Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Apr 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST GEORGIA INTO NORTHERN FLORIDA... ...SUMMARY... Isolated damaging gusts and marginally severe hail remain possible for a few hours this afternoon/evening across southeast Georgia and north Florida. ...Southeast Georgia and northern Florida... Within the past few hours, a transient supercell on the northern fringe of the effective warm sector along the SC coast produced a measured severe (58 mph) wind gust, indicating that the environment across northern FL into southeast GA remains conducive for severe storms. However, convection has struggled to maintain intensity over the past few hours despite steadily diminishing MLCIN - possibly owing to a temporal displacement between the initial storms and the more favorable thermodynamic environment that is currently becoming established. Renewed attempts at convective initiation along the cold front are noted across south-central GA, so a severe wind/hail risk should persist for the next several hours (see forthcoming MCD #504 for details). Latest CAM guidance suggests this potential will be maximized between 21-00 UTC across southeast GA into far northern FL before the front moves off the GA coast and nocturnal cooling begins to hinder surface-based convection further south into the FL peninsula. ..Moore.. 04/21/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sun Apr 21 2024/ ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Apr 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST GEORGIA INTO NORTHERN FLORIDA... ...SUMMARY... Isolated damaging gusts and marginally severe hail remain possible for a few hours this afternoon/evening across southeast Georgia and north Florida. ...Southeast Georgia and northern Florida... Within the past few hours, a transient supercell on the northern fringe of the effective warm sector along the SC coast produced a measured severe (58 mph) wind gust, indicating that the environment across northern FL into southeast GA remains conducive for severe storms. However, convection has struggled to maintain intensity over the past few hours despite steadily diminishing MLCIN - possibly owing to a temporal displacement between the initial storms and the more favorable thermodynamic environment that is currently becoming established. Renewed attempts at convective initiation along the cold front are noted across south-central GA, so a severe wind/hail risk should persist for the next several hours (see forthcoming MCD #504 for details). Latest CAM guidance suggests this potential will be maximized between 21-00 UTC across southeast GA into far northern FL before the front moves off the GA coast and nocturnal cooling begins to hinder surface-based convection further south into the FL peninsula. ..Moore.. 04/21/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sun Apr 21 2024/ ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Apr 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST GEORGIA INTO NORTHERN FLORIDA... ...SUMMARY... Isolated damaging gusts and marginally severe hail remain possible for a few hours this afternoon/evening across southeast Georgia and north Florida. ...Southeast Georgia and northern Florida... Within the past few hours, a transient supercell on the northern fringe of the effective warm sector along the SC coast produced a measured severe (58 mph) wind gust, indicating that the environment across northern FL into southeast GA remains conducive for severe storms. However, convection has struggled to maintain intensity over the past few hours despite steadily diminishing MLCIN - possibly owing to a temporal displacement between the initial storms and the more favorable thermodynamic environment that is currently becoming established. Renewed attempts at convective initiation along the cold front are noted across south-central GA, so a severe wind/hail risk should persist for the next several hours (see forthcoming MCD #504 for details). Latest CAM guidance suggests this potential will be maximized between 21-00 UTC across southeast GA into far northern FL before the front moves off the GA coast and nocturnal cooling begins to hinder surface-based convection further south into the FL peninsula. ..Moore.. 04/21/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sun Apr 21 2024/ ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Apr 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST GEORGIA INTO NORTHERN FLORIDA... ...SUMMARY... Isolated damaging gusts and marginally severe hail remain possible for a few hours this afternoon/evening across southeast Georgia and north Florida. ...Southeast Georgia and northern Florida... Within the past few hours, a transient supercell on the northern fringe of the effective warm sector along the SC coast produced a measured severe (58 mph) wind gust, indicating that the environment across northern FL into southeast GA remains conducive for severe storms. However, convection has struggled to maintain intensity over the past few hours despite steadily diminishing MLCIN - possibly owing to a temporal displacement between the initial storms and the more favorable thermodynamic environment that is currently becoming established. Renewed attempts at convective initiation along the cold front are noted across south-central GA, so a severe wind/hail risk should persist for the next several hours (see forthcoming MCD #504 for details). Latest CAM guidance suggests this potential will be maximized between 21-00 UTC across southeast GA into far northern FL before the front moves off the GA coast and nocturnal cooling begins to hinder surface-based convection further south into the FL peninsula. ..Moore.. 04/21/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sun Apr 21 2024/ ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Apr 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST GEORGIA INTO NORTHERN FLORIDA... ...SUMMARY... Isolated damaging gusts and marginally severe hail remain possible for a few hours this afternoon/evening across southeast Georgia and north Florida. ...Southeast Georgia and northern Florida... Within the past few hours, a transient supercell on the northern fringe of the effective warm sector along the SC coast produced a measured severe (58 mph) wind gust, indicating that the environment across northern FL into southeast GA remains conducive for severe storms. However, convection has struggled to maintain intensity over the past few hours despite steadily diminishing MLCIN - possibly owing to a temporal displacement between the initial storms and the more favorable thermodynamic environment that is currently becoming established. Renewed attempts at convective initiation along the cold front are noted across south-central GA, so a severe wind/hail risk should persist for the next several hours (see forthcoming MCD #504 for details). Latest CAM guidance suggests this potential will be maximized between 21-00 UTC across southeast GA into far northern FL before the front moves off the GA coast and nocturnal cooling begins to hinder surface-based convection further south into the FL peninsula. ..Moore.. 04/21/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sun Apr 21 2024/ ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Apr 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHEAST GEORGIA INTO NORTHERN FLORIDA... ...SUMMARY... Isolated damaging gusts and marginally severe hail remain possible for a few hours this afternoon/evening across southeast Georgia and north Florida. ...Southeast Georgia and northern Florida... Within the past few hours, a transient supercell on the northern fringe of the effective warm sector along the SC coast produced a measured severe (58 mph) wind gust, indicating that the environment across northern FL into southeast GA remains conducive for severe storms. However, convection has struggled to maintain intensity over the past few hours despite steadily diminishing MLCIN - possibly owing to a temporal displacement between the initial storms and the more favorable thermodynamic environment that is currently becoming established. Renewed attempts at convective initiation along the cold front are noted across south-central GA, so a severe wind/hail risk should persist for the next several hours (see forthcoming MCD #504 for details). Latest CAM guidance suggests this potential will be maximized between 21-00 UTC across southeast GA into far northern FL before the front moves off the GA coast and nocturnal cooling begins to hinder surface-based convection further south into the FL peninsula. ..Moore.. 04/21/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sun Apr 21 2024/ ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. Read more

MD 0503 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN FL AND EXTREME SOUTHEAST GA
Mesoscale Discussion 0503 NWS Storm Prediction Center Norman OK 1205 PM CDT Sun Apr 21 2024 Areas affected...Northern FL and Extreme Southeast GA Concerning...Severe potential...Watch unlikely Valid 211705Z - 211900Z Probability of Watch Issuance...20 percent SUMMARY...Ongoing cluster of storms could produce a few damaging gusts from 45 to 60 mph as it moves across northern Florida and extreme southeast Georgia over the next few hours. DISCUSSION...Small convective cluster currently moving across Hamilton and Suwannee Counties in northern FL has shown some signs of intensification over the past half hour or so. This is likely a result of increased air mass destabilization in tandem with gradually strengthening large-scale ascent and mid-level flow attendant to an approaching shortwave trough. Some additional intensification of this cluster is anticipated, with the potential to produce a few damaging gusts from 45 to 60 mph as it moves quickly east-northeastward across northern FL and extreme southeast GA (i.e. Ware and Charlton Counties). Limited spatial extent of this threat will likely preclude the need for a watch, but convective trends will be monitored closely. ..Mosier/Smith.. 04/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAX...TAE... LAT...LON 30268308 30768240 30798148 30148128 29798254 29938315 30268308 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 PM CDT Sun Apr 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEASTERN FLORIDA PENINSULA... ...SUMMARY... Strong to locally severe thunderstorms, capable of marginally severe wind gusts and hail, will be possible across the central and southern Florida Peninsula on Monday. ...Synopsis... A cold front currently draped across the southeastern states to the northern Gulf will continue to slowly push south/southeast over the next 24-48 hours. This feature should reach the central to southern FL peninsula by mid-day Monday. Thunderstorms will likely be focused along this boundary as it pushes towards far south FL by late Monday evening. Across the Plains, more isolated thunderstorms will be possible along a cold front and in the vicinity of a surface low from northeast CO to the upper MS River Valley. ...South Florida... Heating of a moist air mass currently in place across south FL, combined with modest mid-level lapse rates, should support MLCAPE values between 1000-1500 J/kg ahead of the approaching front. Although low-level flow will be somewhat weak, winds aloft will be sufficiently strong to support effective bulk wind differences on the order of 30-40 knots. Elongated, nearly straight hodographs should favor splitting cells with the potential for a couple of right-moving supercells that will pose a large hail threat. However, storm motions and deep-layer shear vectors should largely be along the surface boundary, and weak inhibition may favor multiple thunderstorms along the front by peak heating. These factors could favor upscale growth of cells into clusters by late afternoon, which may limit the supercell potential. Regardless, both discrete/semi-discrete cells and/or more organized clusters should pose a damaging wind threat given low-level lapse rates approaching 8 C/km by mid afternoon. Latest CAM guidance suggests the severe threat is most likely to manifest across the southern portion of the Marginal risk area - particularly in the Miami vicinity as the front arrives by late afternoon. However, a few strong/severe storms will be possible late morning further north. ...Eastern CO to northwest KS... Dry conditions are prevalent across the Plains in the wake of the recent frontal passage. However, modified mid-level Pacific moisture associated with an approaching shortwave trough (currently over portions of the Pacific Northwest) should overspread parts of the central to northern High Plains by Monday afternoon. Modest mid-level moisture atop a deep, well-mixed boundary layer may support sufficient buoyancy for a few thunderstorms with an attendant risk for dry downbursts along a weak surface cold front. Strong to severe outflow gusts are possible based on the forecast thermodynamic profiles, but do not appear to be probable based on convective signals in latest guidance and discrepancies between solutions regarding mid-level saturation (and resultant buoyancy). Forecast trends will be monitored for the need for low-end, wind-driven risk probabilities. ..Moore.. 04/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sun Apr 21 2024 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTH FLORIDA AND SOUTH GEORGIA... ...SUMMARY... Isolated damaging gusts and marginally severe hail will be possible for a few hours this afternoon/evening across south Georgia and north Florida. ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. ..Smith/Jewell.. 04/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sun Apr 21 2024 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTH FLORIDA AND SOUTH GEORGIA... ...SUMMARY... Isolated damaging gusts and marginally severe hail will be possible for a few hours this afternoon/evening across south Georgia and north Florida. ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. ..Smith/Jewell.. 04/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sun Apr 21 2024 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTH FLORIDA AND SOUTH GEORGIA... ...SUMMARY... Isolated damaging gusts and marginally severe hail will be possible for a few hours this afternoon/evening across south Georgia and north Florida. ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. ..Smith/Jewell.. 04/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sun Apr 21 2024 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTH FLORIDA AND SOUTH GEORGIA... ...SUMMARY... Isolated damaging gusts and marginally severe hail will be possible for a few hours this afternoon/evening across south Georgia and north Florida. ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. ..Smith/Jewell.. 04/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sun Apr 21 2024 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTH FLORIDA AND SOUTH GEORGIA... ...SUMMARY... Isolated damaging gusts and marginally severe hail will be possible for a few hours this afternoon/evening across south Georgia and north Florida. ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. ..Smith/Jewell.. 04/21/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sun Apr 21 2024 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTH FLORIDA AND SOUTH GEORGIA... ...SUMMARY... Isolated damaging gusts and marginally severe hail will be possible for a few hours this afternoon/evening across south Georgia and north Florida. ...North FL/south GA this afternoon/evening... Visible satellite imagery late this morning shows a cumulus field and a destabilizing airmass to the east of an ongoing band of convection near a southwest-northeast oriented front. Ample heating over the area to the east of patchy cirrus will promote temperatures warming into the lower 80s deg F. 12z model guidance so far has a negative bias on surface dewpoints across north FL compared to observations (3-6 deg F too dry). This is partially explained by a richer moist profile observed through almost 850 mb via the 12z Tallahassee raob. As a result, slightly higher dewpoints (upper 60s deg F) and greater buoyancy (1000-1500 J/kg MLCAPE) are expected than previously forecast. Water-vapor imagery shows a lead disturbance moving east across the central Gulf Coast, and it will reach the northeast Gulf by late this afternoon/early evening. Ascent and some strengthening in flow will aid in some storm organization (reference 50-kt 2-6 km flow at Tallahassee on the 88D VAD). Limited low-level convergence and a warm layer near 800 mb may act to hinder an otherwise more organized potential severe setup. Regardless, isolated 50-65 mph gusts and marginally severe hail are possible with the stronger storms this afternoon into the early evening. ..Smith/Jewell.. 04/21/2024 Read more