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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 AM CDT Sat May 18 2024 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEBRASKA...KANSAS...SOUTHWEST IOWA AND NORTHWEST MISSOURI... ...SUMMARY... Severe thunderstorms are possible across parts of Nebraska and Kansas into western Iowa and northwest Missouri Monday afternoon into Monday night. More isolated strong to severe storms may extend into parts of the Middle Mississippi Valley and southern Wisconsin. ...Synopsis... An upper shortwave trough is expected to be located over the Lower MO Valley early Monday. This trough will lift northeast across the upper Great Lakes through Monday night. Meanwhile, a broad area of southwesterly flow will continued across the southern/central Plains east of a deepening upper trough over the western U.S. Deep-layer flow will become more amplified and stronger across the central Plains after 00z, as the western trough ejects east toward the High Plains by early Tuesday. At the surface, a cold front will be located from the eastern Dakotas into central NE. This front will continue to shift east through the evening before stalling from southern MN into eastern NE and central KS. Southerly low-level flow ahead of the front will result in a broad area of low to mid 60s F dew points from the Mid/Upper MS Valley into the central/southern Plains. ...KS/NE into southwest IA/northwest MO... Large-scale ascent will be nebulous through the afternoon, and capping will likely suppress convection through at least mid-afternoon. Thereafter, vertical shear will increase along with stronger ascent spreading into the Plains during the evening/overnight as the western trough ejects east. Thunderstorm clusters may initiate by early evening, with the potential for MCS development during the nighttime hours. Convective initiation and evolution is a bit uncertain given several rounds of convection expected for portions of the region prior to Monday evening. However, the overall large-scale pattern supports severe convection capable of all hazards into early Tuesday morning. ...Lower MO Valley to WI... Convection may be ongoing Monday morning from the MO River into central IA, northward into northern WI. How this convection evolves is a bit uncertain. However, some severe potential appears possible into the afternoon, as at least modest destabilization occurs amid somewhat favorable vertical shear. Hail and strong gusts will be possible with this activity through Monday evening. ..Leitman.. 05/18/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 AM CDT Sat May 18 2024 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEBRASKA...KANSAS...SOUTHWEST IOWA AND NORTHWEST MISSOURI... ...SUMMARY... Severe thunderstorms are possible across parts of Nebraska and Kansas into western Iowa and northwest Missouri Monday afternoon into Monday night. More isolated strong to severe storms may extend into parts of the Middle Mississippi Valley and southern Wisconsin. ...Synopsis... An upper shortwave trough is expected to be located over the Lower MO Valley early Monday. This trough will lift northeast across the upper Great Lakes through Monday night. Meanwhile, a broad area of southwesterly flow will continued across the southern/central Plains east of a deepening upper trough over the western U.S. Deep-layer flow will become more amplified and stronger across the central Plains after 00z, as the western trough ejects east toward the High Plains by early Tuesday. At the surface, a cold front will be located from the eastern Dakotas into central NE. This front will continue to shift east through the evening before stalling from southern MN into eastern NE and central KS. Southerly low-level flow ahead of the front will result in a broad area of low to mid 60s F dew points from the Mid/Upper MS Valley into the central/southern Plains. ...KS/NE into southwest IA/northwest MO... Large-scale ascent will be nebulous through the afternoon, and capping will likely suppress convection through at least mid-afternoon. Thereafter, vertical shear will increase along with stronger ascent spreading into the Plains during the evening/overnight as the western trough ejects east. Thunderstorm clusters may initiate by early evening, with the potential for MCS development during the nighttime hours. Convective initiation and evolution is a bit uncertain given several rounds of convection expected for portions of the region prior to Monday evening. However, the overall large-scale pattern supports severe convection capable of all hazards into early Tuesday morning. ...Lower MO Valley to WI... Convection may be ongoing Monday morning from the MO River into central IA, northward into northern WI. How this convection evolves is a bit uncertain. However, some severe potential appears possible into the afternoon, as at least modest destabilization occurs amid somewhat favorable vertical shear. Hail and strong gusts will be possible with this activity through Monday evening. ..Leitman.. 05/18/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0204 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...Synopsis... Mid-level southwesterly flow will begin to strengthen today across the Southwest as troughing amplifies across the western CONUS. Dry and windy conditions are expected across the Southwest as a result of the deeply mixed airmass transporting some of this stronger flow to the surface, and a lee cyclone tightening the surface pressure gradient. Sustained winds may be has high as 20 to 25 mph with single-digit relative humidity. This will support Critical fire weather conditions in local areas with drier fuels, but amid only marginally dry fuels, have elected to keep an Elevated delineation for now. If stronger winds or drier fuels are apparent, an upgrade to Critical may be needed in later outlooks. ..Bentley.. 05/18/2024 ...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 0204 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...Synopsis... Mid-level southwesterly flow will begin to strengthen today across the Southwest as troughing amplifies across the western CONUS. Dry and windy conditions are expected across the Southwest as a result of the deeply mixed airmass transporting some of this stronger flow to the surface, and a lee cyclone tightening the surface pressure gradient. Sustained winds may be has high as 20 to 25 mph with single-digit relative humidity. This will support Critical fire weather conditions in local areas with drier fuels, but amid only marginally dry fuels, have elected to keep an Elevated delineation for now. If stronger winds or drier fuels are apparent, an upgrade to Critical may be needed in later outlooks. ..Bentley.. 05/18/2024 ...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 0204 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...Synopsis... Mid-level southwesterly flow will begin to strengthen today across the Southwest as troughing amplifies across the western CONUS. Dry and windy conditions are expected across the Southwest as a result of the deeply mixed airmass transporting some of this stronger flow to the surface, and a lee cyclone tightening the surface pressure gradient. Sustained winds may be has high as 20 to 25 mph with single-digit relative humidity. This will support Critical fire weather conditions in local areas with drier fuels, but amid only marginally dry fuels, have elected to keep an Elevated delineation for now. If stronger winds or drier fuels are apparent, an upgrade to Critical may be needed in later outlooks. ..Bentley.. 05/18/2024 ...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 0204 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...Synopsis... Mid-level southwesterly flow will begin to strengthen today across the Southwest as troughing amplifies across the western CONUS. Dry and windy conditions are expected across the Southwest as a result of the deeply mixed airmass transporting some of this stronger flow to the surface, and a lee cyclone tightening the surface pressure gradient. Sustained winds may be has high as 20 to 25 mph with single-digit relative humidity. This will support Critical fire weather conditions in local areas with drier fuels, but amid only marginally dry fuels, have elected to keep an Elevated delineation for now. If stronger winds or drier fuels are apparent, an upgrade to Critical may be needed in later outlooks. ..Bentley.. 05/18/2024 ...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 0203 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Mid level ridging will start to build into the central CONUS today with a series of troughs moving through the Northwest and northern Plains. At this time, dry fuels are concentrated across portions of the Southwest and southern High Plains. However, winds will be mostly light across this region on Saturday. Some dry and breezy (15 to 20 mph) conditions are possible across southern Arizona as mid-level flow strengthens, but fuels are not dry enough to support large fires at this time. ..Bentley.. 05/18/2024 ...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 0203 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Mid level ridging will start to build into the central CONUS today with a series of troughs moving through the Northwest and northern Plains. At this time, dry fuels are concentrated across portions of the Southwest and southern High Plains. However, winds will be mostly light across this region on Saturday. Some dry and breezy (15 to 20 mph) conditions are possible across southern Arizona as mid-level flow strengthens, but fuels are not dry enough to support large fires at this time. ..Bentley.. 05/18/2024 ...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 0203 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Mid level ridging will start to build into the central CONUS today with a series of troughs moving through the Northwest and northern Plains. At this time, dry fuels are concentrated across portions of the Southwest and southern High Plains. However, winds will be mostly light across this region on Saturday. Some dry and breezy (15 to 20 mph) conditions are possible across southern Arizona as mid-level flow strengthens, but fuels are not dry enough to support large fires at this time. ..Bentley.. 05/18/2024 ...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 0203 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Mid level ridging will start to build into the central CONUS today with a series of troughs moving through the Northwest and northern Plains. At this time, dry fuels are concentrated across portions of the Southwest and southern High Plains. However, winds will be mostly light across this region on Saturday. Some dry and breezy (15 to 20 mph) conditions are possible across southern Arizona as mid-level flow strengthens, but fuels are not dry enough to support large fires at this time. ..Bentley.. 05/18/2024 ...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 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

000
ABPZ20 KNHC 180515
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Fri May 17 2024

For the eastern North Pacific...east of 140 degrees west longitude:

South of the Coast of Southwestern Mexico:
An elongated area of low pressure located several hundred miles
offshore of the coast of southwestern Mexico continues to produce a
small area of showers and thunderstorms. This activity has become
more diffuse than yesterday, and marginal environmental conditions
due to nearby dry air are likely to limit significant development.
This system should remain nearly stationary during the next day or
so, but by the end of the weekend, the low is forecast to interact
or merge with another system to its east.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

South of the Coast of Southern Mexico:
Disorganized showers and thunderstorms persist several hundred miles
to the south of the coast of southern Mexico along a trough of low
pressure. Development of this system, if any, should be slow to
occur as it moves slowly westward during the next few days.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Papin

MD 0822 CONCERNING SEVERE THUNDERSTORM WATCH 255... FOR SOUTHEASTERN NORTH DAKOTA...NORTHEASTERN SOUTH DAKOTA...WEST CENTRAL/NORTHWESTERN MINNESOTA
Mesoscale Discussion 0822 NWS Storm Prediction Center Norman OK 1137 PM CDT Fri May 17 2024 Areas affected...southeastern North Dakota...northeastern South Dakota...west central/northwestern Minnesota Concerning...Severe Thunderstorm Watch 255... Valid 180437Z - 180600Z The severe weather threat for Severe Thunderstorm Watch 255 continues. SUMMARY...A few locally strong surface gusts remain possible with lingering convection spreading across and east of the Red River vicinity through 1-2 AM CDT, but the severe weather threat appears to have generally diminished. DISCUSSION...A convective outflow driven/enhanced cold front has advanced east of the the Red River, and southeastward through central South Dakota portions of the mid Missouri Valley. Ahead of this boundary, lower/mid-levels remain relatively dry as the boundary-layer continues to cool, resulting in diminishing instability. However, mid-level lapse rates are still steep enough to maintain sufficient instability to support continuing convective development in the presence of strong lift along a 30-50+ kt southerly 850 mb jet axis. While stronger convection is increasingly focused to the cool side of the surface front, thermodynamic profiles may remain conducive to occasional strong, but generally sub-severe, surface gusts in the more vigorous lingering convection as it gradually spreads eastward into the overnight hours. ..Kerr.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...MPX...FGF...ABR...BIS... LAT...LON 48749430 47809432 46519536 45109688 44979819 45569872 46719792 48529655 48929584 48749430 Read more