Severe Storms

WW 0600 Status Updates
STATUS REPORT ON WW 600 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SMITH..08/19/19 ATTN...WFO...BOX...GYX... STATUS REPORT FOR WS 600 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC003-013-015-192000- CT . CONNECTICUT COUNTIES INCLUDED ARE HARTFORD TOLLAND WINDHAM MEC005-023-031-192000- ME . MAINE COUNTIES INCLUDED ARE CUMBERLAND SAGADAHOC YORK MAC005-009-011-013-015-017-021-023-025-027-192000- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BRISTOL ESSEX FRANKLIN HAMPDEN HAMPSHIRE MIDDLESEX NORFOLK PLYMOUTH SUFFOLK WORCESTER Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0136 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes. Previous discussion follows. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0139 AM CDT Mon Aug 19 2019/ ...Synopsis... The upper-level ridge over the western CONUS will continue to amplify into western Canada tomorrow with an upper-level shortwave trough approaching the Pacific Northwest. Subtropical moisture will begin to move into the Southwest as the ridge builds and into southern Montana/northern Wyoming with easterly low-level flow extending westward from the northern Plains. Isolated dry thunderstorms may develop across southern Montana and northern Wyoming. However, fuel conditions and uncertainty regarding thunderstorm coverage preclude introducing an isolated dry thunderstorm area at this time. ...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 0136 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes. Previous discussion follows. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0139 AM CDT Mon Aug 19 2019/ ...Synopsis... The upper-level ridge over the western CONUS will continue to amplify into western Canada tomorrow with an upper-level shortwave trough approaching the Pacific Northwest. Subtropical moisture will begin to move into the Southwest as the ridge builds and into southern Montana/northern Wyoming with easterly low-level flow extending westward from the northern Plains. Isolated dry thunderstorms may develop across southern Montana and northern Wyoming. However, fuel conditions and uncertainty regarding thunderstorm coverage preclude introducing an isolated dry thunderstorm area at this time. ...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 0136 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes. Previous discussion follows. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0139 AM CDT Mon Aug 19 2019/ ...Synopsis... The upper-level ridge over the western CONUS will continue to amplify into western Canada tomorrow with an upper-level shortwave trough approaching the Pacific Northwest. Subtropical moisture will begin to move into the Southwest as the ridge builds and into southern Montana/northern Wyoming with easterly low-level flow extending westward from the northern Plains. Isolated dry thunderstorms may develop across southern Montana and northern Wyoming. However, fuel conditions and uncertainty regarding thunderstorm coverage preclude introducing an isolated dry thunderstorm area at this time. ...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 0136 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes. Previous discussion follows. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0139 AM CDT Mon Aug 19 2019/ ...Synopsis... The upper-level ridge over the western CONUS will continue to amplify into western Canada tomorrow with an upper-level shortwave trough approaching the Pacific Northwest. Subtropical moisture will begin to move into the Southwest as the ridge builds and into southern Montana/northern Wyoming with easterly low-level flow extending westward from the northern Plains. Isolated dry thunderstorms may develop across southern Montana and northern Wyoming. However, fuel conditions and uncertainty regarding thunderstorm coverage preclude introducing an isolated dry thunderstorm area at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1800 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF CENTRAL AND NORTHERN MAINE
Mesoscale Discussion 1800 NWS Storm Prediction Center Norman OK 0120 PM CDT Mon Aug 19 2019 Areas affected...Portions of central and northern Maine Concerning...Severe potential...Watch unlikely Valid 191820Z - 192015Z Probability of Watch Issuance...20 percent SUMMARY...Widely scattered thunderstorms will move over the area this afternoon and pose a limited threat for damaging wind gusts and marginally severe hail. However, at this time the coverage of the threat is expected to remain low enough to preclude a Severe Thunderstorm Watch. DISCUSSION...A mid-level shortwave trough pivoting through the broadly cyclonic mid-upper-level flow, and an approaching pre-frontal trough, is supporting thunderstorm development over western Maine. Although the low-to-mid-level flow approaching the area is somewhat stronger than that farther south, persistent low-level clouds have limited heating over much of the area. Therefore the severe wind threat should be limited to localized pockets of stronger heating where evaporatively-driven downdrafts and surface outflow winds may be enhanced. Some transient updraft rotation in a few of the storms amidst the 0-3 (0-6) km shear of 25-30 (30-35) kt could support some small hail in the stronger updrafts, and some isolated hail approaching an inch in diameter, but this threat is expected to remain low enough, and isolated enough, to preclude a Watch. ..Coniglio/Thompson.. 08/19/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX... LAT...LON 44316879 44276918 44206967 44607021 45117036 46027014 47016949 47206889 47306833 47066791 46226781 45126818 44316879 Read more

No watches are valid as of Mon Aug 19 18:03:02 UTC 2019.

MD 1799 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF CENTRAL TO SOUTHERN NEW ENGLAND INTO FAR SOUTHEAST NEW YORK AND NORTHEAST NEW JERSEY
Mesoscale Discussion 1799 NWS Storm Prediction Center Norman OK 1238 PM CDT Mon Aug 19 2019 Areas affected...Portions of central to southern New England into far southeast New York and northeast New Jersey Concerning...Severe potential...Watch possible Valid 191738Z - 191845Z Probability of Watch Issuance...60 percent SUMMARY...Scattered thunderstorms will expand in coverage by early afternoon and pose a threat for some wind damage through mid-to-late afternoon. A Severe Thunderstorm Watch may be needed between 18-19z. DISCUSSION...Strong heating amidst upper 60s to lower 70s near-surface dewpoints ahead of a mid-level cloud shield is contributing to MLCAPE of 500-1000 J/kg over southwest Maine to 2000-2500 J/kg over central New Jersey. Broad low-level confluence associated with a pre-frontal trough, and the southern fringe of a mid-level shortwave trough traversing southern Quebec, will contribute to scattered thunderstorm development in this environment by early afternoon. Although low-to-deep-layer shear of 20-30 kt is rather marginal for long-lived storm organization, a broken line of multicells should be the dominant mode as suggested by morning convection-allowing guidance. The main threat will be isolated to widely scattered wind damage from sub-cloud evaporation-driven downdrafts supported by somewhat steep low-level lapse rates of 8-8.5 C/km. The coverage of thunderstorms capable of producing wind damage is expected to be modest but may be sufficient to require a Severe Thunderstorm Watch in the 18-19z time period. ..Coniglio/Thompson.. 08/19/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...OKX...ALY...PHI... LAT...LON 43017221 43667164 44107123 44427085 44337037 44056989 43536991 42667009 41727105 40657227 40197329 40407488 40807496 41407440 42747253 43017221 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TUESDAY ACROSS PARTS OF SOUTHEASTERN IOWA AND NORTHWEST MISSOURI...MUCH OF CENTRAL ILLINOIS AND CENTRAL/SOUTHERN INDIANA... ...SUMMARY... An organized cluster of thunderstorms may develop and overspread portions of the middle Mississippi and lower Ohio Valleys Tuesday, accompanied by the risk for severe wind and hail. ...Synopsis... The stronger westerlies will remain confined to areas near/north of the Canadian/U.S. border, but may undergo amplification during this period, as a significant short wave trough pivots inland across the British Columbia coast. Downstream, positively tilted mid/upper ridging is forecast to build across the Canadian prairies into Nunavut and western Hudson Bay, while another significant short wave trough digs southeastward across Manitoba and northwest Ontario, toward the upper Great Lakes region. To the south, a broad plume of very warm elevated mixed-layer air is already beginning to emerge from the Intermountain West/Mexican Plateau/Rockies region. The northeastern periphery of this air mass appears to likely to continue advecting across the middle Missouri Valley region, toward the Upper Midwest, through daybreak Tuesday. As this overspreads seasonably moist boundary layer air, it is expected to contribute to the maintenance of moderate to strong potential instability across a broad area of the interior United States. By early Tuesday, it appears that this will be focused ahead of a stalling initial front extending across southern portions of the Great Lakes region into middle Missouri Valley, and ahead of another surface cold front advancing into the northern Plains and Upper Midwest. This instability is expected to provide support for scattered vigorous thunderstorm activity, as far east as the upper Ohio Valley and northern Mid Atlantic region, Tuesday into Tuesday night. Some of these storms will pose a risk for severe wind and hail, particularly across portions of the middle Mississippi into lower Ohio Valleys. ...Middle Mississippi/Ohio Valleys... A considerable signal remains evident within the latest model output suggesting the potential for the evolution of a large, organized convective system during this period. It appears that forcing for ascent associated with a low amplitude impulse migrating around the northern periphery of the subtropical ridging, near/south of the stronger westerlies, will provide support for the initiation of this activity, perhaps as early as late tonight across southern Iowa. Aided by inflow of moderate to large CAPE, particularly as the boundary layer begins to warm with insolation, there appears potential for considerable intensification Tuesday morning into afternoon, across southeast Iowa and adjacent northwestern Missouri through central Illinois. Aided by deep-layer shear associated with a 30-50 kt mid-level jet streak, and steep mid-level lapse rates, the environment may become supportive of large to very large hail and damaging surface gusts, associated with both downbursts and a strengthening convectively generated surface cold pool. Some uncertainty exists concerning the subsequent track of the convective system, and highest severe probabilities, but this seems most likely to become focused near the northeastern periphery of mid-level ridging, centered (around 700 mb) across southern Missouri. Based on this, activity may gradually turn south-southeastward into/through the lower Ohio Valley by Tuesday evening, although eastward development toward portions of the Upper Ohio Valley may not be out of the question. ...Central Plains into Mid Missouri Valley... More uncertainty exits concerning coverage and location of convective development, particularly with regard to mid/upper support for activity. However, a zone of stronger differential surface heating may provide the general focus for strong/severe storm development across central/southern Nebraska and northeast Kansas late Tuesday afternoon and evening. ...Upper Midwest... Models suggest that an area of mid/upper forcing for ascent, developing ahead of the primary digging short wave trough, may provide support for thunderstorm development during the peak heating across parts of east central Minnesota into northern Wisconsin and adjacent portions of upper Michigan, where the environment may become at least marginally conducive to isolated supercells posing a risk for severe hail and wind. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 30% - Enhanced Hail: 30% SIG - Enhanced ..Kerr.. 08/19/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TUESDAY ACROSS PARTS OF SOUTHEASTERN IOWA AND NORTHWEST MISSOURI...MUCH OF CENTRAL ILLINOIS AND CENTRAL/SOUTHERN INDIANA... ...SUMMARY... An organized cluster of thunderstorms may develop and overspread portions of the middle Mississippi and lower Ohio Valleys Tuesday, accompanied by the risk for severe wind and hail. ...Synopsis... The stronger westerlies will remain confined to areas near/north of the Canadian/U.S. border, but may undergo amplification during this period, as a significant short wave trough pivots inland across the British Columbia coast. Downstream, positively tilted mid/upper ridging is forecast to build across the Canadian prairies into Nunavut and western Hudson Bay, while another significant short wave trough digs southeastward across Manitoba and northwest Ontario, toward the upper Great Lakes region. To the south, a broad plume of very warm elevated mixed-layer air is already beginning to emerge from the Intermountain West/Mexican Plateau/Rockies region. The northeastern periphery of this air mass appears to likely to continue advecting across the middle Missouri Valley region, toward the Upper Midwest, through daybreak Tuesday. As this overspreads seasonably moist boundary layer air, it is expected to contribute to the maintenance of moderate to strong potential instability across a broad area of the interior United States. By early Tuesday, it appears that this will be focused ahead of a stalling initial front extending across southern portions of the Great Lakes region into middle Missouri Valley, and ahead of another surface cold front advancing into the northern Plains and Upper Midwest. This instability is expected to provide support for scattered vigorous thunderstorm activity, as far east as the upper Ohio Valley and northern Mid Atlantic region, Tuesday into Tuesday night. Some of these storms will pose a risk for severe wind and hail, particularly across portions of the middle Mississippi into lower Ohio Valleys. ...Middle Mississippi/Ohio Valleys... A considerable signal remains evident within the latest model output suggesting the potential for the evolution of a large, organized convective system during this period. It appears that forcing for ascent associated with a low amplitude impulse migrating around the northern periphery of the subtropical ridging, near/south of the stronger westerlies, will provide support for the initiation of this activity, perhaps as early as late tonight across southern Iowa. Aided by inflow of moderate to large CAPE, particularly as the boundary layer begins to warm with insolation, there appears potential for considerable intensification Tuesday morning into afternoon, across southeast Iowa and adjacent northwestern Missouri through central Illinois. Aided by deep-layer shear associated with a 30-50 kt mid-level jet streak, and steep mid-level lapse rates, the environment may become supportive of large to very large hail and damaging surface gusts, associated with both downbursts and a strengthening convectively generated surface cold pool. Some uncertainty exists concerning the subsequent track of the convective system, and highest severe probabilities, but this seems most likely to become focused near the northeastern periphery of mid-level ridging, centered (around 700 mb) across southern Missouri. Based on this, activity may gradually turn south-southeastward into/through the lower Ohio Valley by Tuesday evening, although eastward development toward portions of the Upper Ohio Valley may not be out of the question. ...Central Plains into Mid Missouri Valley... More uncertainty exits concerning coverage and location of convective development, particularly with regard to mid/upper support for activity. However, a zone of stronger differential surface heating may provide the general focus for strong/severe storm development across central/southern Nebraska and northeast Kansas late Tuesday afternoon and evening. ...Upper Midwest... Models suggest that an area of mid/upper forcing for ascent, developing ahead of the primary digging short wave trough, may provide support for thunderstorm development during the peak heating across parts of east central Minnesota into northern Wisconsin and adjacent portions of upper Michigan, where the environment may become at least marginally conducive to isolated supercells posing a risk for severe hail and wind. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 30% - Enhanced Hail: 30% SIG - Enhanced ..Kerr.. 08/19/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TUESDAY ACROSS PARTS OF SOUTHEASTERN IOWA AND NORTHWEST MISSOURI...MUCH OF CENTRAL ILLINOIS AND CENTRAL/SOUTHERN INDIANA... ...SUMMARY... An organized cluster of thunderstorms may develop and overspread portions of the middle Mississippi and lower Ohio Valleys Tuesday, accompanied by the risk for severe wind and hail. ...Synopsis... The stronger westerlies will remain confined to areas near/north of the Canadian/U.S. border, but may undergo amplification during this period, as a significant short wave trough pivots inland across the British Columbia coast. Downstream, positively tilted mid/upper ridging is forecast to build across the Canadian prairies into Nunavut and western Hudson Bay, while another significant short wave trough digs southeastward across Manitoba and northwest Ontario, toward the upper Great Lakes region. To the south, a broad plume of very warm elevated mixed-layer air is already beginning to emerge from the Intermountain West/Mexican Plateau/Rockies region. The northeastern periphery of this air mass appears to likely to continue advecting across the middle Missouri Valley region, toward the Upper Midwest, through daybreak Tuesday. As this overspreads seasonably moist boundary layer air, it is expected to contribute to the maintenance of moderate to strong potential instability across a broad area of the interior United States. By early Tuesday, it appears that this will be focused ahead of a stalling initial front extending across southern portions of the Great Lakes region into middle Missouri Valley, and ahead of another surface cold front advancing into the northern Plains and Upper Midwest. This instability is expected to provide support for scattered vigorous thunderstorm activity, as far east as the upper Ohio Valley and northern Mid Atlantic region, Tuesday into Tuesday night. Some of these storms will pose a risk for severe wind and hail, particularly across portions of the middle Mississippi into lower Ohio Valleys. ...Middle Mississippi/Ohio Valleys... A considerable signal remains evident within the latest model output suggesting the potential for the evolution of a large, organized convective system during this period. It appears that forcing for ascent associated with a low amplitude impulse migrating around the northern periphery of the subtropical ridging, near/south of the stronger westerlies, will provide support for the initiation of this activity, perhaps as early as late tonight across southern Iowa. Aided by inflow of moderate to large CAPE, particularly as the boundary layer begins to warm with insolation, there appears potential for considerable intensification Tuesday morning into afternoon, across southeast Iowa and adjacent northwestern Missouri through central Illinois. Aided by deep-layer shear associated with a 30-50 kt mid-level jet streak, and steep mid-level lapse rates, the environment may become supportive of large to very large hail and damaging surface gusts, associated with both downbursts and a strengthening convectively generated surface cold pool. Some uncertainty exists concerning the subsequent track of the convective system, and highest severe probabilities, but this seems most likely to become focused near the northeastern periphery of mid-level ridging, centered (around 700 mb) across southern Missouri. Based on this, activity may gradually turn south-southeastward into/through the lower Ohio Valley by Tuesday evening, although eastward development toward portions of the Upper Ohio Valley may not be out of the question. ...Central Plains into Mid Missouri Valley... More uncertainty exits concerning coverage and location of convective development, particularly with regard to mid/upper support for activity. However, a zone of stronger differential surface heating may provide the general focus for strong/severe storm development across central/southern Nebraska and northeast Kansas late Tuesday afternoon and evening. ...Upper Midwest... Models suggest that an area of mid/upper forcing for ascent, developing ahead of the primary digging short wave trough, may provide support for thunderstorm development during the peak heating across parts of east central Minnesota into northern Wisconsin and adjacent portions of upper Michigan, where the environment may become at least marginally conducive to isolated supercells posing a risk for severe hail and wind. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 30% - Enhanced Hail: 30% SIG - Enhanced ..Kerr.. 08/19/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Aug 19 2019 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TUESDAY ACROSS PARTS OF SOUTHEASTERN IOWA AND NORTHWEST MISSOURI...MUCH OF CENTRAL ILLINOIS AND CENTRAL/SOUTHERN INDIANA... ...SUMMARY... An organized cluster of thunderstorms may develop and overspread portions of the middle Mississippi and lower Ohio Valleys Tuesday, accompanied by the risk for severe wind and hail. ...Synopsis... The stronger westerlies will remain confined to areas near/north of the Canadian/U.S. border, but may undergo amplification during this period, as a significant short wave trough pivots inland across the British Columbia coast. Downstream, positively tilted mid/upper ridging is forecast to build across the Canadian prairies into Nunavut and western Hudson Bay, while another significant short wave trough digs southeastward across Manitoba and northwest Ontario, toward the upper Great Lakes region. To the south, a broad plume of very warm elevated mixed-layer air is already beginning to emerge from the Intermountain West/Mexican Plateau/Rockies region. The northeastern periphery of this air mass appears to likely to continue advecting across the middle Missouri Valley region, toward the Upper Midwest, through daybreak Tuesday. As this overspreads seasonably moist boundary layer air, it is expected to contribute to the maintenance of moderate to strong potential instability across a broad area of the interior United States. By early Tuesday, it appears that this will be focused ahead of a stalling initial front extending across southern portions of the Great Lakes region into middle Missouri Valley, and ahead of another surface cold front advancing into the northern Plains and Upper Midwest. This instability is expected to provide support for scattered vigorous thunderstorm activity, as far east as the upper Ohio Valley and northern Mid Atlantic region, Tuesday into Tuesday night. Some of these storms will pose a risk for severe wind and hail, particularly across portions of the middle Mississippi into lower Ohio Valleys. ...Middle Mississippi/Ohio Valleys... A considerable signal remains evident within the latest model output suggesting the potential for the evolution of a large, organized convective system during this period. It appears that forcing for ascent associated with a low amplitude impulse migrating around the northern periphery of the subtropical ridging, near/south of the stronger westerlies, will provide support for the initiation of this activity, perhaps as early as late tonight across southern Iowa. Aided by inflow of moderate to large CAPE, particularly as the boundary layer begins to warm with insolation, there appears potential for considerable intensification Tuesday morning into afternoon, across southeast Iowa and adjacent northwestern Missouri through central Illinois. Aided by deep-layer shear associated with a 30-50 kt mid-level jet streak, and steep mid-level lapse rates, the environment may become supportive of large to very large hail and damaging surface gusts, associated with both downbursts and a strengthening convectively generated surface cold pool. Some uncertainty exists concerning the subsequent track of the convective system, and highest severe probabilities, but this seems most likely to become focused near the northeastern periphery of mid-level ridging, centered (around 700 mb) across southern Missouri. Based on this, activity may gradually turn south-southeastward into/through the lower Ohio Valley by Tuesday evening, although eastward development toward portions of the Upper Ohio Valley may not be out of the question. ...Central Plains into Mid Missouri Valley... More uncertainty exits concerning coverage and location of convective development, particularly with regard to mid/upper support for activity. However, a zone of stronger differential surface heating may provide the general focus for strong/severe storm development across central/southern Nebraska and northeast Kansas late Tuesday afternoon and evening. ...Upper Midwest... Models suggest that an area of mid/upper forcing for ascent, developing ahead of the primary digging short wave trough, may provide support for thunderstorm development during the peak heating across parts of east central Minnesota into northern Wisconsin and adjacent portions of upper Michigan, where the environment may become at least marginally conducive to isolated supercells posing a risk for severe hail and wind. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 30% - Enhanced Hail: 30% SIG - Enhanced ..Kerr.. 08/19/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Aug 19 2019 Valid 191700Z - 201200Z Expanded the elevated southwestward through Utah and into far northwest Arizona and southern Nevada. While conditions will not be much different from climatology, they are expected to be similar in Utah and Northwest Arizona as they will be in Wyoming. Therefore, an expansion of the elevated was warranted. In addition, added an elevated area for portions of eastern Idaho where it appears winds will be around 15 to 20 mph with RH around 12 to 18 percent this afternoon. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Aug 19 2019/ ...Synopsis... Upper-level ridging will continue to strengthen and amplify over the western CONUS today. Much of the Intermountain West will remain hot/dry, and large-scale flow will be relatively weak across the much of the region. However, some residual stronger mid-level flow will remain over the northern Rockies/vicinity, and a weak mid-level shortwave trough is forecast to move over the northern Rockies as well. An elevated area was added across portions of southern and central Wyoming. West-southwest sustained surface winds of 12-20 mph with gusts of 25-30 mph and RH values of 8-15% are expected this afternoon and into the evening across the area. Additionally, very deep (10,000+ ft), dry, and unstable boundary layers will develop. This will be the fifth consecutive day of dry/breezy conditions with ERCs rising across portions of southern/western/central Wyoming (70-90th percentiles). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Aug 19 2019 Valid 191700Z - 201200Z Expanded the elevated southwestward through Utah and into far northwest Arizona and southern Nevada. While conditions will not be much different from climatology, they are expected to be similar in Utah and Northwest Arizona as they will be in Wyoming. Therefore, an expansion of the elevated was warranted. In addition, added an elevated area for portions of eastern Idaho where it appears winds will be around 15 to 20 mph with RH around 12 to 18 percent this afternoon. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Aug 19 2019/ ...Synopsis... Upper-level ridging will continue to strengthen and amplify over the western CONUS today. Much of the Intermountain West will remain hot/dry, and large-scale flow will be relatively weak across the much of the region. However, some residual stronger mid-level flow will remain over the northern Rockies/vicinity, and a weak mid-level shortwave trough is forecast to move over the northern Rockies as well. An elevated area was added across portions of southern and central Wyoming. West-southwest sustained surface winds of 12-20 mph with gusts of 25-30 mph and RH values of 8-15% are expected this afternoon and into the evening across the area. Additionally, very deep (10,000+ ft), dry, and unstable boundary layers will develop. This will be the fifth consecutive day of dry/breezy conditions with ERCs rising across portions of southern/western/central Wyoming (70-90th percentiles). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Aug 19 2019 Valid 191700Z - 201200Z Expanded the elevated southwestward through Utah and into far northwest Arizona and southern Nevada. While conditions will not be much different from climatology, they are expected to be similar in Utah and Northwest Arizona as they will be in Wyoming. Therefore, an expansion of the elevated was warranted. In addition, added an elevated area for portions of eastern Idaho where it appears winds will be around 15 to 20 mph with RH around 12 to 18 percent this afternoon. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Aug 19 2019/ ...Synopsis... Upper-level ridging will continue to strengthen and amplify over the western CONUS today. Much of the Intermountain West will remain hot/dry, and large-scale flow will be relatively weak across the much of the region. However, some residual stronger mid-level flow will remain over the northern Rockies/vicinity, and a weak mid-level shortwave trough is forecast to move over the northern Rockies as well. An elevated area was added across portions of southern and central Wyoming. West-southwest sustained surface winds of 12-20 mph with gusts of 25-30 mph and RH values of 8-15% are expected this afternoon and into the evening across the area. Additionally, very deep (10,000+ ft), dry, and unstable boundary layers will develop. This will be the fifth consecutive day of dry/breezy conditions with ERCs rising across portions of southern/western/central Wyoming (70-90th percentiles). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Mon Aug 19 2019 Valid 191700Z - 201200Z Expanded the elevated southwestward through Utah and into far northwest Arizona and southern Nevada. While conditions will not be much different from climatology, they are expected to be similar in Utah and Northwest Arizona as they will be in Wyoming. Therefore, an expansion of the elevated was warranted. In addition, added an elevated area for portions of eastern Idaho where it appears winds will be around 15 to 20 mph with RH around 12 to 18 percent this afternoon. ..Bentley.. 08/19/2019 .PREV DISCUSSION... /ISSUED 0131 AM CDT Mon Aug 19 2019/ ...Synopsis... Upper-level ridging will continue to strengthen and amplify over the western CONUS today. Much of the Intermountain West will remain hot/dry, and large-scale flow will be relatively weak across the much of the region. However, some residual stronger mid-level flow will remain over the northern Rockies/vicinity, and a weak mid-level shortwave trough is forecast to move over the northern Rockies as well. An elevated area was added across portions of southern and central Wyoming. West-southwest sustained surface winds of 12-20 mph with gusts of 25-30 mph and RH values of 8-15% are expected this afternoon and into the evening across the area. Additionally, very deep (10,000+ ft), dry, and unstable boundary layers will develop. This will be the fifth consecutive day of dry/breezy conditions with ERCs rising across portions of southern/western/central Wyoming (70-90th percentiles). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Aug 19 2019 Valid 191630Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE TONIGHT ACROSS PARTS OF IA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM NJ INTO SOUTHEAST NEW ENGLAND... ...SUMMARY... A few damaging gusts will be possible from the Mid-Atlantic into New England this afternoon, while large hail and damaging gusts are expected late tonight across Iowa. ...IA late tonight... Low-level warm advection and moistening will focus across IA overnight, on the nose of a 30-35 kt southwesterly low-level jet. The richer moisture observed this morning at TOP and LBF will spread northeastward beneath a warm elevated mixed layer which will act to cap the boundary layer through the day. After 06z, ascent and moistening with the warm advection should be sufficient for elevated thunderstorm development across IA, and storms will subsequently spread southeastward and likely evolve into an MCS. Large hail will be the initial threat with elevated supercells. As storms coalesce into an MCS, there will be increasing potential for damaging surface winds to reach the ground, given large buoyancy (MUCAPE at or above 3000 J/kg), steep midlevel lapse rates, and DCAPE at or above 1000 J/kg. ...New England to the Mid-Atlantic this afternoon/evening... A midlevel shortwave trough will move eastward over PA/NY and New England this afternoon/evening, with an accompanying surface cold front. East of a band of thicker clouds near the front, surface heating and boundary-layer dewpoints ranging from the upper 60s in southern NH to the mid 70s in NJ will contribute to afternoon MLCAPE ranging from 1500 J/kg north to 3000 J/kg south. Midlevel west-southwesterly flow of 25-30 kt and the moderate to strong buoyancy will favor primarily multicell clusters capable of producing occasional wind damage with 45-60 mph outflow gusts. More persistent clouds across Maine will slow surface heating/destabilization, though deep-layer vertical shear will be a little stronger with northward extent compared to southern New England. Farther south, a weak lee trough will persist through the afternoon across the Piedmont, with a warm/moist air mass to its east. Strong surface heating will boost MLCAPE into the 2000-3000 J/kg range east of the surface trough, where DCAPE near 1000 J/kg will favor isolated strong/damaging winds with multicell storms in a weak vertical shear environment. ...Northern Plains through tonight... Low-level moisture is returning northward from the central Plains to the Dakotas, east of a diffuse lee trough. Surface heating/mixing could be sufficient for isolated high-based storms across western ND this evening, but overall storm coverage is expected to remain sparse in response to weak forcing for ascent and a lingering cap. Storm development will be more probable tonight near the international border along a cold front as an embedded speed max moves across southern SK/MB. This convection should be elevated, posing a threat for isolated large hail and a few strong gusts could reach the ground. ...Central High Plains this afternoon/evening... Deep mixing with strong surface heating could support isolated, high-based thunderstorm development this afternoon along the surface lee trough in the vicinity of the KS/CO border. Inverted-v profiles will favor gusty outflow winds with any sustained storms or small clusters for a few hours late this afternoon/evening. ..Thompson/Coniglio.. 08/19/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Aug 19 2019 Valid 191630Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE TONIGHT ACROSS PARTS OF IA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM NJ INTO SOUTHEAST NEW ENGLAND... ...SUMMARY... A few damaging gusts will be possible from the Mid-Atlantic into New England this afternoon, while large hail and damaging gusts are expected late tonight across Iowa. ...IA late tonight... Low-level warm advection and moistening will focus across IA overnight, on the nose of a 30-35 kt southwesterly low-level jet. The richer moisture observed this morning at TOP and LBF will spread northeastward beneath a warm elevated mixed layer which will act to cap the boundary layer through the day. After 06z, ascent and moistening with the warm advection should be sufficient for elevated thunderstorm development across IA, and storms will subsequently spread southeastward and likely evolve into an MCS. Large hail will be the initial threat with elevated supercells. As storms coalesce into an MCS, there will be increasing potential for damaging surface winds to reach the ground, given large buoyancy (MUCAPE at or above 3000 J/kg), steep midlevel lapse rates, and DCAPE at or above 1000 J/kg. ...New England to the Mid-Atlantic this afternoon/evening... A midlevel shortwave trough will move eastward over PA/NY and New England this afternoon/evening, with an accompanying surface cold front. East of a band of thicker clouds near the front, surface heating and boundary-layer dewpoints ranging from the upper 60s in southern NH to the mid 70s in NJ will contribute to afternoon MLCAPE ranging from 1500 J/kg north to 3000 J/kg south. Midlevel west-southwesterly flow of 25-30 kt and the moderate to strong buoyancy will favor primarily multicell clusters capable of producing occasional wind damage with 45-60 mph outflow gusts. More persistent clouds across Maine will slow surface heating/destabilization, though deep-layer vertical shear will be a little stronger with northward extent compared to southern New England. Farther south, a weak lee trough will persist through the afternoon across the Piedmont, with a warm/moist air mass to its east. Strong surface heating will boost MLCAPE into the 2000-3000 J/kg range east of the surface trough, where DCAPE near 1000 J/kg will favor isolated strong/damaging winds with multicell storms in a weak vertical shear environment. ...Northern Plains through tonight... Low-level moisture is returning northward from the central Plains to the Dakotas, east of a diffuse lee trough. Surface heating/mixing could be sufficient for isolated high-based storms across western ND this evening, but overall storm coverage is expected to remain sparse in response to weak forcing for ascent and a lingering cap. Storm development will be more probable tonight near the international border along a cold front as an embedded speed max moves across southern SK/MB. This convection should be elevated, posing a threat for isolated large hail and a few strong gusts could reach the ground. ...Central High Plains this afternoon/evening... Deep mixing with strong surface heating could support isolated, high-based thunderstorm development this afternoon along the surface lee trough in the vicinity of the KS/CO border. Inverted-v profiles will favor gusty outflow winds with any sustained storms or small clusters for a few hours late this afternoon/evening. ..Thompson/Coniglio.. 08/19/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Aug 19 2019 Valid 191630Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE TONIGHT ACROSS PARTS OF IA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM NJ INTO SOUTHEAST NEW ENGLAND... ...SUMMARY... A few damaging gusts will be possible from the Mid-Atlantic into New England this afternoon, while large hail and damaging gusts are expected late tonight across Iowa. ...IA late tonight... Low-level warm advection and moistening will focus across IA overnight, on the nose of a 30-35 kt southwesterly low-level jet. The richer moisture observed this morning at TOP and LBF will spread northeastward beneath a warm elevated mixed layer which will act to cap the boundary layer through the day. After 06z, ascent and moistening with the warm advection should be sufficient for elevated thunderstorm development across IA, and storms will subsequently spread southeastward and likely evolve into an MCS. Large hail will be the initial threat with elevated supercells. As storms coalesce into an MCS, there will be increasing potential for damaging surface winds to reach the ground, given large buoyancy (MUCAPE at or above 3000 J/kg), steep midlevel lapse rates, and DCAPE at or above 1000 J/kg. ...New England to the Mid-Atlantic this afternoon/evening... A midlevel shortwave trough will move eastward over PA/NY and New England this afternoon/evening, with an accompanying surface cold front. East of a band of thicker clouds near the front, surface heating and boundary-layer dewpoints ranging from the upper 60s in southern NH to the mid 70s in NJ will contribute to afternoon MLCAPE ranging from 1500 J/kg north to 3000 J/kg south. Midlevel west-southwesterly flow of 25-30 kt and the moderate to strong buoyancy will favor primarily multicell clusters capable of producing occasional wind damage with 45-60 mph outflow gusts. More persistent clouds across Maine will slow surface heating/destabilization, though deep-layer vertical shear will be a little stronger with northward extent compared to southern New England. Farther south, a weak lee trough will persist through the afternoon across the Piedmont, with a warm/moist air mass to its east. Strong surface heating will boost MLCAPE into the 2000-3000 J/kg range east of the surface trough, where DCAPE near 1000 J/kg will favor isolated strong/damaging winds with multicell storms in a weak vertical shear environment. ...Northern Plains through tonight... Low-level moisture is returning northward from the central Plains to the Dakotas, east of a diffuse lee trough. Surface heating/mixing could be sufficient for isolated high-based storms across western ND this evening, but overall storm coverage is expected to remain sparse in response to weak forcing for ascent and a lingering cap. Storm development will be more probable tonight near the international border along a cold front as an embedded speed max moves across southern SK/MB. This convection should be elevated, posing a threat for isolated large hail and a few strong gusts could reach the ground. ...Central High Plains this afternoon/evening... Deep mixing with strong surface heating could support isolated, high-based thunderstorm development this afternoon along the surface lee trough in the vicinity of the KS/CO border. Inverted-v profiles will favor gusty outflow winds with any sustained storms or small clusters for a few hours late this afternoon/evening. ..Thompson/Coniglio.. 08/19/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Aug 19 2019 Valid 191630Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE TONIGHT ACROSS PARTS OF IA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON FROM NJ INTO SOUTHEAST NEW ENGLAND... ...SUMMARY... A few damaging gusts will be possible from the Mid-Atlantic into New England this afternoon, while large hail and damaging gusts are expected late tonight across Iowa. ...IA late tonight... Low-level warm advection and moistening will focus across IA overnight, on the nose of a 30-35 kt southwesterly low-level jet. The richer moisture observed this morning at TOP and LBF will spread northeastward beneath a warm elevated mixed layer which will act to cap the boundary layer through the day. After 06z, ascent and moistening with the warm advection should be sufficient for elevated thunderstorm development across IA, and storms will subsequently spread southeastward and likely evolve into an MCS. Large hail will be the initial threat with elevated supercells. As storms coalesce into an MCS, there will be increasing potential for damaging surface winds to reach the ground, given large buoyancy (MUCAPE at or above 3000 J/kg), steep midlevel lapse rates, and DCAPE at or above 1000 J/kg. ...New England to the Mid-Atlantic this afternoon/evening... A midlevel shortwave trough will move eastward over PA/NY and New England this afternoon/evening, with an accompanying surface cold front. East of a band of thicker clouds near the front, surface heating and boundary-layer dewpoints ranging from the upper 60s in southern NH to the mid 70s in NJ will contribute to afternoon MLCAPE ranging from 1500 J/kg north to 3000 J/kg south. Midlevel west-southwesterly flow of 25-30 kt and the moderate to strong buoyancy will favor primarily multicell clusters capable of producing occasional wind damage with 45-60 mph outflow gusts. More persistent clouds across Maine will slow surface heating/destabilization, though deep-layer vertical shear will be a little stronger with northward extent compared to southern New England. Farther south, a weak lee trough will persist through the afternoon across the Piedmont, with a warm/moist air mass to its east. Strong surface heating will boost MLCAPE into the 2000-3000 J/kg range east of the surface trough, where DCAPE near 1000 J/kg will favor isolated strong/damaging winds with multicell storms in a weak vertical shear environment. ...Northern Plains through tonight... Low-level moisture is returning northward from the central Plains to the Dakotas, east of a diffuse lee trough. Surface heating/mixing could be sufficient for isolated high-based storms across western ND this evening, but overall storm coverage is expected to remain sparse in response to weak forcing for ascent and a lingering cap. Storm development will be more probable tonight near the international border along a cold front as an embedded speed max moves across southern SK/MB. This convection should be elevated, posing a threat for isolated large hail and a few strong gusts could reach the ground. ...Central High Plains this afternoon/evening... Deep mixing with strong surface heating could support isolated, high-based thunderstorm development this afternoon along the surface lee trough in the vicinity of the KS/CO border. Inverted-v profiles will favor gusty outflow winds with any sustained storms or small clusters for a few hours late this afternoon/evening. ..Thompson/Coniglio.. 08/19/2019 Read more