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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...Synopsis... The strong ridge over the western US is expected to continue to break down under the shortwave trough passing through the northern Rockies. This will support continued advection of monsoon moisture northward into the Great Basin and parts of southern California. By Thursday afternoon, PWAT values are likely to be between 0.5-0.8" with a dry sub-cloud layer and steep low-level lapse rates. Despite slower storm motions and isolated coverage over Utah and parts of Nevada, little wetting rainfall is expected. This should support isolated dry thunderstorm potential the under the upper high and into portions of eastern Idaho and western Wyoming. With dry fuels in place, some lightning ignitions are possible. In addition to the potential for thunderstorms, very warm and unstable conditions are expected on the periphery of the deeper monsoon moisture surge over parts of the southern Great Basin and southern California. Steep mid-level lapse rates and marginal buoyancy will support unstable conditions over much of the Southwest. This could support plume dominated fire growth and pyroconvection near large active fires, with localized extreme fire behavior possible. ..Lyons.. 08/20/2025 ...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 0157 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...Synopsis... The strong ridge over the western US is expected to continue to break down under the shortwave trough passing through the northern Rockies. This will support continued advection of monsoon moisture northward into the Great Basin and parts of southern California. By Thursday afternoon, PWAT values are likely to be between 0.5-0.8" with a dry sub-cloud layer and steep low-level lapse rates. Despite slower storm motions and isolated coverage over Utah and parts of Nevada, little wetting rainfall is expected. This should support isolated dry thunderstorm potential the under the upper high and into portions of eastern Idaho and western Wyoming. With dry fuels in place, some lightning ignitions are possible. In addition to the potential for thunderstorms, very warm and unstable conditions are expected on the periphery of the deeper monsoon moisture surge over parts of the southern Great Basin and southern California. Steep mid-level lapse rates and marginal buoyancy will support unstable conditions over much of the Southwest. This could support plume dominated fire growth and pyroconvection near large active fires, with localized extreme fire behavior possible. ..Lyons.. 08/20/2025 ...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 0157 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...Synopsis... The strong ridge over the western US is expected to continue to break down under the shortwave trough passing through the northern Rockies. This will support continued advection of monsoon moisture northward into the Great Basin and parts of southern California. By Thursday afternoon, PWAT values are likely to be between 0.5-0.8" with a dry sub-cloud layer and steep low-level lapse rates. Despite slower storm motions and isolated coverage over Utah and parts of Nevada, little wetting rainfall is expected. This should support isolated dry thunderstorm potential the under the upper high and into portions of eastern Idaho and western Wyoming. With dry fuels in place, some lightning ignitions are possible. In addition to the potential for thunderstorms, very warm and unstable conditions are expected on the periphery of the deeper monsoon moisture surge over parts of the southern Great Basin and southern California. Steep mid-level lapse rates and marginal buoyancy will support unstable conditions over much of the Southwest. This could support plume dominated fire growth and pyroconvection near large active fires, with localized extreme fire behavior possible. ..Lyons.. 08/20/2025 ...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 0156 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...Synopsis... A strong ridge of high pressure building over the central US is forecast to gradually move west while a weak trough on the western edge, suppresses the northern extent. The increasingly strong height gradient along the western periphery of the ridge will bolster mid-level winds aloft over the Northwest and northern Great Basin. At the surface, a cold front will move into the western Great Basin before stalling this afternoon. The front, and increased flow aloft will support gusty surface winds and isolated storms, increasing fire danger today and tonight. ...Great Basin... Several hours of dry/breezy conditions are expected this afternoon with the breakdown of the upper-level ridge. Very warm temperatures are expected, supporting deep vertical mixing and low boundary-layer RH. West/southwesterly winds of 15-20 mph with gusts of 20-30 mph near the front, and RH below 15% on a widespread basis will support elevated to locally critical fire-weather conditions from southern ID into the Great Basin. Increased southwesterly flow aloft on the western edge of the ridge will help monsoon moisture (PWATs 0.6-0.8 inches) advect northward over NV and western UT. The surface cold front associated with the upper trough will stall over the western Great Basin, serving as a focus for isolated thunderstorm development through the afternoon. Uncertainty remains high regarding coverage of thunderstorms, especially with southern extent. While moisture and instability will be more limited, enough instability and forcing are expected to produce isolated high-based showers and thunderstorms capable of dry lightning. Should these storms develop they may track eastward, persisting overnight into eastern ID and western MT with a continued threat for dry strikes. Additionally, any active large wildfires may have increased chances of deep pyroconvection/localized extreme fire behavior given the steep lapse rates and unstable troposphere. ..Lyons.. 08/20/2025 ...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 0156 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...Synopsis... A strong ridge of high pressure building over the central US is forecast to gradually move west while a weak trough on the western edge, suppresses the northern extent. The increasingly strong height gradient along the western periphery of the ridge will bolster mid-level winds aloft over the Northwest and northern Great Basin. At the surface, a cold front will move into the western Great Basin before stalling this afternoon. The front, and increased flow aloft will support gusty surface winds and isolated storms, increasing fire danger today and tonight. ...Great Basin... Several hours of dry/breezy conditions are expected this afternoon with the breakdown of the upper-level ridge. Very warm temperatures are expected, supporting deep vertical mixing and low boundary-layer RH. West/southwesterly winds of 15-20 mph with gusts of 20-30 mph near the front, and RH below 15% on a widespread basis will support elevated to locally critical fire-weather conditions from southern ID into the Great Basin. Increased southwesterly flow aloft on the western edge of the ridge will help monsoon moisture (PWATs 0.6-0.8 inches) advect northward over NV and western UT. The surface cold front associated with the upper trough will stall over the western Great Basin, serving as a focus for isolated thunderstorm development through the afternoon. Uncertainty remains high regarding coverage of thunderstorms, especially with southern extent. While moisture and instability will be more limited, enough instability and forcing are expected to produce isolated high-based showers and thunderstorms capable of dry lightning. Should these storms develop they may track eastward, persisting overnight into eastern ID and western MT with a continued threat for dry strikes. Additionally, any active large wildfires may have increased chances of deep pyroconvection/localized extreme fire behavior given the steep lapse rates and unstable troposphere. ..Lyons.. 08/20/2025 ...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 0156 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...Synopsis... A strong ridge of high pressure building over the central US is forecast to gradually move west while a weak trough on the western edge, suppresses the northern extent. The increasingly strong height gradient along the western periphery of the ridge will bolster mid-level winds aloft over the Northwest and northern Great Basin. At the surface, a cold front will move into the western Great Basin before stalling this afternoon. The front, and increased flow aloft will support gusty surface winds and isolated storms, increasing fire danger today and tonight. ...Great Basin... Several hours of dry/breezy conditions are expected this afternoon with the breakdown of the upper-level ridge. Very warm temperatures are expected, supporting deep vertical mixing and low boundary-layer RH. West/southwesterly winds of 15-20 mph with gusts of 20-30 mph near the front, and RH below 15% on a widespread basis will support elevated to locally critical fire-weather conditions from southern ID into the Great Basin. Increased southwesterly flow aloft on the western edge of the ridge will help monsoon moisture (PWATs 0.6-0.8 inches) advect northward over NV and western UT. The surface cold front associated with the upper trough will stall over the western Great Basin, serving as a focus for isolated thunderstorm development through the afternoon. Uncertainty remains high regarding coverage of thunderstorms, especially with southern extent. While moisture and instability will be more limited, enough instability and forcing are expected to produce isolated high-based showers and thunderstorms capable of dry lightning. Should these storms develop they may track eastward, persisting overnight into eastern ID and western MT with a continued threat for dry strikes. Additionally, any active large wildfires may have increased chances of deep pyroconvection/localized extreme fire behavior given the steep lapse rates and unstable troposphere. ..Lyons.. 08/20/2025 ...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 0156 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...Synopsis... A strong ridge of high pressure building over the central US is forecast to gradually move west while a weak trough on the western edge, suppresses the northern extent. The increasingly strong height gradient along the western periphery of the ridge will bolster mid-level winds aloft over the Northwest and northern Great Basin. At the surface, a cold front will move into the western Great Basin before stalling this afternoon. The front, and increased flow aloft will support gusty surface winds and isolated storms, increasing fire danger today and tonight. ...Great Basin... Several hours of dry/breezy conditions are expected this afternoon with the breakdown of the upper-level ridge. Very warm temperatures are expected, supporting deep vertical mixing and low boundary-layer RH. West/southwesterly winds of 15-20 mph with gusts of 20-30 mph near the front, and RH below 15% on a widespread basis will support elevated to locally critical fire-weather conditions from southern ID into the Great Basin. Increased southwesterly flow aloft on the western edge of the ridge will help monsoon moisture (PWATs 0.6-0.8 inches) advect northward over NV and western UT. The surface cold front associated with the upper trough will stall over the western Great Basin, serving as a focus for isolated thunderstorm development through the afternoon. Uncertainty remains high regarding coverage of thunderstorms, especially with southern extent. While moisture and instability will be more limited, enough instability and forcing are expected to produce isolated high-based showers and thunderstorms capable of dry lightning. Should these storms develop they may track eastward, persisting overnight into eastern ID and western MT with a continued threat for dry strikes. Additionally, any active large wildfires may have increased chances of deep pyroconvection/localized extreme fire behavior given the steep lapse rates and unstable troposphere. ..Lyons.. 08/20/2025 ...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 0156 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...Synopsis... A strong ridge of high pressure building over the central US is forecast to gradually move west while a weak trough on the western edge, suppresses the northern extent. The increasingly strong height gradient along the western periphery of the ridge will bolster mid-level winds aloft over the Northwest and northern Great Basin. At the surface, a cold front will move into the western Great Basin before stalling this afternoon. The front, and increased flow aloft will support gusty surface winds and isolated storms, increasing fire danger today and tonight. ...Great Basin... Several hours of dry/breezy conditions are expected this afternoon with the breakdown of the upper-level ridge. Very warm temperatures are expected, supporting deep vertical mixing and low boundary-layer RH. West/southwesterly winds of 15-20 mph with gusts of 20-30 mph near the front, and RH below 15% on a widespread basis will support elevated to locally critical fire-weather conditions from southern ID into the Great Basin. Increased southwesterly flow aloft on the western edge of the ridge will help monsoon moisture (PWATs 0.6-0.8 inches) advect northward over NV and western UT. The surface cold front associated with the upper trough will stall over the western Great Basin, serving as a focus for isolated thunderstorm development through the afternoon. Uncertainty remains high regarding coverage of thunderstorms, especially with southern extent. While moisture and instability will be more limited, enough instability and forcing are expected to produce isolated high-based showers and thunderstorms capable of dry lightning. Should these storms develop they may track eastward, persisting overnight into eastern ID and western MT with a continued threat for dry strikes. Additionally, any active large wildfires may have increased chances of deep pyroconvection/localized extreme fire behavior given the steep lapse rates and unstable troposphere. ..Lyons.. 08/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE CENTRAL/EASTERN DAKOTAS INTO PARTS OF MINNESOTA... ...SUMMARY... An isolated severe threat is expected to develop Thursday into Thursday night over parts of the Dakotas into Minnesota, with severe gusts and hail possible. ...Northern Plains into parts of MN... A mid/upper-level shortwave trough is forecast to evolve into a deep-layer cyclone as it moves eastward across parts of the Canadian Prairies on Thursday. A trailing cold front will move through the Dakotas and northwest MN, with a weak frontal wave potentially developing across SD. Diurnal heating of a relatively moist airmass will result in moderate to locally strong destabilization by late afternoon. An embedded mid/upper-level shortwave trough and associated remnant convection is expected to move across MB/ND and northern MN early in the day. In the wake of this shortwave, large-scale ascent is expected to be generally weak until later Thursday night, resulting in uncertainty regarding afternoon/evening storm development. Isolated storm development cannot be ruled out near the front, and potentially near the weak surface low across SD. An increase in storm coverage is expected late Thursday night, as somewhat stronger midlevel height falls and upper-level difluence overspread the region. The strongest mid/upper-level flow will tend to lag behind the front, but deep-layer shear will still be sufficient for some storm organization, including conditional supercell potential. The Marginal Risk has been maintained with this outlook, but greater severe probabilities may eventually be needed, depending on trends regarding storm coverage and timing from parts of the Dakotas into northwest MN. Other strong storms may develop Thursday night across parts of the northern High Plains, within a favorably sheared post-frontal regime. Severe probabilities may eventually need to be expanded westward, if confidence increases in a favored post-frontal corridor. ...Coastal NC... The center of Hurricane Erin is forecast by NHC to remain well offshore of coastal NC on Thursday as it begins moving northeastward. However, the western periphery of Erin's large wind field will result in rather strong deep-layer northerly flow across the Outer Banks and vicinity. If modest diurnal heating can occur, then showers and possibly a few weak storms may develop during the afternoon, though it is uncertain if any such development would be sufficiently vigorous to support convectively augmented gusts. ...Parts of the Southeast/southern Appalachians... Scattered thunderstorms are forecast to develop across parts of the Southeast and southern Appalachians vicinity Thursday afternoon. Deep-layer shear will remain quite weak, but northerly low-midlevel flow may support one or more southward-moving clusters. Poor midlevel lapse rates will tend to limit updraft intensity, and the organized severe threat appears low, but localized tree damage could accompany these storms during the afternoon and early evening. ...Arizona... Thunderstorms are expected to develop Thursday afternoon and evening across parts of AZ, initially near the higher terrain. Isolated strong gusts could accompany these storms. With an amplified upper-level ridge anchored near the Four Corners, midlevel flow will generally be easterly across central/southern AZ. The easterly steering flow and a very hot and well-mixed environment could support a threat of strong outflow gusts into the lower elevations, though it is uncertain if storm coverage will be sufficient for larger-scale outflow development and more than very isolated damaging-wind potential. ..Dean.. 08/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE CENTRAL/EASTERN DAKOTAS INTO PARTS OF MINNESOTA... ...SUMMARY... An isolated severe threat is expected to develop Thursday into Thursday night over parts of the Dakotas into Minnesota, with severe gusts and hail possible. ...Northern Plains into parts of MN... A mid/upper-level shortwave trough is forecast to evolve into a deep-layer cyclone as it moves eastward across parts of the Canadian Prairies on Thursday. A trailing cold front will move through the Dakotas and northwest MN, with a weak frontal wave potentially developing across SD. Diurnal heating of a relatively moist airmass will result in moderate to locally strong destabilization by late afternoon. An embedded mid/upper-level shortwave trough and associated remnant convection is expected to move across MB/ND and northern MN early in the day. In the wake of this shortwave, large-scale ascent is expected to be generally weak until later Thursday night, resulting in uncertainty regarding afternoon/evening storm development. Isolated storm development cannot be ruled out near the front, and potentially near the weak surface low across SD. An increase in storm coverage is expected late Thursday night, as somewhat stronger midlevel height falls and upper-level difluence overspread the region. The strongest mid/upper-level flow will tend to lag behind the front, but deep-layer shear will still be sufficient for some storm organization, including conditional supercell potential. The Marginal Risk has been maintained with this outlook, but greater severe probabilities may eventually be needed, depending on trends regarding storm coverage and timing from parts of the Dakotas into northwest MN. Other strong storms may develop Thursday night across parts of the northern High Plains, within a favorably sheared post-frontal regime. Severe probabilities may eventually need to be expanded westward, if confidence increases in a favored post-frontal corridor. ...Coastal NC... The center of Hurricane Erin is forecast by NHC to remain well offshore of coastal NC on Thursday as it begins moving northeastward. However, the western periphery of Erin's large wind field will result in rather strong deep-layer northerly flow across the Outer Banks and vicinity. If modest diurnal heating can occur, then showers and possibly a few weak storms may develop during the afternoon, though it is uncertain if any such development would be sufficiently vigorous to support convectively augmented gusts. ...Parts of the Southeast/southern Appalachians... Scattered thunderstorms are forecast to develop across parts of the Southeast and southern Appalachians vicinity Thursday afternoon. Deep-layer shear will remain quite weak, but northerly low-midlevel flow may support one or more southward-moving clusters. Poor midlevel lapse rates will tend to limit updraft intensity, and the organized severe threat appears low, but localized tree damage could accompany these storms during the afternoon and early evening. ...Arizona... Thunderstorms are expected to develop Thursday afternoon and evening across parts of AZ, initially near the higher terrain. Isolated strong gusts could accompany these storms. With an amplified upper-level ridge anchored near the Four Corners, midlevel flow will generally be easterly across central/southern AZ. The easterly steering flow and a very hot and well-mixed environment could support a threat of strong outflow gusts into the lower elevations, though it is uncertain if storm coverage will be sufficient for larger-scale outflow development and more than very isolated damaging-wind potential. ..Dean.. 08/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE CENTRAL/EASTERN DAKOTAS INTO PARTS OF MINNESOTA... ...SUMMARY... An isolated severe threat is expected to develop Thursday into Thursday night over parts of the Dakotas into Minnesota, with severe gusts and hail possible. ...Northern Plains into parts of MN... A mid/upper-level shortwave trough is forecast to evolve into a deep-layer cyclone as it moves eastward across parts of the Canadian Prairies on Thursday. A trailing cold front will move through the Dakotas and northwest MN, with a weak frontal wave potentially developing across SD. Diurnal heating of a relatively moist airmass will result in moderate to locally strong destabilization by late afternoon. An embedded mid/upper-level shortwave trough and associated remnant convection is expected to move across MB/ND and northern MN early in the day. In the wake of this shortwave, large-scale ascent is expected to be generally weak until later Thursday night, resulting in uncertainty regarding afternoon/evening storm development. Isolated storm development cannot be ruled out near the front, and potentially near the weak surface low across SD. An increase in storm coverage is expected late Thursday night, as somewhat stronger midlevel height falls and upper-level difluence overspread the region. The strongest mid/upper-level flow will tend to lag behind the front, but deep-layer shear will still be sufficient for some storm organization, including conditional supercell potential. The Marginal Risk has been maintained with this outlook, but greater severe probabilities may eventually be needed, depending on trends regarding storm coverage and timing from parts of the Dakotas into northwest MN. Other strong storms may develop Thursday night across parts of the northern High Plains, within a favorably sheared post-frontal regime. Severe probabilities may eventually need to be expanded westward, if confidence increases in a favored post-frontal corridor. ...Coastal NC... The center of Hurricane Erin is forecast by NHC to remain well offshore of coastal NC on Thursday as it begins moving northeastward. However, the western periphery of Erin's large wind field will result in rather strong deep-layer northerly flow across the Outer Banks and vicinity. If modest diurnal heating can occur, then showers and possibly a few weak storms may develop during the afternoon, though it is uncertain if any such development would be sufficiently vigorous to support convectively augmented gusts. ...Parts of the Southeast/southern Appalachians... Scattered thunderstorms are forecast to develop across parts of the Southeast and southern Appalachians vicinity Thursday afternoon. Deep-layer shear will remain quite weak, but northerly low-midlevel flow may support one or more southward-moving clusters. Poor midlevel lapse rates will tend to limit updraft intensity, and the organized severe threat appears low, but localized tree damage could accompany these storms during the afternoon and early evening. ...Arizona... Thunderstorms are expected to develop Thursday afternoon and evening across parts of AZ, initially near the higher terrain. Isolated strong gusts could accompany these storms. With an amplified upper-level ridge anchored near the Four Corners, midlevel flow will generally be easterly across central/southern AZ. The easterly steering flow and a very hot and well-mixed environment could support a threat of strong outflow gusts into the lower elevations, though it is uncertain if storm coverage will be sufficient for larger-scale outflow development and more than very isolated damaging-wind potential. ..Dean.. 08/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE CENTRAL/EASTERN DAKOTAS INTO PARTS OF MINNESOTA... ...SUMMARY... An isolated severe threat is expected to develop Thursday into Thursday night over parts of the Dakotas into Minnesota, with severe gusts and hail possible. ...Northern Plains into parts of MN... A mid/upper-level shortwave trough is forecast to evolve into a deep-layer cyclone as it moves eastward across parts of the Canadian Prairies on Thursday. A trailing cold front will move through the Dakotas and northwest MN, with a weak frontal wave potentially developing across SD. Diurnal heating of a relatively moist airmass will result in moderate to locally strong destabilization by late afternoon. An embedded mid/upper-level shortwave trough and associated remnant convection is expected to move across MB/ND and northern MN early in the day. In the wake of this shortwave, large-scale ascent is expected to be generally weak until later Thursday night, resulting in uncertainty regarding afternoon/evening storm development. Isolated storm development cannot be ruled out near the front, and potentially near the weak surface low across SD. An increase in storm coverage is expected late Thursday night, as somewhat stronger midlevel height falls and upper-level difluence overspread the region. The strongest mid/upper-level flow will tend to lag behind the front, but deep-layer shear will still be sufficient for some storm organization, including conditional supercell potential. The Marginal Risk has been maintained with this outlook, but greater severe probabilities may eventually be needed, depending on trends regarding storm coverage and timing from parts of the Dakotas into northwest MN. Other strong storms may develop Thursday night across parts of the northern High Plains, within a favorably sheared post-frontal regime. Severe probabilities may eventually need to be expanded westward, if confidence increases in a favored post-frontal corridor. ...Coastal NC... The center of Hurricane Erin is forecast by NHC to remain well offshore of coastal NC on Thursday as it begins moving northeastward. However, the western periphery of Erin's large wind field will result in rather strong deep-layer northerly flow across the Outer Banks and vicinity. If modest diurnal heating can occur, then showers and possibly a few weak storms may develop during the afternoon, though it is uncertain if any such development would be sufficiently vigorous to support convectively augmented gusts. ...Parts of the Southeast/southern Appalachians... Scattered thunderstorms are forecast to develop across parts of the Southeast and southern Appalachians vicinity Thursday afternoon. Deep-layer shear will remain quite weak, but northerly low-midlevel flow may support one or more southward-moving clusters. Poor midlevel lapse rates will tend to limit updraft intensity, and the organized severe threat appears low, but localized tree damage could accompany these storms during the afternoon and early evening. ...Arizona... Thunderstorms are expected to develop Thursday afternoon and evening across parts of AZ, initially near the higher terrain. Isolated strong gusts could accompany these storms. With an amplified upper-level ridge anchored near the Four Corners, midlevel flow will generally be easterly across central/southern AZ. The easterly steering flow and a very hot and well-mixed environment could support a threat of strong outflow gusts into the lower elevations, though it is uncertain if storm coverage will be sufficient for larger-scale outflow development and more than very isolated damaging-wind potential. ..Dean.. 08/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Wed Aug 20 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE CENTRAL/EASTERN DAKOTAS INTO PARTS OF MINNESOTA... ...SUMMARY... An isolated severe threat is expected to develop Thursday into Thursday night over parts of the Dakotas into Minnesota, with severe gusts and hail possible. ...Northern Plains into parts of MN... A mid/upper-level shortwave trough is forecast to evolve into a deep-layer cyclone as it moves eastward across parts of the Canadian Prairies on Thursday. A trailing cold front will move through the Dakotas and northwest MN, with a weak frontal wave potentially developing across SD. Diurnal heating of a relatively moist airmass will result in moderate to locally strong destabilization by late afternoon. An embedded mid/upper-level shortwave trough and associated remnant convection is expected to move across MB/ND and northern MN early in the day. In the wake of this shortwave, large-scale ascent is expected to be generally weak until later Thursday night, resulting in uncertainty regarding afternoon/evening storm development. Isolated storm development cannot be ruled out near the front, and potentially near the weak surface low across SD. An increase in storm coverage is expected late Thursday night, as somewhat stronger midlevel height falls and upper-level difluence overspread the region. The strongest mid/upper-level flow will tend to lag behind the front, but deep-layer shear will still be sufficient for some storm organization, including conditional supercell potential. The Marginal Risk has been maintained with this outlook, but greater severe probabilities may eventually be needed, depending on trends regarding storm coverage and timing from parts of the Dakotas into northwest MN. Other strong storms may develop Thursday night across parts of the northern High Plains, within a favorably sheared post-frontal regime. Severe probabilities may eventually need to be expanded westward, if confidence increases in a favored post-frontal corridor. ...Coastal NC... The center of Hurricane Erin is forecast by NHC to remain well offshore of coastal NC on Thursday as it begins moving northeastward. However, the western periphery of Erin's large wind field will result in rather strong deep-layer northerly flow across the Outer Banks and vicinity. If modest diurnal heating can occur, then showers and possibly a few weak storms may develop during the afternoon, though it is uncertain if any such development would be sufficiently vigorous to support convectively augmented gusts. ...Parts of the Southeast/southern Appalachians... Scattered thunderstorms are forecast to develop across parts of the Southeast and southern Appalachians vicinity Thursday afternoon. Deep-layer shear will remain quite weak, but northerly low-midlevel flow may support one or more southward-moving clusters. Poor midlevel lapse rates will tend to limit updraft intensity, and the organized severe threat appears low, but localized tree damage could accompany these storms during the afternoon and early evening. ...Arizona... Thunderstorms are expected to develop Thursday afternoon and evening across parts of AZ, initially near the higher terrain. Isolated strong gusts could accompany these storms. With an amplified upper-level ridge anchored near the Four Corners, midlevel flow will generally be easterly across central/southern AZ. The easterly steering flow and a very hot and well-mixed environment could support a threat of strong outflow gusts into the lower elevations, though it is uncertain if storm coverage will be sufficient for larger-scale outflow development and more than very isolated damaging-wind potential. ..Dean.. 08/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY ACROSS THE WESTERN AND CENTRAL GULF COAST STATES AND THE INTERNATIONAL BORDER VICINITY OF NORTH DAKOTA... ...SUMMARY... Scattered thunderstorms developing this afternoon and evening across the western and central Gulf Coast states may pose a risk for localized potentially damaging wind gusts. Otherwise, there appears some risk for an isolated severe thunderstorm or two across parts of northern North Dakota. ...Discussion... Models indicate that a prominent mid/upper high will be maintained over the Four Corners vicinity through this period. However, initially amplified ridging extending to its north, as far as the Canadian Prairies, appears likely to become suppressed southeastward toward the central international border vicinity, as a significant short wave perturbation progresses east of the Canadian Rockies into Prairies by late tonight. It appears that this may be accompanied by weak cyclogenesis across southern Saskatchewan toward the central Saskatchewan/Manitoba border vicinity, with a trailing cold front advancing across the Montana international border by late tonight. At the same time, an increasingly sheared perturbation will continue progressing through weak larger-scale mid-level troughing digging across the Northeast, and southeastward around the periphery of the high, across the Ohio/Tennessee Valleys and southern Great Plains. To the southeast of this feature, Hurricane Erin is forecast to turn slowly north-northeastward, offshore of the southern through middle Atlantic Seaboard. ...Gulf Coast States... A diffuse surface frontal zone, reinforced in segments by convective outflow, will continue slowly southward ahead of the mid-level shear axis, likely reaching portions of central Texas through Louisiana and central/northern Mississippi and Alabama by mid to late afternoon. Along and ahead of this front, a corridor of stronger heating of a seasonably moist boundary layer, perhaps still coincident with a residual plume of relatively steep lower/mid-tropospheric lapse rates, may continue to contribute to thermodynamic profiles supportive of localized downbursts and gusty winds on convectively generated surface cold pools. It is not clear that the severe threat will be any more widespread than the sparse coverage of preceding days, but it may perhaps be marginally sufficient to justify 5 percent severe wind probabilities. ...North Dakota... Models indicate that a narrow corridor of moderate to large potential instability may develop along/ahead of the surface cold front, a pre-frontal surface trough and developing warm frontal zone across parts of the Dakotas into eastern Saskatchewan by late this afternoon. However, beneath the nose of a plume of warm and capping elevated mixed-layer air, mid/upper support for the initiation of boundary-layer based thunderstorm development is forecast to generally remain to the north of the international border. While the risk for severe thunderstorms appears largely conditional, guidance does indicate that a weak surface low may develop within the pre-frontal troughing and provide a potential focus for convective development across northwestern North Dakota late this afternoon and evening. If this forcing, coupled with the approach of convective temperatures, is sufficient to overcome the mid-level inhibition, forecast soundings indicate the environment will be conducive to supercell development. ..Kerr/Lyons.. 08/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY ACROSS THE WESTERN AND CENTRAL GULF COAST STATES AND THE INTERNATIONAL BORDER VICINITY OF NORTH DAKOTA... ...SUMMARY... Scattered thunderstorms developing this afternoon and evening across the western and central Gulf Coast states may pose a risk for localized potentially damaging wind gusts. Otherwise, there appears some risk for an isolated severe thunderstorm or two across parts of northern North Dakota. ...Discussion... Models indicate that a prominent mid/upper high will be maintained over the Four Corners vicinity through this period. However, initially amplified ridging extending to its north, as far as the Canadian Prairies, appears likely to become suppressed southeastward toward the central international border vicinity, as a significant short wave perturbation progresses east of the Canadian Rockies into Prairies by late tonight. It appears that this may be accompanied by weak cyclogenesis across southern Saskatchewan toward the central Saskatchewan/Manitoba border vicinity, with a trailing cold front advancing across the Montana international border by late tonight. At the same time, an increasingly sheared perturbation will continue progressing through weak larger-scale mid-level troughing digging across the Northeast, and southeastward around the periphery of the high, across the Ohio/Tennessee Valleys and southern Great Plains. To the southeast of this feature, Hurricane Erin is forecast to turn slowly north-northeastward, offshore of the southern through middle Atlantic Seaboard. ...Gulf Coast States... A diffuse surface frontal zone, reinforced in segments by convective outflow, will continue slowly southward ahead of the mid-level shear axis, likely reaching portions of central Texas through Louisiana and central/northern Mississippi and Alabama by mid to late afternoon. Along and ahead of this front, a corridor of stronger heating of a seasonably moist boundary layer, perhaps still coincident with a residual plume of relatively steep lower/mid-tropospheric lapse rates, may continue to contribute to thermodynamic profiles supportive of localized downbursts and gusty winds on convectively generated surface cold pools. It is not clear that the severe threat will be any more widespread than the sparse coverage of preceding days, but it may perhaps be marginally sufficient to justify 5 percent severe wind probabilities. ...North Dakota... Models indicate that a narrow corridor of moderate to large potential instability may develop along/ahead of the surface cold front, a pre-frontal surface trough and developing warm frontal zone across parts of the Dakotas into eastern Saskatchewan by late this afternoon. However, beneath the nose of a plume of warm and capping elevated mixed-layer air, mid/upper support for the initiation of boundary-layer based thunderstorm development is forecast to generally remain to the north of the international border. While the risk for severe thunderstorms appears largely conditional, guidance does indicate that a weak surface low may develop within the pre-frontal troughing and provide a potential focus for convective development across northwestern North Dakota late this afternoon and evening. If this forcing, coupled with the approach of convective temperatures, is sufficient to overcome the mid-level inhibition, forecast soundings indicate the environment will be conducive to supercell development. ..Kerr/Lyons.. 08/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY ACROSS THE WESTERN AND CENTRAL GULF COAST STATES AND THE INTERNATIONAL BORDER VICINITY OF NORTH DAKOTA... ...SUMMARY... Scattered thunderstorms developing this afternoon and evening across the western and central Gulf Coast states may pose a risk for localized potentially damaging wind gusts. Otherwise, there appears some risk for an isolated severe thunderstorm or two across parts of northern North Dakota. ...Discussion... Models indicate that a prominent mid/upper high will be maintained over the Four Corners vicinity through this period. However, initially amplified ridging extending to its north, as far as the Canadian Prairies, appears likely to become suppressed southeastward toward the central international border vicinity, as a significant short wave perturbation progresses east of the Canadian Rockies into Prairies by late tonight. It appears that this may be accompanied by weak cyclogenesis across southern Saskatchewan toward the central Saskatchewan/Manitoba border vicinity, with a trailing cold front advancing across the Montana international border by late tonight. At the same time, an increasingly sheared perturbation will continue progressing through weak larger-scale mid-level troughing digging across the Northeast, and southeastward around the periphery of the high, across the Ohio/Tennessee Valleys and southern Great Plains. To the southeast of this feature, Hurricane Erin is forecast to turn slowly north-northeastward, offshore of the southern through middle Atlantic Seaboard. ...Gulf Coast States... A diffuse surface frontal zone, reinforced in segments by convective outflow, will continue slowly southward ahead of the mid-level shear axis, likely reaching portions of central Texas through Louisiana and central/northern Mississippi and Alabama by mid to late afternoon. Along and ahead of this front, a corridor of stronger heating of a seasonably moist boundary layer, perhaps still coincident with a residual plume of relatively steep lower/mid-tropospheric lapse rates, may continue to contribute to thermodynamic profiles supportive of localized downbursts and gusty winds on convectively generated surface cold pools. It is not clear that the severe threat will be any more widespread than the sparse coverage of preceding days, but it may perhaps be marginally sufficient to justify 5 percent severe wind probabilities. ...North Dakota... Models indicate that a narrow corridor of moderate to large potential instability may develop along/ahead of the surface cold front, a pre-frontal surface trough and developing warm frontal zone across parts of the Dakotas into eastern Saskatchewan by late this afternoon. However, beneath the nose of a plume of warm and capping elevated mixed-layer air, mid/upper support for the initiation of boundary-layer based thunderstorm development is forecast to generally remain to the north of the international border. While the risk for severe thunderstorms appears largely conditional, guidance does indicate that a weak surface low may develop within the pre-frontal troughing and provide a potential focus for convective development across northwestern North Dakota late this afternoon and evening. If this forcing, coupled with the approach of convective temperatures, is sufficient to overcome the mid-level inhibition, forecast soundings indicate the environment will be conducive to supercell development. ..Kerr/Lyons.. 08/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY ACROSS THE WESTERN AND CENTRAL GULF COAST STATES AND THE INTERNATIONAL BORDER VICINITY OF NORTH DAKOTA... ...SUMMARY... Scattered thunderstorms developing this afternoon and evening across the western and central Gulf Coast states may pose a risk for localized potentially damaging wind gusts. Otherwise, there appears some risk for an isolated severe thunderstorm or two across parts of northern North Dakota. ...Discussion... Models indicate that a prominent mid/upper high will be maintained over the Four Corners vicinity through this period. However, initially amplified ridging extending to its north, as far as the Canadian Prairies, appears likely to become suppressed southeastward toward the central international border vicinity, as a significant short wave perturbation progresses east of the Canadian Rockies into Prairies by late tonight. It appears that this may be accompanied by weak cyclogenesis across southern Saskatchewan toward the central Saskatchewan/Manitoba border vicinity, with a trailing cold front advancing across the Montana international border by late tonight. At the same time, an increasingly sheared perturbation will continue progressing through weak larger-scale mid-level troughing digging across the Northeast, and southeastward around the periphery of the high, across the Ohio/Tennessee Valleys and southern Great Plains. To the southeast of this feature, Hurricane Erin is forecast to turn slowly north-northeastward, offshore of the southern through middle Atlantic Seaboard. ...Gulf Coast States... A diffuse surface frontal zone, reinforced in segments by convective outflow, will continue slowly southward ahead of the mid-level shear axis, likely reaching portions of central Texas through Louisiana and central/northern Mississippi and Alabama by mid to late afternoon. Along and ahead of this front, a corridor of stronger heating of a seasonably moist boundary layer, perhaps still coincident with a residual plume of relatively steep lower/mid-tropospheric lapse rates, may continue to contribute to thermodynamic profiles supportive of localized downbursts and gusty winds on convectively generated surface cold pools. It is not clear that the severe threat will be any more widespread than the sparse coverage of preceding days, but it may perhaps be marginally sufficient to justify 5 percent severe wind probabilities. ...North Dakota... Models indicate that a narrow corridor of moderate to large potential instability may develop along/ahead of the surface cold front, a pre-frontal surface trough and developing warm frontal zone across parts of the Dakotas into eastern Saskatchewan by late this afternoon. However, beneath the nose of a plume of warm and capping elevated mixed-layer air, mid/upper support for the initiation of boundary-layer based thunderstorm development is forecast to generally remain to the north of the international border. While the risk for severe thunderstorms appears largely conditional, guidance does indicate that a weak surface low may develop within the pre-frontal troughing and provide a potential focus for convective development across northwestern North Dakota late this afternoon and evening. If this forcing, coupled with the approach of convective temperatures, is sufficient to overcome the mid-level inhibition, forecast soundings indicate the environment will be conducive to supercell development. ..Kerr/Lyons.. 08/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Wed Aug 20 2025 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY ACROSS THE WESTERN AND CENTRAL GULF COAST STATES AND THE INTERNATIONAL BORDER VICINITY OF NORTH DAKOTA... ...SUMMARY... Scattered thunderstorms developing this afternoon and evening across the western and central Gulf Coast states may pose a risk for localized potentially damaging wind gusts. Otherwise, there appears some risk for an isolated severe thunderstorm or two across parts of northern North Dakota. ...Discussion... Models indicate that a prominent mid/upper high will be maintained over the Four Corners vicinity through this period. However, initially amplified ridging extending to its north, as far as the Canadian Prairies, appears likely to become suppressed southeastward toward the central international border vicinity, as a significant short wave perturbation progresses east of the Canadian Rockies into Prairies by late tonight. It appears that this may be accompanied by weak cyclogenesis across southern Saskatchewan toward the central Saskatchewan/Manitoba border vicinity, with a trailing cold front advancing across the Montana international border by late tonight. At the same time, an increasingly sheared perturbation will continue progressing through weak larger-scale mid-level troughing digging across the Northeast, and southeastward around the periphery of the high, across the Ohio/Tennessee Valleys and southern Great Plains. To the southeast of this feature, Hurricane Erin is forecast to turn slowly north-northeastward, offshore of the southern through middle Atlantic Seaboard. ...Gulf Coast States... A diffuse surface frontal zone, reinforced in segments by convective outflow, will continue slowly southward ahead of the mid-level shear axis, likely reaching portions of central Texas through Louisiana and central/northern Mississippi and Alabama by mid to late afternoon. Along and ahead of this front, a corridor of stronger heating of a seasonably moist boundary layer, perhaps still coincident with a residual plume of relatively steep lower/mid-tropospheric lapse rates, may continue to contribute to thermodynamic profiles supportive of localized downbursts and gusty winds on convectively generated surface cold pools. It is not clear that the severe threat will be any more widespread than the sparse coverage of preceding days, but it may perhaps be marginally sufficient to justify 5 percent severe wind probabilities. ...North Dakota... Models indicate that a narrow corridor of moderate to large potential instability may develop along/ahead of the surface cold front, a pre-frontal surface trough and developing warm frontal zone across parts of the Dakotas into eastern Saskatchewan by late this afternoon. However, beneath the nose of a plume of warm and capping elevated mixed-layer air, mid/upper support for the initiation of boundary-layer based thunderstorm development is forecast to generally remain to the north of the international border. While the risk for severe thunderstorms appears largely conditional, guidance does indicate that a weak surface low may develop within the pre-frontal troughing and provide a potential focus for convective development across northwestern North Dakota late this afternoon and evening. If this forcing, coupled with the approach of convective temperatures, is sufficient to overcome the mid-level inhibition, forecast soundings indicate the environment will be conducive to supercell development. ..Kerr/Lyons.. 08/20/2025 Read more

000
ABPZ20 KNHC 200511
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Tue Aug 19 2025

For the eastern and central North Pacific east of 180 longitude:

Tropical cyclone formation is not expected during the next 7 days.

$$
Forecaster Gibbs

The Auburn Board of Public Works on Aug. 20 announced the end of the water emergency that had been in effect for about 11 months because wells were slow to recharge. Recent ample rainfall in July and August put groundwater levels back in the normal range. News Channel Nebraska (Grand Island, Neb.), Aug 20, 2025 Improving conditions allowed the Auburn Board of Public Works to exit the stage 3 drought emergency contingency and move to stage 2 restrictions. News Channel Nebraska (Grand Island, Neb.), Aug 1, 2025 Nonessential water use continued to be prohibited in Auburn and Peru since October 2024. The Level 3 Water Emergency does not allow water to be used for lawns or gardening. Auburn gets its water from 10 wells near the Little Nemaha River, which is running low. Peru gets its water from Auburn. KETV Newswatch 7 (Omaha, Neb.), May 7, 2025 Auburn’s water wells, two remaining five feet or below, were thought to be stable and should continue to rise with some spring rain. Many Signals Communications (Holton, Kan.), April 3, 2025 The Auburn Board of Public Works extended its water emergency for Auburn and Peru as well levels remained below normal. Water customers were to use water only for essential activities. News Channel Nebraska (Grand Island), Dec 9, 2024 The Auburn Board of Public Works issued a water warning for Auburn and Peru customers as wells are below normal levels due to drought. News Channel Nebraska (Grand Island, Neb.), Oct 7, 2024