Aggregator

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Aug 11 2025 Valid 111700Z - 121200Z Minor adjustments were made to the D1 Fire Weather Outlook Isolated Dry Thunderstorm area across Arizona in alignment with trends in recent guidance. See previous discussion below for more information. ..Thornton.. 08/11/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Aug 11 2025/ ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Aug 11 2025 Valid 111700Z - 121200Z Minor adjustments were made to the D1 Fire Weather Outlook Isolated Dry Thunderstorm area across Arizona in alignment with trends in recent guidance. See previous discussion below for more information. ..Thornton.. 08/11/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Aug 11 2025/ ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Aug 11 2025 Valid 111700Z - 121200Z Minor adjustments were made to the D1 Fire Weather Outlook Isolated Dry Thunderstorm area across Arizona in alignment with trends in recent guidance. See previous discussion below for more information. ..Thornton.. 08/11/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Aug 11 2025/ ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Aug 11 2025 Valid 111700Z - 121200Z Minor adjustments were made to the D1 Fire Weather Outlook Isolated Dry Thunderstorm area across Arizona in alignment with trends in recent guidance. See previous discussion below for more information. ..Thornton.. 08/11/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Aug 11 2025/ ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Aug 11 2025 Valid 111700Z - 121200Z Minor adjustments were made to the D1 Fire Weather Outlook Isolated Dry Thunderstorm area across Arizona in alignment with trends in recent guidance. See previous discussion below for more information. ..Thornton.. 08/11/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Aug 11 2025/ ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Aug 11 2025 Valid 111700Z - 121200Z Minor adjustments were made to the D1 Fire Weather Outlook Isolated Dry Thunderstorm area across Arizona in alignment with trends in recent guidance. See previous discussion below for more information. ..Thornton.. 08/11/2025 .PREV DISCUSSION... /ISSUED 0104 AM CDT Mon Aug 11 2025/ ...Synopsis... Somewhat limited fire weather concerns are expected today across the Southwest/Four Corners region. Very dry conditions will persist across the eastern Great Basin/Four Corners with widespread 5-15% RH minimums expected this afternoon. However, low-level winds are expected to be somewhat weaker today compared to previous days as a surface high gradually builds across the Intermountain west. Sustained winds between 10-15 mph will likely be accompanied by 15-25 mph gusts by around peak heating when boundary-layer mixing will be maximized, but confidence in sustained elevated conditions remains too limited to warrant highlights. Instead, fire weather concerns will manifest as another day of dry thunderstorm potential along the Mogollon Rim. Lightning data and MRMS imagery from the past 24 hours shows a mixture of heavy precipitation cores (QPE values near 0.25 inch) as well as multiple dry lightning strikes. Additionally, a couple of small fire starts were noted over the past 24 hours due to lightning. Similar thermodynamic conditions will be in place this afternoon and will likely yield a similar mixture of wet and dry thunderstorms. Unlikely previous days, thunderstorm coverage may be more limited due to weaker synoptic-scale forcing for ascent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Mon Aug 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the southern Plains, lower Missouri Valley, and the Upper Midwest, mainly this afternoon and evening. ...Lower MO Valley... Visible satellite/radar composite shows an MCV moving east-northeastward over northeast KS late this morning. Regional WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in the 2-6 km layer) associated with this disturbance. Surface analysis places a surface low over the Flint Hills with backed easterly flow across eastern KS into northwest MO. Considerable mid- to high-level cloud debris from early morning convection will be slow to dissipate, but gradual filtering of sunlight and the initial signs of a stratocumulus field over the Flint Hills indicates destabilization is beginning to occur. Models vary considerably (understandably so) regarding the development/evolution of a few potential stronger thunderstorms across the lower MO Valley later this afternoon into the early evening. Some forecast soundings show modest enlargement of the low-level portion of the hodograph, which may support updraft rotation if vigorous updraft development occurs. Given the low probability for severe and potentially supportive environment, have introduced low-severe probabilities this outlook update. ...Southern Plains... Morning analysis shows an outflow reinforced front has advanced southward across the southern High Plains, but has stalled near the I-44 corridor in OK southwestward into the northern periphery of the Permian Basin. Water-vapor imagery shows a mid-level impulse moving across southern CO and embedded within larger-scale troughing from CO/NM into the Upper Midwest. This mid-level trough will gradually pivot eastward over the southern High Plains through the evening. Heating of an adequately moist boundary layer (dewpoints ranging from the lower 70s in central OK to the mid 50s in east-central NM) will yield moderate buoyancy near/north of the diffuse boundary. Weak low-level winds will gradually veer to west-northwesterly and modestly strengthen with height through mid/upper levels, supporting modest deep-layer shear and some updraft organization. Isolated severe hail may occur with initially more cellular development across the southern High Plains, before some clustering potentially occurs late this afternoon/evening farther east into the TX Panhandle and northwest TX with more of a wind threat. While deep-layer shear will likely remain weak farther east across OK, the front/outflow boundary should aid in at least scattered thunderstorms. Isolated large hail and severe gusts are the primary hazards with the stronger thunderstorms. ...North Dakota into Northern Minnesota... No change in thinking from the previous forecast. A mid-level shortwave trough and related surface cold front are forecast to move east-southeastward over ND and northern MN through the period. Modest low-level moisture characterized by mid 50s to perhaps low 60s surface dewpoints should be present ahead of the front across these areas. Diurnal heating and modestly steepened lapse rates aloft should aid in the development of weak instability this afternoon. Thunderstorms should gradually increase in coverage along/ahead of the front this afternoon/evening as they spread eastward over parts of ND into northern MN. The stronger cells may produce marginally severe hail, with sufficient deep-layer shear present for some convective organization. With time, some clustering/upscale growth along the front appears probable, with isolated strong to severe gusts possible. The lack of stronger instability should tend to temper the overall severe threat. ..Smith/Squitieri.. 08/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Mon Aug 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the southern Plains, lower Missouri Valley, and the Upper Midwest, mainly this afternoon and evening. ...Lower MO Valley... Visible satellite/radar composite shows an MCV moving east-northeastward over northeast KS late this morning. Regional WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in the 2-6 km layer) associated with this disturbance. Surface analysis places a surface low over the Flint Hills with backed easterly flow across eastern KS into northwest MO. Considerable mid- to high-level cloud debris from early morning convection will be slow to dissipate, but gradual filtering of sunlight and the initial signs of a stratocumulus field over the Flint Hills indicates destabilization is beginning to occur. Models vary considerably (understandably so) regarding the development/evolution of a few potential stronger thunderstorms across the lower MO Valley later this afternoon into the early evening. Some forecast soundings show modest enlargement of the low-level portion of the hodograph, which may support updraft rotation if vigorous updraft development occurs. Given the low probability for severe and potentially supportive environment, have introduced low-severe probabilities this outlook update. ...Southern Plains... Morning analysis shows an outflow reinforced front has advanced southward across the southern High Plains, but has stalled near the I-44 corridor in OK southwestward into the northern periphery of the Permian Basin. Water-vapor imagery shows a mid-level impulse moving across southern CO and embedded within larger-scale troughing from CO/NM into the Upper Midwest. This mid-level trough will gradually pivot eastward over the southern High Plains through the evening. Heating of an adequately moist boundary layer (dewpoints ranging from the lower 70s in central OK to the mid 50s in east-central NM) will yield moderate buoyancy near/north of the diffuse boundary. Weak low-level winds will gradually veer to west-northwesterly and modestly strengthen with height through mid/upper levels, supporting modest deep-layer shear and some updraft organization. Isolated severe hail may occur with initially more cellular development across the southern High Plains, before some clustering potentially occurs late this afternoon/evening farther east into the TX Panhandle and northwest TX with more of a wind threat. While deep-layer shear will likely remain weak farther east across OK, the front/outflow boundary should aid in at least scattered thunderstorms. Isolated large hail and severe gusts are the primary hazards with the stronger thunderstorms. ...North Dakota into Northern Minnesota... No change in thinking from the previous forecast. A mid-level shortwave trough and related surface cold front are forecast to move east-southeastward over ND and northern MN through the period. Modest low-level moisture characterized by mid 50s to perhaps low 60s surface dewpoints should be present ahead of the front across these areas. Diurnal heating and modestly steepened lapse rates aloft should aid in the development of weak instability this afternoon. Thunderstorms should gradually increase in coverage along/ahead of the front this afternoon/evening as they spread eastward over parts of ND into northern MN. The stronger cells may produce marginally severe hail, with sufficient deep-layer shear present for some convective organization. With time, some clustering/upscale growth along the front appears probable, with isolated strong to severe gusts possible. The lack of stronger instability should tend to temper the overall severe threat. ..Smith/Squitieri.. 08/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Mon Aug 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the southern Plains, lower Missouri Valley, and the Upper Midwest, mainly this afternoon and evening. ...Lower MO Valley... Visible satellite/radar composite shows an MCV moving east-northeastward over northeast KS late this morning. Regional WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in the 2-6 km layer) associated with this disturbance. Surface analysis places a surface low over the Flint Hills with backed easterly flow across eastern KS into northwest MO. Considerable mid- to high-level cloud debris from early morning convection will be slow to dissipate, but gradual filtering of sunlight and the initial signs of a stratocumulus field over the Flint Hills indicates destabilization is beginning to occur. Models vary considerably (understandably so) regarding the development/evolution of a few potential stronger thunderstorms across the lower MO Valley later this afternoon into the early evening. Some forecast soundings show modest enlargement of the low-level portion of the hodograph, which may support updraft rotation if vigorous updraft development occurs. Given the low probability for severe and potentially supportive environment, have introduced low-severe probabilities this outlook update. ...Southern Plains... Morning analysis shows an outflow reinforced front has advanced southward across the southern High Plains, but has stalled near the I-44 corridor in OK southwestward into the northern periphery of the Permian Basin. Water-vapor imagery shows a mid-level impulse moving across southern CO and embedded within larger-scale troughing from CO/NM into the Upper Midwest. This mid-level trough will gradually pivot eastward over the southern High Plains through the evening. Heating of an adequately moist boundary layer (dewpoints ranging from the lower 70s in central OK to the mid 50s in east-central NM) will yield moderate buoyancy near/north of the diffuse boundary. Weak low-level winds will gradually veer to west-northwesterly and modestly strengthen with height through mid/upper levels, supporting modest deep-layer shear and some updraft organization. Isolated severe hail may occur with initially more cellular development across the southern High Plains, before some clustering potentially occurs late this afternoon/evening farther east into the TX Panhandle and northwest TX with more of a wind threat. While deep-layer shear will likely remain weak farther east across OK, the front/outflow boundary should aid in at least scattered thunderstorms. Isolated large hail and severe gusts are the primary hazards with the stronger thunderstorms. ...North Dakota into Northern Minnesota... No change in thinking from the previous forecast. A mid-level shortwave trough and related surface cold front are forecast to move east-southeastward over ND and northern MN through the period. Modest low-level moisture characterized by mid 50s to perhaps low 60s surface dewpoints should be present ahead of the front across these areas. Diurnal heating and modestly steepened lapse rates aloft should aid in the development of weak instability this afternoon. Thunderstorms should gradually increase in coverage along/ahead of the front this afternoon/evening as they spread eastward over parts of ND into northern MN. The stronger cells may produce marginally severe hail, with sufficient deep-layer shear present for some convective organization. With time, some clustering/upscale growth along the front appears probable, with isolated strong to severe gusts possible. The lack of stronger instability should tend to temper the overall severe threat. ..Smith/Squitieri.. 08/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Mon Aug 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the southern Plains, lower Missouri Valley, and the Upper Midwest, mainly this afternoon and evening. ...Lower MO Valley... Visible satellite/radar composite shows an MCV moving east-northeastward over northeast KS late this morning. Regional WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in the 2-6 km layer) associated with this disturbance. Surface analysis places a surface low over the Flint Hills with backed easterly flow across eastern KS into northwest MO. Considerable mid- to high-level cloud debris from early morning convection will be slow to dissipate, but gradual filtering of sunlight and the initial signs of a stratocumulus field over the Flint Hills indicates destabilization is beginning to occur. Models vary considerably (understandably so) regarding the development/evolution of a few potential stronger thunderstorms across the lower MO Valley later this afternoon into the early evening. Some forecast soundings show modest enlargement of the low-level portion of the hodograph, which may support updraft rotation if vigorous updraft development occurs. Given the low probability for severe and potentially supportive environment, have introduced low-severe probabilities this outlook update. ...Southern Plains... Morning analysis shows an outflow reinforced front has advanced southward across the southern High Plains, but has stalled near the I-44 corridor in OK southwestward into the northern periphery of the Permian Basin. Water-vapor imagery shows a mid-level impulse moving across southern CO and embedded within larger-scale troughing from CO/NM into the Upper Midwest. This mid-level trough will gradually pivot eastward over the southern High Plains through the evening. Heating of an adequately moist boundary layer (dewpoints ranging from the lower 70s in central OK to the mid 50s in east-central NM) will yield moderate buoyancy near/north of the diffuse boundary. Weak low-level winds will gradually veer to west-northwesterly and modestly strengthen with height through mid/upper levels, supporting modest deep-layer shear and some updraft organization. Isolated severe hail may occur with initially more cellular development across the southern High Plains, before some clustering potentially occurs late this afternoon/evening farther east into the TX Panhandle and northwest TX with more of a wind threat. While deep-layer shear will likely remain weak farther east across OK, the front/outflow boundary should aid in at least scattered thunderstorms. Isolated large hail and severe gusts are the primary hazards with the stronger thunderstorms. ...North Dakota into Northern Minnesota... No change in thinking from the previous forecast. A mid-level shortwave trough and related surface cold front are forecast to move east-southeastward over ND and northern MN through the period. Modest low-level moisture characterized by mid 50s to perhaps low 60s surface dewpoints should be present ahead of the front across these areas. Diurnal heating and modestly steepened lapse rates aloft should aid in the development of weak instability this afternoon. Thunderstorms should gradually increase in coverage along/ahead of the front this afternoon/evening as they spread eastward over parts of ND into northern MN. The stronger cells may produce marginally severe hail, with sufficient deep-layer shear present for some convective organization. With time, some clustering/upscale growth along the front appears probable, with isolated strong to severe gusts possible. The lack of stronger instability should tend to temper the overall severe threat. ..Smith/Squitieri.. 08/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Mon Aug 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the southern Plains, lower Missouri Valley, and the Upper Midwest, mainly this afternoon and evening. ...Lower MO Valley... Visible satellite/radar composite shows an MCV moving east-northeastward over northeast KS late this morning. Regional WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in the 2-6 km layer) associated with this disturbance. Surface analysis places a surface low over the Flint Hills with backed easterly flow across eastern KS into northwest MO. Considerable mid- to high-level cloud debris from early morning convection will be slow to dissipate, but gradual filtering of sunlight and the initial signs of a stratocumulus field over the Flint Hills indicates destabilization is beginning to occur. Models vary considerably (understandably so) regarding the development/evolution of a few potential stronger thunderstorms across the lower MO Valley later this afternoon into the early evening. Some forecast soundings show modest enlargement of the low-level portion of the hodograph, which may support updraft rotation if vigorous updraft development occurs. Given the low probability for severe and potentially supportive environment, have introduced low-severe probabilities this outlook update. ...Southern Plains... Morning analysis shows an outflow reinforced front has advanced southward across the southern High Plains, but has stalled near the I-44 corridor in OK southwestward into the northern periphery of the Permian Basin. Water-vapor imagery shows a mid-level impulse moving across southern CO and embedded within larger-scale troughing from CO/NM into the Upper Midwest. This mid-level trough will gradually pivot eastward over the southern High Plains through the evening. Heating of an adequately moist boundary layer (dewpoints ranging from the lower 70s in central OK to the mid 50s in east-central NM) will yield moderate buoyancy near/north of the diffuse boundary. Weak low-level winds will gradually veer to west-northwesterly and modestly strengthen with height through mid/upper levels, supporting modest deep-layer shear and some updraft organization. Isolated severe hail may occur with initially more cellular development across the southern High Plains, before some clustering potentially occurs late this afternoon/evening farther east into the TX Panhandle and northwest TX with more of a wind threat. While deep-layer shear will likely remain weak farther east across OK, the front/outflow boundary should aid in at least scattered thunderstorms. Isolated large hail and severe gusts are the primary hazards with the stronger thunderstorms. ...North Dakota into Northern Minnesota... No change in thinking from the previous forecast. A mid-level shortwave trough and related surface cold front are forecast to move east-southeastward over ND and northern MN through the period. Modest low-level moisture characterized by mid 50s to perhaps low 60s surface dewpoints should be present ahead of the front across these areas. Diurnal heating and modestly steepened lapse rates aloft should aid in the development of weak instability this afternoon. Thunderstorms should gradually increase in coverage along/ahead of the front this afternoon/evening as they spread eastward over parts of ND into northern MN. The stronger cells may produce marginally severe hail, with sufficient deep-layer shear present for some convective organization. With time, some clustering/upscale growth along the front appears probable, with isolated strong to severe gusts possible. The lack of stronger instability should tend to temper the overall severe threat. ..Smith/Squitieri.. 08/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Mon Aug 11 2025 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN GREAT PLAINS...LOWER MISSOURI VALLEY...AND UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms are possible across parts of the southern Plains, lower Missouri Valley, and the Upper Midwest, mainly this afternoon and evening. ...Lower MO Valley... Visible satellite/radar composite shows an MCV moving east-northeastward over northeast KS late this morning. Regional WSR-88D VAD data shows an enhanced belt of 850-500 mb flow (40 kt in the 2-6 km layer) associated with this disturbance. Surface analysis places a surface low over the Flint Hills with backed easterly flow across eastern KS into northwest MO. Considerable mid- to high-level cloud debris from early morning convection will be slow to dissipate, but gradual filtering of sunlight and the initial signs of a stratocumulus field over the Flint Hills indicates destabilization is beginning to occur. Models vary considerably (understandably so) regarding the development/evolution of a few potential stronger thunderstorms across the lower MO Valley later this afternoon into the early evening. Some forecast soundings show modest enlargement of the low-level portion of the hodograph, which may support updraft rotation if vigorous updraft development occurs. Given the low probability for severe and potentially supportive environment, have introduced low-severe probabilities this outlook update. ...Southern Plains... Morning analysis shows an outflow reinforced front has advanced southward across the southern High Plains, but has stalled near the I-44 corridor in OK southwestward into the northern periphery of the Permian Basin. Water-vapor imagery shows a mid-level impulse moving across southern CO and embedded within larger-scale troughing from CO/NM into the Upper Midwest. This mid-level trough will gradually pivot eastward over the southern High Plains through the evening. Heating of an adequately moist boundary layer (dewpoints ranging from the lower 70s in central OK to the mid 50s in east-central NM) will yield moderate buoyancy near/north of the diffuse boundary. Weak low-level winds will gradually veer to west-northwesterly and modestly strengthen with height through mid/upper levels, supporting modest deep-layer shear and some updraft organization. Isolated severe hail may occur with initially more cellular development across the southern High Plains, before some clustering potentially occurs late this afternoon/evening farther east into the TX Panhandle and northwest TX with more of a wind threat. While deep-layer shear will likely remain weak farther east across OK, the front/outflow boundary should aid in at least scattered thunderstorms. Isolated large hail and severe gusts are the primary hazards with the stronger thunderstorms. ...North Dakota into Northern Minnesota... No change in thinking from the previous forecast. A mid-level shortwave trough and related surface cold front are forecast to move east-southeastward over ND and northern MN through the period. Modest low-level moisture characterized by mid 50s to perhaps low 60s surface dewpoints should be present ahead of the front across these areas. Diurnal heating and modestly steepened lapse rates aloft should aid in the development of weak instability this afternoon. Thunderstorms should gradually increase in coverage along/ahead of the front this afternoon/evening as they spread eastward over parts of ND into northern MN. The stronger cells may produce marginally severe hail, with sufficient deep-layer shear present for some convective organization. With time, some clustering/upscale growth along the front appears probable, with isolated strong to severe gusts possible. The lack of stronger instability should tend to temper the overall severe threat. ..Smith/Squitieri.. 08/11/2025 Read more

5-Day Uncertainty Track last updated Mon, 11 Aug 2025 14:33:16 GMT


Wind Speed Probabilities last updated Mon, 11 Aug 2025 15:32:55 GMT

Issued at 500 AM HST Mon Aug 11 2025 ZCZC HFOTCDCP3 ALL TTAA00 PHFO DDHHMM Hurricane Henriette Discussion Number 30 NWS Central Pacific Hurricane Center Honolulu HI EP082025 Issued by NWS National Hurricane Center Miami FL 500 AM HST Mon Aug 11 2025 Henriette has been going through some rapid structural changes during the past several hours. A 1138 UTC GMI microwave pass confirmed that an eyewall replacement was in the process of occurring, with a ring of deep convection surrounding a small remnant of the previous eyewall. Since that time, convection appears to have redeveloped in the inner eyewall, and a small eye is trying to form in conventional satellite imagery. Dvorak CI numbers at 1200 UTC from PHFO, SAB, and JTWC ranged between 4.0/65 kt and 4.5/77 kt, while most of the objective numbers are between 70-80 kt. The initial intensity is raised to 75 kt as a blend of all these numbers. The hurricane is moving quickly toward the northwest, or 310/16 kt. The forecast track is remarkably straight and steady during the next 48 hours or so, as Henriette is steered between a mid-level low northwest of the Hawaiian Islands and a large ridge centered off the coast of the Pacific Northwest United States. After 48 hours, the cyclone is expected to turn toward the north-northwest and slow down when it reaches the western periphery of the ridge. Confidence remains high in the track forecast, and the new NHC prediction is right on top of the previous one, lying close to the TVCE and HCCA consensus aids. Henriette probably has another 12-24 hours to take advantage of an environment of sufficiently warm sea surface temperatures, low shear, and upper-level divergence. The NHC forecast therefore shows a little more strengthening in the short term. Although ocean temperatures only become gradually cooler after that time, the atmosphere quickly becomes less conducive with an increase in shear and convergence aloft. Weakening is therefore indicated, at a rate similar to the bulk of the guidance, and Henriette could become post-tropical in about 60 hours when it loses its organized deep convection. The post-tropical cyclone/remnant low is then likely to dissipate by day 5 over the far northern Pacific. FORECAST POSITIONS AND MAX WINDS INIT 11/1500Z 28.8N 156.5W 75 KT 85 MPH 12H 12/0000Z 30.4N 158.6W 80 KT 90 MPH 24H 12/1200Z 32.5N 161.1W 75 KT 85 MPH 36H 13/0000Z 34.5N 163.7W 70 KT 80 MPH 48H 13/1200Z 36.5N 166.4W 50 KT 60 MPH 60H 14/0000Z 38.5N 168.6W 40 KT 45 MPH...POST-TROPICAL 72H 14/1200Z 40.4N 169.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 15/1200Z 43.1N 171.1W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 16/1200Z...DISSIPATED $$ Forecaster Berg NNNN

Issued at 1500 UTC MON AUG 11 2025 ZCZC HFOPWSCP3 ALL TTAA00 PHFO DDHHMM HURRICANE HENRIETTE WIND SPEED PROBABILITIES NUMBER 30 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP082025 ISSUED BY NWS NATIONAL HURRICANE CENTER MIAMI FL 1500 UTC MON AUG 11 2025 AT 1500Z THE CENTER OF HURRICANE HENRIETTE WAS LOCATED NEAR LATITUDE 28.8 NORTH...LONGITUDE 156.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 75 KTS...85 MPH...140 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z MON AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z MON 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI PERIODS TO TO TO TO TO TO TO 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI 12Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 30N 160W 34 14 16(30) 1(31) X(31) X(31) X(31) X(31) 30N 160W 50 1 2( 3) X( 3) X( 3) X( 3) X( 3) X( 3) 35N 160W 34 1 5( 6) 6(12) X(12) X(12) X(12) X(12) 30N 165W 34 X 3( 3) 2( 5) X( 5) X( 5) X( 5) X( 5) 35N 165W 34 X 3( 3) 48(51) 27(78) X(78) X(78) X(78) 35N 165W 50 X X( X) 11(11) 24(35) X(35) X(35) X(35) 35N 165W 64 X X( X) 3( 3) 8(11) X(11) X(11) X(11) 40N 165W 34 X X( X) X( X) 3( 3) 2( 5) X( 5) X( 5) 35N 170W 34 X X( X) X( X) 4( 4) 1( 5) X( 5) X( 5) 40N 170W 34 X X( X) X( X) 1( 1) 21(22) 1(23) X(23) 40N 170W 50 X X( X) X( X) X( X) 4( 4) X( 4) X( 4) $$ FORECASTER BERG NNNN

Issued at 800 AM PDT Mon Aug 11 2025 073 WTPZ44 KNHC 111433 TCDEP4 Post-Tropical Cyclone Ivo Discussion Number 20 NWS National Hurricane Center Miami FL EP092025 800 AM PDT Mon Aug 11 2025 The last bit of convection associated with Ivo dissipated about 15 hours ago, and it has therefore degenerated into a remnant low. Maximum winds are estimated to be 25 kt, and further weakening is forecast as the system moves over colder waters. Ivo is expected to open up into a trough--and thus dissipate--in about 36 hours, as depicted in global model fields. Until that time, a low-level ridge to the north is expected to steer the remnant low westward at about 10 kt, and no major changes were made to the official track forecast. FORECAST POSITIONS AND MAX WINDS INIT 11/1500Z 23.2N 119.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 12H 12/0000Z 23.4N 121.2W 20 KT 25 MPH...POST-TROP/REMNT LOW 24H 12/1200Z 23.5N 123.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 13/0000Z...DISSIPATED $$ Forecaster Berg

5-Day Uncertainty Track last updated Mon, 11 Aug 2025 14:33:16 GMT


Wind Speed Probabilities last updated Mon, 11 Aug 2025 14:33:16 GMT

Issued at 1500 UTC MON AUG 11 2025 734 FOPZ14 KNHC 111432 PWSEP4 POST-TROPICAL CYCLONE IVO WIND SPEED PROBABILITIES NUMBER 20 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 1500 UTC MON AUG 11 2025 AT 1500Z THE CENTER OF POST-TROPICAL CYCLONE IVO WAS LOCATED NEAR LATITUDE 23.2 NORTH...LONGITUDE 119.6 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 25 KTS...30 MPH...45 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z MON AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z MON 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI PERIODS TO TO TO TO TO TO TO 00Z TUE 12Z TUE 00Z WED 12Z WED 12Z THU 12Z FRI 12Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER BERG

Issued at 800 AM PDT Mon Aug 11 2025 485 WTPZ34 KNHC 111432 TCPEP4 BULLETIN Post-Tropical Cyclone Ivo Advisory Number 20 NWS National Hurricane Center Miami FL EP092025 800 AM PDT Mon Aug 11 2025 ...IVO NOW A REMNANT LOW, AND THIS IS THE LAST ADVISORY... SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...23.2N 119.6W ABOUT 615 MI...990 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 800 AM PDT (1500 UTC), the center of Post-Tropical Cyclone Ivo was located near latitude 23.2 North, longitude 119.6 West. Ivo is moving toward the west-northwest near 10 mph (17 km/h). A turn toward the west at a slightly faster forward speed is expected later today. Maximum sustained winds have decreased to near 30 mph (45 km/h) with higher gusts, and Ivo has degenerated into a remnant low. The remnant low is expected to dissipate by late Tuesday. The estimated minimum central pressure is 1008 mb (29.77 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- This is the last public advisory issued by the National Hurricane Center on this system. For additional information on the remnant low please see High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php $$ Forecaster Berg