Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0457 PM CDT Tue Aug 12 2025 Valid 141200Z - 201200Z Upper-level troughing will weaken across the Pacific Northwest on D3/Thursday before a secondary jet streak deepens the trough again D5/Saturday and D6/Sunday. Moisture will increase into the weekend, with showers and thunderstorms with mostly wetting rainfall expected. As the western high shifts into the Four Corners Region through D6/Sunday, monsoonal moisture will return northward across portions of Arizona and Utah. On the periphery of this deeper moisture, isolated dry thunderstorms will be possible across portions of the Great Basin into the Northern Rockies. ...Dry Thunderstorms... With the aforementioned shift of the surface high into the Four Corners region, an increase in wetting rainfall is expected to spread northward across Arizona. A mix of wet/dry thunderstorms may be possible initially across northern Arizona. On the fringe of the deeper moisture surge further north, isolated dry thunderstorms will be possible across portions of central/northern Nevada into southern Idaho, western Wyoming, and central Utah D3/Thursday. This will spread further into Wyoming on D4/Friday. Storm motions will be around 10-15 kts, with PWs around 0.50-0.75" yielding little in terms of meaningful rainfall. Fuels in these regions are critically dry, with little monsoon season rainfall and recorded drought conditions. Moisture will recede southward after the weekend, with potential for less precipitation with thunderstorms along the Mogollon Rim and in northern/central Arizona. This may warrant inclusion of probabilities when status of fuels after precipitation D3-D5 (Thursday-Saturday) is known. ..Thornton.. 08/12/2025 ...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 0457 PM CDT Tue Aug 12 2025 Valid 141200Z - 201200Z Upper-level troughing will weaken across the Pacific Northwest on D3/Thursday before a secondary jet streak deepens the trough again D5/Saturday and D6/Sunday. Moisture will increase into the weekend, with showers and thunderstorms with mostly wetting rainfall expected. As the western high shifts into the Four Corners Region through D6/Sunday, monsoonal moisture will return northward across portions of Arizona and Utah. On the periphery of this deeper moisture, isolated dry thunderstorms will be possible across portions of the Great Basin into the Northern Rockies. ...Dry Thunderstorms... With the aforementioned shift of the surface high into the Four Corners region, an increase in wetting rainfall is expected to spread northward across Arizona. A mix of wet/dry thunderstorms may be possible initially across northern Arizona. On the fringe of the deeper moisture surge further north, isolated dry thunderstorms will be possible across portions of central/northern Nevada into southern Idaho, western Wyoming, and central Utah D3/Thursday. This will spread further into Wyoming on D4/Friday. Storm motions will be around 10-15 kts, with PWs around 0.50-0.75" yielding little in terms of meaningful rainfall. Fuels in these regions are critically dry, with little monsoon season rainfall and recorded drought conditions. Moisture will recede southward after the weekend, with potential for less precipitation with thunderstorms along the Mogollon Rim and in northern/central Arizona. This may warrant inclusion of probabilities when status of fuels after precipitation D3-D5 (Thursday-Saturday) is known. ..Thornton.. 08/12/2025 ...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 0457 PM CDT Tue Aug 12 2025 Valid 141200Z - 201200Z Upper-level troughing will weaken across the Pacific Northwest on D3/Thursday before a secondary jet streak deepens the trough again D5/Saturday and D6/Sunday. Moisture will increase into the weekend, with showers and thunderstorms with mostly wetting rainfall expected. As the western high shifts into the Four Corners Region through D6/Sunday, monsoonal moisture will return northward across portions of Arizona and Utah. On the periphery of this deeper moisture, isolated dry thunderstorms will be possible across portions of the Great Basin into the Northern Rockies. ...Dry Thunderstorms... With the aforementioned shift of the surface high into the Four Corners region, an increase in wetting rainfall is expected to spread northward across Arizona. A mix of wet/dry thunderstorms may be possible initially across northern Arizona. On the fringe of the deeper moisture surge further north, isolated dry thunderstorms will be possible across portions of central/northern Nevada into southern Idaho, western Wyoming, and central Utah D3/Thursday. This will spread further into Wyoming on D4/Friday. Storm motions will be around 10-15 kts, with PWs around 0.50-0.75" yielding little in terms of meaningful rainfall. Fuels in these regions are critically dry, with little monsoon season rainfall and recorded drought conditions. Moisture will recede southward after the weekend, with potential for less precipitation with thunderstorms along the Mogollon Rim and in northern/central Arizona. This may warrant inclusion of probabilities when status of fuels after precipitation D3-D5 (Thursday-Saturday) is known. ..Thornton.. 08/12/2025 ...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 0457 PM CDT Tue Aug 12 2025 Valid 141200Z - 201200Z Upper-level troughing will weaken across the Pacific Northwest on D3/Thursday before a secondary jet streak deepens the trough again D5/Saturday and D6/Sunday. Moisture will increase into the weekend, with showers and thunderstorms with mostly wetting rainfall expected. As the western high shifts into the Four Corners Region through D6/Sunday, monsoonal moisture will return northward across portions of Arizona and Utah. On the periphery of this deeper moisture, isolated dry thunderstorms will be possible across portions of the Great Basin into the Northern Rockies. ...Dry Thunderstorms... With the aforementioned shift of the surface high into the Four Corners region, an increase in wetting rainfall is expected to spread northward across Arizona. A mix of wet/dry thunderstorms may be possible initially across northern Arizona. On the fringe of the deeper moisture surge further north, isolated dry thunderstorms will be possible across portions of central/northern Nevada into southern Idaho, western Wyoming, and central Utah D3/Thursday. This will spread further into Wyoming on D4/Friday. Storm motions will be around 10-15 kts, with PWs around 0.50-0.75" yielding little in terms of meaningful rainfall. Fuels in these regions are critically dry, with little monsoon season rainfall and recorded drought conditions. Moisture will recede southward after the weekend, with potential for less precipitation with thunderstorms along the Mogollon Rim and in northern/central Arizona. This may warrant inclusion of probabilities when status of fuels after precipitation D3-D5 (Thursday-Saturday) is known. ..Thornton.. 08/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1935 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN/EASTERN IL...WESTERN/NORTHERN IN...SOUTHWEST LOWER MI
Mesoscale Discussion 1935 NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Aug 12 2025 Areas affected...southern/eastern IL...western/northern IN...southwest Lower MI Concerning...Severe potential...Watch unlikely Valid 121944Z - 122145Z Probability of Watch Issuance...5 percent SUMMARY...Sporadic strong gusts of 45-60 mph and generally small hail to 1 inch in diameter will be possible with a broken band of thunderstorms slowly progressing from Illinois into parts of Indiana and Lower Michigan. A Severe Thunderstorm Watch is not expected. DISCUSSION...Along a band of low-level confluence, thunderstorms have become increasingly numerous from southeast MO into southwest Lower MI. With surface temperatures of 86-91 F common ahead of this activity, to the west/north of separate convective outflow in central IN, potential for sporadic downbursts exists amid weak lower-level flow. Area VWP data indicate 0-6 km shear around 20 kts across IL into IN, to around 25 kts in southwest Lower MI. Speed change with height is largely concentrated in the mid to upper portion of the buoyancy profile. This suggests small to marginally severe hail may accompany the strongest updrafts. Loose multicell clustering may support a localized, marginal severe wind threat. Based on latest trends, this could be centered in corridors across the IL/IN/MI border area with ongoing storms near/south of Chicagoland and separately to the east-northeast of storms near/east of St. Louis. ..Grams/Smith.. 08/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...GRR...IND...LOT...ILX...LSX... LAT...LON 42588622 42818602 42838532 42298496 41578551 40638690 38888858 38738939 38868968 39388949 40258868 41058804 41728729 41918683 42358633 42588622 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0312 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... CORRECTED FOR NDFD ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Tue Aug 12 2025 Valid 122000Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE GREAT LAKES REGION... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. ...20Z Update... Given the weak mid/upper-level flow, the potential for organized severe wind gusts appears very limited in southeast Arizona/southwest New Mexico. Steep low-level lapse rates may still support strong/gusty outflow however. Elsewhere only minor update the general thunderstorm area were made. See the previous discussion for additional details. ..Wendt.. 08/12/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 12 2025/ ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0234 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN IDAHO... A Critical area was added across portions of the Snake River Plain in southern Idaho with this outlook. Ensemble guidance shows reasonable agreement that sustained winds around 20 mph will overlap with relative humidity reductions to around 15 percent across this region amid critically dry fuels. The Isolated Dry Thunderstorm chances were also expanded further east into southern Idaho in agreement with latest trends in hi-res guidance suggesting convection will be possible across the high terrain. The broad Elevated region across much of the Great Basin, Pacific Northwest, and Northern Rockies. See previous discussion for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0200 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will become more widespread across the West on Wednesday as a strong upper-level wave moves across the region. Short to medium-range guidance shows reasonably good agreement in the southeastward progression of an amplifying upper wave (currently over the northeast Pacific) across the Pacific Northwest and northern Rockies through Wednesday afternoon/evening. Strengthening downslope winds off the Cascades and Sierra Nevada will promote windy and dry conditions across western NV into eastern WA/OR. Further east, robust surface pressure falls attendant to the upper wave will promote strengthening surface winds across a broad swath of the eastern Great Basin and central/northern Rockies. Latest ensemble guidance suggests sustained winds in the upper teens are most probable, though some regions may see sustained winds between 20-25 mph. Spread between ensemble and deterministic solutions limits confidence on where such corridors of higher winds will emerge, but given high probabilities for sub-15% RH, swaths of critical fire weather conditions appear possible. Elevated fire weather conditions may emerge across portions of northern MT as well, but recent fuel guidance suggests fuels are not overly receptive across this region (though fuel trends will be monitored given the forecast for dry/windy conditions). Dry thunderstorms are also possible across the Great Basin Wednesday afternoon. A plume of mid-level moisture moving northward off the CA coast will likely phase with the passage of the upper wave and support adequate buoyancy for high-based convection across portions of east-central CA, central NV, and perhaps into southern ID. Strong diurnal heating and mixing will push LCL heights to above 4 km, which, in conjunction with 20 knot storm motions, will limit precipitation totals and favor dry thunderstorms. While coverage of thunderstorms may be limited, dry fuels across the region should support the fire weather concern. ...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 0234 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN IDAHO... A Critical area was added across portions of the Snake River Plain in southern Idaho with this outlook. Ensemble guidance shows reasonable agreement that sustained winds around 20 mph will overlap with relative humidity reductions to around 15 percent across this region amid critically dry fuels. The Isolated Dry Thunderstorm chances were also expanded further east into southern Idaho in agreement with latest trends in hi-res guidance suggesting convection will be possible across the high terrain. The broad Elevated region across much of the Great Basin, Pacific Northwest, and Northern Rockies. See previous discussion for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0200 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will become more widespread across the West on Wednesday as a strong upper-level wave moves across the region. Short to medium-range guidance shows reasonably good agreement in the southeastward progression of an amplifying upper wave (currently over the northeast Pacific) across the Pacific Northwest and northern Rockies through Wednesday afternoon/evening. Strengthening downslope winds off the Cascades and Sierra Nevada will promote windy and dry conditions across western NV into eastern WA/OR. Further east, robust surface pressure falls attendant to the upper wave will promote strengthening surface winds across a broad swath of the eastern Great Basin and central/northern Rockies. Latest ensemble guidance suggests sustained winds in the upper teens are most probable, though some regions may see sustained winds between 20-25 mph. Spread between ensemble and deterministic solutions limits confidence on where such corridors of higher winds will emerge, but given high probabilities for sub-15% RH, swaths of critical fire weather conditions appear possible. Elevated fire weather conditions may emerge across portions of northern MT as well, but recent fuel guidance suggests fuels are not overly receptive across this region (though fuel trends will be monitored given the forecast for dry/windy conditions). Dry thunderstorms are also possible across the Great Basin Wednesday afternoon. A plume of mid-level moisture moving northward off the CA coast will likely phase with the passage of the upper wave and support adequate buoyancy for high-based convection across portions of east-central CA, central NV, and perhaps into southern ID. Strong diurnal heating and mixing will push LCL heights to above 4 km, which, in conjunction with 20 knot storm motions, will limit precipitation totals and favor dry thunderstorms. While coverage of thunderstorms may be limited, dry fuels across the region should support the fire weather concern. ...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 0234 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN IDAHO... A Critical area was added across portions of the Snake River Plain in southern Idaho with this outlook. Ensemble guidance shows reasonable agreement that sustained winds around 20 mph will overlap with relative humidity reductions to around 15 percent across this region amid critically dry fuels. The Isolated Dry Thunderstorm chances were also expanded further east into southern Idaho in agreement with latest trends in hi-res guidance suggesting convection will be possible across the high terrain. The broad Elevated region across much of the Great Basin, Pacific Northwest, and Northern Rockies. See previous discussion for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0200 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will become more widespread across the West on Wednesday as a strong upper-level wave moves across the region. Short to medium-range guidance shows reasonably good agreement in the southeastward progression of an amplifying upper wave (currently over the northeast Pacific) across the Pacific Northwest and northern Rockies through Wednesday afternoon/evening. Strengthening downslope winds off the Cascades and Sierra Nevada will promote windy and dry conditions across western NV into eastern WA/OR. Further east, robust surface pressure falls attendant to the upper wave will promote strengthening surface winds across a broad swath of the eastern Great Basin and central/northern Rockies. Latest ensemble guidance suggests sustained winds in the upper teens are most probable, though some regions may see sustained winds between 20-25 mph. Spread between ensemble and deterministic solutions limits confidence on where such corridors of higher winds will emerge, but given high probabilities for sub-15% RH, swaths of critical fire weather conditions appear possible. Elevated fire weather conditions may emerge across portions of northern MT as well, but recent fuel guidance suggests fuels are not overly receptive across this region (though fuel trends will be monitored given the forecast for dry/windy conditions). Dry thunderstorms are also possible across the Great Basin Wednesday afternoon. A plume of mid-level moisture moving northward off the CA coast will likely phase with the passage of the upper wave and support adequate buoyancy for high-based convection across portions of east-central CA, central NV, and perhaps into southern ID. Strong diurnal heating and mixing will push LCL heights to above 4 km, which, in conjunction with 20 knot storm motions, will limit precipitation totals and favor dry thunderstorms. While coverage of thunderstorms may be limited, dry fuels across the region should support the fire weather concern. ...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 0234 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN IDAHO... A Critical area was added across portions of the Snake River Plain in southern Idaho with this outlook. Ensemble guidance shows reasonable agreement that sustained winds around 20 mph will overlap with relative humidity reductions to around 15 percent across this region amid critically dry fuels. The Isolated Dry Thunderstorm chances were also expanded further east into southern Idaho in agreement with latest trends in hi-res guidance suggesting convection will be possible across the high terrain. The broad Elevated region across much of the Great Basin, Pacific Northwest, and Northern Rockies. See previous discussion for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0200 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will become more widespread across the West on Wednesday as a strong upper-level wave moves across the region. Short to medium-range guidance shows reasonably good agreement in the southeastward progression of an amplifying upper wave (currently over the northeast Pacific) across the Pacific Northwest and northern Rockies through Wednesday afternoon/evening. Strengthening downslope winds off the Cascades and Sierra Nevada will promote windy and dry conditions across western NV into eastern WA/OR. Further east, robust surface pressure falls attendant to the upper wave will promote strengthening surface winds across a broad swath of the eastern Great Basin and central/northern Rockies. Latest ensemble guidance suggests sustained winds in the upper teens are most probable, though some regions may see sustained winds between 20-25 mph. Spread between ensemble and deterministic solutions limits confidence on where such corridors of higher winds will emerge, but given high probabilities for sub-15% RH, swaths of critical fire weather conditions appear possible. Elevated fire weather conditions may emerge across portions of northern MT as well, but recent fuel guidance suggests fuels are not overly receptive across this region (though fuel trends will be monitored given the forecast for dry/windy conditions). Dry thunderstorms are also possible across the Great Basin Wednesday afternoon. A plume of mid-level moisture moving northward off the CA coast will likely phase with the passage of the upper wave and support adequate buoyancy for high-based convection across portions of east-central CA, central NV, and perhaps into southern ID. Strong diurnal heating and mixing will push LCL heights to above 4 km, which, in conjunction with 20 knot storm motions, will limit precipitation totals and favor dry thunderstorms. While coverage of thunderstorms may be limited, dry fuels across the region should support the fire weather concern. ...Please see www.spc.noaa.gov/fire for graphic product... Read more