Aggregator

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Thu Jul 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE GREAT LAKES INTO THE MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS... ...SUMMARY... Locally damaging thunderstorm wind gusts will be possible from parts of the Great Lakes to the central and southern Plains, mainly this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...Synopsis... Modestly enhanced westerly mid-level flow will be maintained today between an upper trough progressing slowly eastward over central Canada and the north-central CONUS, and upper ridging across the Southeast and Mid-Atlantic. Multiple mid-level MCVs evident on satellite and radar should move generally east-northeastward across parts of the Midwest and Great Lakes today. At the surface, a convectively reinforced front will be draped from Ontario/Quebec southwestward to the southern Plains. This front will likely serve as a focused for additional scattered to numerous thunderstorms this afternoon and evening, some of which could become strong to severe on an isolated basis. ...Great Lakes into the Midwest and Central/Southern Plains... A moist and rather unstable airmass will exist along/ahead of the front today, as diurnal heating aids in the gradual steepening of low-level lapse rates. Stronger mid-level flow and related deep-layer shear should be present across parts of MI and vicinity. Some enhancement to the low/mid-level winds and modest ascent associated with an MCV over northeast WI this morning may also aid in thunderstorm development and organization downstream into parts of northern Lower MI by early afternoon. This area appears to have the best combination of forecast instability and shear, and any thunderstorms which can form here could become severe while posing a threat for both isolated hail and damaging winds. However, low-level flow along/near the front is generally expected to remain veered to southwesterly, which should limit low-level convergence to some extent. Therefore, confidence in overall coverage of severe convection remains too low to include greater severe probabilities across northern Lower MI at this time. Mid-level flow and effective bulk shear values will decrease with southward extent across the Midwest into the southern Plains, away from any remnant MCV influences. This should tend to limit updraft organization with thunderstorms that develop this afternoon across these regions. Still, some potential should exist for loosely organized clusters given the linear low-level forcing. And with steep low-level lapse rates and moderate to strong instability, some of this convection may be capable of producing strong to locally severe winds through the early evening hours before eventually weakening with the loss of daytime heating. ...High Plains... Moderate instability should develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. ..Gleason/Grams.. 07/24/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Thu Jul 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE GREAT LAKES INTO THE MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS... ...SUMMARY... Locally damaging thunderstorm wind gusts will be possible from parts of the Great Lakes to the central and southern Plains, mainly this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...Synopsis... Modestly enhanced westerly mid-level flow will be maintained today between an upper trough progressing slowly eastward over central Canada and the north-central CONUS, and upper ridging across the Southeast and Mid-Atlantic. Multiple mid-level MCVs evident on satellite and radar should move generally east-northeastward across parts of the Midwest and Great Lakes today. At the surface, a convectively reinforced front will be draped from Ontario/Quebec southwestward to the southern Plains. This front will likely serve as a focused for additional scattered to numerous thunderstorms this afternoon and evening, some of which could become strong to severe on an isolated basis. ...Great Lakes into the Midwest and Central/Southern Plains... A moist and rather unstable airmass will exist along/ahead of the front today, as diurnal heating aids in the gradual steepening of low-level lapse rates. Stronger mid-level flow and related deep-layer shear should be present across parts of MI and vicinity. Some enhancement to the low/mid-level winds and modest ascent associated with an MCV over northeast WI this morning may also aid in thunderstorm development and organization downstream into parts of northern Lower MI by early afternoon. This area appears to have the best combination of forecast instability and shear, and any thunderstorms which can form here could become severe while posing a threat for both isolated hail and damaging winds. However, low-level flow along/near the front is generally expected to remain veered to southwesterly, which should limit low-level convergence to some extent. Therefore, confidence in overall coverage of severe convection remains too low to include greater severe probabilities across northern Lower MI at this time. Mid-level flow and effective bulk shear values will decrease with southward extent across the Midwest into the southern Plains, away from any remnant MCV influences. This should tend to limit updraft organization with thunderstorms that develop this afternoon across these regions. Still, some potential should exist for loosely organized clusters given the linear low-level forcing. And with steep low-level lapse rates and moderate to strong instability, some of this convection may be capable of producing strong to locally severe winds through the early evening hours before eventually weakening with the loss of daytime heating. ...High Plains... Moderate instability should develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. ..Gleason/Grams.. 07/24/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Thu Jul 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE GREAT LAKES INTO THE MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS... ...SUMMARY... Locally damaging thunderstorm wind gusts will be possible from parts of the Great Lakes to the central and southern Plains, mainly this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...Synopsis... Modestly enhanced westerly mid-level flow will be maintained today between an upper trough progressing slowly eastward over central Canada and the north-central CONUS, and upper ridging across the Southeast and Mid-Atlantic. Multiple mid-level MCVs evident on satellite and radar should move generally east-northeastward across parts of the Midwest and Great Lakes today. At the surface, a convectively reinforced front will be draped from Ontario/Quebec southwestward to the southern Plains. This front will likely serve as a focused for additional scattered to numerous thunderstorms this afternoon and evening, some of which could become strong to severe on an isolated basis. ...Great Lakes into the Midwest and Central/Southern Plains... A moist and rather unstable airmass will exist along/ahead of the front today, as diurnal heating aids in the gradual steepening of low-level lapse rates. Stronger mid-level flow and related deep-layer shear should be present across parts of MI and vicinity. Some enhancement to the low/mid-level winds and modest ascent associated with an MCV over northeast WI this morning may also aid in thunderstorm development and organization downstream into parts of northern Lower MI by early afternoon. This area appears to have the best combination of forecast instability and shear, and any thunderstorms which can form here could become severe while posing a threat for both isolated hail and damaging winds. However, low-level flow along/near the front is generally expected to remain veered to southwesterly, which should limit low-level convergence to some extent. Therefore, confidence in overall coverage of severe convection remains too low to include greater severe probabilities across northern Lower MI at this time. Mid-level flow and effective bulk shear values will decrease with southward extent across the Midwest into the southern Plains, away from any remnant MCV influences. This should tend to limit updraft organization with thunderstorms that develop this afternoon across these regions. Still, some potential should exist for loosely organized clusters given the linear low-level forcing. And with steep low-level lapse rates and moderate to strong instability, some of this convection may be capable of producing strong to locally severe winds through the early evening hours before eventually weakening with the loss of daytime heating. ...High Plains... Moderate instability should develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. ..Gleason/Grams.. 07/24/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Thu Jul 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE GREAT LAKES INTO THE MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS... ...SUMMARY... Locally damaging thunderstorm wind gusts will be possible from parts of the Great Lakes to the central and southern Plains, mainly this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...Synopsis... Modestly enhanced westerly mid-level flow will be maintained today between an upper trough progressing slowly eastward over central Canada and the north-central CONUS, and upper ridging across the Southeast and Mid-Atlantic. Multiple mid-level MCVs evident on satellite and radar should move generally east-northeastward across parts of the Midwest and Great Lakes today. At the surface, a convectively reinforced front will be draped from Ontario/Quebec southwestward to the southern Plains. This front will likely serve as a focused for additional scattered to numerous thunderstorms this afternoon and evening, some of which could become strong to severe on an isolated basis. ...Great Lakes into the Midwest and Central/Southern Plains... A moist and rather unstable airmass will exist along/ahead of the front today, as diurnal heating aids in the gradual steepening of low-level lapse rates. Stronger mid-level flow and related deep-layer shear should be present across parts of MI and vicinity. Some enhancement to the low/mid-level winds and modest ascent associated with an MCV over northeast WI this morning may also aid in thunderstorm development and organization downstream into parts of northern Lower MI by early afternoon. This area appears to have the best combination of forecast instability and shear, and any thunderstorms which can form here could become severe while posing a threat for both isolated hail and damaging winds. However, low-level flow along/near the front is generally expected to remain veered to southwesterly, which should limit low-level convergence to some extent. Therefore, confidence in overall coverage of severe convection remains too low to include greater severe probabilities across northern Lower MI at this time. Mid-level flow and effective bulk shear values will decrease with southward extent across the Midwest into the southern Plains, away from any remnant MCV influences. This should tend to limit updraft organization with thunderstorms that develop this afternoon across these regions. Still, some potential should exist for loosely organized clusters given the linear low-level forcing. And with steep low-level lapse rates and moderate to strong instability, some of this convection may be capable of producing strong to locally severe winds through the early evening hours before eventually weakening with the loss of daytime heating. ...High Plains... Moderate instability should develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. ..Gleason/Grams.. 07/24/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Thu Jul 24 2025 Valid 241300Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE GREAT LAKES INTO THE MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS... ...SUMMARY... Locally damaging thunderstorm wind gusts will be possible from parts of the Great Lakes to the central and southern Plains, mainly this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...Synopsis... Modestly enhanced westerly mid-level flow will be maintained today between an upper trough progressing slowly eastward over central Canada and the north-central CONUS, and upper ridging across the Southeast and Mid-Atlantic. Multiple mid-level MCVs evident on satellite and radar should move generally east-northeastward across parts of the Midwest and Great Lakes today. At the surface, a convectively reinforced front will be draped from Ontario/Quebec southwestward to the southern Plains. This front will likely serve as a focused for additional scattered to numerous thunderstorms this afternoon and evening, some of which could become strong to severe on an isolated basis. ...Great Lakes into the Midwest and Central/Southern Plains... A moist and rather unstable airmass will exist along/ahead of the front today, as diurnal heating aids in the gradual steepening of low-level lapse rates. Stronger mid-level flow and related deep-layer shear should be present across parts of MI and vicinity. Some enhancement to the low/mid-level winds and modest ascent associated with an MCV over northeast WI this morning may also aid in thunderstorm development and organization downstream into parts of northern Lower MI by early afternoon. This area appears to have the best combination of forecast instability and shear, and any thunderstorms which can form here could become severe while posing a threat for both isolated hail and damaging winds. However, low-level flow along/near the front is generally expected to remain veered to southwesterly, which should limit low-level convergence to some extent. Therefore, confidence in overall coverage of severe convection remains too low to include greater severe probabilities across northern Lower MI at this time. Mid-level flow and effective bulk shear values will decrease with southward extent across the Midwest into the southern Plains, away from any remnant MCV influences. This should tend to limit updraft organization with thunderstorms that develop this afternoon across these regions. Still, some potential should exist for loosely organized clusters given the linear low-level forcing. And with steep low-level lapse rates and moderate to strong instability, some of this convection may be capable of producing strong to locally severe winds through the early evening hours before eventually weakening with the loss of daytime heating. ...High Plains... Moderate instability should develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. ..Gleason/Grams.. 07/24/2025 Read more

000
ABPZ20 KNHC 241136
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Thu Jul 24 2025

For the eastern and central North Pacific east of 180 longitude:

Well Southeast of the Hawaiian Islands:
An area of low pressure is forecast to develop well to the southeast
of the Hawaiian Islands by this weekend. Thereafter, some gradual
development is possible and a tropical depression could form while
the system moves generally westward at 10 to 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium..40 percent.

$$
Forecaster Pasch

000
ABNT20 KNHC 241131
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Thu Jul 24 2025

For the North Atlantic...Caribbean Sea and the Gulf of America:

North-Central Gulf:
A trough of low pressure over the north-central Gulf is currently
producing a broad area of disorganized showers and thunderstorms.
Over the next day or two, this system is forecast to move generally
westward across the north-central portion of the Gulf where some
slow development is possible. By this weekend, the system is likely
to move inland, ending its chances for development. Regardless of
tropical cyclone formation, locally heavy rainfall is possible for
portions of the northern Gulf coast through this weekend.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

$$
Forecaster Kelly

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Jul 24 2025 Valid 271200Z - 011200Z ...DISCUSSION... Models indicate substantive amplification within an initially zonal belt of westerlies across the northern mid-latitude Pacific during the coming days, with several embedded closed lows evolving, including one by the beginning of the period across the northeastern Pacific, on the leading edge of an increasingly blocked regime. Downstream, as another significant low, emerging from the Arctic latitudes, turns across the eastern Northwest Territories into and through Hudson Bay, mid/upper ridging is forecast to build through much of the Canadian Prairies. Gradually, models indicate that amplified ridging will encompass much of interior North America, across and east of the Rockies through the mid to latter portions of next week, while amplified troughing evolves further downstream, across the eastern Canadian provinces, the Great Lakes and Northeast. The evolution of this regime appears likely to be accompanied by a plume of steepening mid-level lapse rates overspreading the northern U.S. Great Plains and adjacent portions of southern Canada, toward the Upper Midwest/Great Lakes, during the early to middle portion of next week, before becoming suppressed southwestward. Aided by the return of seasonably high boundary layer moisture content to areas near and northeast of the lower through middle Missouri Valley, it appears that this will contribute to a broad area of moderate to large potential instability. This environment may become conditionally supportive of the evolution of longer-lived organized thunderstorm clusters, with potential to produce swaths of damaging wind gusts across parts of the northern Great Plains, Upper Midwest and Great Lakes into the Ohio Valley and perhaps parts of the Northeast. However, prior to more substantive mid/upper trough amplification, and the southward advancement of a cold front into much of the northeastern U.S. by the middle of next week, the evolution of any such cluster, south of the international border, will likely largely depend on subtle short wave perturbations progressing through the larger scale ridging. Given the low predictability of these features at this extended range, and the uncertain impacts of their associated convection and outflow on subsequent destabilization, severe probabilities remain low due to the uncertainties. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Jul 24 2025 Valid 271200Z - 011200Z ...DISCUSSION... Models indicate substantive amplification within an initially zonal belt of westerlies across the northern mid-latitude Pacific during the coming days, with several embedded closed lows evolving, including one by the beginning of the period across the northeastern Pacific, on the leading edge of an increasingly blocked regime. Downstream, as another significant low, emerging from the Arctic latitudes, turns across the eastern Northwest Territories into and through Hudson Bay, mid/upper ridging is forecast to build through much of the Canadian Prairies. Gradually, models indicate that amplified ridging will encompass much of interior North America, across and east of the Rockies through the mid to latter portions of next week, while amplified troughing evolves further downstream, across the eastern Canadian provinces, the Great Lakes and Northeast. The evolution of this regime appears likely to be accompanied by a plume of steepening mid-level lapse rates overspreading the northern U.S. Great Plains and adjacent portions of southern Canada, toward the Upper Midwest/Great Lakes, during the early to middle portion of next week, before becoming suppressed southwestward. Aided by the return of seasonably high boundary layer moisture content to areas near and northeast of the lower through middle Missouri Valley, it appears that this will contribute to a broad area of moderate to large potential instability. This environment may become conditionally supportive of the evolution of longer-lived organized thunderstorm clusters, with potential to produce swaths of damaging wind gusts across parts of the northern Great Plains, Upper Midwest and Great Lakes into the Ohio Valley and perhaps parts of the Northeast. However, prior to more substantive mid/upper trough amplification, and the southward advancement of a cold front into much of the northeastern U.S. by the middle of next week, the evolution of any such cluster, south of the international border, will likely largely depend on subtle short wave perturbations progressing through the larger scale ridging. Given the low predictability of these features at this extended range, and the uncertain impacts of their associated convection and outflow on subsequent destabilization, severe probabilities remain low due to the uncertainties. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Jul 24 2025 Valid 271200Z - 011200Z ...DISCUSSION... Models indicate substantive amplification within an initially zonal belt of westerlies across the northern mid-latitude Pacific during the coming days, with several embedded closed lows evolving, including one by the beginning of the period across the northeastern Pacific, on the leading edge of an increasingly blocked regime. Downstream, as another significant low, emerging from the Arctic latitudes, turns across the eastern Northwest Territories into and through Hudson Bay, mid/upper ridging is forecast to build through much of the Canadian Prairies. Gradually, models indicate that amplified ridging will encompass much of interior North America, across and east of the Rockies through the mid to latter portions of next week, while amplified troughing evolves further downstream, across the eastern Canadian provinces, the Great Lakes and Northeast. The evolution of this regime appears likely to be accompanied by a plume of steepening mid-level lapse rates overspreading the northern U.S. Great Plains and adjacent portions of southern Canada, toward the Upper Midwest/Great Lakes, during the early to middle portion of next week, before becoming suppressed southwestward. Aided by the return of seasonably high boundary layer moisture content to areas near and northeast of the lower through middle Missouri Valley, it appears that this will contribute to a broad area of moderate to large potential instability. This environment may become conditionally supportive of the evolution of longer-lived organized thunderstorm clusters, with potential to produce swaths of damaging wind gusts across parts of the northern Great Plains, Upper Midwest and Great Lakes into the Ohio Valley and perhaps parts of the Northeast. However, prior to more substantive mid/upper trough amplification, and the southward advancement of a cold front into much of the northeastern U.S. by the middle of next week, the evolution of any such cluster, south of the international border, will likely largely depend on subtle short wave perturbations progressing through the larger scale ridging. Given the low predictability of these features at this extended range, and the uncertain impacts of their associated convection and outflow on subsequent destabilization, severe probabilities remain low due to the uncertainties. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Jul 24 2025 Valid 271200Z - 011200Z ...DISCUSSION... Models indicate substantive amplification within an initially zonal belt of westerlies across the northern mid-latitude Pacific during the coming days, with several embedded closed lows evolving, including one by the beginning of the period across the northeastern Pacific, on the leading edge of an increasingly blocked regime. Downstream, as another significant low, emerging from the Arctic latitudes, turns across the eastern Northwest Territories into and through Hudson Bay, mid/upper ridging is forecast to build through much of the Canadian Prairies. Gradually, models indicate that amplified ridging will encompass much of interior North America, across and east of the Rockies through the mid to latter portions of next week, while amplified troughing evolves further downstream, across the eastern Canadian provinces, the Great Lakes and Northeast. The evolution of this regime appears likely to be accompanied by a plume of steepening mid-level lapse rates overspreading the northern U.S. Great Plains and adjacent portions of southern Canada, toward the Upper Midwest/Great Lakes, during the early to middle portion of next week, before becoming suppressed southwestward. Aided by the return of seasonably high boundary layer moisture content to areas near and northeast of the lower through middle Missouri Valley, it appears that this will contribute to a broad area of moderate to large potential instability. This environment may become conditionally supportive of the evolution of longer-lived organized thunderstorm clusters, with potential to produce swaths of damaging wind gusts across parts of the northern Great Plains, Upper Midwest and Great Lakes into the Ohio Valley and perhaps parts of the Northeast. However, prior to more substantive mid/upper trough amplification, and the southward advancement of a cold front into much of the northeastern U.S. by the middle of next week, the evolution of any such cluster, south of the international border, will likely largely depend on subtle short wave perturbations progressing through the larger scale ridging. Given the low predictability of these features at this extended range, and the uncertain impacts of their associated convection and outflow on subsequent destabilization, severe probabilities remain low due to the uncertainties. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Jul 24 2025 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SATURDAY THROUGH SATURDAY NIGHT ACROSS PARTS OF THE MIDWEST INTO SOUTHERN PORTIONS OF THE GREAT LAKES REGION AND ACROSS PARTS OF THE NORTHERN ROCKIES INTO THE DAKOTAS... ...SUMMARY... Strong thunderstorms accompanied by potentially damaging wind gusts are possible Saturday through Saturday night, across parts of the Midwest into southern Great Lakes region and across parts of the northern Rockies into the Dakotas. ...Discussion... Models indicate that weak mid-level troughing inland of the Pacific Northwest and across California into the Great Basin will persist through this period, but mid-level heights downstream across the Rockies, much of the Great Plains/Mississippi Valley and adjacent portions of southern Canada are forecast to rise within consolidating large-scale anticyclonic flow. Farther east, subtle mid-level troughing associated with a couple of perturbations may overspread the Great Lakes region. In lower latitudes, it appears that the prominent center of highest mid-level heights (in excess of 594 dm at 500 mb) will begin expanding westward out of the Southeast, toward the central and southern Great Plains. However, a weak wave on its southern periphery may continue slowly inland of the northwest Gulf coast. In lower levels, a remnant frontal zone may become increasingly diffuse while advancing offshore of the northern and middle Atlantic Seaboard, and returning northward through southern portions of the Great Lakes. ...Midwest into southern Great Lakes Region... Confidence is low, but models suggest that a possible convectively augmented perturbation may progress east of the Dakotas through the upper Great Lakes region during this period, with another convectively generated or augmented perturbation, emerging from the Great Plains to its south, turning eastward across the Midwest into southern portions of the Great Lakes. It appears that this may be accompanied by a belt of 20-40 kt westerly lower/mid-tropospheric flow. With the boundary-layer becoming characterized by seasonably high moisture content and sizable CAPE, along and south of the remnant frontal zone by Saturday afternoon, mid-level forcing for ascent may support an evolving cluster of storms. Although mid-level lapse rates may be modest to weak, the modest shear/westerly deep-layer mean flow may be sufficient to support a developing risk for strong to severe wind gusts as activity progresses eastward, aided by heavy precipitation loading and evaporative cooling/melting in downdrafts. ...Northern Rockies into the Dakotas... Confidence is low due to uncertain forcing for convective development across the northern Rockies, and potential for substantive inhibition eastward into the Great Plains. However, models suggest areas of stronger sub-synoptic ascent may overspread the higher terrain of southern Montana by late Saturday afternoon and evening. In the presence of a deeply mixed boundary layer with modest CAPE, this may become supportive of scattered upscale growing thunderstorm development capable of produce strong downbursts. There appears some potential for consolidating cold pools to support intensifying thunderstorm development, with a continuing risk for strong to severe surface gusts, in better potential boundary-layer instability across southeastern Montana into central North Dakota Saturday evening, before activity weakens in the presence of increasing inhibition. ..Kerr.. 07/24/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Jul 24 2025 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SATURDAY THROUGH SATURDAY NIGHT ACROSS PARTS OF THE MIDWEST INTO SOUTHERN PORTIONS OF THE GREAT LAKES REGION AND ACROSS PARTS OF THE NORTHERN ROCKIES INTO THE DAKOTAS... ...SUMMARY... Strong thunderstorms accompanied by potentially damaging wind gusts are possible Saturday through Saturday night, across parts of the Midwest into southern Great Lakes region and across parts of the northern Rockies into the Dakotas. ...Discussion... Models indicate that weak mid-level troughing inland of the Pacific Northwest and across California into the Great Basin will persist through this period, but mid-level heights downstream across the Rockies, much of the Great Plains/Mississippi Valley and adjacent portions of southern Canada are forecast to rise within consolidating large-scale anticyclonic flow. Farther east, subtle mid-level troughing associated with a couple of perturbations may overspread the Great Lakes region. In lower latitudes, it appears that the prominent center of highest mid-level heights (in excess of 594 dm at 500 mb) will begin expanding westward out of the Southeast, toward the central and southern Great Plains. However, a weak wave on its southern periphery may continue slowly inland of the northwest Gulf coast. In lower levels, a remnant frontal zone may become increasingly diffuse while advancing offshore of the northern and middle Atlantic Seaboard, and returning northward through southern portions of the Great Lakes. ...Midwest into southern Great Lakes Region... Confidence is low, but models suggest that a possible convectively augmented perturbation may progress east of the Dakotas through the upper Great Lakes region during this period, with another convectively generated or augmented perturbation, emerging from the Great Plains to its south, turning eastward across the Midwest into southern portions of the Great Lakes. It appears that this may be accompanied by a belt of 20-40 kt westerly lower/mid-tropospheric flow. With the boundary-layer becoming characterized by seasonably high moisture content and sizable CAPE, along and south of the remnant frontal zone by Saturday afternoon, mid-level forcing for ascent may support an evolving cluster of storms. Although mid-level lapse rates may be modest to weak, the modest shear/westerly deep-layer mean flow may be sufficient to support a developing risk for strong to severe wind gusts as activity progresses eastward, aided by heavy precipitation loading and evaporative cooling/melting in downdrafts. ...Northern Rockies into the Dakotas... Confidence is low due to uncertain forcing for convective development across the northern Rockies, and potential for substantive inhibition eastward into the Great Plains. However, models suggest areas of stronger sub-synoptic ascent may overspread the higher terrain of southern Montana by late Saturday afternoon and evening. In the presence of a deeply mixed boundary layer with modest CAPE, this may become supportive of scattered upscale growing thunderstorm development capable of produce strong downbursts. There appears some potential for consolidating cold pools to support intensifying thunderstorm development, with a continuing risk for strong to severe surface gusts, in better potential boundary-layer instability across southeastern Montana into central North Dakota Saturday evening, before activity weakens in the presence of increasing inhibition. ..Kerr.. 07/24/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Jul 24 2025 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SATURDAY THROUGH SATURDAY NIGHT ACROSS PARTS OF THE MIDWEST INTO SOUTHERN PORTIONS OF THE GREAT LAKES REGION AND ACROSS PARTS OF THE NORTHERN ROCKIES INTO THE DAKOTAS... ...SUMMARY... Strong thunderstorms accompanied by potentially damaging wind gusts are possible Saturday through Saturday night, across parts of the Midwest into southern Great Lakes region and across parts of the northern Rockies into the Dakotas. ...Discussion... Models indicate that weak mid-level troughing inland of the Pacific Northwest and across California into the Great Basin will persist through this period, but mid-level heights downstream across the Rockies, much of the Great Plains/Mississippi Valley and adjacent portions of southern Canada are forecast to rise within consolidating large-scale anticyclonic flow. Farther east, subtle mid-level troughing associated with a couple of perturbations may overspread the Great Lakes region. In lower latitudes, it appears that the prominent center of highest mid-level heights (in excess of 594 dm at 500 mb) will begin expanding westward out of the Southeast, toward the central and southern Great Plains. However, a weak wave on its southern periphery may continue slowly inland of the northwest Gulf coast. In lower levels, a remnant frontal zone may become increasingly diffuse while advancing offshore of the northern and middle Atlantic Seaboard, and returning northward through southern portions of the Great Lakes. ...Midwest into southern Great Lakes Region... Confidence is low, but models suggest that a possible convectively augmented perturbation may progress east of the Dakotas through the upper Great Lakes region during this period, with another convectively generated or augmented perturbation, emerging from the Great Plains to its south, turning eastward across the Midwest into southern portions of the Great Lakes. It appears that this may be accompanied by a belt of 20-40 kt westerly lower/mid-tropospheric flow. With the boundary-layer becoming characterized by seasonably high moisture content and sizable CAPE, along and south of the remnant frontal zone by Saturday afternoon, mid-level forcing for ascent may support an evolving cluster of storms. Although mid-level lapse rates may be modest to weak, the modest shear/westerly deep-layer mean flow may be sufficient to support a developing risk for strong to severe wind gusts as activity progresses eastward, aided by heavy precipitation loading and evaporative cooling/melting in downdrafts. ...Northern Rockies into the Dakotas... Confidence is low due to uncertain forcing for convective development across the northern Rockies, and potential for substantive inhibition eastward into the Great Plains. However, models suggest areas of stronger sub-synoptic ascent may overspread the higher terrain of southern Montana by late Saturday afternoon and evening. In the presence of a deeply mixed boundary layer with modest CAPE, this may become supportive of scattered upscale growing thunderstorm development capable of produce strong downbursts. There appears some potential for consolidating cold pools to support intensifying thunderstorm development, with a continuing risk for strong to severe surface gusts, in better potential boundary-layer instability across southeastern Montana into central North Dakota Saturday evening, before activity weakens in the presence of increasing inhibition. ..Kerr.. 07/24/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Jul 24 2025 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SATURDAY THROUGH SATURDAY NIGHT ACROSS PARTS OF THE MIDWEST INTO SOUTHERN PORTIONS OF THE GREAT LAKES REGION AND ACROSS PARTS OF THE NORTHERN ROCKIES INTO THE DAKOTAS... ...SUMMARY... Strong thunderstorms accompanied by potentially damaging wind gusts are possible Saturday through Saturday night, across parts of the Midwest into southern Great Lakes region and across parts of the northern Rockies into the Dakotas. ...Discussion... Models indicate that weak mid-level troughing inland of the Pacific Northwest and across California into the Great Basin will persist through this period, but mid-level heights downstream across the Rockies, much of the Great Plains/Mississippi Valley and adjacent portions of southern Canada are forecast to rise within consolidating large-scale anticyclonic flow. Farther east, subtle mid-level troughing associated with a couple of perturbations may overspread the Great Lakes region. In lower latitudes, it appears that the prominent center of highest mid-level heights (in excess of 594 dm at 500 mb) will begin expanding westward out of the Southeast, toward the central and southern Great Plains. However, a weak wave on its southern periphery may continue slowly inland of the northwest Gulf coast. In lower levels, a remnant frontal zone may become increasingly diffuse while advancing offshore of the northern and middle Atlantic Seaboard, and returning northward through southern portions of the Great Lakes. ...Midwest into southern Great Lakes Region... Confidence is low, but models suggest that a possible convectively augmented perturbation may progress east of the Dakotas through the upper Great Lakes region during this period, with another convectively generated or augmented perturbation, emerging from the Great Plains to its south, turning eastward across the Midwest into southern portions of the Great Lakes. It appears that this may be accompanied by a belt of 20-40 kt westerly lower/mid-tropospheric flow. With the boundary-layer becoming characterized by seasonably high moisture content and sizable CAPE, along and south of the remnant frontal zone by Saturday afternoon, mid-level forcing for ascent may support an evolving cluster of storms. Although mid-level lapse rates may be modest to weak, the modest shear/westerly deep-layer mean flow may be sufficient to support a developing risk for strong to severe wind gusts as activity progresses eastward, aided by heavy precipitation loading and evaporative cooling/melting in downdrafts. ...Northern Rockies into the Dakotas... Confidence is low due to uncertain forcing for convective development across the northern Rockies, and potential for substantive inhibition eastward into the Great Plains. However, models suggest areas of stronger sub-synoptic ascent may overspread the higher terrain of southern Montana by late Saturday afternoon and evening. In the presence of a deeply mixed boundary layer with modest CAPE, this may become supportive of scattered upscale growing thunderstorm development capable of produce strong downbursts. There appears some potential for consolidating cold pools to support intensifying thunderstorm development, with a continuing risk for strong to severe surface gusts, in better potential boundary-layer instability across southeastern Montana into central North Dakota Saturday evening, before activity weakens in the presence of increasing inhibition. ..Kerr.. 07/24/2025 Read more

MD 1769 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL TO EASTERN IA
Mesoscale Discussion 1769 NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Jul 24 2025 Areas affected...central to eastern IA Concerning...Severe potential...Watch unlikely Valid 240546Z - 240715Z Probability of Watch Issuance...20 percent SUMMARY...Strong to localized severe gust threat may accompany a portion of a QLCS, mainly centered on the US-30/I-80 corridors during the next few hours. Expected localized coverage suggests Severe Thunderstorm Watch issuance remains unlikely. DISCUSSION...Some surge within a broader QLCS has occurred within the apex of outflow intersections northwest of the DSM Metro Area, with measured severe gusts at personal weather stations in Carroll County earlier this hour. A swath of 50-65 kt inbound velocities around 2500-3000 ft AGL have recently progressed into Greene County. Given ample buoyancy with MLCAPE of 2000-2500 J/kg and a 40-45 kt rear-inflow jet per OAX VWP data, it is plausible that a confined swath of strong to embedded severe gusts may persist over the next 2-3 hours. This is likely to be centered on the US-30/I-80 corridors, where the portion of the line remains more progressive atop preceding outflow from downshear convection. ..Grams/Gleason.. 07/24/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX... LAT...LON 42259315 42589230 42719178 42689149 42409130 42119149 41669170 41519291 41499374 41629411 42009402 42079379 42259315 MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1157 PM CDT Wed Jul 23 2025 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT ACROSS PARTS OF NEW ENGLAND INTO THE NORTHERN MID ATLANTIC AND ACROSS NORTH DAKOTA AND ADJACENT PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Scattered strong to severe thunderstorms, and perhaps a developing line, may pose a risk of damaging wind gusts across parts of New England and the northern Mid Atlantic on Friday. The development of an organized cluster of storms with potential to produce strong to severe wind gusts is also possible across North Dakota by Friday evening. ...Discussion... Models continue to indicate that fairly significant troughing within the westerlies will dig across Quebec, northern New England and the Canadian Maritimes during this period. Weaker troughing is also forecast to dig into portions of the British Columbia and Pacific Northwest coast, as well as inland across California through the Great Basin. Across much of the Great Plains, Mississippi Valley, and Great Lakes into middle and southern Atlantic Seaboard, mid/upper heights are likely to remain generally high. However, it still appears that a subtle perturbation progressing across and east of the northern Rockies could suppress mid-level heights across North Dakota and adjacent portions of the northern Great Plains late Friday through Friday night. Latest model output appears increasingly suggestive that a notable MCV may evolve within the weak flow across the central Great Plains by early Friday, before migrating slowly northeastward, with a number of weaker convectively generated or enhanced perturbations downstream, across parts of the lower Missouri Valley into southern Great Lakes/Ohio Valley. But, this remains much more uncertain at the present time. In lower levels, a cold front is likely to advance across much of the Northeast, while its trailing flank continues to stall, weaken and perhaps slowly shift northward across the Ohio Valley through central Great Plains. ...New England into northern Mid Atlantic... Latest model output is not much clearer concerning potential storm coverage and the risk of severe weather for Friday. How far south the cold front advances into New England before the boundary-layer is able to destabilize appreciably also remains unclear. However, the front across New England, and the pre-frontal trough across the northern Mid Atlantic, probably will become the focus of at least scattered thunderstorm development, aided by forcing associated with the digging mid-level trough. Lower/mid-tropospheric lapse rates may not become particularly steep, but seasonably high boundary-layer moisture content advecting ahead of the cold front may still contribute to moderate mixed-layer CAPE with daytime heating. In the presence of 20-40+ kt westerly flow in the 850-500 mb layer overspreading much of the region, the environment may become conducive to organized convection, perhaps including a couple of supercells, and upscale growing southeastward propagating clusters or a developing line accompanied by potentially damaging wind gusts. Due to lingering uncertainties, severe probabilities are being maintained at 5 percent, but it is still possible that severe probabilities could be increased in later outlooks for this period. ...North Dakota... The NAM, in particular, continues to generate a notable convective perturbation across North Dakota, mainly late Friday into Friday night. This is supported by other model output to an extent, and is generally focused where lower/mid-tropospheric warm advection might become maximized by Friday evening, on the leading edge of a northward advecting plume of warm and increasingly capping air around the 700 mb level. Beneath steep lower/mid-tropospheric lapse rates, it appears that low-level moistening will contribute to moderate large CAPE supportive of vigorous convection, with thermodynamic profiles conducive to downbursts and a strengthening cold pool as forcing for ascent contributes to consolidating convection. ...Remainder of Great Plains into Ohio Valley... Beneath the mid-level ridging, destabilization across the high plains, and along the remnant front across the central Great Plains through Ohio Valley, may become supportive of widely scattered vigorous thunderstorm development. Due to generally warm mid/upper thermodynamic profiles and weak flow/shear, localized damaging wind gust appears the primary potentially severe hazard. It is not yet clear that the coverage of any such activity will become sufficient to support introduction of 5 percent severe probabilities. ..Kerr.. 07/24/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1157 PM CDT Wed Jul 23 2025 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT ACROSS PARTS OF NEW ENGLAND INTO THE NORTHERN MID ATLANTIC AND ACROSS NORTH DAKOTA AND ADJACENT PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Scattered strong to severe thunderstorms, and perhaps a developing line, may pose a risk of damaging wind gusts across parts of New England and the northern Mid Atlantic on Friday. The development of an organized cluster of storms with potential to produce strong to severe wind gusts is also possible across North Dakota by Friday evening. ...Discussion... Models continue to indicate that fairly significant troughing within the westerlies will dig across Quebec, northern New England and the Canadian Maritimes during this period. Weaker troughing is also forecast to dig into portions of the British Columbia and Pacific Northwest coast, as well as inland across California through the Great Basin. Across much of the Great Plains, Mississippi Valley, and Great Lakes into middle and southern Atlantic Seaboard, mid/upper heights are likely to remain generally high. However, it still appears that a subtle perturbation progressing across and east of the northern Rockies could suppress mid-level heights across North Dakota and adjacent portions of the northern Great Plains late Friday through Friday night. Latest model output appears increasingly suggestive that a notable MCV may evolve within the weak flow across the central Great Plains by early Friday, before migrating slowly northeastward, with a number of weaker convectively generated or enhanced perturbations downstream, across parts of the lower Missouri Valley into southern Great Lakes/Ohio Valley. But, this remains much more uncertain at the present time. In lower levels, a cold front is likely to advance across much of the Northeast, while its trailing flank continues to stall, weaken and perhaps slowly shift northward across the Ohio Valley through central Great Plains. ...New England into northern Mid Atlantic... Latest model output is not much clearer concerning potential storm coverage and the risk of severe weather for Friday. How far south the cold front advances into New England before the boundary-layer is able to destabilize appreciably also remains unclear. However, the front across New England, and the pre-frontal trough across the northern Mid Atlantic, probably will become the focus of at least scattered thunderstorm development, aided by forcing associated with the digging mid-level trough. Lower/mid-tropospheric lapse rates may not become particularly steep, but seasonably high boundary-layer moisture content advecting ahead of the cold front may still contribute to moderate mixed-layer CAPE with daytime heating. In the presence of 20-40+ kt westerly flow in the 850-500 mb layer overspreading much of the region, the environment may become conducive to organized convection, perhaps including a couple of supercells, and upscale growing southeastward propagating clusters or a developing line accompanied by potentially damaging wind gusts. Due to lingering uncertainties, severe probabilities are being maintained at 5 percent, but it is still possible that severe probabilities could be increased in later outlooks for this period. ...North Dakota... The NAM, in particular, continues to generate a notable convective perturbation across North Dakota, mainly late Friday into Friday night. This is supported by other model output to an extent, and is generally focused where lower/mid-tropospheric warm advection might become maximized by Friday evening, on the leading edge of a northward advecting plume of warm and increasingly capping air around the 700 mb level. Beneath steep lower/mid-tropospheric lapse rates, it appears that low-level moistening will contribute to moderate large CAPE supportive of vigorous convection, with thermodynamic profiles conducive to downbursts and a strengthening cold pool as forcing for ascent contributes to consolidating convection. ...Remainder of Great Plains into Ohio Valley... Beneath the mid-level ridging, destabilization across the high plains, and along the remnant front across the central Great Plains through Ohio Valley, may become supportive of widely scattered vigorous thunderstorm development. Due to generally warm mid/upper thermodynamic profiles and weak flow/shear, localized damaging wind gust appears the primary potentially severe hazard. It is not yet clear that the coverage of any such activity will become sufficient to support introduction of 5 percent severe probabilities. ..Kerr.. 07/24/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1157 PM CDT Wed Jul 23 2025 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT ACROSS PARTS OF NEW ENGLAND INTO THE NORTHERN MID ATLANTIC AND ACROSS NORTH DAKOTA AND ADJACENT PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Scattered strong to severe thunderstorms, and perhaps a developing line, may pose a risk of damaging wind gusts across parts of New England and the northern Mid Atlantic on Friday. The development of an organized cluster of storms with potential to produce strong to severe wind gusts is also possible across North Dakota by Friday evening. ...Discussion... Models continue to indicate that fairly significant troughing within the westerlies will dig across Quebec, northern New England and the Canadian Maritimes during this period. Weaker troughing is also forecast to dig into portions of the British Columbia and Pacific Northwest coast, as well as inland across California through the Great Basin. Across much of the Great Plains, Mississippi Valley, and Great Lakes into middle and southern Atlantic Seaboard, mid/upper heights are likely to remain generally high. However, it still appears that a subtle perturbation progressing across and east of the northern Rockies could suppress mid-level heights across North Dakota and adjacent portions of the northern Great Plains late Friday through Friday night. Latest model output appears increasingly suggestive that a notable MCV may evolve within the weak flow across the central Great Plains by early Friday, before migrating slowly northeastward, with a number of weaker convectively generated or enhanced perturbations downstream, across parts of the lower Missouri Valley into southern Great Lakes/Ohio Valley. But, this remains much more uncertain at the present time. In lower levels, a cold front is likely to advance across much of the Northeast, while its trailing flank continues to stall, weaken and perhaps slowly shift northward across the Ohio Valley through central Great Plains. ...New England into northern Mid Atlantic... Latest model output is not much clearer concerning potential storm coverage and the risk of severe weather for Friday. How far south the cold front advances into New England before the boundary-layer is able to destabilize appreciably also remains unclear. However, the front across New England, and the pre-frontal trough across the northern Mid Atlantic, probably will become the focus of at least scattered thunderstorm development, aided by forcing associated with the digging mid-level trough. Lower/mid-tropospheric lapse rates may not become particularly steep, but seasonably high boundary-layer moisture content advecting ahead of the cold front may still contribute to moderate mixed-layer CAPE with daytime heating. In the presence of 20-40+ kt westerly flow in the 850-500 mb layer overspreading much of the region, the environment may become conducive to organized convection, perhaps including a couple of supercells, and upscale growing southeastward propagating clusters or a developing line accompanied by potentially damaging wind gusts. Due to lingering uncertainties, severe probabilities are being maintained at 5 percent, but it is still possible that severe probabilities could be increased in later outlooks for this period. ...North Dakota... The NAM, in particular, continues to generate a notable convective perturbation across North Dakota, mainly late Friday into Friday night. This is supported by other model output to an extent, and is generally focused where lower/mid-tropospheric warm advection might become maximized by Friday evening, on the leading edge of a northward advecting plume of warm and increasingly capping air around the 700 mb level. Beneath steep lower/mid-tropospheric lapse rates, it appears that low-level moistening will contribute to moderate large CAPE supportive of vigorous convection, with thermodynamic profiles conducive to downbursts and a strengthening cold pool as forcing for ascent contributes to consolidating convection. ...Remainder of Great Plains into Ohio Valley... Beneath the mid-level ridging, destabilization across the high plains, and along the remnant front across the central Great Plains through Ohio Valley, may become supportive of widely scattered vigorous thunderstorm development. Due to generally warm mid/upper thermodynamic profiles and weak flow/shear, localized damaging wind gust appears the primary potentially severe hazard. It is not yet clear that the coverage of any such activity will become sufficient to support introduction of 5 percent severe probabilities. ..Kerr.. 07/24/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1157 PM CDT Wed Jul 23 2025 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT ACROSS PARTS OF NEW ENGLAND INTO THE NORTHERN MID ATLANTIC AND ACROSS NORTH DAKOTA AND ADJACENT PORTIONS OF THE GREAT PLAINS... ...SUMMARY... Scattered strong to severe thunderstorms, and perhaps a developing line, may pose a risk of damaging wind gusts across parts of New England and the northern Mid Atlantic on Friday. The development of an organized cluster of storms with potential to produce strong to severe wind gusts is also possible across North Dakota by Friday evening. ...Discussion... Models continue to indicate that fairly significant troughing within the westerlies will dig across Quebec, northern New England and the Canadian Maritimes during this period. Weaker troughing is also forecast to dig into portions of the British Columbia and Pacific Northwest coast, as well as inland across California through the Great Basin. Across much of the Great Plains, Mississippi Valley, and Great Lakes into middle and southern Atlantic Seaboard, mid/upper heights are likely to remain generally high. However, it still appears that a subtle perturbation progressing across and east of the northern Rockies could suppress mid-level heights across North Dakota and adjacent portions of the northern Great Plains late Friday through Friday night. Latest model output appears increasingly suggestive that a notable MCV may evolve within the weak flow across the central Great Plains by early Friday, before migrating slowly northeastward, with a number of weaker convectively generated or enhanced perturbations downstream, across parts of the lower Missouri Valley into southern Great Lakes/Ohio Valley. But, this remains much more uncertain at the present time. In lower levels, a cold front is likely to advance across much of the Northeast, while its trailing flank continues to stall, weaken and perhaps slowly shift northward across the Ohio Valley through central Great Plains. ...New England into northern Mid Atlantic... Latest model output is not much clearer concerning potential storm coverage and the risk of severe weather for Friday. How far south the cold front advances into New England before the boundary-layer is able to destabilize appreciably also remains unclear. However, the front across New England, and the pre-frontal trough across the northern Mid Atlantic, probably will become the focus of at least scattered thunderstorm development, aided by forcing associated with the digging mid-level trough. Lower/mid-tropospheric lapse rates may not become particularly steep, but seasonably high boundary-layer moisture content advecting ahead of the cold front may still contribute to moderate mixed-layer CAPE with daytime heating. In the presence of 20-40+ kt westerly flow in the 850-500 mb layer overspreading much of the region, the environment may become conducive to organized convection, perhaps including a couple of supercells, and upscale growing southeastward propagating clusters or a developing line accompanied by potentially damaging wind gusts. Due to lingering uncertainties, severe probabilities are being maintained at 5 percent, but it is still possible that severe probabilities could be increased in later outlooks for this period. ...North Dakota... The NAM, in particular, continues to generate a notable convective perturbation across North Dakota, mainly late Friday into Friday night. This is supported by other model output to an extent, and is generally focused where lower/mid-tropospheric warm advection might become maximized by Friday evening, on the leading edge of a northward advecting plume of warm and increasingly capping air around the 700 mb level. Beneath steep lower/mid-tropospheric lapse rates, it appears that low-level moistening will contribute to moderate large CAPE supportive of vigorous convection, with thermodynamic profiles conducive to downbursts and a strengthening cold pool as forcing for ascent contributes to consolidating convection. ...Remainder of Great Plains into Ohio Valley... Beneath the mid-level ridging, destabilization across the high plains, and along the remnant front across the central Great Plains through Ohio Valley, may become supportive of widely scattered vigorous thunderstorm development. Due to generally warm mid/upper thermodynamic profiles and weak flow/shear, localized damaging wind gust appears the primary potentially severe hazard. It is not yet clear that the coverage of any such activity will become sufficient to support introduction of 5 percent severe probabilities. ..Kerr.. 07/24/2025 Read more