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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 19 2025 Valid 191630Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY TO THE SOUTHERN/CENTRAL PLAINS...AND OVER PORTIONS OF WESTERN/NORTHERN MONTANA... ...SUMMARY... Scattered thunderstorms capable of producing occasional damaging winds will be possible across parts of the south-central Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur this evening across parts of western and northern Montana. ...Ohio Valley to the Central/Southern Plains... Upper ridging will remain prominent today across the Southwest and southern/central Rockies, as a weak mid/upper-level trough moves east-southeastward across the Great Lakes and OH Valley regions. At the surface, a weak cold front is forecast to advance east-southeastward across parts of the OH Valley and mid MS Valley today, and more slowly southward over portions of the central/southern Plains while weakening. This boundary should aid in at least scattered thunderstorm development through the afternoon as diurnal heating of a moist airmass along/south of the front occurs. While deep-layer flow and related shear are expected to remain generally weak, moderate to strong instability and the steepening of low-level lapse rates may support occasional strong to damaging winds with water-loaded downdrafts within the stronger cores. Only minor adjustments have been made to the broad Marginal Risk based on latest observational and short-term guidance trends. ...Northern Rockies/High Plains... An embedded mid-level shortwave trough will advance northeastward this evening and overnight across parts of the northern Rockies and adjacent High Plains on the western to northern periphery of prominent upper ridging over the Southwest. Isolated to perhaps widely scattered thunderstorms should develop through the evening hours across parts of western MT and vicinity as large-scale ascent associated with the shortwave trough overspreads the northern Rockies. Instability is forecast to remain rather limited, but steepened lapse rates aloft and a well-mixed boundary layer could still aid in some convective downdraft enhancement, with isolated strong to severe gusts possible as convection spreads northeastward towards the international border. ...Coastal Texas... A weak mid-level perturbation with ongoing thunderstorms along parts of the middle TX Coast should continue south-southwestward this afternoon and evening. Low/mid-level flow should remain modest, which will generally limit thunderstorm organization. Still, some clustering could support isolated strong/gusty winds in the presence of increasing instability this afternoon across parts of south-central TX and the lower TX Coast. Confidence in severe-caliber gusts remains too low to include any severe probabilities at this time. ..Gleason/Wendt.. 08/19/2025 Read more

Potential Storm Surge Flooding Map last updated Tue, 19 Aug 2025 15:58:38 GMT

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...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 1005 AM CDT Tue Aug 19 2025 Valid 191700Z - 201200Z Very low RH will continue across much of the Great Basin, West Slope, northern/western Arizona, western Wyoming, and southwest Montana and remaining below Elevated thresholds for 18-24 hours during the outlook period. This will lead to long burning periods once again, and multiple large fires remained active last night in similar conditions. Minor modifications were made to the Elevated area based on the latest observations and high-resolution forecast guidance. Dry thunderstorms are possible in portions of north-central and northeast Arizona on the fringe of monsoonal moisture. However, PWAT values and dewpoints increase slightly today while deeper moisture is expected in the coming days precluding an IsoDryT area. ..Nauslar.. 08/19/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Aug 19 2025/ ...Synopsis... An amplifying mid-level ridge over the Four Corners region will support a large area of hot and dry conditions over much of the Intermountain West. On the northern periphery of the ridge, southwesterly flow aloft will increase ahead of a shortwave trough. This will allow a dry cold front to approach and stall over the northwestern Great Basin. Ahead of the front, very warm and dry conditions are expected. With the increased flow aloft, forecast guidance shows south-southwest surface winds increasing to around 15 mph with gusts to 20-25 mph. The stronger winds amid a very dry airmass will support minimum RH of 5-15%. With regional fuels very dry, elevated fire-weather conditions appear likely. ...Northern Rockies... To the northwest, the mid-level trough and remnant monsoon moisture may support isolated thunderstorm potential across the higher terrain of the northern Rockies. Some lightning is possible, though the highest storm chances are expected over western MT and northeastern ID where less receptive fuels are present. This suggests the threat for ignitions is modest and below 10% coverage for IsoDryT highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

A joint water ban has taken effect for Narragansett and South Kingstown as the southern half of the state was abnormally dry. WLNE-TV ABC 6 (Providence, R.I.), Aug 19, 2025

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Tue Aug 19 2025 Valid 191300Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTH-CENTRAL PLAINS AND OZARKS TO OHIO VALLEY AND NORTHERN ROCKIES... ...SUMMARY... Scattered strong to severe thunderstorms capable of damaging winds will be possible across the south-central Great Plains and Ozarks to the Ohio Valley this afternoon and evening. Isolated severe thunderstorms may also occur across parts of the northern Rockies including western and northern Montana. ...South-central Plains and Ozarks to Ohio Valley... Outside of a few areas of lingering early day convection/small-scale outflows, a hot air mass and relatively high moisture content will reside to the south of a synoptic front extending from the south-central Plains to the Midwest/Ohio Valley. Moderate to strong buoyancy with daytime heating, beneath a residual plume of relatively steep lower/mid-tropospheric lapse rates, will exist particularly across parts of the south-central Plains to Ozark Plateau, including parts of Kansas/Oklahoma to Arkansas/southern Missouri. As storms diurnally develop/increase, upscale-growing thunderstorm development should occur during the mid to late afternoon and early evening. While weak deep-layer winds and shear are likely to limit the risk for organized severe convection, thermodynamic profiles will be conducive for downbursts and severe-caliber wind gusts with the stronger storms, particularly this afternoon through around sunset. ...Northern Rockies including western/northern Montana... The late-day arrival of weak height falls and approaching mid-level perturbation should influence isolated thunderstorm development late this afternoon, and more so into this evening, across parts of northern Idaho in western and eventually northern Montana. Sufficient moisture/buoyancy near and behind a surface front, along with strengthening flow aloft, will support the possibility of some severe storms, and potentially some clustering/organization to the storms as they progress across western/northern Montana. West-southwesterly mean flow strengthening to 30-40+ kt in the cloud-bearing layer, and a residual deep sub-cloud mixed-layer, will likely be sufficient for downward mixing of momentum to contribute to a few strong to severe wind gusts. ..Guyer/Dean.. 08/19/2025 Read more