Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1110 AM CDT Thu Mar 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/Southeast VA... Strong heating ahead of an eastward-developing surface front will allow temperatures to continue climbing into the 70s F this afternoon. Boundary layer moisture is expected to remain modest, with surface dewpoints generally reaching the mid/upper 50s F in a narrow corridor just as the surface front arrives. Morning balloon observations from GSO, RNK, IAD, and WAL show very dry midlevels as well. While some midlevel moistening will occur as strong midlevel southwesterlies overspread the region, overall airmass modification will remain poor. MLCAPE values are expected to remain stunted, generally less than 100-200 J/kg. This may be sufficient for a few lightning flashes as convection develops during the mid afternoon along the surface front. A well-mixed boundary layer to near 850 mb, where 25-40 kt of flow is forecast, is evident in forecast soundings. This may support a few strong gusts to 40 kt, but very poor thermodynamic profiles suggest potential for severe thunderstorms should remain low, precluding severe probabilities. ..Leitman/Squitieri.. 03/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Mar 20 2025 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/southeast VA this afternoon... A midlevel trough and an associated surface cold front will progress eastward from the Appalachians to the Atlantic coast by late this evening/early tonight. Only a narrow corridor of low-level moistening is expected ahead of the front, as a result of only partial air mass modification and poor trajectories from the Gulf and western Atlantic. There could be sufficient heating and moistening for very weak buoyancy (100-200 J/kg MLCAPE) and convection deep enough to produce isolated lightning flashes in a band along the front this afternoon, especially across eastern NC. While there is a low chance for isolated wind damage, the very weak buoyancy does not support the addition of severe wind probabilities. ..Thompson/Dean.. 03/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Mar 20 2025 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/southeast VA this afternoon... A midlevel trough and an associated surface cold front will progress eastward from the Appalachians to the Atlantic coast by late this evening/early tonight. Only a narrow corridor of low-level moistening is expected ahead of the front, as a result of only partial air mass modification and poor trajectories from the Gulf and western Atlantic. There could be sufficient heating and moistening for very weak buoyancy (100-200 J/kg MLCAPE) and convection deep enough to produce isolated lightning flashes in a band along the front this afternoon, especially across eastern NC. While there is a low chance for isolated wind damage, the very weak buoyancy does not support the addition of severe wind probabilities. ..Thompson/Dean.. 03/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Mar 20 2025 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/southeast VA this afternoon... A midlevel trough and an associated surface cold front will progress eastward from the Appalachians to the Atlantic coast by late this evening/early tonight. Only a narrow corridor of low-level moistening is expected ahead of the front, as a result of only partial air mass modification and poor trajectories from the Gulf and western Atlantic. There could be sufficient heating and moistening for very weak buoyancy (100-200 J/kg MLCAPE) and convection deep enough to produce isolated lightning flashes in a band along the front this afternoon, especially across eastern NC. While there is a low chance for isolated wind damage, the very weak buoyancy does not support the addition of severe wind probabilities. ..Thompson/Dean.. 03/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Mar 20 2025 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/southeast VA this afternoon... A midlevel trough and an associated surface cold front will progress eastward from the Appalachians to the Atlantic coast by late this evening/early tonight. Only a narrow corridor of low-level moistening is expected ahead of the front, as a result of only partial air mass modification and poor trajectories from the Gulf and western Atlantic. There could be sufficient heating and moistening for very weak buoyancy (100-200 J/kg MLCAPE) and convection deep enough to produce isolated lightning flashes in a band along the front this afternoon, especially across eastern NC. While there is a low chance for isolated wind damage, the very weak buoyancy does not support the addition of severe wind probabilities. ..Thompson/Dean.. 03/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Mar 20 2025 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm development will be possible today in parts of the Mid-Atlantic and northern Rockies. Severe weather is not expected. ...Eastern NC/southeast VA this afternoon... A midlevel trough and an associated surface cold front will progress eastward from the Appalachians to the Atlantic coast by late this evening/early tonight. Only a narrow corridor of low-level moistening is expected ahead of the front, as a result of only partial air mass modification and poor trajectories from the Gulf and western Atlantic. There could be sufficient heating and moistening for very weak buoyancy (100-200 J/kg MLCAPE) and convection deep enough to produce isolated lightning flashes in a band along the front this afternoon, especially across eastern NC. While there is a low chance for isolated wind damage, the very weak buoyancy does not support the addition of severe wind probabilities. ..Thompson/Dean.. 03/20/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... ...Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ...Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN AND CENTRAL PLAINS INTO THE OZARKS... ...SUMMARY... An isolated severe threat, with potential for large hail, is expected Saturday night into early Sunday morning across parts of the southern and central Plains into the Ozarks. ...Southern and Central Plains/Ozarks... A mid-level trough will dig southeastward across the northern Rockies on Saturday and into the central Plains Saturday night. Moisture advection will take place during the day ahead of the trough across the southern Plains and Ozarks. By early Saturday evening, an axis of instability with surface dewpoints in the 50s F, is forecast from east Texas northward into eastern Oklahoma and southeastern Kansas. A cold front will advance quickly southeastward through the central Plains Saturday evening, as a 50 to 60 knot jet strengthens ahead of the front. Scattered thunderstorms are expected to develop late Saturday evening ahead of the front on the nose of the low-level jet. During the overnight period, convection is forecast to expand eastward from southeast Kansas across the Ozarks. Isolated thunderstorms may also develop further southwestward into northeast Oklahoma and northwest Arkansas. Forecast soundings from 06Z to 12Z on Sunday morning along the instability axis have a low-level temperature inversion below 850 mb. Across parts of southeast Kansas and southwest Missouri, MUCAPE is forecast to be in the 1500 to 2000 J/kg range, with effective shear from 50 to 65 knots. In addition, 700-500 mb lapse rates are forecast to be around 7 C/km. This environment will likely support isolated supercells that are elevated, with potential for large hail. The greatest severe threat is expected to be after midnight, as the low-level jet consolidates over far northeast Oklahoma. The greatest severe threat is expected over southeast Kansas and south-central Missouri, where confidence is the greatest for convection initiation. Further to the southwest across parts of eastern Oklahoma and northwest Arkansas, convective initiation is more uncertain, suggesting that a severe threat there is more conditional. ..Broyles.. 03/20/2025 Read more