Severe Storms

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Thu Aug 15 2019 Valid 181200Z - 231200Z ...DISCUSSION... On Sun/D4, an upper trough will lift north out of the Upper MS Valley and into Ontario, with rising heights across the central states. As such, little large-scale support will be available to focus severe storms, although isolated storms are possible across parts of the central Plains where instability will be large. By Mon/D5, an upper high will build over the southern High Plains, with zonal flow along the northern tier of states. Nocturnal storms are possible across the upper MS Valley late Monday in a warm advection regime. While areas of damaging wind cannot be ruled out with an MCS, predictability is low. The upper high will remain in place or retrograde slightly through the remainder of the period, and southerly winds across the Plains will maintain a somewhat moist, unstable air mass. However, predictability for any minor disturbance within the northwest flow that may focus storms across the northern Plains is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Thu Aug 15 2019 Valid 181200Z - 231200Z ...DISCUSSION... On Sun/D4, an upper trough will lift north out of the Upper MS Valley and into Ontario, with rising heights across the central states. As such, little large-scale support will be available to focus severe storms, although isolated storms are possible across parts of the central Plains where instability will be large. By Mon/D5, an upper high will build over the southern High Plains, with zonal flow along the northern tier of states. Nocturnal storms are possible across the upper MS Valley late Monday in a warm advection regime. While areas of damaging wind cannot be ruled out with an MCS, predictability is low. The upper high will remain in place or retrograde slightly through the remainder of the period, and southerly winds across the Plains will maintain a somewhat moist, unstable air mass. However, predictability for any minor disturbance within the northwest flow that may focus storms across the northern Plains is low. Read more

MD 1742 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN WYOMING...SOUTHWESTERN SOUTH DAKOTA AND NORTHWESTERN NEBRASKA
Mesoscale Discussion 1742 NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Aug 15 2019 Areas affected...Parts of eastern Wyoming...southwestern South Dakota and northwestern Nebraska Concerning...Severe potential...Watch unlikely Valid 150729Z - 150930Z Probability of Watch Issuance...20 percent SUMMARY...A relatively isolated, but intense storm probably will continue to pose at least a localized severe hail and wind threat across northern portions of the Nebraska panhandle through daybreak. Barring further upscale growth, it is not certain that a watch is needed, but trends will continue to be monitored. DISCUSSION...A number of generally low amplitude mid/upper waves appear to be progressing through broader-scale anticyclonic mid/upper flow across the northern Rockies and Plains. In association with one of these perturbations, forcing for ascent appears to be aiding ongoing thunderstorm development now south of the Black Hills, near the western Nebraska/South Dakota border area. The strongest convection, mainly limited to an isolated but sustained supercell, has been confined to areas west/southwest of the Black Hills during the past few hours, aided by inflow of moderate CAPE of 1500-3000 J/kg, in the presence of steep lower/mid-tropospheric lapse rates. Large-scale forcing for ascent associated with warm advection along a tightening mid-level thermal gradient (roughly around 700 mb) also appears to be providing support for this storm. This front extends east-southeastward across northern portions of the Nebraska panhandle, and may provide a continuing focus and support for the maintenance of intense convective development into areas northeast of Alliance NE through 9-11Z. Reflectivity associated with the isolated supercell has recently transitioned to more of a bowing structure, in the presence of strong deep-layer shear, likely accompanied by at least localized strong to severe surface gusts. This threat may continue, along with a risk for severe hail through daybreak. ..Kerr/Thompson.. 08/15/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...CYS... LAT...LON 43660482 43610386 43290276 42800174 42210127 41830188 42040296 42330354 42730405 43250463 43660482 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Thu Aug 15 2019 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE NORTHERN AND CENTRAL PLAINS AND EASTWARD INTO ILLINOIS... ...SUMMARY... Severe storms are possible over parts of the northern and central Plains on Saturday. ...Northern Plains... An upper trough will move east across the Dakotas on Saturday, phasing with a band of stronger midlevel zonal flow over the central Plains. At the surface, a cold front will move across the Dakotas, and will provide lift with upper 50s to lower 60s F dewpoints ahead of the front. Veering wind profiles will exist, but speeds will not be particularly strong. Given that model differences exists regarding the position of the front, will defer a possible Slight Risk for hail and wind to later updates. At this time, the greatest threat appears to be over the eastern Dakotas and into parts of Nebraska where hail or localized severe wind gusts will be possible. ...Central Plains... A more nebulous surface pattern will exist south of I-80 over the Plains with only a weak surface trough over the High Plains, and an expansive area of moisture and instability. A moist and unstable air mass will exist over NE, KS, OK, MO, and IL, with possible early day storms from KS into IL. The strongest heating will occur over TX, western OK and into southern KS, and this will be an area for scattered afternoon storms as the capping is eroded. Other storms are possible along any outflow boundaries from earlier convection, but predictability is low this far in advance. While isolated to scattered strong to severe storms capable of wind or hail are possible, have opted to defer Slight Risk delineation to later outlooks when predictability is greater. ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KANSAS INTO MISSOURI AND WESTERN ILLINOIS...AND OVER PARTS OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are possible from parts of Kansas across Missouri and into western Illinois Friday. A few severe storms are also possible across parts of the central High Plains. ...Synopsis... A belt of moderate cyclonic flow aloft will extend from the northern Rockies across the central Plains and toward the lower Great Lakes with minor disturbances embedded in the flow. Coincident with this enhanced flow will be cool temperatures aloft which will maintain steep midlevel lapse rates and instability. Late in the day, a larger-scale trough amplification will occur over AB, SK and MT. At the surface, low pressure will reside over southwest KS, with a moist and unstable air mass to the east from KS/OK into MO. A boundary reinforced by storms will stretch roughly from KS eastward into western IL, and will provide a focus for storm regeneration. To the west, an embedded shortwave trough will move across WY and into NE, providing lift near a lee trough with scattered severe storms possible. ...Central Plains into the mid MS Valley... An MCS is forecast to exist over MO Friday morning, and will likely persist into IL. Westerly 850 mb winds will maintain instability into this region, and a few severe wind gusts are possible with this activity. In the wake of the early storms, an outflow reinforced boundary is likely somewhere over eastern KS and into central MO. Upper 60s to near 70 F dewpoints beneath steep lapse rates aloft will lead to strong instability, with redevelopment expected during the late afternoon and evening. Damaging winds will be likely, along with large hail. A few supercells are possible initially with a tornado or two possible. Farther southwest, isolated slow-moving storms with localized damaging wind or hail is possible within the low-level lapse rate plume from northwest OK into the TX Panhandle. ...Central and northern High Plains... Steep low-level lapse rates will develop due to heating near and west of the surface trough. While the air mass may remain capped for surface based storms into central NE and northern KS, a narrow zone of instability will develop from southeast WY and western NE into northeast CO and northwest KS. Lift with the upper wave should aid scattered afternoon storms. Long straight-line hodographs will favor hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% SIG - Slight Hail: 15% - Slight ..Jewell.. 08/15/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central Great Plains today. Large to very large hail and severe gusts are forecast with the stronger storms. ...Central and northern Great Plains... A mid-level shortwave trough is forecast to move from eastern MT this morning to the mid-upper MS Valley by daybreak Friday. A weak area of low pressure will develop over western KS while a cold front moves southeastward across the western Dakotas during the day. An elevated cluster of thunderstorms is possible over the central Great Plains associated with a warm advection regime before this activity weakens by the late morning. Considerable uncertainty is apparent and partially attributed to the evolution of storms during the morning. An outflow boundary associated with this early day convection may serve as a focus for additional storms by late afternoon from NE into northern KS. Elongated hodographs would favor supercells with large to very large hail. Isolated storms are forecast farther southwest into southern KS into the TX Panhandle with a wind/hail risk with the sustained/strong storms. Farther north over the Dakotas and Wyoming into western NE, diurnal storms are forecast to develop along the front over the Dakotas and in a post-frontal area over WY. Hail/wind are possible with this activity. ...Upper Ohio Valley... At the surface, a front will advance eastward across upper Ohio Valley with moderate destabilization expected by afternoon. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. A few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Coastal Carolinas... Weak mid-level troughing will slowly move east across the southern Appalachians. A cold front and a sea breeze front will serve as foci for thunderstorm development during the midday through the early evening. A reservoir of rich low-level moisture (low-middle 70s dewpoints) will remain over the coastal plain and combine with strong heating to yield moderate destabilization. Strong gusts (45-55mph, locally higher) occurring in pockets associated with wet microbursts will be capable of isolated wind damage. Storms will weaken by the early evening and dissipate soon after sunset. ..Smith/Cook.. 08/15/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central Great Plains today. Large to very large hail and severe gusts are forecast with the stronger storms. ...Central and northern Great Plains... A mid-level shortwave trough is forecast to move from eastern MT this morning to the mid-upper MS Valley by daybreak Friday. A weak area of low pressure will develop over western KS while a cold front moves southeastward across the western Dakotas during the day. An elevated cluster of thunderstorms is possible over the central Great Plains associated with a warm advection regime before this activity weakens by the late morning. Considerable uncertainty is apparent and partially attributed to the evolution of storms during the morning. An outflow boundary associated with this early day convection may serve as a focus for additional storms by late afternoon from NE into northern KS. Elongated hodographs would favor supercells with large to very large hail. Isolated storms are forecast farther southwest into southern KS into the TX Panhandle with a wind/hail risk with the sustained/strong storms. Farther north over the Dakotas and Wyoming into western NE, diurnal storms are forecast to develop along the front over the Dakotas and in a post-frontal area over WY. Hail/wind are possible with this activity. ...Upper Ohio Valley... At the surface, a front will advance eastward across upper Ohio Valley with moderate destabilization expected by afternoon. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. A few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Coastal Carolinas... Weak mid-level troughing will slowly move east across the southern Appalachians. A cold front and a sea breeze front will serve as foci for thunderstorm development during the midday through the early evening. A reservoir of rich low-level moisture (low-middle 70s dewpoints) will remain over the coastal plain and combine with strong heating to yield moderate destabilization. Strong gusts (45-55mph, locally higher) occurring in pockets associated with wet microbursts will be capable of isolated wind damage. Storms will weaken by the early evening and dissipate soon after sunset. ..Smith/Cook.. 08/15/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central Great Plains today. Large to very large hail and severe gusts are forecast with the stronger storms. ...Central and northern Great Plains... A mid-level shortwave trough is forecast to move from eastern MT this morning to the mid-upper MS Valley by daybreak Friday. A weak area of low pressure will develop over western KS while a cold front moves southeastward across the western Dakotas during the day. An elevated cluster of thunderstorms is possible over the central Great Plains associated with a warm advection regime before this activity weakens by the late morning. Considerable uncertainty is apparent and partially attributed to the evolution of storms during the morning. An outflow boundary associated with this early day convection may serve as a focus for additional storms by late afternoon from NE into northern KS. Elongated hodographs would favor supercells with large to very large hail. Isolated storms are forecast farther southwest into southern KS into the TX Panhandle with a wind/hail risk with the sustained/strong storms. Farther north over the Dakotas and Wyoming into western NE, diurnal storms are forecast to develop along the front over the Dakotas and in a post-frontal area over WY. Hail/wind are possible with this activity. ...Upper Ohio Valley... At the surface, a front will advance eastward across upper Ohio Valley with moderate destabilization expected by afternoon. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. A few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Coastal Carolinas... Weak mid-level troughing will slowly move east across the southern Appalachians. A cold front and a sea breeze front will serve as foci for thunderstorm development during the midday through the early evening. A reservoir of rich low-level moisture (low-middle 70s dewpoints) will remain over the coastal plain and combine with strong heating to yield moderate destabilization. Strong gusts (45-55mph, locally higher) occurring in pockets associated with wet microbursts will be capable of isolated wind damage. Storms will weaken by the early evening and dissipate soon after sunset. ..Smith/Cook.. 08/15/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL AND NORTHERN GREAT PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central Great Plains today. Large to very large hail and severe gusts are forecast with the stronger storms. ...Central and northern Great Plains... A mid-level shortwave trough is forecast to move from eastern MT this morning to the mid-upper MS Valley by daybreak Friday. A weak area of low pressure will develop over western KS while a cold front moves southeastward across the western Dakotas during the day. An elevated cluster of thunderstorms is possible over the central Great Plains associated with a warm advection regime before this activity weakens by the late morning. Considerable uncertainty is apparent and partially attributed to the evolution of storms during the morning. An outflow boundary associated with this early day convection may serve as a focus for additional storms by late afternoon from NE into northern KS. Elongated hodographs would favor supercells with large to very large hail. Isolated storms are forecast farther southwest into southern KS into the TX Panhandle with a wind/hail risk with the sustained/strong storms. Farther north over the Dakotas and Wyoming into western NE, diurnal storms are forecast to develop along the front over the Dakotas and in a post-frontal area over WY. Hail/wind are possible with this activity. ...Upper Ohio Valley... At the surface, a front will advance eastward across upper Ohio Valley with moderate destabilization expected by afternoon. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. A few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Coastal Carolinas... Weak mid-level troughing will slowly move east across the southern Appalachians. A cold front and a sea breeze front will serve as foci for thunderstorm development during the midday through the early evening. A reservoir of rich low-level moisture (low-middle 70s dewpoints) will remain over the coastal plain and combine with strong heating to yield moderate destabilization. Strong gusts (45-55mph, locally higher) occurring in pockets associated with wet microbursts will be capable of isolated wind damage. Storms will weaken by the early evening and dissipate soon after sunset. ..Smith/Cook.. 08/15/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...Synopsis... Elevated fire weather conditions will once again develop across portions of the Intermountain West on D2/Fri. A belt of enhanced mid-level flow will sag southward across portions of Idaho, Wyoming, and northern Colorado as a broad mid-level trough amplifies across the Canadian Rockies. This broadly cyclonic flow pattern will extend eastward across the Plains and through the Great Lakes as well, while weak ridging persists across the southern tier of the CONUS. ...Southwestern Wyoming, northwestern Colorado, and northeastern Utah... Heating/insolation beneath the increasingly strong mid-level flow across the region will result in areas of 15-25 mph surface flow during the afternoon and evening hours. Meanwhile, much of the region has been precipitation free over the last 1-2 weeks except for in higher elevations. RH values will also fall to near critical thresholds in a few areas and fall to as low as 7-10% in northeastern Utah. Widespread elevated fire weather conditions are most likely within the delineated area, though locally elevated fire weather conditions will also extend southward across eastern Utah/western Colorado and also within the Snake River Plain in Idaho where dry fuels exist and local terrain enhancements increase wind speeds. Furthermore, locally critical conditions are likely especially across northeastern Utah and northwestern Colorado, and if models trend any stronger with wind speeds, critical upgrades will need to be introduced. ..Cook.. 08/15/2019 ...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 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...Synopsis... Elevated fire weather conditions will once again develop across portions of the Intermountain West on D2/Fri. A belt of enhanced mid-level flow will sag southward across portions of Idaho, Wyoming, and northern Colorado as a broad mid-level trough amplifies across the Canadian Rockies. This broadly cyclonic flow pattern will extend eastward across the Plains and through the Great Lakes as well, while weak ridging persists across the southern tier of the CONUS. ...Southwestern Wyoming, northwestern Colorado, and northeastern Utah... Heating/insolation beneath the increasingly strong mid-level flow across the region will result in areas of 15-25 mph surface flow during the afternoon and evening hours. Meanwhile, much of the region has been precipitation free over the last 1-2 weeks except for in higher elevations. RH values will also fall to near critical thresholds in a few areas and fall to as low as 7-10% in northeastern Utah. Widespread elevated fire weather conditions are most likely within the delineated area, though locally elevated fire weather conditions will also extend southward across eastern Utah/western Colorado and also within the Snake River Plain in Idaho where dry fuels exist and local terrain enhancements increase wind speeds. Furthermore, locally critical conditions are likely especially across northeastern Utah and northwestern Colorado, and if models trend any stronger with wind speeds, critical upgrades will need to be introduced. ..Cook.. 08/15/2019 ...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 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...Synopsis... Elevated fire weather conditions will once again develop across portions of the Intermountain West on D2/Fri. A belt of enhanced mid-level flow will sag southward across portions of Idaho, Wyoming, and northern Colorado as a broad mid-level trough amplifies across the Canadian Rockies. This broadly cyclonic flow pattern will extend eastward across the Plains and through the Great Lakes as well, while weak ridging persists across the southern tier of the CONUS. ...Southwestern Wyoming, northwestern Colorado, and northeastern Utah... Heating/insolation beneath the increasingly strong mid-level flow across the region will result in areas of 15-25 mph surface flow during the afternoon and evening hours. Meanwhile, much of the region has been precipitation free over the last 1-2 weeks except for in higher elevations. RH values will also fall to near critical thresholds in a few areas and fall to as low as 7-10% in northeastern Utah. Widespread elevated fire weather conditions are most likely within the delineated area, though locally elevated fire weather conditions will also extend southward across eastern Utah/western Colorado and also within the Snake River Plain in Idaho where dry fuels exist and local terrain enhancements increase wind speeds. Furthermore, locally critical conditions are likely especially across northeastern Utah and northwestern Colorado, and if models trend any stronger with wind speeds, critical upgrades will need to be introduced. ..Cook.. 08/15/2019 ...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 1249 AM CDT Thu Aug 15 2019 Valid 161200Z - 171200Z ...Synopsis... Elevated fire weather conditions will once again develop across portions of the Intermountain West on D2/Fri. A belt of enhanced mid-level flow will sag southward across portions of Idaho, Wyoming, and northern Colorado as a broad mid-level trough amplifies across the Canadian Rockies. This broadly cyclonic flow pattern will extend eastward across the Plains and through the Great Lakes as well, while weak ridging persists across the southern tier of the CONUS. ...Southwestern Wyoming, northwestern Colorado, and northeastern Utah... Heating/insolation beneath the increasingly strong mid-level flow across the region will result in areas of 15-25 mph surface flow during the afternoon and evening hours. Meanwhile, much of the region has been precipitation free over the last 1-2 weeks except for in higher elevations. RH values will also fall to near critical thresholds in a few areas and fall to as low as 7-10% in northeastern Utah. Widespread elevated fire weather conditions are most likely within the delineated area, though locally elevated fire weather conditions will also extend southward across eastern Utah/western Colorado and also within the Snake River Plain in Idaho where dry fuels exist and local terrain enhancements increase wind speeds. Furthermore, locally critical conditions are likely especially across northeastern Utah and northwestern Colorado, and if models trend any stronger with wind speeds, critical upgrades will need to be introduced. ..Cook.. 08/15/2019 ...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 1246 AM CDT Thu Aug 15 2019 Valid 151200Z - 161200Z ...Synopsis... A couple of shortwave troughs - one over the northern Plains and another Idaho - will gradually amplify southward/southeastward during the period. These shortwaves will result in a belt of enhanced mid-level flow extending from Oregon east-southeastward to Nebraska. This flow will strengthen atop a warming, yet dry low-level airmass across portions of Idaho and Wyoming, resulting in elevated to locally critical fire weather conditions. ...Eastern Idaho into southern Wyoming... Beneath strengthening mid-level flow, insolation and vertical mixing processes during peak heating hours will result in areas of 15-25 mph westerly surface flow - strongest across the Snake River Plain and areas of southern Wyoming. Meanwhile, RH values will fall to around 15% or so even though models/point forecast soundings indicate the potential for mid/high level clouds to slow boundary layer mixing some. Given areas of dry fuels across the region, atmospheric conditions are most consistent with elevated fire weather thresholds, though a few areas of critical fire weather may occur on a localized basis. ..Cook.. 08/15/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more