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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Fri Apr 05 2024 Valid 051630Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected today or tonight. ...Northern Rockies... Associated with the exit region of the polar jet related to the Western U.S. upper trough, forcing for ascent and modest moisture/buoyancy will lead to at least widely scattered thunderstorms by mid/late afternoon. These storms should generally focus across eastern Idaho and far western Montana this afternoon, and then additional parts of western/southern Montana and Wyoming into this evening. Steep lapse rates and sufficient buoyancy could allow for some stronger storms capable of gusty winds/hail, but organized/sustained severe thunderstorms are not currently expected. ...Coastal Southern California... Isolated low-topped thunderstorms will remain a possibility within the post-frontal environment beneath the mid/upper-level trough, where mid-level temperatures (500 mb) are generally between -25C to -30C. While a couple of east/southeastward-moving stronger storms could materialize through the afternoon near far southern California coastal areas, severe thunderstorms are unlikely given the limited boundary layer moisture and buoyancy (generally a couple hundred J/kg MUCAPE at most). ..Guyer/Squitieri.. 04/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0710 AM CDT Fri Apr 05 2024 Valid 051300Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today or tonight. ...Synopsis... Water-vapor imagery early this morning shows a mid to upper-level low over northern CA and an associated large-scale trough over the West Coast. A mid-level ridge is downstream over the Great Plains to the west of a large-scale trough/mid-level low near the East Coast. The western U.S. trough/low will gradually pivot east through Saturday morning across the Desert Southwest and Great Basin. Isolated thunderstorms are possible across CA/NV/AZ in conjunction with increasing large-scale ascent and sporadic pockets of weak buoyancy. Isolated thunderstorms are also possible across the central and northern Rockies and adjacent plains. Strong gusts cannot be ruled out with a few thunderstorms, but limited buoyancy will likely preclude the development of severe thunderstorms through tonight. ..Smith/Wendt.. 04/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0710 AM CDT Fri Apr 05 2024 Valid 051300Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today or tonight. ...Synopsis... Water-vapor imagery early this morning shows a mid to upper-level low over northern CA and an associated large-scale trough over the West Coast. A mid-level ridge is downstream over the Great Plains to the west of a large-scale trough/mid-level low near the East Coast. The western U.S. trough/low will gradually pivot east through Saturday morning across the Desert Southwest and Great Basin. Isolated thunderstorms are possible across CA/NV/AZ in conjunction with increasing large-scale ascent and sporadic pockets of weak buoyancy. Isolated thunderstorms are also possible across the central and northern Rockies and adjacent plains. Strong gusts cannot be ruled out with a few thunderstorms, but limited buoyancy will likely preclude the development of severe thunderstorms through tonight. ..Smith/Wendt.. 04/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0710 AM CDT Fri Apr 05 2024 Valid 051300Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today or tonight. ...Synopsis... Water-vapor imagery early this morning shows a mid to upper-level low over northern CA and an associated large-scale trough over the West Coast. A mid-level ridge is downstream over the Great Plains to the west of a large-scale trough/mid-level low near the East Coast. The western U.S. trough/low will gradually pivot east through Saturday morning across the Desert Southwest and Great Basin. Isolated thunderstorms are possible across CA/NV/AZ in conjunction with increasing large-scale ascent and sporadic pockets of weak buoyancy. Isolated thunderstorms are also possible across the central and northern Rockies and adjacent plains. Strong gusts cannot be ruled out with a few thunderstorms, but limited buoyancy will likely preclude the development of severe thunderstorms through tonight. ..Smith/Wendt.. 04/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0710 AM CDT Fri Apr 05 2024 Valid 051300Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today or tonight. ...Synopsis... Water-vapor imagery early this morning shows a mid to upper-level low over northern CA and an associated large-scale trough over the West Coast. A mid-level ridge is downstream over the Great Plains to the west of a large-scale trough/mid-level low near the East Coast. The western U.S. trough/low will gradually pivot east through Saturday morning across the Desert Southwest and Great Basin. Isolated thunderstorms are possible across CA/NV/AZ in conjunction with increasing large-scale ascent and sporadic pockets of weak buoyancy. Isolated thunderstorms are also possible across the central and northern Rockies and adjacent plains. Strong gusts cannot be ruled out with a few thunderstorms, but limited buoyancy will likely preclude the development of severe thunderstorms through tonight. ..Smith/Wendt.. 04/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0710 AM CDT Fri Apr 05 2024 Valid 051300Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today or tonight. ...Synopsis... Water-vapor imagery early this morning shows a mid to upper-level low over northern CA and an associated large-scale trough over the West Coast. A mid-level ridge is downstream over the Great Plains to the west of a large-scale trough/mid-level low near the East Coast. The western U.S. trough/low will gradually pivot east through Saturday morning across the Desert Southwest and Great Basin. Isolated thunderstorms are possible across CA/NV/AZ in conjunction with increasing large-scale ascent and sporadic pockets of weak buoyancy. Isolated thunderstorms are also possible across the central and northern Rockies and adjacent plains. Strong gusts cannot be ruled out with a few thunderstorms, but limited buoyancy will likely preclude the development of severe thunderstorms through tonight. ..Smith/Wendt.. 04/05/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Fri Apr 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... ...Monday/Day 4 to Wednesday/Day 6... The medium-range models continue to forecast the development of an upper-level low across the Desert Southwest on Monday. The low is forecast to move eastward across the southwestern states on Tuesday and into the southern Plains on Wednesday. During this period, mid-level flow is forecast to be southwesterly across the southern Plains and lower Mississippi Valley. As the system approaches, low-level moisture will return northward into the southern Plains, and moderate instability/deep-layer shear will likely be in place from central, east and north Texas eastward into the Louisiana. This will be the favored area for severe thunderstorm development from Monday afternoon to Tuesday night. On Wednesday, the upper-level low, and an associated cold front, is forecast to move through the southern Plains. Ahead of the front, low-level moisture is expected to be maximized from east Texas eastward to the central Gulf Coast. Some models, including the ECMWF and GFS, show potential for the development of a large MCS across the lower Mississippi Valley. These solutions suggest that instability and deep-layer shear will support a severe threat Wednesday afternoon and evening. ...Thursday/Day 7 and Friday/Day 8... On Thursday and Friday, the upper-level system is forecast to move eastward from the Ark-La-Tex to the southern Appalachians. Ahead of the system, a moist airmass is expected to be in place from the Gulf Coast states and Tennessee Valley eastward to the southern Atlantic Seaboard. As a cold front moves eastward across the Southeast, thunderstorm development may take place along and ahead of the front during the afternoon and evening on Thursday and Friday. Instability and deep-layer shear is forecast to be strong enough to support a severe threat. However, there is considerable uncertainty at this range in the Day to 4 to 8 period, concerning the timing of the upper-level trough and positioning of the cold front. For this reason, predictability remains too low to add a severe threat at this time. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Fri Apr 05 2024 Valid 071200Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER TO MID MISSISSIPPI VALLEY...INTO WESTERN PARTS OF THE OHIO AND TENNESSEE VALLEYS... ...SUMMARY... Strong thunderstorms with marginally severe wind gusts will be possible on Sunday from the lower to mid Mississippi Valley eastward into western parts of the Ohio and Tennessee Valleys. Hail could also occur in parts of the mid Mississippi Valley. ...Lower to Mid Mississippi Valley/Western Ohio and Tennessee Valleys... An upper-level low is forecast to move eastward into the mid Missouri Valley on Sunday, as a mid-level trough moves eastward into the Ozarks. At the surface, a low is forecast to move into the mid Missouri Valley, as a warm front advances northeastward into the mid Mississippi Valley. Along the warm front, a narrow corridor of low-level moisture will be in place, with the moist axis extending southeastward, and then southward into the mid Mississippi Valley. Surface dewpoints are forecast to be in the 50s F along much of this moist axis. Thunderstorms are expected to form near the moist axis during the afternoon, along the leading edge of a band of strong large-scale ascent. Forecast soundings near the moist axis at 21Z Sunday suggest that MUCAPE will be around 500 J/kg, and that 0-6 km shear will be in the 60 to 70 knot range. 0-3 km lapse are forecast to be near 7.5 C/km. This environment should support marginally severe gusts as cells move eastward toward the lower Ohio and western Tennessee Valley during the late afternoon and early evening. Hail will also be possible, especially where buoyancy is greatest. Further south-southwest, surface dewpoints are forecast to reach the lower to mid 60s F across much of the lower Mississippi Valley. Surface heating and low-level convergence near the moist axis should result in isolated convective initiation. Weak instability is expected to develop, with MUCAPE generally peaking in the 500 to 750 J/kg range. This, along with 0-6 km shear near 50 knots, and steep low-level lapse rates should be enough for marginally severe wind gusts. ..Broyles.. 04/05/2024 Read more