Severe Storms

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CDT Thu Mar 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range guidance continues to indicate that large-scale mid-level troughing, digging inland of the U.S. Pacific coast this coming weekend with at least a couple of significant embedded short wave perturbations, will progress through much of the Great Plains and Mississippi Valley through early next week. As the lead short wave trough emerges from the Southwest on Sunday, rather strong surface cyclogenesis is forecast to proceed from the lee of the Front Range into the adjacent high plains. Although it still appears that low-level moisture return to the developing warm sector will be on the lower margins for severe thunderstorm development, steepening lapse rates will probably compensate, in the presence of intensifying wind fields and strong forcing for ascent to the east of the deepening low. As a mid/upper jet streak, perhaps including southwesterly winds increasing to 90-100 kt, crosses the southern Texas Panhandle through western Oklahoma by Sunday evening, it appears that the environment may become conducive to organized convective development. This probably will include a few supercells initially, then a narrow evolving squall line posing increasing risk for severe winds, in addition to large hail and couple of tornadoes, before weakening late Sunday evening. The deep, but perhaps weakening cyclone, is then forecast to migrate through the lower Missouri Valley into Upper Midwest on Monday, but the primary severe weather potential seems likely to shift into the lower Mississippi Valley late Monday into Monday night. This is where forcing near a secondary frontal wave, as a trailing mid-level short wave emerges from the Southwest, may interact with better low-level moisture return from the Gulf of Mexico and support renewed vigorous thunderstorm development. By Monday evening, if not earlier, this probably will again include a risk for supercells, and a developing squall line, which may maintain strength through the evening before weakening overnight. Thereafter, pattern developments become more unclear, but a strong mid/upper jet emanating from the mid-latitude Pacific, with a number of amplifying waves, is forecast to spread across the southern mid-latitudes of the U.S., and one or two may be accompanied by renewed cyclogenesis to the east of the Rockies. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CDT Thu Mar 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range guidance continues to indicate that large-scale mid-level troughing, digging inland of the U.S. Pacific coast this coming weekend with at least a couple of significant embedded short wave perturbations, will progress through much of the Great Plains and Mississippi Valley through early next week. As the lead short wave trough emerges from the Southwest on Sunday, rather strong surface cyclogenesis is forecast to proceed from the lee of the Front Range into the adjacent high plains. Although it still appears that low-level moisture return to the developing warm sector will be on the lower margins for severe thunderstorm development, steepening lapse rates will probably compensate, in the presence of intensifying wind fields and strong forcing for ascent to the east of the deepening low. As a mid/upper jet streak, perhaps including southwesterly winds increasing to 90-100 kt, crosses the southern Texas Panhandle through western Oklahoma by Sunday evening, it appears that the environment may become conducive to organized convective development. This probably will include a few supercells initially, then a narrow evolving squall line posing increasing risk for severe winds, in addition to large hail and couple of tornadoes, before weakening late Sunday evening. The deep, but perhaps weakening cyclone, is then forecast to migrate through the lower Missouri Valley into Upper Midwest on Monday, but the primary severe weather potential seems likely to shift into the lower Mississippi Valley late Monday into Monday night. This is where forcing near a secondary frontal wave, as a trailing mid-level short wave emerges from the Southwest, may interact with better low-level moisture return from the Gulf of Mexico and support renewed vigorous thunderstorm development. By Monday evening, if not earlier, this probably will again include a risk for supercells, and a developing squall line, which may maintain strength through the evening before weakening overnight. Thereafter, pattern developments become more unclear, but a strong mid/upper jet emanating from the mid-latitude Pacific, with a number of amplifying waves, is forecast to spread across the southern mid-latitudes of the U.S., and one or two may be accompanied by renewed cyclogenesis to the east of the Rockies. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CDT Thu Mar 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range guidance continues to indicate that large-scale mid-level troughing, digging inland of the U.S. Pacific coast this coming weekend with at least a couple of significant embedded short wave perturbations, will progress through much of the Great Plains and Mississippi Valley through early next week. As the lead short wave trough emerges from the Southwest on Sunday, rather strong surface cyclogenesis is forecast to proceed from the lee of the Front Range into the adjacent high plains. Although it still appears that low-level moisture return to the developing warm sector will be on the lower margins for severe thunderstorm development, steepening lapse rates will probably compensate, in the presence of intensifying wind fields and strong forcing for ascent to the east of the deepening low. As a mid/upper jet streak, perhaps including southwesterly winds increasing to 90-100 kt, crosses the southern Texas Panhandle through western Oklahoma by Sunday evening, it appears that the environment may become conducive to organized convective development. This probably will include a few supercells initially, then a narrow evolving squall line posing increasing risk for severe winds, in addition to large hail and couple of tornadoes, before weakening late Sunday evening. The deep, but perhaps weakening cyclone, is then forecast to migrate through the lower Missouri Valley into Upper Midwest on Monday, but the primary severe weather potential seems likely to shift into the lower Mississippi Valley late Monday into Monday night. This is where forcing near a secondary frontal wave, as a trailing mid-level short wave emerges from the Southwest, may interact with better low-level moisture return from the Gulf of Mexico and support renewed vigorous thunderstorm development. By Monday evening, if not earlier, this probably will again include a risk for supercells, and a developing squall line, which may maintain strength through the evening before weakening overnight. Thereafter, pattern developments become more unclear, but a strong mid/upper jet emanating from the mid-latitude Pacific, with a number of amplifying waves, is forecast to spread across the southern mid-latitudes of the U.S., and one or two may be accompanied by renewed cyclogenesis to the east of the Rockies. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CDT Thu Mar 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... Medium-range guidance continues to indicate that large-scale mid-level troughing, digging inland of the U.S. Pacific coast this coming weekend with at least a couple of significant embedded short wave perturbations, will progress through much of the Great Plains and Mississippi Valley through early next week. As the lead short wave trough emerges from the Southwest on Sunday, rather strong surface cyclogenesis is forecast to proceed from the lee of the Front Range into the adjacent high plains. Although it still appears that low-level moisture return to the developing warm sector will be on the lower margins for severe thunderstorm development, steepening lapse rates will probably compensate, in the presence of intensifying wind fields and strong forcing for ascent to the east of the deepening low. As a mid/upper jet streak, perhaps including southwesterly winds increasing to 90-100 kt, crosses the southern Texas Panhandle through western Oklahoma by Sunday evening, it appears that the environment may become conducive to organized convective development. This probably will include a few supercells initially, then a narrow evolving squall line posing increasing risk for severe winds, in addition to large hail and couple of tornadoes, before weakening late Sunday evening. The deep, but perhaps weakening cyclone, is then forecast to migrate through the lower Missouri Valley into Upper Midwest on Monday, but the primary severe weather potential seems likely to shift into the lower Mississippi Valley late Monday into Monday night. This is where forcing near a secondary frontal wave, as a trailing mid-level short wave emerges from the Southwest, may interact with better low-level moisture return from the Gulf of Mexico and support renewed vigorous thunderstorm development. By Monday evening, if not earlier, this probably will again include a risk for supercells, and a developing squall line, which may maintain strength through the evening before weakening overnight. Thereafter, pattern developments become more unclear, but a strong mid/upper jet emanating from the mid-latitude Pacific, with a number of amplifying waves, is forecast to spread across the southern mid-latitudes of the U.S., and one or two may be accompanied by renewed cyclogenesis to the east of the Rockies. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Mar 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SATURDAY ACROSS PARTS OF SOUTHERN FLORIDA AND PARTS OF COASTAL NORTH CAROLINA... ...SUMMARY... Strong thunderstorms posing at least some risk for severe weather may approach or perhaps spread inland across the Outer Banks vicinity of North Carolina early Saturday, as the risk for strong to severe thunderstorm development diminishes across parts of southern Florida. ...Synopsis... As a more progressive regime continues to spread across the central into eastern mid-latitude Pacific, blocking initially centered over the northeastern Pacific is forecast to gradually begin to breakdown. As this occurs, models suggest that downstream flow may undergo amplification across the southern mid- and subtropical latitudes, inland of the Pacific coast into the western Atlantic. It appears that this will include large-scale mid-level troughing digging across the Pacific coast through the Southwest, with at least a couple of significant embedded short wave perturbations. This will be preceded by building ridging across the Great Plains into Mississippi Valley, and digging mid-level troughing offshore of the southern Atlantic Seaboard. In higher latitudes, a vigorous short wave impulse turning eastward across the Great Lakes by 12Z Saturday (to the south of an elongating circulation across southern Hudson Bay into northern Manitoba) is forecast to accelerate east-northeastward through much of the St. Lawrence Valley by early Sunday, trailed by a perturbation emerging from the troughing to the south. Initially accelerating northeastward to the lee of the southern Appalachians at the outset of the period, there appears increasing consensus that this trailing impulse may support a compact deepening surface low, within elongating surface troughing mostly offshore of the Atlantic coast. However, there is considerable lingering spread concerning this and other sub-synoptic developments across and east of the Atlantic Seaboard. In the wake of the developing surface low, a significant ongoing cold intrusion to the lee of the Rockies is forecast to overtake the offshore surface troughing late Saturday through Saturday night. Models indicate that the southwestern flank of this cold air will stall and begin to undergo modification across the lower Mississippi Valley into central high plains, as surface troughing begins to deepen to the lee of the Front Range and southern Rockies. ...Florida... It is possible that an outflow boundary may linger across parts of the southern peninsula and/or Florida Keys into Saturday morning, with potential for continuing vigorous thunderstorm development accompanied by at least some risk for strong, gusty winds. It appears that this boundary will shift off to the east and south by midday, if not earlier. In its wake, models indicate low-level flow quickly veering to an increasingly westerly component across the remainder of the peninsula, leading to diminishing convective potential ahead of a weak approaching cold front. ...Eastern North Carolina... Severe weather potential appears largely conditional, depending on the evolution and track of the primary surface low. However, the inland advection of a moist unstable warm sector appears at least possible early Saturday, within a strongly sheared environment across the Outer and Inner Banks vicinity. This may provide a window of opportunity for organized convective development, including supercells. ..Kerr.. 03/21/2024 Read more

MD 0273 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR MIDDLE TX GULF COAST
Mesoscale Discussion 0273 NWS Storm Prediction Center Norman OK 0142 AM CDT Thu Mar 21 2024 Areas affected...Middle TX Gulf Coast Concerning...Severe potential...Watch possible Valid 210642Z - 210845Z Probability of Watch Issuance...40 percent SUMMARY...A couple supercells may develop over the Middle Texas Gulf Coast, with more probable supercell development in the adjacent offshore waters of the western Gulf through the pre-dawn hours. Isolated large hail should be the primary threat over land. DISCUSSION...Weak mid-level convection persists across parts of Deep South TX within a corridor of modest warm theta-e advection. Bulk of evening guidance suggest this activity will deepen into storms and intensify during the next few hours by about 09Z. This appears to be on-track per time-series of VWP data from BRO showing some increase in 1-2 km flow over the past couple hours and the CRP VWP showing a similar trend in the past 30 minutes. With upper 60s surface dew points as far north as CRP, adequate buoyancy will be present once storms initiate. The bulk of the development should occur near and to the north of the modest surface-based instability plume, yielding convection becoming increasingly elevated with northeast extent along the coastal plain. Ample deep-layer shear and steep mid-level lapse rates should support potential for a couple supercells capable of large hail. The bulk of longer-lived, more intense supercells should be confined off the coast from the Corpus Christi to Matagorda Bay vicinity. ..Grams/Thompson.. 03/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...HGX...CRP...BRO... LAT...LON 28849719 29169655 29209586 29089557 28949540 28599542 27929661 27359705 27109746 27079795 27379810 28129791 28849719 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Mar 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... Elevated fire-weather conditions are possible on Friday afternoon across portions of West TX. Elsewhere, a progressive weather pattern and associated widespread precipitation -- along with a trailing cold front and milder conditions -- will temper any fire-weather threat. ...West TX... In the wake of an ejecting, mid-level trough, modest west-northwesterly flow is forecast over eastern NM and West TX. This will lead to dry, downsloping flow and deepening, well-mixed boundary layers across West TX. Critical-level relative humidities (10-15 percent) are possible across the region by mid-afternoon. Given a lack of more robust cyclone development, surface wind speeds are expected to be more tempered around 10-15 mph. Parts of the region also recently experienced some wetting precipitation, but this was relatively limited (around 0.1 inches) and localized in nature. Given forecast ERCs in the 70-80th percentiles and generally persistent dry and windy conditions, Elevated fire-weather conditions appear possible in the delineated area Friday afternoon. ..Flournoy.. 03/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CDT Wed Mar 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY THROUGH FRIDAY NIGHT NEAR THE NORTHEASTERN GULF COAST AND ACROSS PARTS OF SOUTHERN FLORIDA AND THE FLORIDA KEYS... ...SUMMARY... One or two clusters of strong thunderstorms may impact portions of southern Florida and the Keys Friday into Friday evening, accompanied by at least some risk for damaging winds and a tornado or two. More isolated strong to severe thunderstorm development may impact northeastern Gulf coastal areas into Friday night. ...Synopsis... It appears that blocking centered over the northeastern Pacific will generally persist through this period, but guidance continues to indicate at least some weakening, as a more progressive regime gradually develops across the central toward eastern mid-latitude Pacific. There remains variability within and among the model output concerning the extent of this weakening, and the eastward acceleration of an associated mid-level low toward the northern U.S. Pacific coast. This may have at least some impact on downstream synoptic developments within the broadly confluent split flow across North America. In the higher-latitude branch, one significant occluding cyclone is forecast to continue migrating northeast and east of the Canadian Maritimes. An elongating upstream cyclonic circulation may become quasi-stationary near the southwestern shores of Hudson Bay, with a series of lower amplitude perturbations digging to its west through south, across the international border. In lower levels, the leading edge of another significant cold intrusion is forecast to nose as far south as the Texas Panhandle and Red River vicinity, and as far east as the lower Great Lakes and Ohio Valley by 12Z Saturday. In lower latitudes, mid-level troughing is still forecast to progress slowly across and east of the lower Mississippi Valley and north central Gulf of Mexico. One smaller-scale perturbation may emerge from its base and become increasingly sheared across and to the east of the southern Appalachians, while another digs across the northwestern through north central Gulf of Mexico by late Friday night. Models continue to differ concerning these features, and the larger-scale troughing will be preceded by a subtropical perturbation which is likely to be in the process of progressing into and across the Florida peninsula by early Friday. It does appear that a broad area of deepening surface low pressure will develop northeastward across much of the eastern Gulf and South Atlantic Coast states. However, sizable spread is evident within the model output concerning sub-synoptic through convective-scale developments across the Southeast, Gulf of Mexico and offshore Atlantic. ...Southeast... Even with the aforementioned uncertainties, it does appear that an initially dry/potentially cool low-level environment, across much of the Florida peninsula through eastern Gulf Coast region, will tend to maintain generally stable conditions inland of coastal areas as initial convection supported by warm advection overspreads it. However, based on various model output, including some convection-allowing guidance, there appears potential for at least one initially organized convective cluster to overspread the Florida Keys/southern Florida peninsula vicinity, coincident with a warm front off the southeastern Gulf of Mexico early Friday. Given sufficient boundary-layer destabilization in the presence of strong deep-layer shear, this may be accompanied by a risk for damaging wind gusts and perhaps a tornado or two. Thereafter, it appears that widespread convective development, perhaps including organizing clusters, may continue along trailing convective outflow gradually advancing across and east-southeast of the southeastern Gulf of Mexico through early Saturday. Convective potential to the north of this outflow remains unclear. However, models do indicate that substantive boundary-layer destabilization is possible across much of the northeastern Gulf of Mexico by late Friday night, ahead of a weak southeastward advancing cold front. Still ahead of the mid-level troughing axis, this environment may support additional scattered strong thunderstorm development which might spread inland across coastal areas before weakening. ..Kerr.. 03/21/2024 Read more