Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1201 AM CDT Thu Aug 22 2019 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN VIRGINIA INTO NORTH CAROLINA...AND OVER THE NORTHERN AND CENTRAL HIGH PLAINS... ...SUMMARY... Isolated severe wind gusts are possible Friday over parts of North Carolina and southern Virginia, with hail and localized strong gusts possible over the northern and central High Plains. ...Synopsis... A positive-tilt upper trough will move across the Northeast with around 30 kt midlevel winds trailing across the Mid Atlantic. A front will drift southward across VA during the day, providing lift for storms, some capable of wind damage, from VA into NC. The westward extension of this front will move into Plains, with southeast surface winds maintaining 60s F dewpoints into the High Plains. A compact shortwave trough will move from WY into the Dakotas, providing cool air aloft and maximizing instability for a few strong to severe storms capable of hail. ...Southern VA into NC... Areas of thunderstorms may be ongoing Friday morning from eastern KY across WV and into western VA in association with lift near the right entrance region of the upper jet. Preceding this activity, heating of a moist air mass will lead to around 2000 J/kg MLCAPE, allowing ongoing activity to strengthen during the day. New development is also likely eastward along the front. While this boundary will be parallel to the upper flow, a southeastward propagation is expected as storms merge outflows, with locally damaging winds possible in an otherwise weak shear environment. ...Northern and central High Plains... Temperatures aloft will become cool for this time of year with the weak upper trough. Shear will not increase much, but southeast low-level winds will maintain ample moisture into eastern WY and CO, with isolated strong storms likely by late afternoon forming near the Front Range. Additional storms are likely over the Black Hills. Storms are generally expected to move east, within a narrow north-south corridor of hail or marginal wind threat with capping to the east. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Jewell.. 08/22/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1201 AM CDT Thu Aug 22 2019 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN VIRGINIA INTO NORTH CAROLINA...AND OVER THE NORTHERN AND CENTRAL HIGH PLAINS... ...SUMMARY... Isolated severe wind gusts are possible Friday over parts of North Carolina and southern Virginia, with hail and localized strong gusts possible over the northern and central High Plains. ...Synopsis... A positive-tilt upper trough will move across the Northeast with around 30 kt midlevel winds trailing across the Mid Atlantic. A front will drift southward across VA during the day, providing lift for storms, some capable of wind damage, from VA into NC. The westward extension of this front will move into Plains, with southeast surface winds maintaining 60s F dewpoints into the High Plains. A compact shortwave trough will move from WY into the Dakotas, providing cool air aloft and maximizing instability for a few strong to severe storms capable of hail. ...Southern VA into NC... Areas of thunderstorms may be ongoing Friday morning from eastern KY across WV and into western VA in association with lift near the right entrance region of the upper jet. Preceding this activity, heating of a moist air mass will lead to around 2000 J/kg MLCAPE, allowing ongoing activity to strengthen during the day. New development is also likely eastward along the front. While this boundary will be parallel to the upper flow, a southeastward propagation is expected as storms merge outflows, with locally damaging winds possible in an otherwise weak shear environment. ...Northern and central High Plains... Temperatures aloft will become cool for this time of year with the weak upper trough. Shear will not increase much, but southeast low-level winds will maintain ample moisture into eastern WY and CO, with isolated strong storms likely by late afternoon forming near the Front Range. Additional storms are likely over the Black Hills. Storms are generally expected to move east, within a narrow north-south corridor of hail or marginal wind threat with capping to the east. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Jewell.. 08/22/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1201 AM CDT Thu Aug 22 2019 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN VIRGINIA INTO NORTH CAROLINA...AND OVER THE NORTHERN AND CENTRAL HIGH PLAINS... ...SUMMARY... Isolated severe wind gusts are possible Friday over parts of North Carolina and southern Virginia, with hail and localized strong gusts possible over the northern and central High Plains. ...Synopsis... A positive-tilt upper trough will move across the Northeast with around 30 kt midlevel winds trailing across the Mid Atlantic. A front will drift southward across VA during the day, providing lift for storms, some capable of wind damage, from VA into NC. The westward extension of this front will move into Plains, with southeast surface winds maintaining 60s F dewpoints into the High Plains. A compact shortwave trough will move from WY into the Dakotas, providing cool air aloft and maximizing instability for a few strong to severe storms capable of hail. ...Southern VA into NC... Areas of thunderstorms may be ongoing Friday morning from eastern KY across WV and into western VA in association with lift near the right entrance region of the upper jet. Preceding this activity, heating of a moist air mass will lead to around 2000 J/kg MLCAPE, allowing ongoing activity to strengthen during the day. New development is also likely eastward along the front. While this boundary will be parallel to the upper flow, a southeastward propagation is expected as storms merge outflows, with locally damaging winds possible in an otherwise weak shear environment. ...Northern and central High Plains... Temperatures aloft will become cool for this time of year with the weak upper trough. Shear will not increase much, but southeast low-level winds will maintain ample moisture into eastern WY and CO, with isolated strong storms likely by late afternoon forming near the Front Range. Additional storms are likely over the Black Hills. Storms are generally expected to move east, within a narrow north-south corridor of hail or marginal wind threat with capping to the east. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Jewell.. 08/22/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Thu Aug 22 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN AND CENTRAL HIGH PLAINS AND FROM OK INTO THE MID-ATLANTIC AND NEW ENGLAND... ...SUMMARY... Isolated severe wind gusts are possible this afternoon and evening from Oklahoma eastward across the Ohio Valley and into parts of the mid-Atlantic and New England. Meanwhile, hail or wind, occasionally reaching severe levels, will also be possible over the central and northern High Plains area. ...Synopsis... A couple of upper level troughs and associated surface cold fronts will result in a few areas of strong, occasionally severe storms today. The first trough will pivot eastward from the upper Great Lakes to the Northeast. A band of stronger southwesterly deep-layer flow will overspread much of the northeastern U.S. from around PA northward while a surface cold front shifts eastward. The western extent of the front will drop more slowly south/southeast across the Midwest, extending from southern MO toward Chesapeake Bay by Friday morning. Several weak shortwave impulses and remnant MCVs will float through westerly flow from OK to the Mid-Atlantic ahead of the southward-sagging front, aiding in the development of sporadically strong thunderstorm clusters. Further northwest, a shortwave trough will migrate eastward across the northern Rockies. A surface cold front will progress eastward across MT/WY during the afternoon and evening, while a surface trough strengthens southeasterly low level flow in a moist upslope flow regime across the northern High Plains. This will focus another area for strong storm potential during the afternoon and evening across parts of the northern and central High Plains. ...Mid-Atlantic and New England... A warm and very moist airmass will reside ahead of the surface cold front. Overall, west/southwesterly flow will be rather modest, with the strongest flow residing over the Northeast. A corridor of modest destabilization will overlap with this relatively stronger flow, and a few fast moving storm clusters or line segments are possible from PA northward through coastal ME. A few strong wind gusts could accompany this activity, though the overall threat should remain limited by poor midlevel lapse rates and in the absence of stronger shear. Further south toward the Chesapeake and VA/NC Piedmont vicinity, thunderstorm clusters are expected to develop in vicinity of a lee trough as subtle shortwave impulses migrate across the Appalachians. The airmass across this area will be very moist with PW values greater than 2 inches forecast. Strong heating will result in moderate destabilization and some strong gusts in wet microbursts will be possible. ...Oklahoma toward the Ohio Valley... Deep-layer westerly flow will remain weak across the region. However, several shortwave impulses are forecast to migrate through westerly flow while a myriad of outflow boundaries and MCVs from prior convection influence thunderstorm development during the afternoon. Steep lapse rates and moderate instability will be sufficient for severe storms, but weak flow will limit overall organization. Nevertheless a few strong to severe storms are possible with strong downburst winds being the main threat. Should an adequate cold pool develop, very steep low level lapse rates could support a surging cluster/bow with an increased threat for damaging wind, but confidence in this scenario is low, precluding higher probabilities. ...Portions of the Northern/Central High Plains... Strong southeasterly upslope flow in the vicinity of a pre-frontal lee trough will bring upper 50s to low 60s surface dewpoints across the High Plains of MT/WY/CO. Strong heating and very steep midlevel lapse rates will result in 2000-3000 J/kg MLCAPE by afternoon. While southeast flow through around 2 km will be strong, mid and upper-level flow will remain rather weak. Nevertheless, as forcing increases with the approach of a surface cold front and the upper trough, scattered thunderstorms are expected. A deeply mixed sub-cloud layer will support strong downburst winds, especially as clusters/line segments are favored. However, very steep midlevel lapse rates also will support some potential for hail initially. In the absence of stronger shear, will maintain Marginal risk. Further west across the higher terrain of south-central into southwest MT, a couple of storms could produce gusty winds and hail as the cold front moves through during the early afternoon. ..Leitman.. 08/22/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Thu Aug 22 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN AND CENTRAL HIGH PLAINS AND FROM OK INTO THE MID-ATLANTIC AND NEW ENGLAND... ...SUMMARY... Isolated severe wind gusts are possible this afternoon and evening from Oklahoma eastward across the Ohio Valley and into parts of the mid-Atlantic and New England. Meanwhile, hail or wind, occasionally reaching severe levels, will also be possible over the central and northern High Plains area. ...Synopsis... A couple of upper level troughs and associated surface cold fronts will result in a few areas of strong, occasionally severe storms today. The first trough will pivot eastward from the upper Great Lakes to the Northeast. A band of stronger southwesterly deep-layer flow will overspread much of the northeastern U.S. from around PA northward while a surface cold front shifts eastward. The western extent of the front will drop more slowly south/southeast across the Midwest, extending from southern MO toward Chesapeake Bay by Friday morning. Several weak shortwave impulses and remnant MCVs will float through westerly flow from OK to the Mid-Atlantic ahead of the southward-sagging front, aiding in the development of sporadically strong thunderstorm clusters. Further northwest, a shortwave trough will migrate eastward across the northern Rockies. A surface cold front will progress eastward across MT/WY during the afternoon and evening, while a surface trough strengthens southeasterly low level flow in a moist upslope flow regime across the northern High Plains. This will focus another area for strong storm potential during the afternoon and evening across parts of the northern and central High Plains. ...Mid-Atlantic and New England... A warm and very moist airmass will reside ahead of the surface cold front. Overall, west/southwesterly flow will be rather modest, with the strongest flow residing over the Northeast. A corridor of modest destabilization will overlap with this relatively stronger flow, and a few fast moving storm clusters or line segments are possible from PA northward through coastal ME. A few strong wind gusts could accompany this activity, though the overall threat should remain limited by poor midlevel lapse rates and in the absence of stronger shear. Further south toward the Chesapeake and VA/NC Piedmont vicinity, thunderstorm clusters are expected to develop in vicinity of a lee trough as subtle shortwave impulses migrate across the Appalachians. The airmass across this area will be very moist with PW values greater than 2 inches forecast. Strong heating will result in moderate destabilization and some strong gusts in wet microbursts will be possible. ...Oklahoma toward the Ohio Valley... Deep-layer westerly flow will remain weak across the region. However, several shortwave impulses are forecast to migrate through westerly flow while a myriad of outflow boundaries and MCVs from prior convection influence thunderstorm development during the afternoon. Steep lapse rates and moderate instability will be sufficient for severe storms, but weak flow will limit overall organization. Nevertheless a few strong to severe storms are possible with strong downburst winds being the main threat. Should an adequate cold pool develop, very steep low level lapse rates could support a surging cluster/bow with an increased threat for damaging wind, but confidence in this scenario is low, precluding higher probabilities. ...Portions of the Northern/Central High Plains... Strong southeasterly upslope flow in the vicinity of a pre-frontal lee trough will bring upper 50s to low 60s surface dewpoints across the High Plains of MT/WY/CO. Strong heating and very steep midlevel lapse rates will result in 2000-3000 J/kg MLCAPE by afternoon. While southeast flow through around 2 km will be strong, mid and upper-level flow will remain rather weak. Nevertheless, as forcing increases with the approach of a surface cold front and the upper trough, scattered thunderstorms are expected. A deeply mixed sub-cloud layer will support strong downburst winds, especially as clusters/line segments are favored. However, very steep midlevel lapse rates also will support some potential for hail initially. In the absence of stronger shear, will maintain Marginal risk. Further west across the higher terrain of south-central into southwest MT, a couple of storms could produce gusty winds and hail as the cold front moves through during the early afternoon. ..Leitman.. 08/22/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Thu Aug 22 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN AND CENTRAL HIGH PLAINS AND FROM OK INTO THE MID-ATLANTIC AND NEW ENGLAND... ...SUMMARY... Isolated severe wind gusts are possible this afternoon and evening from Oklahoma eastward across the Ohio Valley and into parts of the mid-Atlantic and New England. Meanwhile, hail or wind, occasionally reaching severe levels, will also be possible over the central and northern High Plains area. ...Synopsis... A couple of upper level troughs and associated surface cold fronts will result in a few areas of strong, occasionally severe storms today. The first trough will pivot eastward from the upper Great Lakes to the Northeast. A band of stronger southwesterly deep-layer flow will overspread much of the northeastern U.S. from around PA northward while a surface cold front shifts eastward. The western extent of the front will drop more slowly south/southeast across the Midwest, extending from southern MO toward Chesapeake Bay by Friday morning. Several weak shortwave impulses and remnant MCVs will float through westerly flow from OK to the Mid-Atlantic ahead of the southward-sagging front, aiding in the development of sporadically strong thunderstorm clusters. Further northwest, a shortwave trough will migrate eastward across the northern Rockies. A surface cold front will progress eastward across MT/WY during the afternoon and evening, while a surface trough strengthens southeasterly low level flow in a moist upslope flow regime across the northern High Plains. This will focus another area for strong storm potential during the afternoon and evening across parts of the northern and central High Plains. ...Mid-Atlantic and New England... A warm and very moist airmass will reside ahead of the surface cold front. Overall, west/southwesterly flow will be rather modest, with the strongest flow residing over the Northeast. A corridor of modest destabilization will overlap with this relatively stronger flow, and a few fast moving storm clusters or line segments are possible from PA northward through coastal ME. A few strong wind gusts could accompany this activity, though the overall threat should remain limited by poor midlevel lapse rates and in the absence of stronger shear. Further south toward the Chesapeake and VA/NC Piedmont vicinity, thunderstorm clusters are expected to develop in vicinity of a lee trough as subtle shortwave impulses migrate across the Appalachians. The airmass across this area will be very moist with PW values greater than 2 inches forecast. Strong heating will result in moderate destabilization and some strong gusts in wet microbursts will be possible. ...Oklahoma toward the Ohio Valley... Deep-layer westerly flow will remain weak across the region. However, several shortwave impulses are forecast to migrate through westerly flow while a myriad of outflow boundaries and MCVs from prior convection influence thunderstorm development during the afternoon. Steep lapse rates and moderate instability will be sufficient for severe storms, but weak flow will limit overall organization. Nevertheless a few strong to severe storms are possible with strong downburst winds being the main threat. Should an adequate cold pool develop, very steep low level lapse rates could support a surging cluster/bow with an increased threat for damaging wind, but confidence in this scenario is low, precluding higher probabilities. ...Portions of the Northern/Central High Plains... Strong southeasterly upslope flow in the vicinity of a pre-frontal lee trough will bring upper 50s to low 60s surface dewpoints across the High Plains of MT/WY/CO. Strong heating and very steep midlevel lapse rates will result in 2000-3000 J/kg MLCAPE by afternoon. While southeast flow through around 2 km will be strong, mid and upper-level flow will remain rather weak. Nevertheless, as forcing increases with the approach of a surface cold front and the upper trough, scattered thunderstorms are expected. A deeply mixed sub-cloud layer will support strong downburst winds, especially as clusters/line segments are favored. However, very steep midlevel lapse rates also will support some potential for hail initially. In the absence of stronger shear, will maintain Marginal risk. Further west across the higher terrain of south-central into southwest MT, a couple of storms could produce gusty winds and hail as the cold front moves through during the early afternoon. ..Leitman.. 08/22/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 PM CDT Wed Aug 21 2019 Valid 220100Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS TO THE LOWER OHIO VALLEY... ...SUMMARY... Strong, isolated severe storms are possible this evening into the overnight hours across parts of the High Plains into Kansas, eastward toward southern Indiana and northern Kentucky. Strong gusts will be the main concern, but some marginally severe hail is possible as well. ...WY/CO High Plains eastward toward the Lower OH Valley... Strong to isolated severe thunderstorms were ongoing this evening in a modestly sheared, moderately unstable airmass. Several shortwave impulses will continue to move through west/northwesterly flow from the central High Plains toward the Midwest through the overnight hours while a surface boundary extending across KS eastward into MO/IL/IN remains nearly stationary. Warm advection atop the boundary will result in elevated storms through the overnight hours. However, modest effective shear (25-35 kt) and midlevel lapse rates (6.5-7 C/km per 00z regional RAOBs) should limit overall severe potential/storm organization in the absence of a stronger developing low level jet overnight. Nevertheless, strong to isolated severe storms are possible in the short term across the central High Plains where lapse rates are steeper. Though this threat should wane over the next couple of hours as the boundary layer stabilizes. Further east, storm clusters may produce periods of strong gusts through storm mergers/outflow interactions, but overall severe threat should remain limited by elevated nature of the convection. ...Northeastern States... The severe threat will continue to quickly diminish this evening as storms approach and move off the coast. Additionally, the boundary layer will continue to stabilize with the loss of daytime heating and subtle forcing continues to weaken as the shortwave impulse lifts northeast of the region. A couple of strong storms may persist the next hour or so, but the overall threat has diminished sufficiently to remove severe probabilities this evening. ..Leitman.. 08/22/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 PM CDT Wed Aug 21 2019 Valid 220100Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS TO THE LOWER OHIO VALLEY... ...SUMMARY... Strong, isolated severe storms are possible this evening into the overnight hours across parts of the High Plains into Kansas, eastward toward southern Indiana and northern Kentucky. Strong gusts will be the main concern, but some marginally severe hail is possible as well. ...WY/CO High Plains eastward toward the Lower OH Valley... Strong to isolated severe thunderstorms were ongoing this evening in a modestly sheared, moderately unstable airmass. Several shortwave impulses will continue to move through west/northwesterly flow from the central High Plains toward the Midwest through the overnight hours while a surface boundary extending across KS eastward into MO/IL/IN remains nearly stationary. Warm advection atop the boundary will result in elevated storms through the overnight hours. However, modest effective shear (25-35 kt) and midlevel lapse rates (6.5-7 C/km per 00z regional RAOBs) should limit overall severe potential/storm organization in the absence of a stronger developing low level jet overnight. Nevertheless, strong to isolated severe storms are possible in the short term across the central High Plains where lapse rates are steeper. Though this threat should wane over the next couple of hours as the boundary layer stabilizes. Further east, storm clusters may produce periods of strong gusts through storm mergers/outflow interactions, but overall severe threat should remain limited by elevated nature of the convection. ...Northeastern States... The severe threat will continue to quickly diminish this evening as storms approach and move off the coast. Additionally, the boundary layer will continue to stabilize with the loss of daytime heating and subtle forcing continues to weaken as the shortwave impulse lifts northeast of the region. A couple of strong storms may persist the next hour or so, but the overall threat has diminished sufficiently to remove severe probabilities this evening. ..Leitman.. 08/22/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 PM CDT Wed Aug 21 2019 Valid 220100Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS TO THE LOWER OHIO VALLEY... ...SUMMARY... Strong, isolated severe storms are possible this evening into the overnight hours across parts of the High Plains into Kansas, eastward toward southern Indiana and northern Kentucky. Strong gusts will be the main concern, but some marginally severe hail is possible as well. ...WY/CO High Plains eastward toward the Lower OH Valley... Strong to isolated severe thunderstorms were ongoing this evening in a modestly sheared, moderately unstable airmass. Several shortwave impulses will continue to move through west/northwesterly flow from the central High Plains toward the Midwest through the overnight hours while a surface boundary extending across KS eastward into MO/IL/IN remains nearly stationary. Warm advection atop the boundary will result in elevated storms through the overnight hours. However, modest effective shear (25-35 kt) and midlevel lapse rates (6.5-7 C/km per 00z regional RAOBs) should limit overall severe potential/storm organization in the absence of a stronger developing low level jet overnight. Nevertheless, strong to isolated severe storms are possible in the short term across the central High Plains where lapse rates are steeper. Though this threat should wane over the next couple of hours as the boundary layer stabilizes. Further east, storm clusters may produce periods of strong gusts through storm mergers/outflow interactions, but overall severe threat should remain limited by elevated nature of the convection. ...Northeastern States... The severe threat will continue to quickly diminish this evening as storms approach and move off the coast. Additionally, the boundary layer will continue to stabilize with the loss of daytime heating and subtle forcing continues to weaken as the shortwave impulse lifts northeast of the region. A couple of strong storms may persist the next hour or so, but the overall threat has diminished sufficiently to remove severe probabilities this evening. ..Leitman.. 08/22/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 PM CDT Wed Aug 21 2019 Valid 220100Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS TO THE LOWER OHIO VALLEY... ...SUMMARY... Strong, isolated severe storms are possible this evening into the overnight hours across parts of the High Plains into Kansas, eastward toward southern Indiana and northern Kentucky. Strong gusts will be the main concern, but some marginally severe hail is possible as well. ...WY/CO High Plains eastward toward the Lower OH Valley... Strong to isolated severe thunderstorms were ongoing this evening in a modestly sheared, moderately unstable airmass. Several shortwave impulses will continue to move through west/northwesterly flow from the central High Plains toward the Midwest through the overnight hours while a surface boundary extending across KS eastward into MO/IL/IN remains nearly stationary. Warm advection atop the boundary will result in elevated storms through the overnight hours. However, modest effective shear (25-35 kt) and midlevel lapse rates (6.5-7 C/km per 00z regional RAOBs) should limit overall severe potential/storm organization in the absence of a stronger developing low level jet overnight. Nevertheless, strong to isolated severe storms are possible in the short term across the central High Plains where lapse rates are steeper. Though this threat should wane over the next couple of hours as the boundary layer stabilizes. Further east, storm clusters may produce periods of strong gusts through storm mergers/outflow interactions, but overall severe threat should remain limited by elevated nature of the convection. ...Northeastern States... The severe threat will continue to quickly diminish this evening as storms approach and move off the coast. Additionally, the boundary layer will continue to stabilize with the loss of daytime heating and subtle forcing continues to weaken as the shortwave impulse lifts northeast of the region. A couple of strong storms may persist the next hour or so, but the overall threat has diminished sufficiently to remove severe probabilities this evening. ..Leitman.. 08/22/2019 Read more

WW 0611 Status Updates
STATUS REPORT ON WW 611 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 SE LIC TO 25 NE COS TO 35 NW COS. ..DIAL..08/22/19 ATTN...WFO...BOU...PUB...CYS... STATUS REPORT FOR WS 611 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-013-014-031-035-039-059-069-123-220240- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE BOULDER BROOMFIELD DENVER DOUGLAS ELBERT JEFFERSON LARIMER WELD WYC001-015-021-031-220240- WY . WYOMING COUNTIES INCLUDED ARE ALBANY GOSHEN LARAMIE PLATTE 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 611 SEVERE TSTM CO WY 212045Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 611 NWS Storm Prediction Center Norman OK 245 PM MDT Wed Aug 21 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Southeast Wyoming * Effective this Wednesday afternoon and evening from 245 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Isolated severe storms, in the form of sustained multicells and a few transient supercells, are expected to develop along the foothills/I-25 corridor of eastern Colorado into southeast Wyoming. Isolated large hail will be the primary risk as storms drift east-southeastward through late afternoon/evening, although localized severe-caliber winds could also occur, particularly across east-central Colorado. The severe thunderstorm watch area is approximately along and 45 statute miles east and west of a line from 75 miles north northeast of Laramie WY to 30 miles southeast of Pueblo CO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 609...WW 610... 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 450. Mean storm motion vector 32020. ...Guyer Read more

MD 1831 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST KANSAS...SOUTHWEST MISSOURI AND EXTREME NORTHERN OKLAHOMA
Mesoscale Discussion 1831 NWS Storm Prediction Center Norman OK 0744 PM CDT Wed Aug 21 2019 Areas affected...southeast Kansas...southwest Missouri and extreme northern Oklahoma Concerning...Severe potential...Watch unlikely Valid 220044Z - 220245Z Probability of Watch Issuance...20 percent SUMMARY...Isolated downburst winds and some hail will remain possible next couple hours as storms develop through southeast Kansas and southwest Missouri early this evening. Due to the expected short duration of the threat, a WW will probably not be needed. DISCUSSION...Storms that initiated along a quasistationary front across east central KS have recently undergone an intensity increase with isolated wind gusts in excess of 60 MPH reported during the past hour. Based on latest objective analysis, storms are approaching a corridor of stronger instability in warm sector with temperatures around 90F and low 70s F dewpoints supporting 3000+ MLCAPE. Recent VWP from Wichita KS indicate veering winds in the lowest 2 km and 30-35 kt sfc-6 km shear. Storms will continue developing southeast this evening, primarily along and north of convectively reinforced front. The downstream environment should support mostly multicells, but possibly a couple transient supercell structures with isolated damaging wind and hail possible through 03Z. ..Dial/Grams.. 08/22/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN... LAT...LON 37799768 38119588 38629357 37999308 37129467 36909663 37159752 37799768 Read more

WW 0609 Status Updates
100- STATUS REPORT ON WW 609 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 WSW ACK TO 10 SSE GON TO 20 ENE BDR TO 10 SSE POU TO 15 ENE POU TO 25 WSW BDL TO 5 NE BDL TO 15 WSW ORH TO 25 N PVD TO 35 ENE HYA. WW 609 WILL BE ALLOWED TO EXPIRE AT 220100Z. ..NAUSLAR..08/22/19 ATTN...WFO...OKX...BOX...ALY...GYX... STATUS REPORT FOR WS 609 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC003-005-007-009-011-013-015-220100- CT . CONNECTICUT COUNTIES INCLUDED ARE HARTFORD LITCHFIELD MIDDLESEX NEW HAVEN NEW LONDON TOLLAND WINDHAM MAC001-005-007-019-220100- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BARNSTABLE BRISTOL DUKES NANTUCKET NYC027-220100- Read more

WW 0609 Status Updates
040- STATUS REPORT ON WW 609 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 ESE JFK TO 15 ESE BDR TO 20 WNW BDR TO 15 WSW POU TO 20 WNW POU TO 20 N POU TO 20 WSW BAF TO 20 NNE BAF TO 25 S EEN TO 20 WNW BOS TO 50 E BOS. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1829 ..NAUSLAR..08/21/19 ATTN...WFO...OKX...BOX...ALY...GYX... STATUS REPORT FOR WS 609 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC001-003-005-007-009-011-013-015-220040- CT . CONNECTICUT COUNTIES INCLUDED ARE FAIRFIELD HARTFORD LITCHFIELD MIDDLESEX NEW HAVEN NEW LONDON TOLLAND WINDHAM MAC001-005-007-013-015-017-019-021-023-025-027-220040- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BARNSTABLE BRISTOL DUKES HAMPDEN HAMPSHIRE MIDDLESEX NANTUCKET NORFOLK PLYMOUTH SUFFOLK WORCESTER Read more

WW 609 SEVERE TSTM CT MA ME NH NJ NY RI VT CW 211750Z - 220100Z
0- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 609 NWS Storm Prediction Center Norman OK 150 PM EDT Wed Aug 21 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Connecticut Massachusetts Far southern Maine Southern New Hampshire Northern New Jersey Southeast New York Rhode Island Southern Vermont Coastal Waters * Effective this Wednesday afternoon and evening from 150 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Storms will continue to develop and intensify particularly across far eastern New York and southern New England, near and south of a warm front that will continue to spread slowly northward. Some supercells with a hail/tornado risk aside from damaging winds are most probable across southern New England, with damaging winds otherwise expected with the strongest storms. The severe thunderstorm watch area is approximately along and 85 statute miles north and south of a line from 30 miles west northwest of Poughkeepsie NY to 40 miles east of Boston MA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24025. ...Guyer Read more

WW 0610 Status Updates
STATUS REPORT ON WW 610 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SSW DCA TO 15 WSW BWI TO 30 NE BWI TO 15 SSW TTN TO 5 E EWR. ..NAUSLAR..08/21/19 ATTN...WFO...LWX...PHI...CTP... STATUS REPORT FOR WS 610 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DEC001-003-005-212340- DE . DELAWARE COUNTIES INCLUDED ARE KENT NEW CASTLE SUSSEX MDC003-009-011-017-029-033-035-041-212340- MD . MARYLAND COUNTIES INCLUDED ARE ANNE ARUNDEL CALVERT CAROLINE CHARLES KENT PRINCE GEORGES QUEEN ANNE'S TALBOT NJC001-005-007-009-011-015-025-029-033-212340- NJ . NEW JERSEY COUNTIES INCLUDED ARE ATLANTIC BURLINGTON CAMDEN CAPE MAY CUMBERLAND GLOUCESTER Read more

WW 0610 Status Updates
STATUS REPORT ON WW 610 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SSW DCA TO 15 WSW BWI TO 30 NE BWI TO 15 SSW TTN TO 5 E EWR. ..NAUSLAR..08/21/19 ATTN...WFO...LWX...PHI...CTP... STATUS REPORT FOR WS 610 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DEC001-003-005-212340- DE . DELAWARE COUNTIES INCLUDED ARE KENT NEW CASTLE SUSSEX MDC003-009-011-017-029-033-035-041-212340- MD . MARYLAND COUNTIES INCLUDED ARE ANNE ARUNDEL CALVERT CAROLINE CHARLES KENT PRINCE GEORGES QUEEN ANNE'S TALBOT NJC001-005-007-009-011-015-025-029-033-212340- NJ . NEW JERSEY COUNTIES INCLUDED ARE ATLANTIC BURLINGTON CAMDEN CAPE MAY CUMBERLAND GLOUCESTER Read more

WW 0611 Status Updates
STATUS REPORT ON WW 611 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1830 ..DIAL..08/21/19 ATTN...WFO...BOU...PUB...CYS... STATUS REPORT FOR WS 611 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-013-014-025-031-035-039-041-059-069-089-101-119-123- 220040- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE BOULDER BROOMFIELD CROWLEY DENVER DOUGLAS ELBERT EL PASO JEFFERSON LARIMER OTERO PUEBLO TELLER WELD WYC001-015-021-031-220040- WY . WYOMING COUNTIES INCLUDED ARE ALBANY GOSHEN LARAMIE PLATTE THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more

WW 0611 Status Updates
STATUS REPORT ON WW 611 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1830 ..EDWARDS..08/21/19 ATTN...WFO...BOU...PUB...CYS... STATUS REPORT FOR WS 611 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-013-014-025-031-035-039-041-059-069-089-101-119-123- 212340- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE BOULDER BROOMFIELD CROWLEY DENVER DOUGLAS ELBERT EL PASO JEFFERSON LARIMER OTERO PUEBLO TELLER WELD WYC001-015-021-031-212340- WY . WYOMING COUNTIES INCLUDED ARE ALBANY GOSHEN LARAMIE PLATTE THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more