Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0319 PM CDT Wed Aug 14 2024 Valid 161200Z - 221200Z Fire weather concerns are expected to primarily reside across portions of the Great Basin this weekend, perhaps persisting into next week. Long-range ensemble guidance continues to show low probabilities for wetting rainfall across much of CA, NV, and central TX through the forecast period. This will be driven by a gradually amplifying upper-level regime with upper ridging over the south-central CONUS and the establishment of a robust trough along the West Coast. Fuels across both regions should continue to dry and will support fire weather concerns if/when winds can approach critical thresholds. ...D4/Sat to D5/Sun - Nevada... A mid-level impulse embedded within the mean upper trough is forecast to pivot across northern CA into the northern Great Basin through D4/Saturday. Strong mid-level flow associated with this feature will overspread the central to northern Sierra Nevada, resulting in strengthening downslope winds with somewhat widespread dry/breezy conditions across western and central NV. Afternoon relative humidity values in the teens should be common with winds between 15-25 mph. Given antecedent dry fuels, fire weather concerns are expected, though confidence in the coverage of 20+ mph remains limited away from the immediate lee side of the Sierras, and precludes higher risk probabilities. Breezy downslope winds should persist into D5/Sunday, but may be more limited in scope given weaker mid-level winds compared to Saturday. Overall, a west/southwesterly mid/upper-level flow regime should persist into early next week and may continue to support periods of elevated fire weather conditions across NV. ...Texas... Recent fuel and fire reports from north-central TX and southern OK indicate that grasses and shrubs are undergoing rapid drying amid increasingly hot temperatures. Forecast highs through the forecast period are expected to exceed 100 F each day (likely reaching near 105 F for many locations). While areas north of the Red River may see occasional rain/thunderstorm chances later this week, little to no precipitation is expected across central to western TX. These hot/dry conditions will promote further expansion of burnable fuels and steadily increasing ERCs across the region. The building upper ridge will modulate the potential for surface winds to exceed critical threshold, but fire concerns may emerge if winds trend higher than currently forecast. ..Moore.. 08/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0319 PM CDT Wed Aug 14 2024 Valid 161200Z - 221200Z Fire weather concerns are expected to primarily reside across portions of the Great Basin this weekend, perhaps persisting into next week. Long-range ensemble guidance continues to show low probabilities for wetting rainfall across much of CA, NV, and central TX through the forecast period. This will be driven by a gradually amplifying upper-level regime with upper ridging over the south-central CONUS and the establishment of a robust trough along the West Coast. Fuels across both regions should continue to dry and will support fire weather concerns if/when winds can approach critical thresholds. ...D4/Sat to D5/Sun - Nevada... A mid-level impulse embedded within the mean upper trough is forecast to pivot across northern CA into the northern Great Basin through D4/Saturday. Strong mid-level flow associated with this feature will overspread the central to northern Sierra Nevada, resulting in strengthening downslope winds with somewhat widespread dry/breezy conditions across western and central NV. Afternoon relative humidity values in the teens should be common with winds between 15-25 mph. Given antecedent dry fuels, fire weather concerns are expected, though confidence in the coverage of 20+ mph remains limited away from the immediate lee side of the Sierras, and precludes higher risk probabilities. Breezy downslope winds should persist into D5/Sunday, but may be more limited in scope given weaker mid-level winds compared to Saturday. Overall, a west/southwesterly mid/upper-level flow regime should persist into early next week and may continue to support periods of elevated fire weather conditions across NV. ...Texas... Recent fuel and fire reports from north-central TX and southern OK indicate that grasses and shrubs are undergoing rapid drying amid increasingly hot temperatures. Forecast highs through the forecast period are expected to exceed 100 F each day (likely reaching near 105 F for many locations). While areas north of the Red River may see occasional rain/thunderstorm chances later this week, little to no precipitation is expected across central to western TX. These hot/dry conditions will promote further expansion of burnable fuels and steadily increasing ERCs across the region. The building upper ridge will modulate the potential for surface winds to exceed critical threshold, but fire concerns may emerge if winds trend higher than currently forecast. ..Moore.. 08/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0319 PM CDT Wed Aug 14 2024 Valid 161200Z - 221200Z Fire weather concerns are expected to primarily reside across portions of the Great Basin this weekend, perhaps persisting into next week. Long-range ensemble guidance continues to show low probabilities for wetting rainfall across much of CA, NV, and central TX through the forecast period. This will be driven by a gradually amplifying upper-level regime with upper ridging over the south-central CONUS and the establishment of a robust trough along the West Coast. Fuels across both regions should continue to dry and will support fire weather concerns if/when winds can approach critical thresholds. ...D4/Sat to D5/Sun - Nevada... A mid-level impulse embedded within the mean upper trough is forecast to pivot across northern CA into the northern Great Basin through D4/Saturday. Strong mid-level flow associated with this feature will overspread the central to northern Sierra Nevada, resulting in strengthening downslope winds with somewhat widespread dry/breezy conditions across western and central NV. Afternoon relative humidity values in the teens should be common with winds between 15-25 mph. Given antecedent dry fuels, fire weather concerns are expected, though confidence in the coverage of 20+ mph remains limited away from the immediate lee side of the Sierras, and precludes higher risk probabilities. Breezy downslope winds should persist into D5/Sunday, but may be more limited in scope given weaker mid-level winds compared to Saturday. Overall, a west/southwesterly mid/upper-level flow regime should persist into early next week and may continue to support periods of elevated fire weather conditions across NV. ...Texas... Recent fuel and fire reports from north-central TX and southern OK indicate that grasses and shrubs are undergoing rapid drying amid increasingly hot temperatures. Forecast highs through the forecast period are expected to exceed 100 F each day (likely reaching near 105 F for many locations). While areas north of the Red River may see occasional rain/thunderstorm chances later this week, little to no precipitation is expected across central to western TX. These hot/dry conditions will promote further expansion of burnable fuels and steadily increasing ERCs across the region. The building upper ridge will modulate the potential for surface winds to exceed critical threshold, but fire concerns may emerge if winds trend higher than currently forecast. ..Moore.. 08/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0319 PM CDT Wed Aug 14 2024 Valid 161200Z - 221200Z Fire weather concerns are expected to primarily reside across portions of the Great Basin this weekend, perhaps persisting into next week. Long-range ensemble guidance continues to show low probabilities for wetting rainfall across much of CA, NV, and central TX through the forecast period. This will be driven by a gradually amplifying upper-level regime with upper ridging over the south-central CONUS and the establishment of a robust trough along the West Coast. Fuels across both regions should continue to dry and will support fire weather concerns if/when winds can approach critical thresholds. ...D4/Sat to D5/Sun - Nevada... A mid-level impulse embedded within the mean upper trough is forecast to pivot across northern CA into the northern Great Basin through D4/Saturday. Strong mid-level flow associated with this feature will overspread the central to northern Sierra Nevada, resulting in strengthening downslope winds with somewhat widespread dry/breezy conditions across western and central NV. Afternoon relative humidity values in the teens should be common with winds between 15-25 mph. Given antecedent dry fuels, fire weather concerns are expected, though confidence in the coverage of 20+ mph remains limited away from the immediate lee side of the Sierras, and precludes higher risk probabilities. Breezy downslope winds should persist into D5/Sunday, but may be more limited in scope given weaker mid-level winds compared to Saturday. Overall, a west/southwesterly mid/upper-level flow regime should persist into early next week and may continue to support periods of elevated fire weather conditions across NV. ...Texas... Recent fuel and fire reports from north-central TX and southern OK indicate that grasses and shrubs are undergoing rapid drying amid increasingly hot temperatures. Forecast highs through the forecast period are expected to exceed 100 F each day (likely reaching near 105 F for many locations). While areas north of the Red River may see occasional rain/thunderstorm chances later this week, little to no precipitation is expected across central to western TX. These hot/dry conditions will promote further expansion of burnable fuels and steadily increasing ERCs across the region. The building upper ridge will modulate the potential for surface winds to exceed critical threshold, but fire concerns may emerge if winds trend higher than currently forecast. ..Moore.. 08/14/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1899 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR MUCH OF WYOMING
Mesoscale Discussion 1899 NWS Storm Prediction Center Norman OK 0112 PM CDT Wed Aug 14 2024 Areas affected...much of Wyoming Concerning...Severe potential...Watch unlikely Valid 141812Z - 142045Z Probability of Watch Issuance...5 percent SUMMARY...Widely scattered strong storms, some with small to marginally severe hail, appear likely to continue to develop with increasing potential to produce localized severe surface gusts through 3-5 PM MDT. DISCUSSION...A significant upper-level trough is in the process of slowly progressing east of the northern Intermountain Region into northern Rockies. Beneath the mid-level cold core of this feature, large-scale ascent and destabilization are contributing to an area of sustained convective development and embedded thunderstorms, with additional scattered thunderstorms initiating in advance of this cluster across the Absaroka, Wind River and Bighorn Ranges of Wyoming. Across downstream lower elevations, boundary-layer warming and mixing are well underway in response to insolation, with surface temperature/dew point spreads already exceeding 30 F at some locations. With further heating and cooling aloft, mixed-layer CAPE in excess of 500 J/kg (and perhaps locally up to around 1000 J/kg) is forecast to continue to develop through mid/late afternoon. As this occurs, scattered thunderstorm development is likely to be maintained and intensify. Beneath modestly sheared mean westerly flow, including speeds on the order of 25-30 kt in the cloud-bearing layer, stronger storms may be accompanied by small to, perhaps, marginally severe hail. And negative buoyancy, aided by melting and evaporative cooling, in downdrafts may increasingly support localized strong to severe surface gusts through 21-23Z. ..Kerr/Thompson.. 08/14/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...CYS...RIW...SLC...PIH... LAT...LON 44560819 44220616 43580501 41820495 41250589 41200812 41111017 42901021 43311103 43911109 44401005 44560819 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS 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. ...20z Update... No changes are needed to the current Convective Outlook. Across the Slight Risk region in KS/NE/MS/IA, air mass recovery has been ongoing in the wake of a morning MCS. Temperatures have warmed into the upper 70s to mid 80s with mid 70s dew points increasing as as a modified outflow boundary drifts slowly northeast. This region will be the focus for the main severe threat through the afternoon and evening as a surface low and attendant cold front move eastward into the region and modified outflow/pseudo warm front lifts northward. Initial supercell development is expected by late afternoon/early evening with potential for a tornado or two and large hail. Clustering of supercells into linear segments later in the evening will support an increasing risk in damaging wind through the evening/overnight. A Marginal Risk continues across the Great Basin into the northern Rockies as well as across the central/high Plains. Scattered thunderstorm development in these regions will pose potential for strong to severe wind and some instances of severe hail. ..Thornton/Thompson.. 08/14/2024 .PREV DISCUSSION... /ISSUED 1126 AM CDT Wed Aug 14 2024/ ...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. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Aug 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES INTO THE OH/TN VALLEYS...MID SOUTH...OZARKS...SOUTHERN KS...NORTHERN OK... ...SUMMARY... At least isolated strong to severe thunderstorms may develop Friday over portions of the Great Lakes into the Ohio/Tennessee Valleys, and potentially across parts of the Ozarks into the central and southern Plains. ...Synopsis... A mid/upper-level trough is forecast to move slowly eastward across parts of the Great Lakes, Midwest, and Ohio Valley on Friday. A belt of enhanced mid-level flow should be present from the east-central Plains to parts of the mid MS Valley into the OH Valley, and related deep-layer shear should be sufficient for some updraft organization with thunderstorms that can develop through the period. A weak surface low should likewise move slowly eastward over the Great Lakes vicinity. A weak front/wind shift is forecast to extend south-southwestward from this surface low. ...Great Lakes into the Midwest and Ohio/Tennessee Valleys... Extensive convection may be ongoing Friday morning across the Ohio Valley vicinity. Some intensification of morning storms cannot be ruled out through the day, though the primary severe threat is currently expected with storms that will develop in the wake of early convection during the afternoon and evening. Diurnal heating and rich low-level moisture will support pockets of moderate to locally strong destabilization by late afternoon across parts of the Midwest and Ohio/Tennessee Valleys. Moderate midlevel flow will support sufficient deep-layer shear for storm organization, and a conditionally favorable severe environment may eventually develop over a broad region near/ahead of the front. Details of storm initiation and evolution remain unclear, due to the influence of morning convection and generally weak convergence near the surface front. However, a few stronger cells/clusters may evolve during the afternoon and evening, posing a threat of damaging wind and hail. Greater severe probabilities may eventually be needed, once confidence increases in the location of one or more favored corridors of severe potential within the broader risk area. ...Ozarks into parts of KS/OK... The trailing portion of the cold front will likely extend from southern MO into southern KS/northern OK by late Friday afternoon. At least isolated storm development will be possible in the vicinity of the front, with some signal for convection to persist into Friday night as it moves east-southeastward. Moderate to strong buoyancy and modestly supportive deep-layer shear could result in a threat of isolated strong/damaging gusts and hail with the more robust storms from late Friday afternoon into Friday evening. ..Dean.. 08/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Aug 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES INTO THE OH/TN VALLEYS...MID SOUTH...OZARKS...SOUTHERN KS...NORTHERN OK... ...SUMMARY... At least isolated strong to severe thunderstorms may develop Friday over portions of the Great Lakes into the Ohio/Tennessee Valleys, and potentially across parts of the Ozarks into the central and southern Plains. ...Synopsis... A mid/upper-level trough is forecast to move slowly eastward across parts of the Great Lakes, Midwest, and Ohio Valley on Friday. A belt of enhanced mid-level flow should be present from the east-central Plains to parts of the mid MS Valley into the OH Valley, and related deep-layer shear should be sufficient for some updraft organization with thunderstorms that can develop through the period. A weak surface low should likewise move slowly eastward over the Great Lakes vicinity. A weak front/wind shift is forecast to extend south-southwestward from this surface low. ...Great Lakes into the Midwest and Ohio/Tennessee Valleys... Extensive convection may be ongoing Friday morning across the Ohio Valley vicinity. Some intensification of morning storms cannot be ruled out through the day, though the primary severe threat is currently expected with storms that will develop in the wake of early convection during the afternoon and evening. Diurnal heating and rich low-level moisture will support pockets of moderate to locally strong destabilization by late afternoon across parts of the Midwest and Ohio/Tennessee Valleys. Moderate midlevel flow will support sufficient deep-layer shear for storm organization, and a conditionally favorable severe environment may eventually develop over a broad region near/ahead of the front. Details of storm initiation and evolution remain unclear, due to the influence of morning convection and generally weak convergence near the surface front. However, a few stronger cells/clusters may evolve during the afternoon and evening, posing a threat of damaging wind and hail. Greater severe probabilities may eventually be needed, once confidence increases in the location of one or more favored corridors of severe potential within the broader risk area. ...Ozarks into parts of KS/OK... The trailing portion of the cold front will likely extend from southern MO into southern KS/northern OK by late Friday afternoon. At least isolated storm development will be possible in the vicinity of the front, with some signal for convection to persist into Friday night as it moves east-southeastward. Moderate to strong buoyancy and modestly supportive deep-layer shear could result in a threat of isolated strong/damaging gusts and hail with the more robust storms from late Friday afternoon into Friday evening. ..Dean.. 08/14/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Aug 14 2024 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES INTO THE OH/TN VALLEYS...MID SOUTH...OZARKS...SOUTHERN KS...NORTHERN OK... ...SUMMARY... At least isolated strong to severe thunderstorms may develop Friday over portions of the Great Lakes into the Ohio/Tennessee Valleys, and potentially across parts of the Ozarks into the central and southern Plains. ...Synopsis... A mid/upper-level trough is forecast to move slowly eastward across parts of the Great Lakes, Midwest, and Ohio Valley on Friday. A belt of enhanced mid-level flow should be present from the east-central Plains to parts of the mid MS Valley into the OH Valley, and related deep-layer shear should be sufficient for some updraft organization with thunderstorms that can develop through the period. A weak surface low should likewise move slowly eastward over the Great Lakes vicinity. A weak front/wind shift is forecast to extend south-southwestward from this surface low. ...Great Lakes into the Midwest and Ohio/Tennessee Valleys... Extensive convection may be ongoing Friday morning across the Ohio Valley vicinity. Some intensification of morning storms cannot be ruled out through the day, though the primary severe threat is currently expected with storms that will develop in the wake of early convection during the afternoon and evening. Diurnal heating and rich low-level moisture will support pockets of moderate to locally strong destabilization by late afternoon across parts of the Midwest and Ohio/Tennessee Valleys. Moderate midlevel flow will support sufficient deep-layer shear for storm organization, and a conditionally favorable severe environment may eventually develop over a broad region near/ahead of the front. Details of storm initiation and evolution remain unclear, due to the influence of morning convection and generally weak convergence near the surface front. However, a few stronger cells/clusters may evolve during the afternoon and evening, posing a threat of damaging wind and hail. Greater severe probabilities may eventually be needed, once confidence increases in the location of one or more favored corridors of severe potential within the broader risk area. ...Ozarks into parts of KS/OK... The trailing portion of the cold front will likely extend from southern MO into southern KS/northern OK by late Friday afternoon. At least isolated storm development will be possible in the vicinity of the front, with some signal for convection to persist into Friday night as it moves east-southeastward. Moderate to strong buoyancy and modestly supportive deep-layer shear could result in a threat of isolated strong/damaging gusts and hail with the more robust storms from late Friday afternoon into Friday evening. ..Dean.. 08/14/2024 Read more