Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Wed Aug 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KS INTO PARTS OF THE MID MS VALLEY AND MIDWEST... ...SUMMARY... Scattered severe thunderstorms appear possible across parts of the Midwest, mid Mississippi Valley, and central Plains on Thursday. Damaging winds and large hail should be the main threats, but a couple tornadoes may also occur. ...Synopsis... A mid/upper-level trough is forecast to evolve into a closed low on Thursday over parts of central/northern MN. As this occurs, a surface low will move from parts of MN/IA toward the upper Great Lakes, as a trailing cold front moves through parts of the upper Midwest into the central/southern Great Plains. ...Midwest into the mid MS Valley vicinity... In the wake of morning convection, moist low-level southwesterly flow will support airmass recovery and robust destabilization by afternoon from parts of the east-central Plains into the mid MS Valley and Midwest. MLCAPE may increase into the 2500-4000 J/kg range, while some increase in midlevel flow across the warm sector will support effective shear of 30-45 kt, resulting in a conditionally favorable severe-thunderstorm environment across a relatively broad region. The details of convective development and evolution continue to be uncertain, with generally weak convergence expected along the primary front, and with the location of any outflow boundaries yet to be determined. However, isolated to widely scattered storm development will be possible during the afternoon and early evening, both near the front and any other remnant boundaries. A somewhat greater coverage of storms will be possible later Thursday evening from southern WI into parts of IL/MO, in response to a midlevel jet maximum moving through the base of the trough. Supercells with a threat of large hail, damaging wind, and a couple tornadoes will be possible with initial development during the afternoon and early evening, with some upscale growth and an increase in damaging-wind potential possible later in the convective evolution. Some threat for at least isolated damaging wind could persist into Thursday night, though the southern/eastern extent of any organized severe potential remains uncertain. ...Eastern NE into western/central IA... There is some signal for at least isolated storm development within a post-frontal regime across parts of NE/IA and vicinity, which would potentially be aided by a low-amplitude shortwave moving through the base of the larger-scale trough. The post-frontal environment will remain favorable for organized convection, with moderate to locally strong buoyancy and favorable midlevel lapse rates and deep-layer shear. Some threat for large hail and localized damaging wind could accompany any robust storms within this regime during the afternoon and evening. Greater severe probabilities may be needed for parts of this region if confidence in this scenario increases. ...Southern KS into OK... With robust daytime heating, a deeply mixed boundary layer is expected to develop along/south of the front across parts of southern KS into OK. While deep-layer shear should remain weak across most of this region, moderate to strong instability and steepened low to mid-level lapse rates should support mainly an isolated severe wind threat with high-based thunderstorms that can develop. Occasional hail may also occur with the strongest cores. ..Dean.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Aug 14 2024 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT FOR THE MIDDLE MO VALLEY... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across portions of the middle Missouri Valley. ...MO Valley area this afternoon through tonight... An MCV over northwest IA will continue eastward today, while clusters of thunderstorms are ongoing this morning from central MO to northern AR within a low-level warm advection regime. Warm advection will slowly weaken through the day, but convective outflow with the central MO storm cluster may result in those storms persisting well into the afternoon while spreading southward. Otherwise, outflow from the morning convection will slowly modify from eastern KS into southeast NE, in advance of a midlevel shortwave trough over the central High Plains, and an associated surface cold front moving southeastward across northwest KS. The cold front and the front/outflow intersection will focus thunderstorm development late this afternoon/evening from central KS to southeast NE/southwest IA, and storms will subsequently spread eastward tonight as one or more storm clusters/MCSs across northern MO/southern IA. Low-level shear/hodograph curvature will be maintained this afternoon within the modifying outflow across the SLGT risk area, where semi-discrete supercells and a couple of tornadoes will be possible. Isolated very large hail (2-2.5 inches in diameter) will also with any persistent supercells, though the severe threat will transition primarily to damaging winds (60-75 mph) by late evening into tonight as storms grow upscale. Farther northwest, a separate clustering of storms is possible in central SD, south of the ongoing convection across southern ND. Surface heating in cloud breaks and weak ascent downstream from an ejecting midlevel trough will help focus thunderstorm development by 21-00z. Low-midlevel vertical shear will not be particularly strong and flow aloft will be strongly backed, which suggests a fairly quick growth into a line segment. Isolated damaging gusts and large hail will be possible for a few hours late this afternoon/evening. ...WY and vicinity this afternoon... An embedded vorticity maximum over southeast ID will progress eastward over WY this afternoon/evening. There will be sufficient low-midlevel moisture and surface heating for high-based thunderstorm development by early afternoon in advance of the vorticity maximum. Given steep low-level lapse rates and modest enhancement to midlevel flow (near 30 kt), strong outflow winds of 50-60 mph will be possible with this convection through the afternoon. ..Thompson/Weinman.. 08/14/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 1044 AM CDT Wed Aug 14 2024 Valid 141700Z - 151200Z The previous forecast remains on track based on morning observations and latest guidance. Isolated thunderstorms remain likely after 00 UTC across far northern CA, spreading into central and eastern OR through 12 UTC Thursday. Pockets of wetting rainfall are possible, but PWAT values around 0.75 inches and storm motions between 20-25 knots should support the potential for sporadic dry lightning strikes over a region with dry fuels. Other forecast concerns outlined in the previous discussion below remain valid. ..Moore.. 08/14/2024 .PREV DISCUSSION... /ISSUED 0126 AM CDT Wed Aug 14 2024/ ...Synopsis... A mid-level shortwave trough is forecast to cross the northern California coast Wednesday evening into Thursday morning, bringing with it forcing for ascent supportive of isolated dry thunderstorms. The greatest chances for dry thunderstorms will be across portions of northern California and southern Oregon. ...Dry Thunderstorms... Forecast sounding profiles still suggest the most unstable/buoyant parcels will originate at temperatures near or colder than 0 C, leaving some uncertainty in charge separation/lightning potential across the Northwest. However, forcing from the shortwave trough should be sufficient enough for at least some thunderstorm development overnight Wednesday into Thursday morning over receptive fuels. ...Dry/Windy... The strongest surface winds supportive of Elevated fire-weather conditions across the Western U.S. will be confined to diurnally/terrain-driven corridors that are too localized for highlights at this time. ...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 14 2024 Valid 141300Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NEBRASKA...SOUTHWEST IOWA...NORTHEAST KANSAS...AND NORTHWEST MISSOURI... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across adjacent portions of the mid and lower Missouri Valley. ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level shortwave trough over WY/CO moving east-northeast. This upper feature is forecast to rotate through the base of a larger-scale trough and move into the eastern ND/northern MN vicinity by daybreak Thursday. In its wake, an upstream perturbation will move from southeast OR/southern ID into NE by late tonight. Consequently, an upper ridge will shift eastward from the lower-mid MO Valley through the mid MS Valley during the period. At the surface, weak/broad low pressure initially over the High Plains is forecast to gradually consolidate as it shifts eastward across the central Plains, in tandem with the advance of the upper trough. As this occurs, a cool front will shift southeastward across the central Plains through the afternoon and evening. Overnight, further consolidation of the surface low is expected as it moves slowly northeastward into southern Minnesota, while the trailing front sharpens, extending from the low southwestward across Kansas and into New Mexico by the end of the period. ...Mid to lower Missouri Valley... Mid morning radar/IR satellite mosaic shows an MCS over northern MO/IA with a well-developed MCV moving east-northeast over northeast NE. This activity will continue to weaken this morning and become increasingly displaced from KS/NE where a renewed focus for thunderstorm development will occur later today. The remnant outflow boundary will likely persist into the afternoon across the southeastern Nebraska/northwestern Missouri/southwestern Iowa area and modify as heating occurs to the west edge of the MCS cirrus canopy. Rich low-level moisture was sampled this morning on the Topeka, KS 12 UTC raob (16.7 g/kg lowest 100-mb mean mixing ratio). Southerly low-level flow will aid in moistening the airmass as insolation contributes to moderate to strong buoyancy (2000-4000 J/kg MLCAPE) by peak heating. By late afternoon as low pressure and the cold front shifts eastward into this area, the low/front and remnant outflow should all provide low-level foci for storm initiation. With enhanced southerly low-level flow ahead of the advancing mid-level trough beneath moderate (30 to 40 kt) mid-level westerlies, resulting shear suggests that initial storms will likely be supercells capable of producing large hail (1 to 2.5 inches in diameter). Enlarged hodographs along and north of the modified outflow boundary suggest a tornado risk will probably accompany a couple of the more intense supercells, where surface to 0.5 km flow remains relatively backed beneath a belt of 30-40 700-mb flow. Given modest flow above 300 mb, upscale growth into a cluster is forecast to occur relatively quickly during the early evening with a band further consolidating into a eastward-moving line by mid to late evening. Coincident with the transition to upscale growth, the tornado risk will gradually wane and severe gusts capable of wind damage will become the primary concern. This activity will likely persist as a linear MCS but the severe threat should lessen with east extent towards the MS River late. ...Wyoming and vicinity eastward across the northern and central Plains... As the upper trough -- comprised of several vorticity maxima embedded in the broader cyclonic flow field -- shifts across the Rockies toward/into the Plains, daytime heating beneath cooler air at mid levels will support modest destabilization across a broad area. Ascent -- focused near favored higher terrain areas and near various weak surface boundaries -- will contribute to widely scattered thunderstorm development during the afternoon. Moderate mid-level westerlies will contribute to shear sufficient for a few stronger storms -- and attendant risks for hail and locally strong/severe wind gusts into the evening hours. ..Smith.. 08/14/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Wed Aug 14 2024 Valid 141300Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN NEBRASKA...SOUTHWEST IOWA...NORTHEAST KANSAS...AND NORTHWEST MISSOURI... ...SUMMARY... Scattered severe thunderstorms capable of all hazards are possible late this afternoon through the evening across adjacent portions of the mid and lower Missouri Valley. ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level shortwave trough over WY/CO moving east-northeast. This upper feature is forecast to rotate through the base of a larger-scale trough and move into the eastern ND/northern MN vicinity by daybreak Thursday. In its wake, an upstream perturbation will move from southeast OR/southern ID into NE by late tonight. Consequently, an upper ridge will shift eastward from the lower-mid MO Valley through the mid MS Valley during the period. At the surface, weak/broad low pressure initially over the High Plains is forecast to gradually consolidate as it shifts eastward across the central Plains, in tandem with the advance of the upper trough. As this occurs, a cool front will shift southeastward across the central Plains through the afternoon and evening. Overnight, further consolidation of the surface low is expected as it moves slowly northeastward into southern Minnesota, while the trailing front sharpens, extending from the low southwestward across Kansas and into New Mexico by the end of the period. ...Mid to lower Missouri Valley... Mid morning radar/IR satellite mosaic shows an MCS over northern MO/IA with a well-developed MCV moving east-northeast over northeast NE. This activity will continue to weaken this morning and become increasingly displaced from KS/NE where a renewed focus for thunderstorm development will occur later today. The remnant outflow boundary will likely persist into the afternoon across the southeastern Nebraska/northwestern Missouri/southwestern Iowa area and modify as heating occurs to the west edge of the MCS cirrus canopy. Rich low-level moisture was sampled this morning on the Topeka, KS 12 UTC raob (16.7 g/kg lowest 100-mb mean mixing ratio). Southerly low-level flow will aid in moistening the airmass as insolation contributes to moderate to strong buoyancy (2000-4000 J/kg MLCAPE) by peak heating. By late afternoon as low pressure and the cold front shifts eastward into this area, the low/front and remnant outflow should all provide low-level foci for storm initiation. With enhanced southerly low-level flow ahead of the advancing mid-level trough beneath moderate (30 to 40 kt) mid-level westerlies, resulting shear suggests that initial storms will likely be supercells capable of producing large hail (1 to 2.5 inches in diameter). Enlarged hodographs along and north of the modified outflow boundary suggest a tornado risk will probably accompany a couple of the more intense supercells, where surface to 0.5 km flow remains relatively backed beneath a belt of 30-40 700-mb flow. Given modest flow above 300 mb, upscale growth into a cluster is forecast to occur relatively quickly during the early evening with a band further consolidating into a eastward-moving line by mid to late evening. Coincident with the transition to upscale growth, the tornado risk will gradually wane and severe gusts capable of wind damage will become the primary concern. This activity will likely persist as a linear MCS but the severe threat should lessen with east extent towards the MS River late. ...Wyoming and vicinity eastward across the northern and central Plains... As the upper trough -- comprised of several vorticity maxima embedded in the broader cyclonic flow field -- shifts across the Rockies toward/into the Plains, daytime heating beneath cooler air at mid levels will support modest destabilization across a broad area. Ascent -- focused near favored higher terrain areas and near various weak surface boundaries -- will contribute to widely scattered thunderstorm development during the afternoon. Moderate mid-level westerlies will contribute to shear sufficient for a few stronger storms -- and attendant risks for hail and locally strong/severe wind gusts into the evening hours. ..Smith.. 08/14/2024 Read more