Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Wed Aug 28 2019 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN WI TO NORTHEAST KS... ...SUMMARY... Some severe threat exists with thunderstorms that form along a front from the upper Midwest to the central Plains. Wind and hail are the primary threats. ...Upper Midwest to Central Plains... Notable mid-level height falls are forecast to spread across the upper MS Valley into the upper Great Lakes region ahead of a strong short-wave trough Thursday. This feature will shift into eastern ON by the end of the period, only glancing portions of the US near the international border. In the wake of the short wave, surface pressures will build across the High Plains from AB/SK into the mid MO Valley, forcing a front to a position from central WI - central IA - southern NE by 18z. This boundary will likely serve as the primary forcing mechanism for potentially robust convection by late afternoon. Latest short-term model guidance (NAM in particular) suggests higher-PW air mass will advance north across the Plains late day1, then become entrained along/ahead of the boundary before being shunted downstream toward the Great Lakes. This appears to be underway early this afternoon with mid 60s surface dew points now advancing north across western KS. Models insist strong boundary-layer heating will occur ahead of the wind shift and this will aid buoyancy as moisture advects northeast ahead of the front. Latest thinking is convective temperatures will be breached between 21-23z and frontal ascent should encourage deep convection. With modest northwesterly flow aloft there is reason to believe organized frontal convection will evolve then mature as it propagates southeast during the evening hours. Longer-lived thunderstorm complex may ultimately evolve over portions of KS/western MO as some hint of a LLJ will be maintained across this region during the overnight hours. Wind/hail are the primary threats. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 15% - Slight Hail: 5% - Marginal ..Darrow.. 08/28/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Wed Aug 28 2019 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN WI TO NORTHEAST KS... ...SUMMARY... Some severe threat exists with thunderstorms that form along a front from the upper Midwest to the central Plains. Wind and hail are the primary threats. ...Upper Midwest to Central Plains... Notable mid-level height falls are forecast to spread across the upper MS Valley into the upper Great Lakes region ahead of a strong short-wave trough Thursday. This feature will shift into eastern ON by the end of the period, only glancing portions of the US near the international border. In the wake of the short wave, surface pressures will build across the High Plains from AB/SK into the mid MO Valley, forcing a front to a position from central WI - central IA - southern NE by 18z. This boundary will likely serve as the primary forcing mechanism for potentially robust convection by late afternoon. Latest short-term model guidance (NAM in particular) suggests higher-PW air mass will advance north across the Plains late day1, then become entrained along/ahead of the boundary before being shunted downstream toward the Great Lakes. This appears to be underway early this afternoon with mid 60s surface dew points now advancing north across western KS. Models insist strong boundary-layer heating will occur ahead of the wind shift and this will aid buoyancy as moisture advects northeast ahead of the front. Latest thinking is convective temperatures will be breached between 21-23z and frontal ascent should encourage deep convection. With modest northwesterly flow aloft there is reason to believe organized frontal convection will evolve then mature as it propagates southeast during the evening hours. Longer-lived thunderstorm complex may ultimately evolve over portions of KS/western MO as some hint of a LLJ will be maintained across this region during the overnight hours. Wind/hail are the primary threats. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 15% - Slight Hail: 5% - Marginal ..Darrow.. 08/28/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1111 AM CDT Wed Aug 28 2019 Valid 281630Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NEW MEXICO... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...New Mexico... Through the afternoon, breaks in low-level cloud cover and continued surface heating will allow for convective temperatures to be reached by around 20-21Z or so in the immediate lee of central NM higher terrain. This will result in an environment with steep tropospheric lapse rates and modest (20-25 kt) northwesterly mid-level flow atop weak (10-15 kt) low-level southerly flow. Storms that develop in this environment may exhibit weak supercellular characteristics while drifting southward in and near the MRGL area through the afternoon. Isolated instances of large hail and damaging wind gusts will be likely with this diurnally driven activity, and the overall severe risk should wane through the early overnight hours. ..Cook.. 08/28/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1111 AM CDT Wed Aug 28 2019 Valid 281630Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NEW MEXICO... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...New Mexico... Through the afternoon, breaks in low-level cloud cover and continued surface heating will allow for convective temperatures to be reached by around 20-21Z or so in the immediate lee of central NM higher terrain. This will result in an environment with steep tropospheric lapse rates and modest (20-25 kt) northwesterly mid-level flow atop weak (10-15 kt) low-level southerly flow. Storms that develop in this environment may exhibit weak supercellular characteristics while drifting southward in and near the MRGL area through the afternoon. Isolated instances of large hail and damaging wind gusts will be likely with this diurnally driven activity, and the overall severe risk should wane through the early overnight hours. ..Cook.. 08/28/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1111 AM CDT Wed Aug 28 2019 Valid 281630Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NEW MEXICO... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...New Mexico... Through the afternoon, breaks in low-level cloud cover and continued surface heating will allow for convective temperatures to be reached by around 20-21Z or so in the immediate lee of central NM higher terrain. This will result in an environment with steep tropospheric lapse rates and modest (20-25 kt) northwesterly mid-level flow atop weak (10-15 kt) low-level southerly flow. Storms that develop in this environment may exhibit weak supercellular characteristics while drifting southward in and near the MRGL area through the afternoon. Isolated instances of large hail and damaging wind gusts will be likely with this diurnally driven activity, and the overall severe risk should wane through the early overnight hours. ..Cook.. 08/28/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1111 AM CDT Wed Aug 28 2019 Valid 281630Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NEW MEXICO... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...New Mexico... Through the afternoon, breaks in low-level cloud cover and continued surface heating will allow for convective temperatures to be reached by around 20-21Z or so in the immediate lee of central NM higher terrain. This will result in an environment with steep tropospheric lapse rates and modest (20-25 kt) northwesterly mid-level flow atop weak (10-15 kt) low-level southerly flow. Storms that develop in this environment may exhibit weak supercellular characteristics while drifting southward in and near the MRGL area through the afternoon. Isolated instances of large hail and damaging wind gusts will be likely with this diurnally driven activity, and the overall severe risk should wane through the early overnight hours. ..Cook.. 08/28/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1102 AM CDT Wed Aug 28 2019 Valid 281700Z - 291200Z Minor modifications were made to the isolated dry thunderstorm area in portions of northern California, northwest Nevada, and eastern Oregon based on observed lightning this morning and latest forecast guidance. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 08/28/2019 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 28 2019/ ...Synopsis... The upper-level ridge across the West will shift slowly eastward today. Off the Pacific Northwest coast, a subtle shortwave trough will approach from the southwest ahead of a more substantial trough in the central Pacific. This lead shortwave will bring moisture from a remnant tropical disturbance. Within the Great Basin, the upper-level anticyclone will be positioned within the Desert Southwest and aid in monsoonal moisture influx into the region. Broad cyclonic flow will be present across the upper-Midwest and eastern CONUS. A shortwave trough will dig into the northern Plains. As this occurs mid-level flow will be enhanced across the central Rockies during the afternoon. ...Pacific Northwest and Great Basin... Thunderstorm activity will increase with the continued advection of mid-level moisture into a broad area. Lightning over dry fuels will increase the risk fire ignitions across the highlighted ISODRYT area. Daytime heating across the higher terrain will be the main driver of convection from northwest Arizona, southwestern Utah, central Nevada, and northern California. Scattered coverage of storms is possible in the central Nevada vicinity; however, the likelihood of wetting rainfall is too great to introduce SCTDRYT highlights. In Oregon, some thunderstorm activity is possible during the afternoon. Based on the timing of the shortwave trough, storms will become more likely during the evening/overnight. There is some possibility that lighting may occur farther east in Oregon than the highlighted area, but very minimal buoyancy has limited confidence below 10%. ...Southern Wyoming and adjacent northern Colorado... Dry/windy conditions are likely across the Great Divide Basin, portions of the Laramie range, and into north-central Colorado. Slight strengthening of the mid-level winds during the afternoon along with the passage of a cold front will increase surface winds to 15-20 mph with some areas locally higher. Afternoon RH will fall to 10-15%. The active Pedro Mountain fire will be impacted by these elevated fire weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1102 AM CDT Wed Aug 28 2019 Valid 281700Z - 291200Z Minor modifications were made to the isolated dry thunderstorm area in portions of northern California, northwest Nevada, and eastern Oregon based on observed lightning this morning and latest forecast guidance. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 08/28/2019 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 28 2019/ ...Synopsis... The upper-level ridge across the West will shift slowly eastward today. Off the Pacific Northwest coast, a subtle shortwave trough will approach from the southwest ahead of a more substantial trough in the central Pacific. This lead shortwave will bring moisture from a remnant tropical disturbance. Within the Great Basin, the upper-level anticyclone will be positioned within the Desert Southwest and aid in monsoonal moisture influx into the region. Broad cyclonic flow will be present across the upper-Midwest and eastern CONUS. A shortwave trough will dig into the northern Plains. As this occurs mid-level flow will be enhanced across the central Rockies during the afternoon. ...Pacific Northwest and Great Basin... Thunderstorm activity will increase with the continued advection of mid-level moisture into a broad area. Lightning over dry fuels will increase the risk fire ignitions across the highlighted ISODRYT area. Daytime heating across the higher terrain will be the main driver of convection from northwest Arizona, southwestern Utah, central Nevada, and northern California. Scattered coverage of storms is possible in the central Nevada vicinity; however, the likelihood of wetting rainfall is too great to introduce SCTDRYT highlights. In Oregon, some thunderstorm activity is possible during the afternoon. Based on the timing of the shortwave trough, storms will become more likely during the evening/overnight. There is some possibility that lighting may occur farther east in Oregon than the highlighted area, but very minimal buoyancy has limited confidence below 10%. ...Southern Wyoming and adjacent northern Colorado... Dry/windy conditions are likely across the Great Divide Basin, portions of the Laramie range, and into north-central Colorado. Slight strengthening of the mid-level winds during the afternoon along with the passage of a cold front will increase surface winds to 15-20 mph with some areas locally higher. Afternoon RH will fall to 10-15%. The active Pedro Mountain fire will be impacted by these elevated fire weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1102 AM CDT Wed Aug 28 2019 Valid 281700Z - 291200Z Minor modifications were made to the isolated dry thunderstorm area in portions of northern California, northwest Nevada, and eastern Oregon based on observed lightning this morning and latest forecast guidance. Otherwise, the forecast remains on track, and please see the discussion below for more details. ..Nauslar.. 08/28/2019 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 28 2019/ ...Synopsis... The upper-level ridge across the West will shift slowly eastward today. Off the Pacific Northwest coast, a subtle shortwave trough will approach from the southwest ahead of a more substantial trough in the central Pacific. This lead shortwave will bring moisture from a remnant tropical disturbance. Within the Great Basin, the upper-level anticyclone will be positioned within the Desert Southwest and aid in monsoonal moisture influx into the region. Broad cyclonic flow will be present across the upper-Midwest and eastern CONUS. A shortwave trough will dig into the northern Plains. As this occurs mid-level flow will be enhanced across the central Rockies during the afternoon. ...Pacific Northwest and Great Basin... Thunderstorm activity will increase with the continued advection of mid-level moisture into a broad area. Lightning over dry fuels will increase the risk fire ignitions across the highlighted ISODRYT area. Daytime heating across the higher terrain will be the main driver of convection from northwest Arizona, southwestern Utah, central Nevada, and northern California. Scattered coverage of storms is possible in the central Nevada vicinity; however, the likelihood of wetting rainfall is too great to introduce SCTDRYT highlights. In Oregon, some thunderstorm activity is possible during the afternoon. Based on the timing of the shortwave trough, storms will become more likely during the evening/overnight. There is some possibility that lighting may occur farther east in Oregon than the highlighted area, but very minimal buoyancy has limited confidence below 10%. ...Southern Wyoming and adjacent northern Colorado... Dry/windy conditions are likely across the Great Divide Basin, portions of the Laramie range, and into north-central Colorado. Slight strengthening of the mid-level winds during the afternoon along with the passage of a cold front will increase surface winds to 15-20 mph with some areas locally higher. Afternoon RH will fall to 10-15%. The active Pedro Mountain fire will be impacted by these elevated fire weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 28 2019 Valid 281300Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHEAST NM... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...Northeast NM... Upper 50s to low 60s surface dew points are prevalent amid light easterly winds. While low-level winds will largely become southerly, a weak upslope component should be maintained into the Raton Mesa and Sangre de Cristos through late afternoon. Early-day stratus should dissipate with surface temperatures warming into the 80s by peak heating. A belt of confluent mid-level northwesterlies from 20-30 kt at 500-mb could support a couple rotating updrafts off the higher terrain capable of locally severe hail/wind. ..Grams/Mosier.. 08/28/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 28 2019 Valid 281300Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHEAST NM... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...Northeast NM... Upper 50s to low 60s surface dew points are prevalent amid light easterly winds. While low-level winds will largely become southerly, a weak upslope component should be maintained into the Raton Mesa and Sangre de Cristos through late afternoon. Early-day stratus should dissipate with surface temperatures warming into the 80s by peak heating. A belt of confluent mid-level northwesterlies from 20-30 kt at 500-mb could support a couple rotating updrafts off the higher terrain capable of locally severe hail/wind. ..Grams/Mosier.. 08/28/2019 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 28 2019 Valid 281300Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHEAST NM... ...SUMMARY... Isolated severe thunderstorms are possible between 3 to 8 PM MDT over northeast New Mexico. ...Northeast NM... Upper 50s to low 60s surface dew points are prevalent amid light easterly winds. While low-level winds will largely become southerly, a weak upslope component should be maintained into the Raton Mesa and Sangre de Cristos through late afternoon. Early-day stratus should dissipate with surface temperatures warming into the 80s by peak heating. A belt of confluent mid-level northwesterlies from 20-30 kt at 500-mb could support a couple rotating updrafts off the higher terrain capable of locally severe hail/wind. ..Grams/Mosier.. 08/28/2019 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Wed Aug 28 2019 Valid 311200Z - 051200Z ...DISCUSSION... ...Northern Plains to Great Lakes/Midwest and parts of the Northeast... On Days 4-5/Sat-Sun a slightly weaker but persist upper trough will remain centered over the Great Lakes vicinity. The western upper ridge will shift slightly eastward and re-intensify. A surface high will lift northeast from New England into the north Atlantic while a lee low/trough over the High Plains develops. This pattern will allow Gulf moisture to return northward across much of the Plains and Midwest by early next week. While timing varies, forecast guidance shows several shortwave impulses migrating through northwest flow from the northern Plains toward the Great Lakes Monday and Tuesday to the Northeast on Wednesday. Areas of strong storms will be possible each day Mon-Wed as the shortwaves migrate east. Timing of these features and the northward moisture return and effects from prior days convection will influence severe potential each day. Given that these mesoscale processes are not resolved well at longer timescales, and timing differences of larger-scale feature in the GFS and ECMWF, uncertainty is too great at this time to include severe probabilities at this time. ...Southeastern U.S... Current track guidance from the National Hurricane Center brings Tropical Storm Dorian near the eastern Florida coast by Sunday. Forecast guidance varies in the track of Dorian into early next week, but an associated risk for tropical cyclone related tornado may impact portions of the southeastern U.S. as early as Day 5/Sun into early next week. Forecast impacts will be closely collaborated with NHC as Dorian approaches the U.S. mainland in the coming days. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Wed Aug 28 2019 Valid 311200Z - 051200Z ...DISCUSSION... ...Northern Plains to Great Lakes/Midwest and parts of the Northeast... On Days 4-5/Sat-Sun a slightly weaker but persist upper trough will remain centered over the Great Lakes vicinity. The western upper ridge will shift slightly eastward and re-intensify. A surface high will lift northeast from New England into the north Atlantic while a lee low/trough over the High Plains develops. This pattern will allow Gulf moisture to return northward across much of the Plains and Midwest by early next week. While timing varies, forecast guidance shows several shortwave impulses migrating through northwest flow from the northern Plains toward the Great Lakes Monday and Tuesday to the Northeast on Wednesday. Areas of strong storms will be possible each day Mon-Wed as the shortwaves migrate east. Timing of these features and the northward moisture return and effects from prior days convection will influence severe potential each day. Given that these mesoscale processes are not resolved well at longer timescales, and timing differences of larger-scale feature in the GFS and ECMWF, uncertainty is too great at this time to include severe probabilities at this time. ...Southeastern U.S... Current track guidance from the National Hurricane Center brings Tropical Storm Dorian near the eastern Florida coast by Sunday. Forecast guidance varies in the track of Dorian into early next week, but an associated risk for tropical cyclone related tornado may impact portions of the southeastern U.S. as early as Day 5/Sun into early next week. Forecast impacts will be closely collaborated with NHC as Dorian approaches the U.S. mainland in the coming days. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Wed Aug 28 2019 Valid 311200Z - 051200Z ...DISCUSSION... ...Northern Plains to Great Lakes/Midwest and parts of the Northeast... On Days 4-5/Sat-Sun a slightly weaker but persist upper trough will remain centered over the Great Lakes vicinity. The western upper ridge will shift slightly eastward and re-intensify. A surface high will lift northeast from New England into the north Atlantic while a lee low/trough over the High Plains develops. This pattern will allow Gulf moisture to return northward across much of the Plains and Midwest by early next week. While timing varies, forecast guidance shows several shortwave impulses migrating through northwest flow from the northern Plains toward the Great Lakes Monday and Tuesday to the Northeast on Wednesday. Areas of strong storms will be possible each day Mon-Wed as the shortwaves migrate east. Timing of these features and the northward moisture return and effects from prior days convection will influence severe potential each day. Given that these mesoscale processes are not resolved well at longer timescales, and timing differences of larger-scale feature in the GFS and ECMWF, uncertainty is too great at this time to include severe probabilities at this time. ...Southeastern U.S... Current track guidance from the National Hurricane Center brings Tropical Storm Dorian near the eastern Florida coast by Sunday. Forecast guidance varies in the track of Dorian into early next week, but an associated risk for tropical cyclone related tornado may impact portions of the southeastern U.S. as early as Day 5/Sun into early next week. Forecast impacts will be closely collaborated with NHC as Dorian approaches the U.S. mainland in the coming days. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0341 AM CDT Wed Aug 28 2019 Valid 311200Z - 051200Z ...DISCUSSION... ...Northern Plains to Great Lakes/Midwest and parts of the Northeast... On Days 4-5/Sat-Sun a slightly weaker but persist upper trough will remain centered over the Great Lakes vicinity. The western upper ridge will shift slightly eastward and re-intensify. A surface high will lift northeast from New England into the north Atlantic while a lee low/trough over the High Plains develops. This pattern will allow Gulf moisture to return northward across much of the Plains and Midwest by early next week. While timing varies, forecast guidance shows several shortwave impulses migrating through northwest flow from the northern Plains toward the Great Lakes Monday and Tuesday to the Northeast on Wednesday. Areas of strong storms will be possible each day Mon-Wed as the shortwaves migrate east. Timing of these features and the northward moisture return and effects from prior days convection will influence severe potential each day. Given that these mesoscale processes are not resolved well at longer timescales, and timing differences of larger-scale feature in the GFS and ECMWF, uncertainty is too great at this time to include severe probabilities at this time. ...Southeastern U.S... Current track guidance from the National Hurricane Center brings Tropical Storm Dorian near the eastern Florida coast by Sunday. Forecast guidance varies in the track of Dorian into early next week, but an associated risk for tropical cyclone related tornado may impact portions of the southeastern U.S. as early as Day 5/Sun into early next week. Forecast impacts will be closely collaborated with NHC as Dorian approaches the U.S. mainland in the coming days. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 AM CDT Wed Aug 28 2019 Valid 301200Z - 311200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... While strong storms are possible across parts of the central and southern Plains on Friday, confidence is too low at this time to include severe probabilities. ...Synopsis... A mean upper level trough will persist from the northern/central Plains to the Mid-Atlantic/Northeast on Friday. The western upper ridge shift east from near the Pacific Northwest coast over the northern Rockies. Several shortwave impulses will migrate through northwesterly flow aloft from the central High Plains into the southern Plains. A surface cold front will progress eastward across the northeastern U.S., moving offshore by Saturday morning. The western extent of the front will stall and become somewhat diffuse from the lower Ohio Valley into KS. Convection may be ongoing across parts of KS into northern OK at the beginning of the period. The exact location/extent of this activity and its evolution through the morning hours will influence severe potential during the afternoon and evening across parts of the central and southern Plains. ...Central/Southern Plains... Unusually rich boundary layer moisture for late August will be in place across much of the southern Plains into KS, with surface dewpoints at least in the mid to upper 60s. Guidance varies on the evolution of morning convection across KS, with some models maintaining storms through the morning into northern OK with later intensification downstream from central OK into north TX and possible the TX Panhandle through the evening hours. Other guidance develops additional convection in moist upslope flow across southwest NE into western KS by late afternoon, with a convective complex shifting south into the OK/TX Panhandles and western OK. The greatest destabilization during the afternoon appears to be across parts of western TX into western/southern OK where cloud cover may be less than areas to the north. However, forecast soundings show quite a bit of capping due to effects of convection in the Day 2/Thu period and ongoing activity at the beginning of Day 3/Fri. While some severe potential is possible across parts of the central/southern Plains on Friday, confidence is too low at this time to pinpoint exactly where severe storms are likely to develop and how this conditional activity will evolve through the period. ..Leitman.. 08/28/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 AM CDT Wed Aug 28 2019 Valid 301200Z - 311200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... While strong storms are possible across parts of the central and southern Plains on Friday, confidence is too low at this time to include severe probabilities. ...Synopsis... A mean upper level trough will persist from the northern/central Plains to the Mid-Atlantic/Northeast on Friday. The western upper ridge shift east from near the Pacific Northwest coast over the northern Rockies. Several shortwave impulses will migrate through northwesterly flow aloft from the central High Plains into the southern Plains. A surface cold front will progress eastward across the northeastern U.S., moving offshore by Saturday morning. The western extent of the front will stall and become somewhat diffuse from the lower Ohio Valley into KS. Convection may be ongoing across parts of KS into northern OK at the beginning of the period. The exact location/extent of this activity and its evolution through the morning hours will influence severe potential during the afternoon and evening across parts of the central and southern Plains. ...Central/Southern Plains... Unusually rich boundary layer moisture for late August will be in place across much of the southern Plains into KS, with surface dewpoints at least in the mid to upper 60s. Guidance varies on the evolution of morning convection across KS, with some models maintaining storms through the morning into northern OK with later intensification downstream from central OK into north TX and possible the TX Panhandle through the evening hours. Other guidance develops additional convection in moist upslope flow across southwest NE into western KS by late afternoon, with a convective complex shifting south into the OK/TX Panhandles and western OK. The greatest destabilization during the afternoon appears to be across parts of western TX into western/southern OK where cloud cover may be less than areas to the north. However, forecast soundings show quite a bit of capping due to effects of convection in the Day 2/Thu period and ongoing activity at the beginning of Day 3/Fri. While some severe potential is possible across parts of the central/southern Plains on Friday, confidence is too low at this time to pinpoint exactly where severe storms are likely to develop and how this conditional activity will evolve through the period. ..Leitman.. 08/28/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 AM CDT Wed Aug 28 2019 Valid 301200Z - 311200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... While strong storms are possible across parts of the central and southern Plains on Friday, confidence is too low at this time to include severe probabilities. ...Synopsis... A mean upper level trough will persist from the northern/central Plains to the Mid-Atlantic/Northeast on Friday. The western upper ridge shift east from near the Pacific Northwest coast over the northern Rockies. Several shortwave impulses will migrate through northwesterly flow aloft from the central High Plains into the southern Plains. A surface cold front will progress eastward across the northeastern U.S., moving offshore by Saturday morning. The western extent of the front will stall and become somewhat diffuse from the lower Ohio Valley into KS. Convection may be ongoing across parts of KS into northern OK at the beginning of the period. The exact location/extent of this activity and its evolution through the morning hours will influence severe potential during the afternoon and evening across parts of the central and southern Plains. ...Central/Southern Plains... Unusually rich boundary layer moisture for late August will be in place across much of the southern Plains into KS, with surface dewpoints at least in the mid to upper 60s. Guidance varies on the evolution of morning convection across KS, with some models maintaining storms through the morning into northern OK with later intensification downstream from central OK into north TX and possible the TX Panhandle through the evening hours. Other guidance develops additional convection in moist upslope flow across southwest NE into western KS by late afternoon, with a convective complex shifting south into the OK/TX Panhandles and western OK. The greatest destabilization during the afternoon appears to be across parts of western TX into western/southern OK where cloud cover may be less than areas to the north. However, forecast soundings show quite a bit of capping due to effects of convection in the Day 2/Thu period and ongoing activity at the beginning of Day 3/Fri. While some severe potential is possible across parts of the central/southern Plains on Friday, confidence is too low at this time to pinpoint exactly where severe storms are likely to develop and how this conditional activity will evolve through the period. ..Leitman.. 08/28/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0211 AM CDT Wed Aug 28 2019 Valid 291200Z - 301200Z ...Synopsis... The upper-level anticyclone over the Desert Southwest will retrograde westward during the D2/Thursday period. Monsoonal moisture will remain across much of the Great Basin and into parts of the central Rockies. A shortwave trough will continue its progression into Oregon. Thunderstorm activity over dry fuels will be the main concern as mid-level winds will weaken across the West with an attendant weakening of surface flow. Locally elevated fire weather conditions will be possible in terrain-favored areas of the central Rockies and Great Basin. The greatest chance for a more robust wind/RH concern will be in northwest Nevada where a mid-level wind speed max will impact the region during the late afternoon/evening. ...Oregon...far southern Washington...southern Idaho...central/eastern Utah...western Colorado... Thunderstorm development is likely during the afternoon across these areas. Well-mixed boundary layers should keep precipitation to a minimum in most locations. Western Oregon, potentially west of the Cascades, will also see thunderstorms early in the period with aid from mid-level ascent. Scattered coverage is possible in central Oregon/Utah. However, PWAT near 1 inch (Oregon) and slow storm motions (Utah) increase the likelihood of wetting rainfall such that a SCTDRYT area will not be introduced. ..Wendt.. 08/28/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more