Severe Storms

WW 0631 Status Updates
STATUS REPORT ON WW 631 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WSW BIS TO 55 NNE BIS TO 20 NW DVL. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1913 ..MOSIER..09/02/19 ATTN...WFO...BIS... STATUS REPORT FOR WS 631 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC015-031-043-093-103-022140- ND . NORTH DAKOTA COUNTIES INCLUDED ARE BURLEIGH FOSTER KIDDER STUTSMAN WELLS 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

MD 1915 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SOUTHEAST ND...WEST-CENTRAL MN...FAR NORTHEAST SD
Mesoscale Discussion 1915 NWS Storm Prediction Center Norman OK 0334 PM CDT Mon Sep 02 2019 Areas affected...Southeast ND...West-Central MN...Far Northeast SD Concerning...Severe potential...Watch likely Valid 022034Z - 022200Z Probability of Watch Issuance...95 percent SUMMARY...Strengthening MCS across central SD is expected to persist downstream in southeast ND, west-central MN, and far northeast SD. A downstream watch will likely be needed. DISCUSSION...Current storm motion takes the ongoing MCS across central ND to the edge of Severe Thunderstorm Watch 631 before 22Z. Convective inhibition currently remains in place over the downstream environment across southeast ND, west-central MN, and far northeastern SD. However, increasing moisture advection and diurnal heating will contribute to an erosion of at least some of this inhibition. In addition to the weakening convective inhibition and building instability, the strong warm-air advection is expected to persist. All of these factors combined with the organized character of the ongoing MCS suggest the severe threat will continue downstream. Some acceleration of the MCS is also possible along with higher probability for strong wind gusts at the surface. A downstream watch will likely be needed to cover the resulting severe weather threat. ..Mosier/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...FGF...ABR...BIS... LAT...LON 47309893 47729790 46999509 45629493 45419668 46019960 47309893 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... AMENDED TO ADD SIG WIND ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... AMENDED TO ADD SIG WIND ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... AMENDED TO ADD SIG WIND ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Mon Sep 02 2019 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NORTH DAKOTA INTO WESTERN WISCONSIN... ...SUMMARY... Severe thunderstorms are possible this afternoon through early Tuesday morning across parts of the Northern Plains and Upper Midwest, with the most likely corridor from North Dakota to central Minnesota and west-central Wisconsin. Other severe storms are possible across the Northeast States, along with a low tornado risk along the Florida east coast. ...Northern Plains and Upper Mississippi Valley... Changes to this outlook include an east/southeast expansion in the risk categories to include more of western Wisconsin for an anticipated MCS and/or cluster of storms. Strong instability continues to develop south of the warm front from SD into southern MN. An initial cluster of storms over central ND will continue southeastward with a damaging wind and hail threat, increasing later this evening and overnight as the system encounter warmer air. In addition, a tornado or two will be possible given favorable shear profiles. For more information regarding ongoing storms over ND, see mesoscale discussion 1913. ..Jewell.. 09/02/2019 .PREV DISCUSSION... /ISSUED 1147 AM CDT Mon Sep 02 2019/ ...Dakotas/Upper Midwest... Severe thunderstorm potential is expected to steadily increase this afternoon into tonight, initially across the Dakotas this afternoon and into Minnesota and western Wisconsin late this evening/overnight, with all severe-weather-related risks possible. A consequential shortwave trough by late-summer standards will continue to amplify/dig southeastward over southern portions of Alberta/Saskatchewan today, reaching the eastern Dakotas and Minnesota tonight. Increasing mid-level height falls and strengthening deep-layer winds will be associated with this trough, all while a moist air mass steadily spreads northward in relation to a northward-moving warm front across the region. Initially, a band of mid-level warm advection will support elevated convection spreading from northeast Montana/northwest North Dakota, some of which may be capable of severe hail. See Mesoscale Discussion 1911 for short-term details. It is likely that convection will further increase in coverage/organization this afternoon while becoming increasingly near-surface-based in closer proximity to the warm front with an increasing damaging wind potential aside from large hail. It appears likely that a well-organized MCS will evolve by late afternoon/early evening. Although some questions exist regarding the stability of the low-level thermodynamic environment late tonight, storm organization/forward acceleration will be influenced by a dramatic strengthening of 850/700 mb winds. This suggests damaging wind potential will likely further increase late this evening/early overnight, particularly in closer proximity to the warm front, as the MCS accelerates east-southeastward across a broad part of central Minnesota. Damaging winds aside, this will also include some potential for QLCS-related tornadoes along with continued severe hail potential. ...Southern New England through northern Virginia... Bands of convection are moving across southern New England and northern New Jersey/southeast New York at midday. Surface-based buoyancy will tend to remain modest where low-level hodographs will remain modestly enlarged, but isolated damaging wind and/or brief tornado is possible. Farther southwest, across a broader part of the Mid-Atlantic region, isolated to scattered thunderstorms may develop as a weaker upstream impulse shifts east from Lower Michigan and interacts with a lee surface trough. Adequate deep-layer shear will exist for isolated strong gusts and marginally severe hail. ...Florida Atlantic coast... Hurricane Dorian is forecast to drift northwestward through the period; reference NHC forecasts for the latest details. Dorian should remain far enough offshore to limit the overall tornado threat as typical on the western periphery of hurricanes. That said, low-level hodographs should gain some additional length/curvature through late today and tonight as winds strengthen along the east coast of the Peninsula. Any cells that can develop in outer rainbands this afternoon into tonight might pose a risk for a brief tornado. Read more

MD 1914 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE MID-ATLANTIC INTO THE NORTHEAST
Mesoscale Discussion 1914 NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Sep 02 2019 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Watch unlikely Valid 021958Z - 022230Z Probability of Watch Issuance...20 percent SUMMARY...Storms are developing along and ahead of a cold front across Upstate New York stretching into central Pennsylvania. Marginally severe wind/hail are possible, and a brief, weak tornado may also be possible where surface winds are backed. DISCUSSION...A broad upper-level trough is moving over Ontario/Quebec today with a mid-level disturbance rotating around the base of it across the eastern Great Lakes into the Northeast. An associated surface cold front is pushing east/southeast across the region with storms developing along/ahead of it currently. Insolation behind storms/showers that moved through earlier have increased MLCAPE to 500-1000+ J/kg as surface temperatures have warmed into the 70s and low 80s F with 65-70 F dewpoints. Buoyancy and instability should continue to increase and also shift eastward with time as the upper-level wave progresses and as heating continues behind the eastward moving showers in New England. Isolated damaging wind is possible given increasing low-level lapse rates and large hail is also possible with effective bulk shear of 30-40 knots. A broken line of storms is expected to develop with a few storms possibly developing ahead of it. These storms will move eastward this afternoon/evening with some weak, transient supercellular structures possible. A brief, weak tornado is possible across portions of southern New England/New York where backed low-level flow exists. Given the marginal and relatively expected isolated severe risk, a watch issuance is unlikely. ..Nauslar/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...OKX...ALY...PHI...BGM...CTP... LAT...LON 40657637 40507695 40377741 40477777 40707794 40957795 41207748 41947596 42677380 43057255 43147212 43157180 43067141 42737122 42237114 41957124 41577196 41447239 41417256 41297304 41207378 40657637 Read more

WW 0631 Status Updates
STATUS REPORT ON WW 631 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 WSW N60 TO 55 WNW DVL. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1913 ..MOSIER..09/02/19 ATTN...WFO...BIS... STATUS REPORT FOR WS 631 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC015-031-043-055-057-059-065-069-083-093-103-022040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE BURLEIGH FOSTER KIDDER MCLEAN MERCER MORTON OLIVER PIERCE SHERIDAN STUTSMAN WELLS 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

MD 1913 CONCERNING SEVERE THUNDERSTORM WATCH 631... FOR CENTRAL ND
Mesoscale Discussion 1913 NWS Storm Prediction Center Norman OK 0247 PM CDT Mon Sep 02 2019 Areas affected...Central ND Concerning...Severe Thunderstorm Watch 631... Valid 021947Z - 022115Z The severe weather threat for Severe Thunderstorm Watch 631 continues. SUMMARY...Large hail and strong wind gusts remain possible with the line of storms moving quickly across central ND. DISCUSSION...Current estimated storm motion on the forward-propagating MCS moving through central ND is 290 degrees at 36 kt. Some increase in forward motion is possible over the next few hours as mid-level flow gradually increases and the system matures. Thus far, the primary threat with the MCS has been large hail, owing to its predominantly elevated character. Moisture advection continues within the downstream air mass but the low-level stratus remains in place. Delayed erosion of this stratus layer has stunted insolation immediately downstream of the MCS across central ND, limiting destabilization (shown well on the 18Z BIS sounding). More thinning of the stratus layer is beginning to occur across southeast ND where temperatures are now in the upper 60s/low 70s. Current expectation is for the MCS to maintain strength as it continues southeastward, perhaps increasing its forward speed. Limited downstream destabilization has likely limited strong wind gusts thus far. However, gusts are expected to become increasingly likely this afternoon as the downstream air mass becomes more favorable for surface-based storms. ..Mosier.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 48300267 48750127 47999804 46339851 46510218 48300267 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... A few mixed mode (i.e., dry/wet) thunderstorms are possible along the leading edge of the northward-moving monsoonal moisture surge across portions of Nevada into western Utah Day 2/Tuesday afternoon/evening. However, the expected relatively quick transition towards generally wetter thunderstorms -- with precipitable water values rapidly increasing above 0.75" -- coupled with relatively sparse fuels for large fire spread across portions of this area preclude the introduction of a fire weather area at this time. Otherwise, the fire weather forecast remains on track. See previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 02 2019/ ...Synopsis... An upper-level ridge will remain fortified across the western CONUS, with another mid-level shortwave trough cresting the ridge and traversing the Pacific Northwest during the Day 2/Tuesday period. As such, mildly breezy and dry conditions may be observed east of the Cascades. Deep-layer ascent and marginal instability accompanying the aforementioned shortwave may yield very isolated thunderstorm development across parts of the Pacific Northwest. ...Pacific Northwest... Downslope flow along the lee of the Cascades, particularly in Oregon, may support up to 15 mph sustained westerly winds and 15-20% RH by afternoon peak heating. Currently, the latest model guidance differs in the placement and timing of elevated conditions, precluding a delineation. In addition, enhanced lift may also foster the development of a couple thunderstorms, especially along the lee of the northern Cascades in Washington. Given precipitable water values in the 0.50-0.75 inch range, a dry strike or two cannot be ruled out. ...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 0218 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... A few mixed mode (i.e., dry/wet) thunderstorms are possible along the leading edge of the northward-moving monsoonal moisture surge across portions of Nevada into western Utah Day 2/Tuesday afternoon/evening. However, the expected relatively quick transition towards generally wetter thunderstorms -- with precipitable water values rapidly increasing above 0.75" -- coupled with relatively sparse fuels for large fire spread across portions of this area preclude the introduction of a fire weather area at this time. Otherwise, the fire weather forecast remains on track. See previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 02 2019/ ...Synopsis... An upper-level ridge will remain fortified across the western CONUS, with another mid-level shortwave trough cresting the ridge and traversing the Pacific Northwest during the Day 2/Tuesday period. As such, mildly breezy and dry conditions may be observed east of the Cascades. Deep-layer ascent and marginal instability accompanying the aforementioned shortwave may yield very isolated thunderstorm development across parts of the Pacific Northwest. ...Pacific Northwest... Downslope flow along the lee of the Cascades, particularly in Oregon, may support up to 15 mph sustained westerly winds and 15-20% RH by afternoon peak heating. Currently, the latest model guidance differs in the placement and timing of elevated conditions, precluding a delineation. In addition, enhanced lift may also foster the development of a couple thunderstorms, especially along the lee of the northern Cascades in Washington. Given precipitable water values in the 0.50-0.75 inch range, a dry strike or two cannot be ruled out. ...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 0218 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... A few mixed mode (i.e., dry/wet) thunderstorms are possible along the leading edge of the northward-moving monsoonal moisture surge across portions of Nevada into western Utah Day 2/Tuesday afternoon/evening. However, the expected relatively quick transition towards generally wetter thunderstorms -- with precipitable water values rapidly increasing above 0.75" -- coupled with relatively sparse fuels for large fire spread across portions of this area preclude the introduction of a fire weather area at this time. Otherwise, the fire weather forecast remains on track. See previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 02 2019/ ...Synopsis... An upper-level ridge will remain fortified across the western CONUS, with another mid-level shortwave trough cresting the ridge and traversing the Pacific Northwest during the Day 2/Tuesday period. As such, mildly breezy and dry conditions may be observed east of the Cascades. Deep-layer ascent and marginal instability accompanying the aforementioned shortwave may yield very isolated thunderstorm development across parts of the Pacific Northwest. ...Pacific Northwest... Downslope flow along the lee of the Cascades, particularly in Oregon, may support up to 15 mph sustained westerly winds and 15-20% RH by afternoon peak heating. Currently, the latest model guidance differs in the placement and timing of elevated conditions, precluding a delineation. In addition, enhanced lift may also foster the development of a couple thunderstorms, especially along the lee of the northern Cascades in Washington. Given precipitable water values in the 0.50-0.75 inch range, a dry strike or two cannot be ruled out. ...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 0218 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... A few mixed mode (i.e., dry/wet) thunderstorms are possible along the leading edge of the northward-moving monsoonal moisture surge across portions of Nevada into western Utah Day 2/Tuesday afternoon/evening. However, the expected relatively quick transition towards generally wetter thunderstorms -- with precipitable water values rapidly increasing above 0.75" -- coupled with relatively sparse fuels for large fire spread across portions of this area preclude the introduction of a fire weather area at this time. Otherwise, the fire weather forecast remains on track. See previous discussion below for more information on tomorrow's fire weather forecast. ..Elliott.. 09/02/2019 .PREV DISCUSSION... /ISSUED 0150 AM CDT Mon Sep 02 2019/ ...Synopsis... An upper-level ridge will remain fortified across the western CONUS, with another mid-level shortwave trough cresting the ridge and traversing the Pacific Northwest during the Day 2/Tuesday period. As such, mildly breezy and dry conditions may be observed east of the Cascades. Deep-layer ascent and marginal instability accompanying the aforementioned shortwave may yield very isolated thunderstorm development across parts of the Pacific Northwest. ...Pacific Northwest... Downslope flow along the lee of the Cascades, particularly in Oregon, may support up to 15 mph sustained westerly winds and 15-20% RH by afternoon peak heating. Currently, the latest model guidance differs in the placement and timing of elevated conditions, precluding a delineation. In addition, enhanced lift may also foster the development of a couple thunderstorms, especially along the lee of the northern Cascades in Washington. Given precipitable water values in the 0.50-0.75 inch range, a dry strike or two cannot be ruled out. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0631 Status Updates
STATUS FOR WATCH 0631 HAS NOT BEEN ISSUED YET Read more

MD 1912 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE MID-ATLANTIC INTO THE NORTHEAST
Mesoscale Discussion 1912 NWS Storm Prediction Center Norman OK 0101 PM CDT Mon Sep 02 2019 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Watch unlikely Valid 021801Z - 022000Z Probability of Watch Issuance...20 percent SUMMARY...Storms are developing across portions of the Mid-Atlantic into the Northeast. These storms could produce marginally severe hail/wind and a brief, weak tornado. DISCUSSION...A broad upper-level trough is over Ontario/Quebec with multiple mid-level disturbance rotating around the base of it across the eastern Great Lakes into the Northeast. A surface pressure trough is extending southward through eastern New York helping to enhance surface convergence with south-southeast surface winds ahead of it. Storms within a narrow corridor across northern New Jersey into NYC/vicinity may become capable of a brief, weak tornado given the backing low-level winds. However, cloud cover has limited insolation across this area thus far, inhibiting low-level instability. Farther south in southeast Pennsylvania into northern Virginia, the Cu field is maturing, but updrafts are struggling to mature via satellite/radar imagery. As buoyancy/instability increase during the afternoon, storms will develop amid MLCAPE of 1000-1500 J/kg and move eastward. Shear is increasing with time with the passage of the upper-level trough to the north, which will allow some marginal storm organization. A broken line of storms is likely to form with marginally severe hail/wind possible. Given the isolated, marginal severe risk, a watch issuance is unlikely. ..Nauslar/Guyer.. 09/02/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...CTP...LWX...PBZ... LAT...LON 40657549 41017429 41247330 41097297 40697279 40307313 39827389 39567460 39007665 39137863 39407923 39637884 39917801 40327709 40657549 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Mon Sep 02 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN INTO CENTRAL ILLINOIS... ...SUMMARY... Severe storms are likely from Lower Michigan southwestward into Illinois, and across northern Indiana and Ohio on Tuesday. ...Synopsis... A strong shortwave trough will move east from the Upper MS Valley across the Great Lakes, with 70-80 kt mid and upper flow sweeping across MN, WI and MI. At the surface, low pressure will deepen as it moves east across Upper MI with a cold front extending roughly from Lake MI into northern IL and northern MO by late afternoon. Ahead of the front, increasing southwesterly winds will bring mid to upper 60s F dewpoints northward ahead of the cold front into Lower MI. Strong deep-layer shear along with cold temperatures aloft which will result in a favorable environment for severe storms. Elsewhere, Hurricane Dorian is forecast to remain off the FL east coast, with a few associated strong thunderstorms possible there. ...WI...Lower MI...IL...IN...OH... Storms may be ongoing Tuesday morning over parts of southern WI, possibly a continuation of the previous day's MCS, well ahead of the cold front and in a region of strong low-level warm advection. Should instability be strong enough, this system could persist into Lower MI with hail or wind. Otherwise, strong instability will develop ahead of the primary cold front, with strong shear and hodographs favorable for supercells. Very large hail will be possible with cells developing along the front later in the day, with a tornado threat into Lower MI where SRH will be greater. A damaging bow is possible as well should the storm mode become more linear, with strong mean wind speeds aloft resulting in fast motions. Storms are expected to be more isolated into central IL. Farther southwest into MO, a capping inversion may mostly prohibit deep convection. However, low-level convergence near the front may support an isolated cell during the peak heating hours, with a conditional hail or wind threat. ...Florida east coast: central through northern... Hurricane Dorian is forecast to remain offshore the FL east coast on Tuesday. However, low-level convergence and banded convection around the west side of the system will persist and spread slowly northward. While not climatologically optimal along the west side of the track, effective SRH around 200 m2/s2 during the day, increasing to over 300 m2/s2 into Wednesday morning may support a few rotating thunderstorms or a brief/weak tornado. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 09/02/2019 Read more