Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0734 AM CDT Thu Aug 14 2025 Valid 141300Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Thunderstorms capable of producing large hail and severe wind gusts may occur this afternoon into tonight across parts of the northern/central Plains and upper Mississippi Valley. ...Northern/Central Plains into the Upper Mississippi Valley... Ongoing elevated thunderstorms across parts of eastern SD this morning are occurring in association with a low-amplitude shortwave trough and related low-level warm advection. This activity has remained sub-severe through much of the early morning hours, but it could still pose an isolated hail threat in the short term given weak MUCAPE and sufficient deep-layer shear. It remains unclear whether additional thunderstorm development will occur later this afternoon across parts of southern MN and vicinity as the shortwave trough continues eastward across the upper MS Valley. The airmass across this area will gradually destabilize through the day, but capping may tend to inhibit additional development. Still, a conditional threat for isolated severe hail/wind exists if robust thunderstorms can initiate, so have maintained the Marginal Risk across southern MN for this possibility. Thunderstorms across southern Manitoba this morning are expected to generally remain along/north of the international border as they continue eastward into western Ontario. A fairly strong mid/upper-level trough will progress eastward today across Saskatchewan/Manitoba, with the southern fringe of this perturbation glancing the northern Plains later today. Enhanced westerly mid-level flow will overspread ND and northern MN late this afternoon though tonight, while a surface cold front advances east-southeastward across the northern Plains through the period. Low-level moisture will continue to stream northward ahead of the front, with evapotranspiration also aiding surface dewpoints potentially reaching into the upper 60s to perhaps low 70s by early evening. Ample daytime heating and steep lapse rates aloft will aid in the development of at least 2500-3500 J/kg of MLCAPE by late afternoon. The primary uncertainty regarding convective development along the front is a capped 850-700 mb layer and weak forcing with southward extent across the northern Plains, as the primary upper trough will remain across Canada through the period. Even so, low-level convergence along the front may become sufficient for cells to initiate by early evening, mainly across parts of eastern ND into northwest MN where MLCIN should be weakest. Any convection which can be sustained could pose a threat for large to isolated very large hail given a favorable thermodynamic and kinematic environment. Some potential for upscale growth into clusters along the front remains apparent this evening into the early overnight hours, with greater severe wind threat. However, inhibition will quickly increase with eastward extent across MN as nocturnal cooling of the boundary layer occurs; so, the severe wind threat remains uncertain. Finally, scattered high-based thunderstorms should occur this afternoon and evening farther south across parts of the central High Plains. As this convection spreads eastward and encounters greater instability along/east of a surface lee trough, it may become capable of producing isolated severe gusts and perhaps marginally severe hail. The lack of stronger forcing aloft and modest deep-layer shear should temper the overall severe threat with southward extent. ..Gleason/Leitman.. 08/14/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0734 AM CDT Thu Aug 14 2025 Valid 141300Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Thunderstorms capable of producing large hail and severe wind gusts may occur this afternoon into tonight across parts of the northern/central Plains and upper Mississippi Valley. ...Northern/Central Plains into the Upper Mississippi Valley... Ongoing elevated thunderstorms across parts of eastern SD this morning are occurring in association with a low-amplitude shortwave trough and related low-level warm advection. This activity has remained sub-severe through much of the early morning hours, but it could still pose an isolated hail threat in the short term given weak MUCAPE and sufficient deep-layer shear. It remains unclear whether additional thunderstorm development will occur later this afternoon across parts of southern MN and vicinity as the shortwave trough continues eastward across the upper MS Valley. The airmass across this area will gradually destabilize through the day, but capping may tend to inhibit additional development. Still, a conditional threat for isolated severe hail/wind exists if robust thunderstorms can initiate, so have maintained the Marginal Risk across southern MN for this possibility. Thunderstorms across southern Manitoba this morning are expected to generally remain along/north of the international border as they continue eastward into western Ontario. A fairly strong mid/upper-level trough will progress eastward today across Saskatchewan/Manitoba, with the southern fringe of this perturbation glancing the northern Plains later today. Enhanced westerly mid-level flow will overspread ND and northern MN late this afternoon though tonight, while a surface cold front advances east-southeastward across the northern Plains through the period. Low-level moisture will continue to stream northward ahead of the front, with evapotranspiration also aiding surface dewpoints potentially reaching into the upper 60s to perhaps low 70s by early evening. Ample daytime heating and steep lapse rates aloft will aid in the development of at least 2500-3500 J/kg of MLCAPE by late afternoon. The primary uncertainty regarding convective development along the front is a capped 850-700 mb layer and weak forcing with southward extent across the northern Plains, as the primary upper trough will remain across Canada through the period. Even so, low-level convergence along the front may become sufficient for cells to initiate by early evening, mainly across parts of eastern ND into northwest MN where MLCIN should be weakest. Any convection which can be sustained could pose a threat for large to isolated very large hail given a favorable thermodynamic and kinematic environment. Some potential for upscale growth into clusters along the front remains apparent this evening into the early overnight hours, with greater severe wind threat. However, inhibition will quickly increase with eastward extent across MN as nocturnal cooling of the boundary layer occurs; so, the severe wind threat remains uncertain. Finally, scattered high-based thunderstorms should occur this afternoon and evening farther south across parts of the central High Plains. As this convection spreads eastward and encounters greater instability along/east of a surface lee trough, it may become capable of producing isolated severe gusts and perhaps marginally severe hail. The lack of stronger forcing aloft and modest deep-layer shear should temper the overall severe threat with southward extent. ..Gleason/Leitman.. 08/14/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0734 AM CDT Thu Aug 14 2025 Valid 141300Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN NORTH DAKOTA INTO NORTHWEST MINNESOTA... ...SUMMARY... Thunderstorms capable of producing large hail and severe wind gusts may occur this afternoon into tonight across parts of the northern/central Plains and upper Mississippi Valley. ...Northern/Central Plains into the Upper Mississippi Valley... Ongoing elevated thunderstorms across parts of eastern SD this morning are occurring in association with a low-amplitude shortwave trough and related low-level warm advection. This activity has remained sub-severe through much of the early morning hours, but it could still pose an isolated hail threat in the short term given weak MUCAPE and sufficient deep-layer shear. It remains unclear whether additional thunderstorm development will occur later this afternoon across parts of southern MN and vicinity as the shortwave trough continues eastward across the upper MS Valley. The airmass across this area will gradually destabilize through the day, but capping may tend to inhibit additional development. Still, a conditional threat for isolated severe hail/wind exists if robust thunderstorms can initiate, so have maintained the Marginal Risk across southern MN for this possibility. Thunderstorms across southern Manitoba this morning are expected to generally remain along/north of the international border as they continue eastward into western Ontario. A fairly strong mid/upper-level trough will progress eastward today across Saskatchewan/Manitoba, with the southern fringe of this perturbation glancing the northern Plains later today. Enhanced westerly mid-level flow will overspread ND and northern MN late this afternoon though tonight, while a surface cold front advances east-southeastward across the northern Plains through the period. Low-level moisture will continue to stream northward ahead of the front, with evapotranspiration also aiding surface dewpoints potentially reaching into the upper 60s to perhaps low 70s by early evening. Ample daytime heating and steep lapse rates aloft will aid in the development of at least 2500-3500 J/kg of MLCAPE by late afternoon. The primary uncertainty regarding convective development along the front is a capped 850-700 mb layer and weak forcing with southward extent across the northern Plains, as the primary upper trough will remain across Canada through the period. Even so, low-level convergence along the front may become sufficient for cells to initiate by early evening, mainly across parts of eastern ND into northwest MN where MLCIN should be weakest. Any convection which can be sustained could pose a threat for large to isolated very large hail given a favorable thermodynamic and kinematic environment. Some potential for upscale growth into clusters along the front remains apparent this evening into the early overnight hours, with greater severe wind threat. However, inhibition will quickly increase with eastward extent across MN as nocturnal cooling of the boundary layer occurs; so, the severe wind threat remains uncertain. Finally, scattered high-based thunderstorms should occur this afternoon and evening farther south across parts of the central High Plains. As this convection spreads eastward and encounters greater instability along/east of a surface lee trough, it may become capable of producing isolated severe gusts and perhaps marginally severe hail. The lack of stronger forcing aloft and modest deep-layer shear should temper the overall severe threat with southward extent. ..Gleason/Leitman.. 08/14/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CDT Thu Aug 14 2025 Valid 171200Z - 221200Z ...DISCUSSION... An upper ridge is forecast to build over the Plains and Rockies through Tuesday/D6, with the upper high retrograding from the central Plains to the Four Corners. East of the ridge axis, northwest midlevel flow of 20-30 kt will persist over the upper MS Valley/Great Lakes, with a large area of moisture and instability roughly from MN/IA to IL/IN. This pattern should support corridors of thunderstorms in the low-level warm advection zone, or along the northern instability gradient through Tuesday/D6. While areas of strong wind gusts will be possible, the overall severe probably is less than the 15% threshold over this large zone. The upper ridge may flatten over the northern Rockies/Plains beyond D6, with perhaps an eventual northwest flow regime coinciding with residual instability, supporting at least minimal severe potential over the northern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CDT Thu Aug 14 2025 Valid 171200Z - 221200Z ...DISCUSSION... An upper ridge is forecast to build over the Plains and Rockies through Tuesday/D6, with the upper high retrograding from the central Plains to the Four Corners. East of the ridge axis, northwest midlevel flow of 20-30 kt will persist over the upper MS Valley/Great Lakes, with a large area of moisture and instability roughly from MN/IA to IL/IN. This pattern should support corridors of thunderstorms in the low-level warm advection zone, or along the northern instability gradient through Tuesday/D6. While areas of strong wind gusts will be possible, the overall severe probably is less than the 15% threshold over this large zone. The upper ridge may flatten over the northern Rockies/Plains beyond D6, with perhaps an eventual northwest flow regime coinciding with residual instability, supporting at least minimal severe potential over the northern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CDT Thu Aug 14 2025 Valid 171200Z - 221200Z ...DISCUSSION... An upper ridge is forecast to build over the Plains and Rockies through Tuesday/D6, with the upper high retrograding from the central Plains to the Four Corners. East of the ridge axis, northwest midlevel flow of 20-30 kt will persist over the upper MS Valley/Great Lakes, with a large area of moisture and instability roughly from MN/IA to IL/IN. This pattern should support corridors of thunderstorms in the low-level warm advection zone, or along the northern instability gradient through Tuesday/D6. While areas of strong wind gusts will be possible, the overall severe probably is less than the 15% threshold over this large zone. The upper ridge may flatten over the northern Rockies/Plains beyond D6, with perhaps an eventual northwest flow regime coinciding with residual instability, supporting at least minimal severe potential over the northern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CDT Thu Aug 14 2025 Valid 171200Z - 221200Z ...DISCUSSION... An upper ridge is forecast to build over the Plains and Rockies through Tuesday/D6, with the upper high retrograding from the central Plains to the Four Corners. East of the ridge axis, northwest midlevel flow of 20-30 kt will persist over the upper MS Valley/Great Lakes, with a large area of moisture and instability roughly from MN/IA to IL/IN. This pattern should support corridors of thunderstorms in the low-level warm advection zone, or along the northern instability gradient through Tuesday/D6. While areas of strong wind gusts will be possible, the overall severe probably is less than the 15% threshold over this large zone. The upper ridge may flatten over the northern Rockies/Plains beyond D6, with perhaps an eventual northwest flow regime coinciding with residual instability, supporting at least minimal severe potential over the northern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CDT Thu Aug 14 2025 Valid 171200Z - 221200Z ...DISCUSSION... An upper ridge is forecast to build over the Plains and Rockies through Tuesday/D6, with the upper high retrograding from the central Plains to the Four Corners. East of the ridge axis, northwest midlevel flow of 20-30 kt will persist over the upper MS Valley/Great Lakes, with a large area of moisture and instability roughly from MN/IA to IL/IN. This pattern should support corridors of thunderstorms in the low-level warm advection zone, or along the northern instability gradient through Tuesday/D6. While areas of strong wind gusts will be possible, the overall severe probably is less than the 15% threshold over this large zone. The upper ridge may flatten over the northern Rockies/Plains beyond D6, with perhaps an eventual northwest flow regime coinciding with residual instability, supporting at least minimal severe potential over the northern Plains. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0326 AM CDT Thu Aug 14 2025 Valid 171200Z - 221200Z ...DISCUSSION... An upper ridge is forecast to build over the Plains and Rockies through Tuesday/D6, with the upper high retrograding from the central Plains to the Four Corners. East of the ridge axis, northwest midlevel flow of 20-30 kt will persist over the upper MS Valley/Great Lakes, with a large area of moisture and instability roughly from MN/IA to IL/IN. This pattern should support corridors of thunderstorms in the low-level warm advection zone, or along the northern instability gradient through Tuesday/D6. While areas of strong wind gusts will be possible, the overall severe probably is less than the 15% threshold over this large zone. The upper ridge may flatten over the northern Rockies/Plains beyond D6, with perhaps an eventual northwest flow regime coinciding with residual instability, supporting at least minimal severe potential over the northern Plains. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Sporadic strong storms are possible Saturday from the Black Hills eastward to Wisconsin. ...Synopsis and Discussion... An upper ridge will remain over the Plains on Saturday, with the upper high centered over MO. Low-level moisture will remain abundant over much of the Plains and MS Valley, with southerly winds along and south of an east-west oriented front. This front will stretch roughly from SD to WI, and provide a focus for bouts of thunderstorms through the period. Areas of storms may be ongoing Saturday morning from SD into WI, where warm southwest winds will continually impinge upon the frontal zone. Some of this activity could produce sporadic strong gusts. Later in the day, further destabilization could result in a renewal of storms from central MN into WI. While moderately unstable, deep-layer shear will be modest, with somewhat disorganized storm modes possible. Predictability is too low to denote the exact corridor for isolated severe at this time. Farther west, afternoon storms will be possible over the Black Hills and surrounding areas, especially late in the day and into the evening. Some of this initial activity could produce localized hail or strong gusts. Low-level winds will be weak, with little overall focus. As such, will defer possible low probabilities to later updates. ..Jewell.. 08/14/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Sporadic strong storms are possible Saturday from the Black Hills eastward to Wisconsin. ...Synopsis and Discussion... An upper ridge will remain over the Plains on Saturday, with the upper high centered over MO. Low-level moisture will remain abundant over much of the Plains and MS Valley, with southerly winds along and south of an east-west oriented front. This front will stretch roughly from SD to WI, and provide a focus for bouts of thunderstorms through the period. Areas of storms may be ongoing Saturday morning from SD into WI, where warm southwest winds will continually impinge upon the frontal zone. Some of this activity could produce sporadic strong gusts. Later in the day, further destabilization could result in a renewal of storms from central MN into WI. While moderately unstable, deep-layer shear will be modest, with somewhat disorganized storm modes possible. Predictability is too low to denote the exact corridor for isolated severe at this time. Farther west, afternoon storms will be possible over the Black Hills and surrounding areas, especially late in the day and into the evening. Some of this initial activity could produce localized hail or strong gusts. Low-level winds will be weak, with little overall focus. As such, will defer possible low probabilities to later updates. ..Jewell.. 08/14/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Sporadic strong storms are possible Saturday from the Black Hills eastward to Wisconsin. ...Synopsis and Discussion... An upper ridge will remain over the Plains on Saturday, with the upper high centered over MO. Low-level moisture will remain abundant over much of the Plains and MS Valley, with southerly winds along and south of an east-west oriented front. This front will stretch roughly from SD to WI, and provide a focus for bouts of thunderstorms through the period. Areas of storms may be ongoing Saturday morning from SD into WI, where warm southwest winds will continually impinge upon the frontal zone. Some of this activity could produce sporadic strong gusts. Later in the day, further destabilization could result in a renewal of storms from central MN into WI. While moderately unstable, deep-layer shear will be modest, with somewhat disorganized storm modes possible. Predictability is too low to denote the exact corridor for isolated severe at this time. Farther west, afternoon storms will be possible over the Black Hills and surrounding areas, especially late in the day and into the evening. Some of this initial activity could produce localized hail or strong gusts. Low-level winds will be weak, with little overall focus. As such, will defer possible low probabilities to later updates. ..Jewell.. 08/14/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Sporadic strong storms are possible Saturday from the Black Hills eastward to Wisconsin. ...Synopsis and Discussion... An upper ridge will remain over the Plains on Saturday, with the upper high centered over MO. Low-level moisture will remain abundant over much of the Plains and MS Valley, with southerly winds along and south of an east-west oriented front. This front will stretch roughly from SD to WI, and provide a focus for bouts of thunderstorms through the period. Areas of storms may be ongoing Saturday morning from SD into WI, where warm southwest winds will continually impinge upon the frontal zone. Some of this activity could produce sporadic strong gusts. Later in the day, further destabilization could result in a renewal of storms from central MN into WI. While moderately unstable, deep-layer shear will be modest, with somewhat disorganized storm modes possible. Predictability is too low to denote the exact corridor for isolated severe at this time. Farther west, afternoon storms will be possible over the Black Hills and surrounding areas, especially late in the day and into the evening. Some of this initial activity could produce localized hail or strong gusts. Low-level winds will be weak, with little overall focus. As such, will defer possible low probabilities to later updates. ..Jewell.. 08/14/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CDT Thu Aug 14 2025 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Sporadic strong storms are possible Saturday from the Black Hills eastward to Wisconsin. ...Synopsis and Discussion... An upper ridge will remain over the Plains on Saturday, with the upper high centered over MO. Low-level moisture will remain abundant over much of the Plains and MS Valley, with southerly winds along and south of an east-west oriented front. This front will stretch roughly from SD to WI, and provide a focus for bouts of thunderstorms through the period. Areas of storms may be ongoing Saturday morning from SD into WI, where warm southwest winds will continually impinge upon the frontal zone. Some of this activity could produce sporadic strong gusts. Later in the day, further destabilization could result in a renewal of storms from central MN into WI. While moderately unstable, deep-layer shear will be modest, with somewhat disorganized storm modes possible. Predictability is too low to denote the exact corridor for isolated severe at this time. Farther west, afternoon storms will be possible over the Black Hills and surrounding areas, especially late in the day and into the evening. Some of this initial activity could produce localized hail or strong gusts. Low-level winds will be weak, with little overall focus. As such, will defer possible low probabilities to later updates. ..Jewell.. 08/14/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0143 AM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...Synopsis... Fire weather concerns will continue into Friday across the Great Basin and parts of the northern Rockies. The upper wave currently moving into CA will gradually shift east into the Great Basin over the next 48 hours. This will maintain a weak surface low over the Intermountain West while also supporting a northward surge of deeper monsoonal moisture from AZ into UT, CO, and parts of southern WY. Dry conditions - both at the surface and aloft - will support elevated fire weather conditions as well as dry thunderstorm chances. Latest ensemble guidance suggests a corridor of 15-20 mph winds will likely emerge from southern NV into western UT and eastern ID. Several hours of elevated fire weather conditions are probable as RH values fall into the 10-15% range by late afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture on the northwestern fringe of the monsoonal surge will support a swath of 100-500 J/kg MUCAPE across central NV into western WY. Dry boundary layer conditions under the weak buoyancy coupled with 15-25 knot storm motions will favor dry thunderstorms. Latest CAM guidance shows a reasonably strong signal for convection, though coverage may be more limited compared to previous days as stronger synoptic forcing for ascent will likely remain displaced to the south/southeast. Regardless, receptive fuels over the region will continue to yield a lightning-driven fire weather concern. ..Moore.. 08/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0143 AM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...Synopsis... Fire weather concerns will continue into Friday across the Great Basin and parts of the northern Rockies. The upper wave currently moving into CA will gradually shift east into the Great Basin over the next 48 hours. This will maintain a weak surface low over the Intermountain West while also supporting a northward surge of deeper monsoonal moisture from AZ into UT, CO, and parts of southern WY. Dry conditions - both at the surface and aloft - will support elevated fire weather conditions as well as dry thunderstorm chances. Latest ensemble guidance suggests a corridor of 15-20 mph winds will likely emerge from southern NV into western UT and eastern ID. Several hours of elevated fire weather conditions are probable as RH values fall into the 10-15% range by late afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture on the northwestern fringe of the monsoonal surge will support a swath of 100-500 J/kg MUCAPE across central NV into western WY. Dry boundary layer conditions under the weak buoyancy coupled with 15-25 knot storm motions will favor dry thunderstorms. Latest CAM guidance shows a reasonably strong signal for convection, though coverage may be more limited compared to previous days as stronger synoptic forcing for ascent will likely remain displaced to the south/southeast. Regardless, receptive fuels over the region will continue to yield a lightning-driven fire weather concern. ..Moore.. 08/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0143 AM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...Synopsis... Fire weather concerns will continue into Friday across the Great Basin and parts of the northern Rockies. The upper wave currently moving into CA will gradually shift east into the Great Basin over the next 48 hours. This will maintain a weak surface low over the Intermountain West while also supporting a northward surge of deeper monsoonal moisture from AZ into UT, CO, and parts of southern WY. Dry conditions - both at the surface and aloft - will support elevated fire weather conditions as well as dry thunderstorm chances. Latest ensemble guidance suggests a corridor of 15-20 mph winds will likely emerge from southern NV into western UT and eastern ID. Several hours of elevated fire weather conditions are probable as RH values fall into the 10-15% range by late afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture on the northwestern fringe of the monsoonal surge will support a swath of 100-500 J/kg MUCAPE across central NV into western WY. Dry boundary layer conditions under the weak buoyancy coupled with 15-25 knot storm motions will favor dry thunderstorms. Latest CAM guidance shows a reasonably strong signal for convection, though coverage may be more limited compared to previous days as stronger synoptic forcing for ascent will likely remain displaced to the south/southeast. Regardless, receptive fuels over the region will continue to yield a lightning-driven fire weather concern. ..Moore.. 08/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0143 AM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...Synopsis... Fire weather concerns will continue into Friday across the Great Basin and parts of the northern Rockies. The upper wave currently moving into CA will gradually shift east into the Great Basin over the next 48 hours. This will maintain a weak surface low over the Intermountain West while also supporting a northward surge of deeper monsoonal moisture from AZ into UT, CO, and parts of southern WY. Dry conditions - both at the surface and aloft - will support elevated fire weather conditions as well as dry thunderstorm chances. Latest ensemble guidance suggests a corridor of 15-20 mph winds will likely emerge from southern NV into western UT and eastern ID. Several hours of elevated fire weather conditions are probable as RH values fall into the 10-15% range by late afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture on the northwestern fringe of the monsoonal surge will support a swath of 100-500 J/kg MUCAPE across central NV into western WY. Dry boundary layer conditions under the weak buoyancy coupled with 15-25 knot storm motions will favor dry thunderstorms. Latest CAM guidance shows a reasonably strong signal for convection, though coverage may be more limited compared to previous days as stronger synoptic forcing for ascent will likely remain displaced to the south/southeast. Regardless, receptive fuels over the region will continue to yield a lightning-driven fire weather concern. ..Moore.. 08/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0143 AM CDT Thu Aug 14 2025 Valid 151200Z - 161200Z ...Synopsis... Fire weather concerns will continue into Friday across the Great Basin and parts of the northern Rockies. The upper wave currently moving into CA will gradually shift east into the Great Basin over the next 48 hours. This will maintain a weak surface low over the Intermountain West while also supporting a northward surge of deeper monsoonal moisture from AZ into UT, CO, and parts of southern WY. Dry conditions - both at the surface and aloft - will support elevated fire weather conditions as well as dry thunderstorm chances. Latest ensemble guidance suggests a corridor of 15-20 mph winds will likely emerge from southern NV into western UT and eastern ID. Several hours of elevated fire weather conditions are probable as RH values fall into the 10-15% range by late afternoon. Similar to previous days, a combination of steep mid-level lapse rates and modest mid-level moisture on the northwestern fringe of the monsoonal surge will support a swath of 100-500 J/kg MUCAPE across central NV into western WY. Dry boundary layer conditions under the weak buoyancy coupled with 15-25 knot storm motions will favor dry thunderstorms. Latest CAM guidance shows a reasonably strong signal for convection, though coverage may be more limited compared to previous days as stronger synoptic forcing for ascent will likely remain displaced to the south/southeast. Regardless, receptive fuels over the region will continue to yield a lightning-driven fire weather concern. ..Moore.. 08/14/2025 ...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 1252 AM CDT Thu Aug 14 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHEASTERN GREAT BASIN... ...Synopsis... Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies. A slight uptick in fire activity over the past 24 hours across the Great Basin and northern Rockies confirms that receptive fuels remain in place across much of the region. ...Dry Thunderstorms... Early-morning water-vapor imagery depicts a plume of mid-level moisture across the Great Basin ahead of a migratory upper trough moving into CA. This moisture plume supported isolated dry thunderstorms yesterday across the region, and will similarly foster 100-500 J/kg MUCAPE from central NV northeastward into portions of ID, WY, UT, and CO. Regional 00z soundings and recent GOES imagery are sampling PWAT values between 0.3 to 0.6 inch, which when combined with very dry boundary-layer conditions, will support dry thunderstorms. A combination of ascent ahead of the approaching wave, modest lift within the right-entrance region of a departing upper jet, and orographic ascent will support isolated thunderstorms across a broad swath of the region. Latest CAM guidance continues to show the potential for several smaller corridors of concentrated thunderstorms. Where exactly these corridors will emerge through the afternoon remains somewhat uncertain, but the general consensus is that areas of higher thunderstorm coverage are likely. The Isolated dry thunderstorm risk area has been expanded to capture the reasonable envelope of dry thunderstorm potential with receptive fuels. Similarly, the Scattered dry thunderstorm risk area was adjusted to highlight the most probable corridors of greater thunderstorm coverage. ...Hot/Dry/Windy... Very dry conditions will prevail across the Great Basin region with another day of RH minimums in the single digits to low teens. Surface pressure falls ahead of the approaching trough will promote breezy conditions with sustained winds around 15 mph across much of the eastern Great Basin into far western Colorado. Portions of the Snake River Plain in eastern ID, as well as the eastern slopes of the Bitterroot Mountains will see similar wind speeds within a modest downslope flow regime. Gusts between 20-25 mph will support transient critical fire weather conditions across both regions. ..Moore.. 08/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more