Severe Storms

MD 1937 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE OREGON AND WASHINGTON
Mesoscale Discussion 1937 NWS Storm Prediction Center Norman OK 0636 PM CDT Sat Sep 07 2019 Areas affected...Portions of the Oregon and Washington Concerning...Severe potential...Watch unlikely Valid 072336Z - 080200Z Probability of Watch Issuance...5 percent SUMMARY...Thunderstorms are forecast to increase in coverage into the overnight. The strongest storms may pose a marginal risk of isolated strong wind gusts and marginally severe hail. DISCUSSION...Radar, satellite, and lightning trends suggest thunderstorms are gradually increasing in coverage and intensity along/near the crest of the Cascades in Oregon and Washington. Thunderstorm activity is expected to remain mostly isolated to widely scattered over the next several hours, before coverage increases markedly overnight as ascent associated with a negatively tilted trough further impinges on the area. The environment across the area is currently characterized by MLCAPE of 500-1000 J/kg and effective bulk shear of 30-40 knots, which should promote semi-organized multicell thunderstorms (or transient supercell structures) that may be capable of producing isolated strong wind gusts and marginally severe hail over the next several hours. While thunderstorm coverage will increase overnight, intensity should decrease as boundary layer cooling ensues and buoyancy is reduced. A Severe Thunderstorm Watch is not currently expected due to the limited areal extent and the marginal nature of the threat. ..Elliott/Thompson.. 09/07/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OTX...PDT...SEW...PQR... LAT...LON 45222223 47332190 48712217 49102234 49142152 49152040 49151939 49131899 45801934 45161987 44652037 44292109 44392187 45222223 Read more

No watches are valid as of Sat Sep 7 23:41:06 UTC 2019.

MD 1937 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE OREGON AND WASHINGTON
Mesoscale Discussion 1937 NWS Storm Prediction Center Norman OK 0636 PM CDT Sat Sep 07 2019 Areas affected...Portions of the Oregon and Washington Concerning...Severe potential...Watch unlikely Valid 072336Z - 080200Z Probability of Watch Issuance...5 percent SUMMARY...Thunderstorms are forecast to increase in coverage into the overnight. The strongest storms may pose a marginal risk of isolated strong wind gusts and marginally severe hail. DISCUSSION...Radar, satellite, and lightning trends suggest thunderstorms are gradually increasing in coverage and intensity along/near the crest of the Cascades in Oregon and Washington. Thunderstorm activity is expected to remain mostly isolated to widely scattered over the next several hours, before coverage increases markedly overnight as ascent associated with a negatively tilted trough further impinges on the area. The environment across the area is currently characterized by MLCAPE of 500-1000 J/kg and effective bulk shear of 30-40 knots, which should promote semi-organized multicell thunderstorms (or transient supercell structures) that may be capable of producing isolated strong wind gusts and marginally severe hail over the next several hours. While thunderstorm coverage will increase overnight, intensity should decrease as boundary layer cooling ensues and buoyancy is reduced. A Severe Thunderstorm Watch is not currently expected due to the limited areal extent and the marginal nature of the threat. ..Elliott/Thompson.. 09/07/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OTX...PDT...SEW...PQR... LAT...LON 45222223 47332190 48712217 49102234 49142152 49152040 49151939 49131899 45801934 45161987 44652037 44292109 44392187 45222223 Read more

No Mesoscale Discussions are in effect as of Sat Sep 7 22:31:06 UTC 2019.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2019 Valid 072000Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS AND NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail will remain possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...20Z Update... No changes have been made to the Marginal Risk areas across the central Plains and Pacific Northwest. ..Gleason.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sat Sep 07 2019/ ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2019 Valid 072000Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS AND NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail will remain possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...20Z Update... No changes have been made to the Marginal Risk areas across the central Plains and Pacific Northwest. ..Gleason.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sat Sep 07 2019/ ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2019 Valid 072000Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS AND NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail will remain possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...20Z Update... No changes have been made to the Marginal Risk areas across the central Plains and Pacific Northwest. ..Gleason.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sat Sep 07 2019/ ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2019 Valid 072000Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS AND NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail will remain possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...20Z Update... No changes have been made to the Marginal Risk areas across the central Plains and Pacific Northwest. ..Gleason.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1124 AM CDT Sat Sep 07 2019/ ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0139 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN UTAH... Confidence has increased that enough areal coverage and temporal extent of gusty winds (exceeding 30 mph at times) and low RH (around 12-15%) to introduce a critical fire weather area for southeastern Utah Sunday afternoon. Fuels are sufficiently dry in this region to promote fire spread as well. An elevated delineation surrounds the critical fire weather area, although locally critical fire weather conditions can be expected especially in west-central Utah and east-central Nevada during peak heating. A few thunderstorms cannot be completely ruled out in northern Utah during the afternoon, though some of these storms may be wetting in nature. Locally critical fire weather can also be expected across portions of southern California due to Sundowner winds. See the previous discussion below for more information. ..Cook.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1255 AM CDT Sat Sep 07 2019/ ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ...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 0139 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN UTAH... Confidence has increased that enough areal coverage and temporal extent of gusty winds (exceeding 30 mph at times) and low RH (around 12-15%) to introduce a critical fire weather area for southeastern Utah Sunday afternoon. Fuels are sufficiently dry in this region to promote fire spread as well. An elevated delineation surrounds the critical fire weather area, although locally critical fire weather conditions can be expected especially in west-central Utah and east-central Nevada during peak heating. A few thunderstorms cannot be completely ruled out in northern Utah during the afternoon, though some of these storms may be wetting in nature. Locally critical fire weather can also be expected across portions of southern California due to Sundowner winds. See the previous discussion below for more information. ..Cook.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1255 AM CDT Sat Sep 07 2019/ ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ...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 0139 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN UTAH... Confidence has increased that enough areal coverage and temporal extent of gusty winds (exceeding 30 mph at times) and low RH (around 12-15%) to introduce a critical fire weather area for southeastern Utah Sunday afternoon. Fuels are sufficiently dry in this region to promote fire spread as well. An elevated delineation surrounds the critical fire weather area, although locally critical fire weather conditions can be expected especially in west-central Utah and east-central Nevada during peak heating. A few thunderstorms cannot be completely ruled out in northern Utah during the afternoon, though some of these storms may be wetting in nature. Locally critical fire weather can also be expected across portions of southern California due to Sundowner winds. See the previous discussion below for more information. ..Cook.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1255 AM CDT Sat Sep 07 2019/ ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ...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 0139 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN UTAH... Confidence has increased that enough areal coverage and temporal extent of gusty winds (exceeding 30 mph at times) and low RH (around 12-15%) to introduce a critical fire weather area for southeastern Utah Sunday afternoon. Fuels are sufficiently dry in this region to promote fire spread as well. An elevated delineation surrounds the critical fire weather area, although locally critical fire weather conditions can be expected especially in west-central Utah and east-central Nevada during peak heating. A few thunderstorms cannot be completely ruled out in northern Utah during the afternoon, though some of these storms may be wetting in nature. Locally critical fire weather can also be expected across portions of southern California due to Sundowner winds. See the previous discussion below for more information. ..Cook.. 09/07/2019 .PREV DISCUSSION... /ISSUED 1255 AM CDT Sat Sep 07 2019/ ...Synopsis... Mid/upper-level longwave troughing is forecast to become established across the western CONUS Day 2/Sunday. As this occurs, a shortwave trough embedded near the base of the longwave trough will move from the Great Basin into the central Rockies throughout the period. ...Southwest and southern Great Basin... Elevated to locally critical conditions are possible across portions of the southwest into the southern Great Basin Day 2/Sunday afternoon/evening as enhanced mid-level flow attendant to the aforementioned shortwave trough overspreads the area and is mixed to the surface. At this time, the best potential for critical fire weather conditions appears to be across portions of southern Utah and northern Arizona, where sustained winds of around 20-25 mph are expected to overlap near critical minimum RH values. However, uncertainty regarding coverage of critical RH values and quality of fuel receptiveness due to recent precipitation precludes the introduction of a critical fire weather area at this time. ...Southern California: Santa Barbara County... Elevated fire weather conditions may already be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara County at 12Z Day 2/Sunday due to poor overnight RH recoveries and persistent Sundowner winds. Elevated fire weather conditions should then increase in coverage over the Santa Barbara South Coast and adjacent foothills by afternoon/evening as gusty Sundowner winds increase and overlap areas with minimum RH values of around 15-25% and receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL ROCKIES/HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorms with strong/gusty winds and hail will be possible across parts of the central Rockies and adjacent High Plains Sunday afternoon and evening. ...Central Rockies/High Plains... Upper troughing will develop eastward across the Great Basin to the northern/central Rockies by Sunday evening, while downstream upper ridging shifts eastward over the Plains. At the surface, an area of low pressure should deepen over southeastern CO through the afternoon, while a separate low develops over northern WY as ascent associated with the upper trough overspreads the central Rockies/High Plains. A nearly stationary surface boundary should extend east/west across KS into northeastern CO Sunday morning, and this front should generally move little through Sunday evening. Storms ongoing at the start of the period across the eastern Great Basin should increase in both coverage and intensity as they develop eastward across the central Rockies by early Sunday afternoon. Mid-level winds attendant to the upper trough are not forecast to be overly strong (around 25-35 kt at 500 mb). But, enough veering/strengthening with height through low/mid levels combined with around 1000-2000 J/kg of MLCAPE along/south of the surface boundary will probably allow for some updraft organization as convection spreads eastward across the central High Plains Sunday afternoon and evening. Tendency should be for storms to congeal into a couple of clusters and spread east-northeastward. Some hail may occur with initial development over the higher terrain, with isolated strong/gusty winds potentially becoming more of a concern across the central High Plains Sunday evening. ...Missouri into the Mid Mississippi Valley... A small cluster of storms may be ongoing at the start of the period across northern/central MO and western IL in a low-level warm air advection regime. A southwesterly low-level jet is expected to quickly weaken through the morning across this region, and a corresponding decrease in storm coverage is anticipated. While a very isolated strong wind gust cannot be ruled out with this morning activity before it weakens, the overall threat appears too isolated to warrant any severe probabilities at this time. The potential for additional storms to develop Sunday afternoon along any residual outflow boundaries or the stationary front also appears highly uncertain, as upper ridging and large-scale subsidence should slowly overspread this region. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/07/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL ROCKIES/HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorms with strong/gusty winds and hail will be possible across parts of the central Rockies and adjacent High Plains Sunday afternoon and evening. ...Central Rockies/High Plains... Upper troughing will develop eastward across the Great Basin to the northern/central Rockies by Sunday evening, while downstream upper ridging shifts eastward over the Plains. At the surface, an area of low pressure should deepen over southeastern CO through the afternoon, while a separate low develops over northern WY as ascent associated with the upper trough overspreads the central Rockies/High Plains. A nearly stationary surface boundary should extend east/west across KS into northeastern CO Sunday morning, and this front should generally move little through Sunday evening. Storms ongoing at the start of the period across the eastern Great Basin should increase in both coverage and intensity as they develop eastward across the central Rockies by early Sunday afternoon. Mid-level winds attendant to the upper trough are not forecast to be overly strong (around 25-35 kt at 500 mb). But, enough veering/strengthening with height through low/mid levels combined with around 1000-2000 J/kg of MLCAPE along/south of the surface boundary will probably allow for some updraft organization as convection spreads eastward across the central High Plains Sunday afternoon and evening. Tendency should be for storms to congeal into a couple of clusters and spread east-northeastward. Some hail may occur with initial development over the higher terrain, with isolated strong/gusty winds potentially becoming more of a concern across the central High Plains Sunday evening. ...Missouri into the Mid Mississippi Valley... A small cluster of storms may be ongoing at the start of the period across northern/central MO and western IL in a low-level warm air advection regime. A southwesterly low-level jet is expected to quickly weaken through the morning across this region, and a corresponding decrease in storm coverage is anticipated. While a very isolated strong wind gust cannot be ruled out with this morning activity before it weakens, the overall threat appears too isolated to warrant any severe probabilities at this time. The potential for additional storms to develop Sunday afternoon along any residual outflow boundaries or the stationary front also appears highly uncertain, as upper ridging and large-scale subsidence should slowly overspread this region. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/07/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL ROCKIES/HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorms with strong/gusty winds and hail will be possible across parts of the central Rockies and adjacent High Plains Sunday afternoon and evening. ...Central Rockies/High Plains... Upper troughing will develop eastward across the Great Basin to the northern/central Rockies by Sunday evening, while downstream upper ridging shifts eastward over the Plains. At the surface, an area of low pressure should deepen over southeastern CO through the afternoon, while a separate low develops over northern WY as ascent associated with the upper trough overspreads the central Rockies/High Plains. A nearly stationary surface boundary should extend east/west across KS into northeastern CO Sunday morning, and this front should generally move little through Sunday evening. Storms ongoing at the start of the period across the eastern Great Basin should increase in both coverage and intensity as they develop eastward across the central Rockies by early Sunday afternoon. Mid-level winds attendant to the upper trough are not forecast to be overly strong (around 25-35 kt at 500 mb). But, enough veering/strengthening with height through low/mid levels combined with around 1000-2000 J/kg of MLCAPE along/south of the surface boundary will probably allow for some updraft organization as convection spreads eastward across the central High Plains Sunday afternoon and evening. Tendency should be for storms to congeal into a couple of clusters and spread east-northeastward. Some hail may occur with initial development over the higher terrain, with isolated strong/gusty winds potentially becoming more of a concern across the central High Plains Sunday evening. ...Missouri into the Mid Mississippi Valley... A small cluster of storms may be ongoing at the start of the period across northern/central MO and western IL in a low-level warm air advection regime. A southwesterly low-level jet is expected to quickly weaken through the morning across this region, and a corresponding decrease in storm coverage is anticipated. While a very isolated strong wind gust cannot be ruled out with this morning activity before it weakens, the overall threat appears too isolated to warrant any severe probabilities at this time. The potential for additional storms to develop Sunday afternoon along any residual outflow boundaries or the stationary front also appears highly uncertain, as upper ridging and large-scale subsidence should slowly overspread this region. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/07/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sat Sep 07 2019 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL ROCKIES/HIGH PLAINS... ...SUMMARY... Isolated severe thunderstorms with strong/gusty winds and hail will be possible across parts of the central Rockies and adjacent High Plains Sunday afternoon and evening. ...Central Rockies/High Plains... Upper troughing will develop eastward across the Great Basin to the northern/central Rockies by Sunday evening, while downstream upper ridging shifts eastward over the Plains. At the surface, an area of low pressure should deepen over southeastern CO through the afternoon, while a separate low develops over northern WY as ascent associated with the upper trough overspreads the central Rockies/High Plains. A nearly stationary surface boundary should extend east/west across KS into northeastern CO Sunday morning, and this front should generally move little through Sunday evening. Storms ongoing at the start of the period across the eastern Great Basin should increase in both coverage and intensity as they develop eastward across the central Rockies by early Sunday afternoon. Mid-level winds attendant to the upper trough are not forecast to be overly strong (around 25-35 kt at 500 mb). But, enough veering/strengthening with height through low/mid levels combined with around 1000-2000 J/kg of MLCAPE along/south of the surface boundary will probably allow for some updraft organization as convection spreads eastward across the central High Plains Sunday afternoon and evening. Tendency should be for storms to congeal into a couple of clusters and spread east-northeastward. Some hail may occur with initial development over the higher terrain, with isolated strong/gusty winds potentially becoming more of a concern across the central High Plains Sunday evening. ...Missouri into the Mid Mississippi Valley... A small cluster of storms may be ongoing at the start of the period across northern/central MO and western IL in a low-level warm air advection regime. A southwesterly low-level jet is expected to quickly weaken through the morning across this region, and a corresponding decrease in storm coverage is anticipated. While a very isolated strong wind gust cannot be ruled out with this morning activity before it weakens, the overall threat appears too isolated to warrant any severe probabilities at this time. The potential for additional storms to develop Sunday afternoon along any residual outflow boundaries or the stationary front also appears highly uncertain, as upper ridging and large-scale subsidence should slowly overspread this region. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/07/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sat Sep 07 2019 Valid 071630Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS...AND NEAR THE NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail are possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. ..Hart/Wendt.. 09/07/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sat Sep 07 2019 Valid 071630Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS...AND NEAR THE NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail are possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. ..Hart/Wendt.. 09/07/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sat Sep 07 2019 Valid 071630Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS...AND NEAR THE NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail are possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. ..Hart/Wendt.. 09/07/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Sat Sep 07 2019 Valid 071630Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS...AND NEAR THE NORTHERN CASCADES... ...SUMMARY... Isolated severe wind and hail are possible today from thunderstorms over parts of the central Plains, and near the northern Cascades. ...Central Plains... A well-defined shortwave trough is moving quickly eastward today across eastern MT/WY. This feature will help to initiate scattered thunderstorm development this afternoon and evening from parts of eastern CO and western KS into portions of SD/NE/MO/IA. Low-level winds are forecast to be relatively weak across the central Plains, limiting overall convective organization. However, multiple remnant surface boundaries should be sufficient for a few clusters of multicell and occasional supercell storms through the evening. Forecast soundings suggest a risk of isolated strong/severe storms capable of gusty/damaging winds and hail. Given the weak low-level winds and expectation of rather disorganized convective, will maintain the ongoing MRGL risk with only minor changes. ...Pacific Northwest... A rather deep upper trough is approaching the OR/CA coast today. Strengthening wind fields and cooling aloft will aid initiation of scattered thunderstorms over central OR/WA along and east of the Cascades. Organized severe storms are not expected. However, the strongest cells could result in gusty winds and hail for a few hours this afternoon and evening. ..Hart/Wendt.. 09/07/2019 Read more