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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Fri Sep 20 2024 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDWEST...CENTRAL PLAINS...AND NORTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe thunderstorms are possible during the late afternoon over parts of the Midwest including southwest Lower Michigan, Illinois, and Indiana. Isolated strong to severe storms are also possible across parts of the south-central Plains and the northern High Plains. ...20Z Update... No changes are needed to the ongoing forecast. See the previous discussion for additional details. ..Wendt.. 09/20/2024 .PREV DISCUSSION... /ISSUED 1136 AM CDT Fri Sep 20 2024/ ...Central Plains... Low-level moisture will advect north-northwestward throughout the day associated with a warm front. As a result, low to mid 60s dewpoints will likely be in place across south-central/southeast KS during the late afternoon. Dewpoints will likely be in upper 50s farther west in southwest KS, with notably drier conditions across the adjacent TX/OK Panhandles where downsloping southwesterly surface winds are likely. Southwesterly flow aloft ahead of the approaching upper low will advect steep mid-level lapse rates northeastward through the southern High Plains into western portions of the central Plains. Modest buoyancy is anticipated during the late afternoon where these lapse rates overlay the more favorable low-level moisture across southern KS. Limited large-scale ascent and low-level confluence near the warm front are anticipated over this region as well, with isolated to widely scattered high-based thunderstorms anticipated. Vertical shear will be modest, but still strong enough for persistent/organized storm structures, and the potential for some strong gusts with the more robust storms. Some isolated hail is also possible over south-central KS where buoyancy is maximized. Low-level moisture will continue advection northward during the evening and overnight, with a strengthening low-level jet anticipated as well. Consequently, additional thunderstorm development is expected after 04Z over northeast KS and adjacent far southeast NE and northwest MO. Isolated hail is possible with the strongest storms. ...Midwest including Illinois/Indiana to Lower Michigan... Upper 60s to low 70s dewpoints are expected from southwest Lower MI southwestward across western IN, southern IL, and southeast MO. Daytime heating of this moist low-level air mass will yield a moderately unstable and uncapped air mass ahead of the approaching front, and thunderstorm development is anticipated as the front interacts with this airmass. Moderate vertical shear will be in place, but poor lapse rates and notable mid-level dry air could make updraft maintenance difficult. A multicellular storm mode is anticipated. Highest storm coverage is expected over southwest Lower MI and western IN, with warm mid-level temperatures tending to limit coverage farther southwest. Locally strong wind gusts will be the primary severe risk, with isolated, marginally severe hail possible as well. ...Northern Montana/northwest North Dakota... At least widely scattered low-topped thunderstorms should develop across northern Montana and/or move into the region from southern Alberta as a cold front moves southeastward. This will be influenced by a southeastward-digging shortwave trough and a related strengthening of cyclonic westerlies within its base. Even with modest overall buoyancy, a diurnal steepening of low-level lapse rates and strengthening low/mid-tropospheric westerlies could potentially yield severe-caliber convectively enhanced wind gusts late this afternoon through around sunset. Read more

No Mesoscale Discussions are in effect as of Fri Sep 20 19:59:02 UTC 2024.

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Fri Sep 20 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central Missouri. ...Southern Plains to Missouri... The Marginal Risk has been expanded somewhat across west TX, but the forecast scenario remains similar. While some uncertainty remains regarding the most favorable corridor, strong to locally severe storms will be possible from the TX Permian Basin vicinity northeastward into parts of Missouri on Sunday. An upper trough over the central/southern Rockies Sunday morning will track east over the central/southern Plains. Around 40-50 kt southwesterly flow will overspread northwest TX into KS/OK and MO ahead of this feature. At the surface, a cold front will move southeast across the Mid-MS Valley to southern Plains. Convection may be ongoing across portions of the central/southern Plains to the Mid-MS Valley Sunday morning, resulting in some uncertainty regarding destabilization through peak heating. Nevertheless, a seasonably moist airmass and favorable vertical shear will support organized thunderstorm clusters during the afternoon/evening along/ahead of the advancing cold front. Some risk for damaging gusts and/or hail will accompany this activity from parts of west TX into MO. ..Dean.. 09/20/2024 Read more

000
ABPZ20 KNHC 201745
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Fri Sep 20 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Central Portion of the East Pacific:
An area of low pressure could form well to the southwest of the
southwestern coast of Mexico this weekend. Environmental
conditions appear conducive for some slow development of this
system, and a tropical depression could form during the next few
days while it slowly moves generally northward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

$$
Forecaster Roberts

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NM AND WEST TX... ...SUMMARY... Scattered severe storms are possible Saturday afternoon to early evening across parts of the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains vicinity... A southern stream mid/upper-level low and attendant trough will progress east across the Four Corners and southern Rockies on Saturday. Strong southwesterly flow aloft associated with the ejecting trough will become oriented over eastern NM into the OK/TX Panhandles by 00z/Sunday. While diurnal heating will result in some boundary layer mixing, south/southeasterly low-level flow will result in persistent theta-e advection, and dewpoints from the upper 50s to low 60s F are expected. Steepening midlevel lapse rates will contribute to modest destabilization, with 1000-1500 J/kg MLCAPE forecast across parts of eastern NM into the TX Panhandle/South Plains vicinity. Vertically veering wind profiles amid strengthening midlevel flow will support supercells, though a tendency toward increasing storm coverage and redevelopment may result in some clustering with time. Large hail, sporadic strong/severe gusts, and a tornado or two are all possible. Additional strong storms are possible to the north and west across northern NM into south-central CO beneath the core of mid/upper low. Instability will be weaker across this area, but isolated strong gusts and hail will still be possible with the strongest storms. ...Western PA into northern/central VA... A low-amplitude mid/upper-level shortwave trough is forecast to move across the Northeast on Saturday. Northwesterly deep-layer flow will overspread the Upper OH Valley toward the Mid-Atlantic coast. A corridor of low to mid 60s F dewpoints and pockets of stronger heating will support weak to locally moderate destabilization. Modest vertical shear (around 25-30 kt effective shear) will aid in at least transient organized updrafts. Elongated/straight hodographs and relatively cool temperatures aloft suggest marginally severe hail will be possible with the stronger cells. Locally strong gusts also will be possible where stronger heating and steepening of low-level lapse rates occurs. ...Central Plains to Mid-MO Valley and Upper Midwest... The forecast for this region remains quite uncertain for Saturday. Most guidance depicts ongoing elevated convection across parts of IA/MO Saturday morning. The evolution of this activity will impact how the airmass destabilizes/recovers late in the afternoon across the region. Nevertheless, thunderstorm development may increase during the afternoon/evening over the Upper Midwest into the mid MO Valley, as a northern stream upper trough traverses the Canadian Prairies and the international border vicinity, and an attendant cold front moves through the region. In areas that are not overly affected by early-day convection, diurnal heating and relatively steep midlevel lapse rates atop 60s F dewpoints will support moderate destabilization, while deep-layer shear becomes at least marginally supportive of organized storms. Some guidance suggests a cluster of elevated convection may develop across Iowa during the morning and intensify as it moves east-northeastward. Otherwise, isolated storms may develop near the front during the afternoon, with increasing storm coverage into the evening. Relatively elongated hodographs will support some hail potential with the strongest storms, while localized damaging winds will also be possible, especially if any stronger clusters do evolve with time. Farther south, the magnitude of destabilization into central KS remains uncertain and could be rather limited, though increasing midlevel flow would support some organized convection if robust storms can develop. A strong storm or two also cannot be ruled out with morning convection across MO, and again near any outflow boundaries during the afternoon/evening. However, confidence remains quite low regarding storm evolution in this area. ..Dean.. 09/20/2024 Read more