Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Sat Aug 16 2025 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN AND CENTRAL SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA... ...SUMMARY... A small organized cluster of thunderstorms with potential to produce a swath of strong to severe wind gusts still appears possible across parts of the central Dakotas later this evening into the overnight hours. More sporadic strong thunderstorms with potential to produce severe wind and hail are possible in a corridor across the Midwest into Great Lakes vicinity. ...01Z Update... In the wake of a weakening convective perturbation shifting east-southeastward through the Great Lakes region, modest mid-level height rises across eastern portions of the northern Great Plains will gradually overspread the Upper Midwest and adjacent Great Lakes region overnight. In the presence of weak and/or weakening deep-layer shear, and weak mid/upper support for convective development, the probabilities for the evolution of a sustained organized severe storm cluster appear to be lowering. However, weak low-level warm advection to the immediate cool side of convective outflow, and a quasi-stationary frontal zone extending roughly from west-northwest of the Dubuque IA vicinity into the middle Missouri Valley, is forecast to contribute to a corridor of increasing thunderstorm development overnight. Although mid-level profiles appear relatively warm, a plume of dry lower/mid-tropospheric air with steep lapse rates may contribute to a risk for localized strong wind gusts and some hail in sporadic stronger storms. Upstream, across the middle Missouri Valley, as a weak mid-level short wave trough slowly shifts eastward into the western Dakotas, models continue to suggest that associated scattered thunderstorm development may gradually consolidate into an organizing cluster, perhaps aided by lift associated with warm advection on the nose of a strengthening southerly low-level jet. As this occurs, although deep-layer mean wind fields will remain generally weak, modest shear and thermodynamic profiles with steep lower/mid-tropospheric lapse rates and sizable CAPE may contribute to potential for the development of strong to severe wind gusts overnight. ..Kerr.. 08/17/2025 Read more

WW 0596 Status Updates
STATUS REPORT ON WW 596 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WSW JVL TO 30 SE RAC TO 40 WNW BEH. ..LYONS..08/16/25 ATTN...WFO...LOT...DVN...MKX... STATUS REPORT FOR WS 596 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-031-037-043-089-093-097-111-141-177-197-201-170040- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE COOK DE KALB DUPAGE KANE KENDALL LAKE MCHENRY OGLE STEPHENSON WILL WINNEBAGO INC089-127-170040- IN . INDIANA COUNTIES INCLUDED ARE LAKE PORTER LMZ740-741-742-743-744-745-777-779-170040- CW . ADJACENT COASTAL WATERS INCLUDED ARE Read more

MD 1968 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR WESTERN SOUTH DAKOTA
Mesoscale Discussion 1968 NWS Storm Prediction Center Norman OK 0636 PM CDT Sat Aug 16 2025 Areas affected...western South Dakota Concerning...Severe potential...Watch possible Valid 162336Z - 170130Z Probability of Watch Issuance...40 percent SUMMARY...Severe thunderstorm potential will increase this afternoon into the evening. Large hail may be an initial concern, but the primary severe threat should be damaging winds. DISCUSSION...Strong heating of a moist airmass across western South Dakota has resulted in a strongly unstable environment with MUCAPE in excess of 3000 J/kg in areas. Within this environment, thunderstorms are gradually increasing in coverage in response to strengthening large-scale ascent ahead of another shortwave trough moving around the periphery of the southern Plains ridge. Continued southeast-to-east surface winds beneath westerly flow aloft will maintain a sheared (ESHR around 35-40 knots) environment across the region. The combination of a strongly unstable and sheared environment should result in a gradual increase in thunderstorm intensity late this afternoon into the evening. The primary threat will be strong, damaging thunderstorm winds as thunderstorm coverage increases later this evening and thunderstorm outflows congeal ahead of the aforementioned trough. Isolated large to perhaps significant hail may occur with the strongest, more discrete thunderstorms. The need for a severe thunderstorm watch this evening remains somewhat unclear, but may increase this evening into the overnight hours. The most likely onset of more widespread severe potential should be after 9 PM MDT. However, conditions will be monitored through the evening in the event coverage and intensity begins to increase. ..Marsh/Smith.. 08/16/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...BIS...LBF...UNR...BYZ... LAT...LON 42800197 43310375 44510434 45780402 46130352 45920163 45520078 44390047 43250061 42800197 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

WW 0596 Status Updates
STATUS REPORT ON WW 596 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WSW JVL TO 30 SE RAC TO 40 WNW BEH. ..LYONS..08/16/25 ATTN...WFO...LOT...DVN...MKX... STATUS REPORT FOR WS 596 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-031-037-043-089-093-097-111-141-177-197-201-170040- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE COOK DE KALB DUPAGE KANE KENDALL LAKE MCHENRY OGLE STEPHENSON WILL WINNEBAGO INC089-127-170040- IN . INDIANA COUNTIES INCLUDED ARE LAKE PORTER LMZ740-741-742-743-744-745-777-779-170040- CW . ADJACENT COASTAL WATERS INCLUDED ARE Read more

WW 596 SEVERE TSTM IL IN WI LM 161855Z - 170000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 596 NWS Storm Prediction Center Norman OK 155 PM CDT Sat Aug 16 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Illinois Far Northwest Indiana Far Southeast Wisconsin Lake Michigan * Effective this Saturday afternoon and evening from 155 PM until 700 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorm cluster currently ongoing over far southeast WI is expected to continue southeastward through northern IL and northwest IN this afternoon and evening. The airmass in these areas is very unstable and supportive of robust updrafts capable of large hail and damaging gusts. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 40 miles north northeast of Janesville WI to 45 miles west of Valparaiso IN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29030. ...Mosier Read more

No Mesoscale Discussions are in effect as of Sat Aug 16 22:46:11 UTC 2025.

MD 1967 CONCERNING SEVERE THUNDERSTORM WATCH 596... FOR NORTHERN ILLINOIS AND NORTHWEST INDIANA
Mesoscale Discussion 1967 NWS Storm Prediction Center Norman OK 0444 PM CDT Sat Aug 16 2025 Areas affected...northern Illinois and northwest Indiana Concerning...Severe Thunderstorm Watch 596... Valid 162144Z - 162245Z The severe weather threat for Severe Thunderstorm Watch 596 continues. SUMMARY...A cluster of severe storms will move southeastward over the Chicago Metro through the next 1-2 hours. Damaging gusts and some hail are likely. DISCUSSION...As of 2145 UTC, local radar showed a cluster of severe thunderstorms ongoing over portions of northern IL. Over the last half hour, several report of severe wind gusts and 1-1.5 inch hail have occurred with these cells. Continued intensification appears likely as these cells track southeastward at 30 kt along a buoyancy gradient of 3000-4000 J/kg of MLCAPE and local lake breeze boundaries. These cells will continue across the Chicago Metro through the next 1-2 hours with damaging gusts of 60-70 mph and hail up to the size of golf balls likely. As storms exit northern IL into northwest IN, some loss of organization is expected as vertical shear decreases to the south. However, large buoyancy and the strong cold pool should continue to support some severe risk over the next couple of hours. ..Lyons.. 08/16/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...LOT... LAT...LON 42008899 42228784 41938744 41588687 41238688 40968732 40948804 41338867 41368876 42008899 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

WW 0596 Status Updates
STATUS REPORT ON WW 596 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 WSW MSN TO 45 W MKG. ..LYONS..08/16/25 ATTN...WFO...LOT...DVN...MKX... STATUS REPORT FOR WS 596 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-031-037-043-089-093-097-111-141-177-197-201-162340- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE COOK DE KALB DUPAGE KANE KENDALL LAKE MCHENRY OGLE STEPHENSON WILL WINNEBAGO INC089-127-162340- IN . INDIANA COUNTIES INCLUDED ARE LAKE PORTER WIC025-045-049-055-059-065-079-101-105-127-133-162340- WI . WISCONSIN COUNTIES INCLUDED ARE DANE GREEN IOWA Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Aug 16 2025 Valid 181200Z - 241200Z ...Day 3-5/Monday-Wednesday... An expanding and strengthening mid-level ridge over the Four Corners region will bring above normal temperatures but relatively light winds to much of the Intermountain West through the midweek. Mid-level troughing across the Pacific Northwest is expected to begin translating northeastward along the northern periphery of the ridge by Day 5/Wednesday, inviting drier conditions to filter into the Northwestern U.S. Ridge positioning will also usher in a northward surge of elevated monsoon moisture into the Desert Southwest by Day 4/Tuesday and by Day 5/Wednesday across the Eastern Great Basin. A dry boundary layer in place across the Four Corners and Great Basin regions will support limited rainfall from higher terrain convection and thunderstorms. Fuels are expected to remain quite dry and receptive across this region with a particular threat from new lightning ignitions. A 10 percent probability area for dry thunderstorms was introduced for Day 5/Wednesday. Farther north, the mid-level trough could support additional thunderstorms across portions of the central/northern ID and western MT Day 4-5/Tuesday-Wednesday but some uncertainty regarding antecedent rainfall distribution along with marginal fuel dryness precludes introduction of dry thunderstorm probabilities at this time. ...Day 6-8/Thursday-Saturday... Deeper monsoon moisture moving into Great Basin, with PWATs around 1.00 inch as well as rising surface dewpoints/relative humidity, should begin to limit dry lightning potential late in the week across the Great Basin and Four Corners regions with at least some wetting rains expected. Nonetheless, multiple days of higher terrain showers and thunderstorms will expand across much of the Intermountain West late next week. Lighter winds overall are expected under a building ridge over the Western U.S. along with steadily increasing temperatures, particularly across the western coastal states. A thermal trough begins to set up across CA late next week, further drying fuelscapes across the region as temperatures reach into the 100s in valley/interior locations. ..Williams.. 08/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Aug 16 2025 Valid 181200Z - 241200Z ...Day 3-5/Monday-Wednesday... An expanding and strengthening mid-level ridge over the Four Corners region will bring above normal temperatures but relatively light winds to much of the Intermountain West through the midweek. Mid-level troughing across the Pacific Northwest is expected to begin translating northeastward along the northern periphery of the ridge by Day 5/Wednesday, inviting drier conditions to filter into the Northwestern U.S. Ridge positioning will also usher in a northward surge of elevated monsoon moisture into the Desert Southwest by Day 4/Tuesday and by Day 5/Wednesday across the Eastern Great Basin. A dry boundary layer in place across the Four Corners and Great Basin regions will support limited rainfall from higher terrain convection and thunderstorms. Fuels are expected to remain quite dry and receptive across this region with a particular threat from new lightning ignitions. A 10 percent probability area for dry thunderstorms was introduced for Day 5/Wednesday. Farther north, the mid-level trough could support additional thunderstorms across portions of the central/northern ID and western MT Day 4-5/Tuesday-Wednesday but some uncertainty regarding antecedent rainfall distribution along with marginal fuel dryness precludes introduction of dry thunderstorm probabilities at this time. ...Day 6-8/Thursday-Saturday... Deeper monsoon moisture moving into Great Basin, with PWATs around 1.00 inch as well as rising surface dewpoints/relative humidity, should begin to limit dry lightning potential late in the week across the Great Basin and Four Corners regions with at least some wetting rains expected. Nonetheless, multiple days of higher terrain showers and thunderstorms will expand across much of the Intermountain West late next week. Lighter winds overall are expected under a building ridge over the Western U.S. along with steadily increasing temperatures, particularly across the western coastal states. A thermal trough begins to set up across CA late next week, further drying fuelscapes across the region as temperatures reach into the 100s in valley/interior locations. ..Williams.. 08/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Aug 16 2025 Valid 181200Z - 241200Z ...Day 3-5/Monday-Wednesday... An expanding and strengthening mid-level ridge over the Four Corners region will bring above normal temperatures but relatively light winds to much of the Intermountain West through the midweek. Mid-level troughing across the Pacific Northwest is expected to begin translating northeastward along the northern periphery of the ridge by Day 5/Wednesday, inviting drier conditions to filter into the Northwestern U.S. Ridge positioning will also usher in a northward surge of elevated monsoon moisture into the Desert Southwest by Day 4/Tuesday and by Day 5/Wednesday across the Eastern Great Basin. A dry boundary layer in place across the Four Corners and Great Basin regions will support limited rainfall from higher terrain convection and thunderstorms. Fuels are expected to remain quite dry and receptive across this region with a particular threat from new lightning ignitions. A 10 percent probability area for dry thunderstorms was introduced for Day 5/Wednesday. Farther north, the mid-level trough could support additional thunderstorms across portions of the central/northern ID and western MT Day 4-5/Tuesday-Wednesday but some uncertainty regarding antecedent rainfall distribution along with marginal fuel dryness precludes introduction of dry thunderstorm probabilities at this time. ...Day 6-8/Thursday-Saturday... Deeper monsoon moisture moving into Great Basin, with PWATs around 1.00 inch as well as rising surface dewpoints/relative humidity, should begin to limit dry lightning potential late in the week across the Great Basin and Four Corners regions with at least some wetting rains expected. Nonetheless, multiple days of higher terrain showers and thunderstorms will expand across much of the Intermountain West late next week. Lighter winds overall are expected under a building ridge over the Western U.S. along with steadily increasing temperatures, particularly across the western coastal states. A thermal trough begins to set up across CA late next week, further drying fuelscapes across the region as temperatures reach into the 100s in valley/interior locations. ..Williams.. 08/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Aug 16 2025 Valid 181200Z - 241200Z ...Day 3-5/Monday-Wednesday... An expanding and strengthening mid-level ridge over the Four Corners region will bring above normal temperatures but relatively light winds to much of the Intermountain West through the midweek. Mid-level troughing across the Pacific Northwest is expected to begin translating northeastward along the northern periphery of the ridge by Day 5/Wednesday, inviting drier conditions to filter into the Northwestern U.S. Ridge positioning will also usher in a northward surge of elevated monsoon moisture into the Desert Southwest by Day 4/Tuesday and by Day 5/Wednesday across the Eastern Great Basin. A dry boundary layer in place across the Four Corners and Great Basin regions will support limited rainfall from higher terrain convection and thunderstorms. Fuels are expected to remain quite dry and receptive across this region with a particular threat from new lightning ignitions. A 10 percent probability area for dry thunderstorms was introduced for Day 5/Wednesday. Farther north, the mid-level trough could support additional thunderstorms across portions of the central/northern ID and western MT Day 4-5/Tuesday-Wednesday but some uncertainty regarding antecedent rainfall distribution along with marginal fuel dryness precludes introduction of dry thunderstorm probabilities at this time. ...Day 6-8/Thursday-Saturday... Deeper monsoon moisture moving into Great Basin, with PWATs around 1.00 inch as well as rising surface dewpoints/relative humidity, should begin to limit dry lightning potential late in the week across the Great Basin and Four Corners regions with at least some wetting rains expected. Nonetheless, multiple days of higher terrain showers and thunderstorms will expand across much of the Intermountain West late next week. Lighter winds overall are expected under a building ridge over the Western U.S. along with steadily increasing temperatures, particularly across the western coastal states. A thermal trough begins to set up across CA late next week, further drying fuelscapes across the region as temperatures reach into the 100s in valley/interior locations. ..Williams.. 08/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Aug 16 2025 Valid 181200Z - 241200Z ...Day 3-5/Monday-Wednesday... An expanding and strengthening mid-level ridge over the Four Corners region will bring above normal temperatures but relatively light winds to much of the Intermountain West through the midweek. Mid-level troughing across the Pacific Northwest is expected to begin translating northeastward along the northern periphery of the ridge by Day 5/Wednesday, inviting drier conditions to filter into the Northwestern U.S. Ridge positioning will also usher in a northward surge of elevated monsoon moisture into the Desert Southwest by Day 4/Tuesday and by Day 5/Wednesday across the Eastern Great Basin. A dry boundary layer in place across the Four Corners and Great Basin regions will support limited rainfall from higher terrain convection and thunderstorms. Fuels are expected to remain quite dry and receptive across this region with a particular threat from new lightning ignitions. A 10 percent probability area for dry thunderstorms was introduced for Day 5/Wednesday. Farther north, the mid-level trough could support additional thunderstorms across portions of the central/northern ID and western MT Day 4-5/Tuesday-Wednesday but some uncertainty regarding antecedent rainfall distribution along with marginal fuel dryness precludes introduction of dry thunderstorm probabilities at this time. ...Day 6-8/Thursday-Saturday... Deeper monsoon moisture moving into Great Basin, with PWATs around 1.00 inch as well as rising surface dewpoints/relative humidity, should begin to limit dry lightning potential late in the week across the Great Basin and Four Corners regions with at least some wetting rains expected. Nonetheless, multiple days of higher terrain showers and thunderstorms will expand across much of the Intermountain West late next week. Lighter winds overall are expected under a building ridge over the Western U.S. along with steadily increasing temperatures, particularly across the western coastal states. A thermal trough begins to set up across CA late next week, further drying fuelscapes across the region as temperatures reach into the 100s in valley/interior locations. ..Williams.. 08/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Aug 16 2025 Valid 181200Z - 241200Z ...Day 3-5/Monday-Wednesday... An expanding and strengthening mid-level ridge over the Four Corners region will bring above normal temperatures but relatively light winds to much of the Intermountain West through the midweek. Mid-level troughing across the Pacific Northwest is expected to begin translating northeastward along the northern periphery of the ridge by Day 5/Wednesday, inviting drier conditions to filter into the Northwestern U.S. Ridge positioning will also usher in a northward surge of elevated monsoon moisture into the Desert Southwest by Day 4/Tuesday and by Day 5/Wednesday across the Eastern Great Basin. A dry boundary layer in place across the Four Corners and Great Basin regions will support limited rainfall from higher terrain convection and thunderstorms. Fuels are expected to remain quite dry and receptive across this region with a particular threat from new lightning ignitions. A 10 percent probability area for dry thunderstorms was introduced for Day 5/Wednesday. Farther north, the mid-level trough could support additional thunderstorms across portions of the central/northern ID and western MT Day 4-5/Tuesday-Wednesday but some uncertainty regarding antecedent rainfall distribution along with marginal fuel dryness precludes introduction of dry thunderstorm probabilities at this time. ...Day 6-8/Thursday-Saturday... Deeper monsoon moisture moving into Great Basin, with PWATs around 1.00 inch as well as rising surface dewpoints/relative humidity, should begin to limit dry lightning potential late in the week across the Great Basin and Four Corners regions with at least some wetting rains expected. Nonetheless, multiple days of higher terrain showers and thunderstorms will expand across much of the Intermountain West late next week. Lighter winds overall are expected under a building ridge over the Western U.S. along with steadily increasing temperatures, particularly across the western coastal states. A thermal trough begins to set up across CA late next week, further drying fuelscapes across the region as temperatures reach into the 100s in valley/interior locations. ..Williams.. 08/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more