Severe Storms

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Mon Aug 12 2019 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE SOUTHEAST STATES AND CENTRAL HIGH PLAINS... ...SUMMARY... A few strong to severe storms with isolated damaging wind will be possible over the southeast states Wednesday afternoon. Isolated strong to severe storms will also be possible over a portion of the central High Plains. ...Synopsis... Trend will be for synoptic upper trough to amplify over the eastern U.S. Wednesday with subtropical high building into the southwestern states. At the start of the period a cold front will stretch from eastern NC southwest through the southeast states into central TX and this boundary will advance slowly southeast during the day. ...Southeast States... Rich low-level moisture with 70s F dewpoints will reside in pre-frontal warm sector supporting moderate to strong instability as the surface layer warms with 2000-3000 J/kg MLCAPE expected. Storms should develop within the weakly capped environment along the front by early afternoon and spread southeast. The moist warm sector will have been shunted well south of the stronger westerlies with weak winds aloft supportive of pulse and multicell storms, possibly evolving into line segments along the front. Isolated downburst winds will be the main threat through early evening. ...Central High Plains... A corridor of low 60s F dewpoints will reside over the central High Plains beneath steep lapse rates supporting 1500-2000 J/kg MLCAPE. This region will remain within a belt of moderate northwesterly winds aloft with 35-45 kt effective bulk shear. Background forcing is expected to remain weak, but isolated storms may develop over the higher terrain and spread southeast as well as along a lee trough. The environment will conditionally support a threat for supercells capable of large hail and downburst winds and have therefore introduced a MRGL risk category. If it begins to appear storm coverage will be greater than currently anticipated, then a SLGT risk might be needed in later outlooks. ..Dial.. 08/12/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Mon Aug 12 2019 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE SOUTHEAST STATES AND CENTRAL HIGH PLAINS... ...SUMMARY... A few strong to severe storms with isolated damaging wind will be possible over the southeast states Wednesday afternoon. Isolated strong to severe storms will also be possible over a portion of the central High Plains. ...Synopsis... Trend will be for synoptic upper trough to amplify over the eastern U.S. Wednesday with subtropical high building into the southwestern states. At the start of the period a cold front will stretch from eastern NC southwest through the southeast states into central TX and this boundary will advance slowly southeast during the day. ...Southeast States... Rich low-level moisture with 70s F dewpoints will reside in pre-frontal warm sector supporting moderate to strong instability as the surface layer warms with 2000-3000 J/kg MLCAPE expected. Storms should develop within the weakly capped environment along the front by early afternoon and spread southeast. The moist warm sector will have been shunted well south of the stronger westerlies with weak winds aloft supportive of pulse and multicell storms, possibly evolving into line segments along the front. Isolated downburst winds will be the main threat through early evening. ...Central High Plains... A corridor of low 60s F dewpoints will reside over the central High Plains beneath steep lapse rates supporting 1500-2000 J/kg MLCAPE. This region will remain within a belt of moderate northwesterly winds aloft with 35-45 kt effective bulk shear. Background forcing is expected to remain weak, but isolated storms may develop over the higher terrain and spread southeast as well as along a lee trough. The environment will conditionally support a threat for supercells capable of large hail and downburst winds and have therefore introduced a MRGL risk category. If it begins to appear storm coverage will be greater than currently anticipated, then a SLGT risk might be needed in later outlooks. ..Dial.. 08/12/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Mon Aug 12 2019 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE SOUTHEAST STATES AND CENTRAL HIGH PLAINS... ...SUMMARY... A few strong to severe storms with isolated damaging wind will be possible over the southeast states Wednesday afternoon. Isolated strong to severe storms will also be possible over a portion of the central High Plains. ...Synopsis... Trend will be for synoptic upper trough to amplify over the eastern U.S. Wednesday with subtropical high building into the southwestern states. At the start of the period a cold front will stretch from eastern NC southwest through the southeast states into central TX and this boundary will advance slowly southeast during the day. ...Southeast States... Rich low-level moisture with 70s F dewpoints will reside in pre-frontal warm sector supporting moderate to strong instability as the surface layer warms with 2000-3000 J/kg MLCAPE expected. Storms should develop within the weakly capped environment along the front by early afternoon and spread southeast. The moist warm sector will have been shunted well south of the stronger westerlies with weak winds aloft supportive of pulse and multicell storms, possibly evolving into line segments along the front. Isolated downburst winds will be the main threat through early evening. ...Central High Plains... A corridor of low 60s F dewpoints will reside over the central High Plains beneath steep lapse rates supporting 1500-2000 J/kg MLCAPE. This region will remain within a belt of moderate northwesterly winds aloft with 35-45 kt effective bulk shear. Background forcing is expected to remain weak, but isolated storms may develop over the higher terrain and spread southeast as well as along a lee trough. The environment will conditionally support a threat for supercells capable of large hail and downburst winds and have therefore introduced a MRGL risk category. If it begins to appear storm coverage will be greater than currently anticipated, then a SLGT risk might be needed in later outlooks. ..Dial.. 08/12/2019 Read more

WW 0574 Status Updates
STATUS REPORT ON WW 574 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NE RSL TO 35 SSE HSI TO 25 SE HSI TO 30 SSW EAR TO 20 W EAR. ..KERR..08/12/19 ATTN...WFO...TOP...DDC...GLD...GID...ICT...OAX... STATUS REPORT FOR WS 574 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC027-029-089-105-123-143-157-201-120740- KS . KANSAS COUNTIES INCLUDED ARE CLAY CLOUD JEWELL LINCOLN MITCHELL OTTAWA REPUBLIC WASHINGTON NEC001-019-035-059-067-079-081-093-095-099-109-121-129-143-151- 159-163-169-185-120740- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BUFFALO CLAY FILLMORE GAGE HALL HAMILTON HOWARD JEFFERSON KEARNEY LANCASTER MERRICK NUCKOLLS POLK SALINE SEWARD SHERMAN THAYER YORK Read more

MD 1713 CONCERNING SEVERE THUNDERSTORM WATCH 574... FOR NORTHEAST KANSAS AND SOUTHEAST NEBRASKA INTO NORTHWEST MISSOURI AND SOUTHEAST IOWA
Mesoscale Discussion 1713 NWS Storm Prediction Center Norman OK 0115 AM CDT Mon Aug 12 2019 Areas affected...Northeast Kansas and southeast Nebraska into northwest Missouri and southeast Iowa Concerning...Severe Thunderstorm Watch 574... Valid 120615Z - 120745Z The severe weather threat for Severe Thunderstorm Watch 574 continues. SUMMARY...Thunderstorm activity posing at least some continuing risk for potentially damaging surface gusts probably will continue through daybreak. A new severe thunderstorm watch likely will be issued east of severe thunderstorm watch 574 within the next hour or so. DISCUSSION...Vigorous convective development persists and continues to spread northeastward and eastward across parts of southern Nebraska and northern Kansas, accompanied by occasional strong to severe wind gusts. Strongest gusts have recently been focused near a lower/mid tropospheric cyclonic vorticity center now migrating across the Kearney NE area, and along the leading edge of the stronger/deeper portion of the surface cold pool approaching the Concordia KS and Hebron NE areas. North and east of a weak warm front, extending from its intersection with the cold pool, roughly near the state border, east southeastward into the Interstate 70 corridor of northeast Kansas, inflow of somewhat cooler and more stable boundary layer air may weaken convection during the next few hours as it approaches the Missouri River. Maintenance of strong thunderstorm development seems most likely in closer proximity to the warm front, where forcing for ascent associated with warm advection, on the nose of a 30-50 kt low-level jet, will become focused by 3-5 AM, as the jet gradually continues to veer from southerly to southwesterly. High moisture content concentrated along the front is contributing to large CAPE of 2000-4000 J/kg, in the presence of strong deep layer shear (largely due to veering of wind fields with height). Within this regime, the evolution of another organizing cluster on the southern flank of the ongoing activity appears possible. ..Kerr.. 08/12/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...OAX...TOP...GID... LAT...LON 40379727 41009806 40809531 39709427 39009472 38869618 39079736 40379727 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE MIDDLE ATLANTIC REGION... ...SUMMARY... Severe storms are expected Tuesday afternoon and early evening over the Middle Atlantic into southern portion of the Ohio Valley. Other strong to severe storms are possible over the Tennessee Valley and the central High Plains. ...Middle Atlantic and southern Ohio Valley regions... A convectively enhanced vorticity maximum embedded within a broad upper trough should reach OH by 12Z Tuesday, and this feature will continue east into the Northeast States and the northern portion of the Mid Atlantic during the day. At the start of the period a cold front will extend from a weak low over IN southwestward into northern TX. A warm or stationary front will stretch eastward from the low into southern PA. Storms will likely be ongoing from OH to western PA within zone of isentropic ascent north of stationary front. South of this activity, diabatic warming of the moistening surface layer will result in moderate instability with 1500-2000 J/kg MLCAPE expected. Additional storms should develop by late morning or afternoon in vicinity of the warm front across southern PA and northern VA, as well as farther south and west over the higher terrain and spread eastward into the warm sector. The NAM indicates the strongest kinematic environment, but might be overdone with convective feedback. Nevertheless, this region will reside within belt of moderate westerlies with 30-40 kt effective bulk shear supportive of organized storms including supercells. If enough destabilization can occur along the warm front, low-level hodographs may become supportive of a few tornadoes. Otherwise damaging wind will be the main threat. Other storms are expected to develop along southwestern extension of the cold front, especially from KY into the TN Valley during the afternoon where both the thermodynamic and kinematic parameter space should support mostly multicells and line segments with damaging wind the main threats. ...Central High Plains... A few storms are expected to develop along a lee trough and higher terrain within an evolving easterly post-frontal regime across the central High Plains. Modest low-level moisture beneath steep lapse rates will support up to 2000 j/kg MLCAPE, and this region will reside within belt of modest northwesterly winds aloft with 30-35 effective bulk shear. This environment may support a few instances of large hail and strong wind gusts before activity weakens by mid evening. Due to uncertainties regarding storm coverage will leave MRGL this update, but this region will continue to be monitored for a possible SLGT risk in later outlooks. ...Upper Mississippi Valley region... Isolated storms may develop over the upper Midwest in association with a southeast-advancing shortwave trough and within a weakly unstable environment. A belt of stronger unidirectional winds aloft will support up to 40 kt effective bulk shear. A few storms could produce locally strong wind gusts and hail, but overall threat should remain marginal. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 30% - Enhanced Hail: 15% - Slight ..Dial.. 08/12/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE MIDDLE ATLANTIC REGION... ...SUMMARY... Severe storms are expected Tuesday afternoon and early evening over the Middle Atlantic into southern portion of the Ohio Valley. Other strong to severe storms are possible over the Tennessee Valley and the central High Plains. ...Middle Atlantic and southern Ohio Valley regions... A convectively enhanced vorticity maximum embedded within a broad upper trough should reach OH by 12Z Tuesday, and this feature will continue east into the Northeast States and the northern portion of the Mid Atlantic during the day. At the start of the period a cold front will extend from a weak low over IN southwestward into northern TX. A warm or stationary front will stretch eastward from the low into southern PA. Storms will likely be ongoing from OH to western PA within zone of isentropic ascent north of stationary front. South of this activity, diabatic warming of the moistening surface layer will result in moderate instability with 1500-2000 J/kg MLCAPE expected. Additional storms should develop by late morning or afternoon in vicinity of the warm front across southern PA and northern VA, as well as farther south and west over the higher terrain and spread eastward into the warm sector. The NAM indicates the strongest kinematic environment, but might be overdone with convective feedback. Nevertheless, this region will reside within belt of moderate westerlies with 30-40 kt effective bulk shear supportive of organized storms including supercells. If enough destabilization can occur along the warm front, low-level hodographs may become supportive of a few tornadoes. Otherwise damaging wind will be the main threat. Other storms are expected to develop along southwestern extension of the cold front, especially from KY into the TN Valley during the afternoon where both the thermodynamic and kinematic parameter space should support mostly multicells and line segments with damaging wind the main threats. ...Central High Plains... A few storms are expected to develop along a lee trough and higher terrain within an evolving easterly post-frontal regime across the central High Plains. Modest low-level moisture beneath steep lapse rates will support up to 2000 j/kg MLCAPE, and this region will reside within belt of modest northwesterly winds aloft with 30-35 effective bulk shear. This environment may support a few instances of large hail and strong wind gusts before activity weakens by mid evening. Due to uncertainties regarding storm coverage will leave MRGL this update, but this region will continue to be monitored for a possible SLGT risk in later outlooks. ...Upper Mississippi Valley region... Isolated storms may develop over the upper Midwest in association with a southeast-advancing shortwave trough and within a weakly unstable environment. A belt of stronger unidirectional winds aloft will support up to 40 kt effective bulk shear. A few storms could produce locally strong wind gusts and hail, but overall threat should remain marginal. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 30% - Enhanced Hail: 15% - Slight ..Dial.. 08/12/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE MIDDLE ATLANTIC REGION... ...SUMMARY... Severe storms are expected Tuesday afternoon and early evening over the Middle Atlantic into southern portion of the Ohio Valley. Other strong to severe storms are possible over the Tennessee Valley and the central High Plains. ...Middle Atlantic and southern Ohio Valley regions... A convectively enhanced vorticity maximum embedded within a broad upper trough should reach OH by 12Z Tuesday, and this feature will continue east into the Northeast States and the northern portion of the Mid Atlantic during the day. At the start of the period a cold front will extend from a weak low over IN southwestward into northern TX. A warm or stationary front will stretch eastward from the low into southern PA. Storms will likely be ongoing from OH to western PA within zone of isentropic ascent north of stationary front. South of this activity, diabatic warming of the moistening surface layer will result in moderate instability with 1500-2000 J/kg MLCAPE expected. Additional storms should develop by late morning or afternoon in vicinity of the warm front across southern PA and northern VA, as well as farther south and west over the higher terrain and spread eastward into the warm sector. The NAM indicates the strongest kinematic environment, but might be overdone with convective feedback. Nevertheless, this region will reside within belt of moderate westerlies with 30-40 kt effective bulk shear supportive of organized storms including supercells. If enough destabilization can occur along the warm front, low-level hodographs may become supportive of a few tornadoes. Otherwise damaging wind will be the main threat. Other storms are expected to develop along southwestern extension of the cold front, especially from KY into the TN Valley during the afternoon where both the thermodynamic and kinematic parameter space should support mostly multicells and line segments with damaging wind the main threats. ...Central High Plains... A few storms are expected to develop along a lee trough and higher terrain within an evolving easterly post-frontal regime across the central High Plains. Modest low-level moisture beneath steep lapse rates will support up to 2000 j/kg MLCAPE, and this region will reside within belt of modest northwesterly winds aloft with 30-35 effective bulk shear. This environment may support a few instances of large hail and strong wind gusts before activity weakens by mid evening. Due to uncertainties regarding storm coverage will leave MRGL this update, but this region will continue to be monitored for a possible SLGT risk in later outlooks. ...Upper Mississippi Valley region... Isolated storms may develop over the upper Midwest in association with a southeast-advancing shortwave trough and within a weakly unstable environment. A belt of stronger unidirectional winds aloft will support up to 40 kt effective bulk shear. A few storms could produce locally strong wind gusts and hail, but overall threat should remain marginal. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 30% - Enhanced Hail: 15% - Slight ..Dial.. 08/12/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE MIDDLE ATLANTIC REGION... ...SUMMARY... Severe storms are expected Tuesday afternoon and early evening over the Middle Atlantic into southern portion of the Ohio Valley. Other strong to severe storms are possible over the Tennessee Valley and the central High Plains. ...Middle Atlantic and southern Ohio Valley regions... A convectively enhanced vorticity maximum embedded within a broad upper trough should reach OH by 12Z Tuesday, and this feature will continue east into the Northeast States and the northern portion of the Mid Atlantic during the day. At the start of the period a cold front will extend from a weak low over IN southwestward into northern TX. A warm or stationary front will stretch eastward from the low into southern PA. Storms will likely be ongoing from OH to western PA within zone of isentropic ascent north of stationary front. South of this activity, diabatic warming of the moistening surface layer will result in moderate instability with 1500-2000 J/kg MLCAPE expected. Additional storms should develop by late morning or afternoon in vicinity of the warm front across southern PA and northern VA, as well as farther south and west over the higher terrain and spread eastward into the warm sector. The NAM indicates the strongest kinematic environment, but might be overdone with convective feedback. Nevertheless, this region will reside within belt of moderate westerlies with 30-40 kt effective bulk shear supportive of organized storms including supercells. If enough destabilization can occur along the warm front, low-level hodographs may become supportive of a few tornadoes. Otherwise damaging wind will be the main threat. Other storms are expected to develop along southwestern extension of the cold front, especially from KY into the TN Valley during the afternoon where both the thermodynamic and kinematic parameter space should support mostly multicells and line segments with damaging wind the main threats. ...Central High Plains... A few storms are expected to develop along a lee trough and higher terrain within an evolving easterly post-frontal regime across the central High Plains. Modest low-level moisture beneath steep lapse rates will support up to 2000 j/kg MLCAPE, and this region will reside within belt of modest northwesterly winds aloft with 30-35 effective bulk shear. This environment may support a few instances of large hail and strong wind gusts before activity weakens by mid evening. Due to uncertainties regarding storm coverage will leave MRGL this update, but this region will continue to be monitored for a possible SLGT risk in later outlooks. ...Upper Mississippi Valley region... Isolated storms may develop over the upper Midwest in association with a southeast-advancing shortwave trough and within a weakly unstable environment. A belt of stronger unidirectional winds aloft will support up to 40 kt effective bulk shear. A few storms could produce locally strong wind gusts and hail, but overall threat should remain marginal. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 30% - Enhanced Hail: 15% - Slight ..Dial.. 08/12/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Aug 12 2019 Valid 131200Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE MIDDLE ATLANTIC REGION... ...SUMMARY... Severe storms are expected Tuesday afternoon and early evening over the Middle Atlantic into southern portion of the Ohio Valley. Other strong to severe storms are possible over the Tennessee Valley and the central High Plains. ...Middle Atlantic and southern Ohio Valley regions... A convectively enhanced vorticity maximum embedded within a broad upper trough should reach OH by 12Z Tuesday, and this feature will continue east into the Northeast States and the northern portion of the Mid Atlantic during the day. At the start of the period a cold front will extend from a weak low over IN southwestward into northern TX. A warm or stationary front will stretch eastward from the low into southern PA. Storms will likely be ongoing from OH to western PA within zone of isentropic ascent north of stationary front. South of this activity, diabatic warming of the moistening surface layer will result in moderate instability with 1500-2000 J/kg MLCAPE expected. Additional storms should develop by late morning or afternoon in vicinity of the warm front across southern PA and northern VA, as well as farther south and west over the higher terrain and spread eastward into the warm sector. The NAM indicates the strongest kinematic environment, but might be overdone with convective feedback. Nevertheless, this region will reside within belt of moderate westerlies with 30-40 kt effective bulk shear supportive of organized storms including supercells. If enough destabilization can occur along the warm front, low-level hodographs may become supportive of a few tornadoes. Otherwise damaging wind will be the main threat. Other storms are expected to develop along southwestern extension of the cold front, especially from KY into the TN Valley during the afternoon where both the thermodynamic and kinematic parameter space should support mostly multicells and line segments with damaging wind the main threats. ...Central High Plains... A few storms are expected to develop along a lee trough and higher terrain within an evolving easterly post-frontal regime across the central High Plains. Modest low-level moisture beneath steep lapse rates will support up to 2000 j/kg MLCAPE, and this region will reside within belt of modest northwesterly winds aloft with 30-35 effective bulk shear. This environment may support a few instances of large hail and strong wind gusts before activity weakens by mid evening. Due to uncertainties regarding storm coverage will leave MRGL this update, but this region will continue to be monitored for a possible SLGT risk in later outlooks. ...Upper Mississippi Valley region... Isolated storms may develop over the upper Midwest in association with a southeast-advancing shortwave trough and within a weakly unstable environment. A belt of stronger unidirectional winds aloft will support up to 40 kt effective bulk shear. A few storms could produce locally strong wind gusts and hail, but overall threat should remain marginal. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 30% - Enhanced Hail: 15% - Slight ..Dial.. 08/12/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Mon Aug 12 2019 Valid 121200Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST IA TO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...Mid MS/OH Valley Region... An impressive amount of deep convection has developed over the central Plains early this morning ahead of a disturbance that should approach western IA by sunrise. A reservoir of untapped buoyancy currently extends ahead of the MCS over eastern KS which should aid eastward progression of organized convection into the beginning of the upcoming day1 period. Latest NAM model guidance suggests leading edge of this activity will be near the MO River at sunrise; however, current speed/movement of the convection is considerably faster and storms could advance into western IA by 09z. It's not entirely clear whether the MCS will slow its forward propagation so confidence in timing/placement of this complex of storms is somewhat in doubt. Current outlook is predicated on MCS slowing a bit toward sunrise. For these reasons have adjusted severe probs west across IA/northern MO to account for possible severe at the beginning of the period. If boundary layer is able to warm/destabilize ahead of this activity, as NAM currently depicts, environmental parameters would seem supportive of organized convection continuing downstream, with some upward evolution expected by late morning. If convection maintains MCS structure then damaging winds will be the primary threat. However, forecast soundings across southeast IA into west-central IL exhibit favorable CAPE/shear for supercells and possible tornadoes. Will introduce low tornado probs to account for possible discrete updrafts by early afternoon. ...Eastern Dakotas... Early-morning water-vapor imagery depicts a well-defined short-wave trough over MT/WY shifting east toward the northern Plains. This feature is forecast to advance into the western Dakotas by 13/00z where it should aid scattered convection along/ahead of progressive wind shift. Hail/wind are the primary risks with scattered storms later today. ...ME... Weak mid-level height falls are forecast to spread south across ME later Monday. Deep westerly flow should allow boundary layer to warm such that inhibition is removed by 17z ahead of a zone of weak low-level confluence. Isolated thunderstorms are expected to develop across northern New England within a flow regime that could support storm organization capable of producing isolated damaging wind gusts. ..Darrow/Cook.. 08/12/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Mon Aug 12 2019 Valid 121200Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST IA TO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...Mid MS/OH Valley Region... An impressive amount of deep convection has developed over the central Plains early this morning ahead of a disturbance that should approach western IA by sunrise. A reservoir of untapped buoyancy currently extends ahead of the MCS over eastern KS which should aid eastward progression of organized convection into the beginning of the upcoming day1 period. Latest NAM model guidance suggests leading edge of this activity will be near the MO River at sunrise; however, current speed/movement of the convection is considerably faster and storms could advance into western IA by 09z. It's not entirely clear whether the MCS will slow its forward propagation so confidence in timing/placement of this complex of storms is somewhat in doubt. Current outlook is predicated on MCS slowing a bit toward sunrise. For these reasons have adjusted severe probs west across IA/northern MO to account for possible severe at the beginning of the period. If boundary layer is able to warm/destabilize ahead of this activity, as NAM currently depicts, environmental parameters would seem supportive of organized convection continuing downstream, with some upward evolution expected by late morning. If convection maintains MCS structure then damaging winds will be the primary threat. However, forecast soundings across southeast IA into west-central IL exhibit favorable CAPE/shear for supercells and possible tornadoes. Will introduce low tornado probs to account for possible discrete updrafts by early afternoon. ...Eastern Dakotas... Early-morning water-vapor imagery depicts a well-defined short-wave trough over MT/WY shifting east toward the northern Plains. This feature is forecast to advance into the western Dakotas by 13/00z where it should aid scattered convection along/ahead of progressive wind shift. Hail/wind are the primary risks with scattered storms later today. ...ME... Weak mid-level height falls are forecast to spread south across ME later Monday. Deep westerly flow should allow boundary layer to warm such that inhibition is removed by 17z ahead of a zone of weak low-level confluence. Isolated thunderstorms are expected to develop across northern New England within a flow regime that could support storm organization capable of producing isolated damaging wind gusts. ..Darrow/Cook.. 08/12/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Mon Aug 12 2019 Valid 121200Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST IA TO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...Mid MS/OH Valley Region... An impressive amount of deep convection has developed over the central Plains early this morning ahead of a disturbance that should approach western IA by sunrise. A reservoir of untapped buoyancy currently extends ahead of the MCS over eastern KS which should aid eastward progression of organized convection into the beginning of the upcoming day1 period. Latest NAM model guidance suggests leading edge of this activity will be near the MO River at sunrise; however, current speed/movement of the convection is considerably faster and storms could advance into western IA by 09z. It's not entirely clear whether the MCS will slow its forward propagation so confidence in timing/placement of this complex of storms is somewhat in doubt. Current outlook is predicated on MCS slowing a bit toward sunrise. For these reasons have adjusted severe probs west across IA/northern MO to account for possible severe at the beginning of the period. If boundary layer is able to warm/destabilize ahead of this activity, as NAM currently depicts, environmental parameters would seem supportive of organized convection continuing downstream, with some upward evolution expected by late morning. If convection maintains MCS structure then damaging winds will be the primary threat. However, forecast soundings across southeast IA into west-central IL exhibit favorable CAPE/shear for supercells and possible tornadoes. Will introduce low tornado probs to account for possible discrete updrafts by early afternoon. ...Eastern Dakotas... Early-morning water-vapor imagery depicts a well-defined short-wave trough over MT/WY shifting east toward the northern Plains. This feature is forecast to advance into the western Dakotas by 13/00z where it should aid scattered convection along/ahead of progressive wind shift. Hail/wind are the primary risks with scattered storms later today. ...ME... Weak mid-level height falls are forecast to spread south across ME later Monday. Deep westerly flow should allow boundary layer to warm such that inhibition is removed by 17z ahead of a zone of weak low-level confluence. Isolated thunderstorms are expected to develop across northern New England within a flow regime that could support storm organization capable of producing isolated damaging wind gusts. ..Darrow/Cook.. 08/12/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Mon Aug 12 2019 Valid 121200Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST IA TO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...Mid MS/OH Valley Region... An impressive amount of deep convection has developed over the central Plains early this morning ahead of a disturbance that should approach western IA by sunrise. A reservoir of untapped buoyancy currently extends ahead of the MCS over eastern KS which should aid eastward progression of organized convection into the beginning of the upcoming day1 period. Latest NAM model guidance suggests leading edge of this activity will be near the MO River at sunrise; however, current speed/movement of the convection is considerably faster and storms could advance into western IA by 09z. It's not entirely clear whether the MCS will slow its forward propagation so confidence in timing/placement of this complex of storms is somewhat in doubt. Current outlook is predicated on MCS slowing a bit toward sunrise. For these reasons have adjusted severe probs west across IA/northern MO to account for possible severe at the beginning of the period. If boundary layer is able to warm/destabilize ahead of this activity, as NAM currently depicts, environmental parameters would seem supportive of organized convection continuing downstream, with some upward evolution expected by late morning. If convection maintains MCS structure then damaging winds will be the primary threat. However, forecast soundings across southeast IA into west-central IL exhibit favorable CAPE/shear for supercells and possible tornadoes. Will introduce low tornado probs to account for possible discrete updrafts by early afternoon. ...Eastern Dakotas... Early-morning water-vapor imagery depicts a well-defined short-wave trough over MT/WY shifting east toward the northern Plains. This feature is forecast to advance into the western Dakotas by 13/00z where it should aid scattered convection along/ahead of progressive wind shift. Hail/wind are the primary risks with scattered storms later today. ...ME... Weak mid-level height falls are forecast to spread south across ME later Monday. Deep westerly flow should allow boundary layer to warm such that inhibition is removed by 17z ahead of a zone of weak low-level confluence. Isolated thunderstorms are expected to develop across northern New England within a flow regime that could support storm organization capable of producing isolated damaging wind gusts. ..Darrow/Cook.. 08/12/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Mon Aug 12 2019 Valid 121200Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST IA TO CENTRAL IL... ...SUMMARY... Severe thunderstorms are likely today over the middle Mississippi Valley to the Ohio Valley. Damaging gusts are the primary risk but a few tornadoes are possible. ...Mid MS/OH Valley Region... An impressive amount of deep convection has developed over the central Plains early this morning ahead of a disturbance that should approach western IA by sunrise. A reservoir of untapped buoyancy currently extends ahead of the MCS over eastern KS which should aid eastward progression of organized convection into the beginning of the upcoming day1 period. Latest NAM model guidance suggests leading edge of this activity will be near the MO River at sunrise; however, current speed/movement of the convection is considerably faster and storms could advance into western IA by 09z. It's not entirely clear whether the MCS will slow its forward propagation so confidence in timing/placement of this complex of storms is somewhat in doubt. Current outlook is predicated on MCS slowing a bit toward sunrise. For these reasons have adjusted severe probs west across IA/northern MO to account for possible severe at the beginning of the period. If boundary layer is able to warm/destabilize ahead of this activity, as NAM currently depicts, environmental parameters would seem supportive of organized convection continuing downstream, with some upward evolution expected by late morning. If convection maintains MCS structure then damaging winds will be the primary threat. However, forecast soundings across southeast IA into west-central IL exhibit favorable CAPE/shear for supercells and possible tornadoes. Will introduce low tornado probs to account for possible discrete updrafts by early afternoon. ...Eastern Dakotas... Early-morning water-vapor imagery depicts a well-defined short-wave trough over MT/WY shifting east toward the northern Plains. This feature is forecast to advance into the western Dakotas by 13/00z where it should aid scattered convection along/ahead of progressive wind shift. Hail/wind are the primary risks with scattered storms later today. ...ME... Weak mid-level height falls are forecast to spread south across ME later Monday. Deep westerly flow should allow boundary layer to warm such that inhibition is removed by 17z ahead of a zone of weak low-level confluence. Isolated thunderstorms are expected to develop across northern New England within a flow regime that could support storm organization capable of producing isolated damaging wind gusts. ..Darrow/Cook.. 08/12/2019 Read more

WW 0573 Status Updates
STATUS REPORT ON WW 573 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NNW BHK TO 30 SE OLF TO 65 NNE OLF. ..KERR..08/12/19 ATTN...WFO...GGW... STATUS REPORT FOR WS 573 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC021-083-085-109-120640- MT . MONTANA COUNTIES INCLUDED ARE DAWSON RICHLAND ROOSEVELT WIBAUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0573 Status Updates
STATUS REPORT ON WW 573 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NNW BHK TO 30 SE OLF TO 65 NNE OLF. ..KERR..08/12/19 ATTN...WFO...GGW... STATUS REPORT FOR WS 573 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC021-083-085-109-120640- MT . MONTANA COUNTIES INCLUDED ARE DAWSON RICHLAND ROOSEVELT WIBAUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 573 SEVERE TSTM MT 112305Z - 120700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 573 NWS Storm Prediction Center Norman OK 505 PM MDT Sun Aug 11 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Montana * Effective this Sunday afternoon and Monday morning from 505 PM until 100 AM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Scattered large hail and isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...Clusters of thunderstorms over central Montana will track east-northeastward across the watch area this evening. A few supercells and bow echoes capable of damaging winds and large hail are possible. The severe thunderstorm watch area is approximately along and 80 statute miles north and south of a line from 85 miles west southwest of Glasgow MT to 10 miles north northeast of Sidney MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 569...WW 570...WW 571...WW 572... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

MD 1712 CONCERNING SEVERE THUNDERSTORM WATCH 574... FOR SOUTHERN NEBRASKA/NORTHERN KANSAS
Mesoscale Discussion 1712 NWS Storm Prediction Center Norman OK 1130 PM CDT Sun Aug 11 2019 Areas affected...southern Nebraska/northern Kansas Concerning...Severe Thunderstorm Watch 574... Valid 120430Z - 120630Z The severe weather threat for Severe Thunderstorm Watch 574 continues. SUMMARY...Severe risk continues across WW 574 -- particularly across the north-central Kansas/south-central Nebraska border counties. Risk for damaging winds, including the possibility for winds in excess of 70 MPH, remains evident. DISCUSSION...Latest radar loop shows a well-defined bow echo moving east-northeastward at 45 kt across the southern Nebraska/northern Kansas area, with the surging apex of the bow right along the border, affecting Harlon and Franklin Counties in Nebraska, and Phillips and Smith Counties in Kansas. While no obs sites have been in the direct path of the bow's apex, where the strongest winds are indicated by radar, gusts in excess of 70 MPH appear likely to be occurring. With a very moist/unstable airmass downstream of the convection available to continue to fuel stout updrafts, expect damaging wind risk to continue spreading across the watch area. ..Goss.. 08/12/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OAX...TOP...ICT...GID...LBF...DDC...GLD... LAT...LON 38730022 39050033 40840038 41099636 39249659 38730022 Read more

WW 0572 Status Updates
STATUS REPORT ON WW 572 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 SSE GLD TO 25 E GLD TO 40 S MCK TO 20 WSW MCK TO 55 ENE SNY. ..GOSS..08/12/19 ATTN...WFO...GLD...LBF... STATUS REPORT FOR WT 572 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC039-063-109-179-193-120440- KS . KANSAS COUNTIES INCLUDED ARE DECATUR GOVE LOGAN SHERIDAN THOMAS NEC063-085-087-101-111-135-145-120440- NE . NEBRASKA COUNTIES INCLUDED ARE FRONTIER HAYES HITCHCOCK KEITH LINCOLN PERKINS RED WILLOW THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more