARY... Isolated strong to severe thunderstorms appear possible during the late afternoon to mid-evening from parts of far east Texas into the lower/mid Mississippi Valley. ...Synopsis... A deep mid/upper-level cyclone initially centered over the Nebraska Sand Hills vicinity is forecast to gradually weaken and move northeastward through the day. A related surface low will also gradually weaken as it moves from eastern NE toward northwest/north-central IA. A trailing front will move eastward across parts of the mid MS Valley into the ArkLaTex region. ...Lower/Mid Mississippi Valley vicinity... Low-level moistening in advance of the cold front will allow for weak to moderate destabilization across parts of the lower/mid MS Valley, with MLCAPE generally increasing into the 500-1000 J/kg range this afternoon. Moderately strong midlevel flow will support effective shear of 45-55 kt, resulting in a conditionally favorable supercell environment. However, with stronger large-scale ascent displaced to the north of the better instability, and only weak to modest midlevel lapse rates expected regionwide, storm coverage and intensity will likely be limited to some extent. While it may take some time for storms to mature, a couple of supercells could evolve by late afternoon into early evening across parts of the lower/mid MS Valley, with more isolated development eventually possible into far east TX and western LA. Low-level shear/SRH will be sufficient for a tornado or two, if mature supercells can be sustained. Otherwise, isolated hail and strong/damaging gusts could accompany the strongest storms, before the threat wanes by late evening. ...Iowa/northern MO... Low-topped convection may develop this afternoon along an occluded front that will extend across parts of IA into northern MO/western IL. Guidance varies regarding the extent of diurnal heating and destabilization near this front. If sufficient heating and steepening of low-level lapse rates can occur, then there could be a nonzero threat for a brief tornado where vorticity is maximized near the boundary. Confidence in this scenario remains too low to include probabilities at this time. ..Dean/Bentley.. 04/07/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Sun Apr 07 2024 Valid 071200Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF FAR EAST TEXAS INTO THE LOWER/MID MISSISSIPPI VALLEY... ...SUMMARY... Isolated strong to severe thunderstorms appear possible during the late afternoon to mid-evening from parts of far east Texas into the lower/mid Mississippi Valley. ...Synopsis... A deep mid/upper-level cyclone initially centered over the Nebraska Sand Hills vicinity is forecast to gradually weaken and move northeastward through the day. A related surface low will also gradually weaken as it moves from eastern NE toward northwest/north-central IA. A trailing front will move eastward across parts of the mid MS Valley into the ArkLaTex region. ...Lower/Mid Mississippi Valley vicinity... Low-level moistening in advance of the cold front will allow for weak to moderate destabilization across parts of the lower/mid MS Valley, with MLCAPE generally increasing into the 500-1000 J/kg range this afternoon. Moderately strong midlevel flow will support effective shear of 45-55 kt, resulting in a conditionally favorable supercell environment. However, with stronger large-scale ascent displaced to the north of the better instability, and only weak to modest midlevel lapse rates expected regionwide, storm coverage and intensity will likely be limited to some extent. While it may take some time for storms to mature, a couple of supercells could evolve by late afternoon into early evening across parts of the lower/mid MS Valley, with more isolated development eventually possible into far east TX and western LA. Low-level shear/SRH will be sufficient for a tornado or two, if mature supercells can be sustained. Otherwise, isolated hail and strong/damaging gusts could accompany the strongest storms, before the threat wanes by late evening. ...Iowa/northern MO... Low-topped convection may develop this afternoon along an occluded front that will extend across parts of IA into northern MO/western IL. Guidance varies regarding the extent of diurnal heating and destabilization near this front. If sufficient heating and steepening of low-level lapse rates can occur, then there could be a nonzero threat for a brief tornado where vorticity is maximized near the boundary. Confidence in this scenario remains too low to include probabilities at this time. ..Dean/Bentley.. 04/07/2024 Read more