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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0450 PM CDT Sun Aug 10 2025 Valid 121200Z - 181200Z Upper-level troughing will develop across the Pacific Northwest D3/Tuesday into D4/Wednesday, bringing an increase to winds amid dry conditions. Rain and thunderstorm chances may increase across this region by late in the period. As the western highs shifts into the Four Corners Region, monsoonal moisture may return northward across portions of Arizona through mid to lake week, with lingering isolated dry thunderstorm chances before a shift to more wetting rainfall potential. ...Dry Thunderstorms... Isolated thunderstorms D3/Tuesday - D5/Thursday will become more widely scattered with a gradual increase in moisture northward as the western high shifts into the Four Corners region through the weekend. This may lead to an increase in wetting rainfall, with less potential for dry thunderstorms. Some lingering isolated dry thunderstorm chances may be possible, but for now this threat appears too low for inclusion of any areas. ...Wind/RH... Breezy conditions are expected across the Pacific Northwest as the pattern becomes more progressive, with broad troughing and several shortwave disturbances moving through early to mid-week. The most widespread winds are expected D4/Wednesday, when Elevated to locally Critical conditions are expected across portions of the Columbia River Basin in eastern Washington and Oregon as a trough moves inland and enhanced westerly flow overspreads the Cascade Range. A 40% delineation was added with this outlook to cover this potential. ..Thornton.. 08/10/2025 ...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 0450 PM CDT Sun Aug 10 2025 Valid 121200Z - 181200Z Upper-level troughing will develop across the Pacific Northwest D3/Tuesday into D4/Wednesday, bringing an increase to winds amid dry conditions. Rain and thunderstorm chances may increase across this region by late in the period. As the western highs shifts into the Four Corners Region, monsoonal moisture may return northward across portions of Arizona through mid to lake week, with lingering isolated dry thunderstorm chances before a shift to more wetting rainfall potential. ...Dry Thunderstorms... Isolated thunderstorms D3/Tuesday - D5/Thursday will become more widely scattered with a gradual increase in moisture northward as the western high shifts into the Four Corners region through the weekend. This may lead to an increase in wetting rainfall, with less potential for dry thunderstorms. Some lingering isolated dry thunderstorm chances may be possible, but for now this threat appears too low for inclusion of any areas. ...Wind/RH... Breezy conditions are expected across the Pacific Northwest as the pattern becomes more progressive, with broad troughing and several shortwave disturbances moving through early to mid-week. The most widespread winds are expected D4/Wednesday, when Elevated to locally Critical conditions are expected across portions of the Columbia River Basin in eastern Washington and Oregon as a trough moves inland and enhanced westerly flow overspreads the Cascade Range. A 40% delineation was added with this outlook to cover this potential. ..Thornton.. 08/10/2025 ...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 0450 PM CDT Sun Aug 10 2025 Valid 121200Z - 181200Z Upper-level troughing will develop across the Pacific Northwest D3/Tuesday into D4/Wednesday, bringing an increase to winds amid dry conditions. Rain and thunderstorm chances may increase across this region by late in the period. As the western highs shifts into the Four Corners Region, monsoonal moisture may return northward across portions of Arizona through mid to lake week, with lingering isolated dry thunderstorm chances before a shift to more wetting rainfall potential. ...Dry Thunderstorms... Isolated thunderstorms D3/Tuesday - D5/Thursday will become more widely scattered with a gradual increase in moisture northward as the western high shifts into the Four Corners region through the weekend. This may lead to an increase in wetting rainfall, with less potential for dry thunderstorms. Some lingering isolated dry thunderstorm chances may be possible, but for now this threat appears too low for inclusion of any areas. ...Wind/RH... Breezy conditions are expected across the Pacific Northwest as the pattern becomes more progressive, with broad troughing and several shortwave disturbances moving through early to mid-week. The most widespread winds are expected D4/Wednesday, when Elevated to locally Critical conditions are expected across portions of the Columbia River Basin in eastern Washington and Oregon as a trough moves inland and enhanced westerly flow overspreads the Cascade Range. A 40% delineation was added with this outlook to cover this potential. ..Thornton.. 08/10/2025 ...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 0450 PM CDT Sun Aug 10 2025 Valid 121200Z - 181200Z Upper-level troughing will develop across the Pacific Northwest D3/Tuesday into D4/Wednesday, bringing an increase to winds amid dry conditions. Rain and thunderstorm chances may increase across this region by late in the period. As the western highs shifts into the Four Corners Region, monsoonal moisture may return northward across portions of Arizona through mid to lake week, with lingering isolated dry thunderstorm chances before a shift to more wetting rainfall potential. ...Dry Thunderstorms... Isolated thunderstorms D3/Tuesday - D5/Thursday will become more widely scattered with a gradual increase in moisture northward as the western high shifts into the Four Corners region through the weekend. This may lead to an increase in wetting rainfall, with less potential for dry thunderstorms. Some lingering isolated dry thunderstorm chances may be possible, but for now this threat appears too low for inclusion of any areas. ...Wind/RH... Breezy conditions are expected across the Pacific Northwest as the pattern becomes more progressive, with broad troughing and several shortwave disturbances moving through early to mid-week. The most widespread winds are expected D4/Wednesday, when Elevated to locally Critical conditions are expected across portions of the Columbia River Basin in eastern Washington and Oregon as a trough moves inland and enhanced westerly flow overspreads the Cascade Range. A 40% delineation was added with this outlook to cover this potential. ..Thornton.. 08/10/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Sun Aug 10 21:47:15 UTC 2025.

5-Day Uncertainty Track last updated Sun, 10 Aug 2025 20:33:17 GMT


Wind Speed Probabilities last updated Sun, 10 Aug 2025 21:27:21 GMT

5-Day Uncertainty Track last updated Sun, 10 Aug 2025 20:33:17 GMT


Wind Speed Probabilities last updated Sun, 10 Aug 2025 20:33:17 GMT

Issued at 2100 UTC SUN AUG 10 2025 686 FOPZ14 KNHC 102031 PWSEP4 TROPICAL STORM IVO WIND SPEED PROBABILITIES NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 2100 UTC SUN AUG 10 2025 AT 2100Z THE CENTER OF TROPICAL STORM IVO WAS LOCATED NEAR LATITUDE 22.1 NORTH...LONGITUDE 117.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 35 KTS...40 MPH...65 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 18Z SUN AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 18Z SUN 06Z MON 18Z MON 06Z TUE 18Z TUE 18Z WED 18Z THU PERIODS TO TO TO TO TO TO TO 06Z MON 18Z MON 06Z TUE 18Z TUE 18Z WED 18Z THU 18Z FRI FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER BERG

Issued at 200 PM PDT Sun Aug 10 2025 613 WTPZ44 KNHC 102032 TCDEP4 Tropical Storm Ivo Discussion Number 17 NWS National Hurricane Center Miami FL EP092025 200 PM PDT Sun Aug 10 2025 Even over waters of 23-24 degrees Celsius, Ivo is managing to maintain a persistent area of deep convection. A recent ASCAT pass showed maximum winds of 30 kt. Accounting for the instrument's sampling limitations, and combined with satellite estimates still running around 35 kt, it is estimated that Ivo is hanging on to tropical storm status. Sea surface temperatures drop by another 2-3 degrees along Ivo's forecast track, so weakening is expected to resume tonight, and simulated satellite images from the GFS and ECMWF show that deep convection could finally be gone by Monday morning. Degeneration into a remnant low is forecast by 24 hours, followed by dissipation into a trough in 60 hours. Ivo is moving west-northwestward (285 deg) at 10 kt. This motion should continue for the next 12 hours, followed by a slight bend to the west in 24 hours as Ivo stays situated to the south of the low- to mid-level ridge. The track models are tightly clustered, and the new NHC forecast is mainly an update of the previous prediction. FORECAST POSITIONS AND MAX WINDS INIT 10/2100Z 22.1N 117.2W 35 KT 40 MPH 12H 11/0600Z 22.5N 118.6W 30 KT 35 MPH 24H 11/1800Z 22.8N 120.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 12/0600Z 22.9N 123.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 12/1800Z 22.9N 125.3W 15 KT 15 MPH...POST-TROP/REMNT LOW 60H 13/0600Z...DISSIPATED $$ Forecaster Berg

Issued at 200 PM PDT Sun Aug 10 2025 826 WTPZ34 KNHC 102031 TCPEP4 BULLETIN Tropical Storm Ivo Advisory Number 17 NWS National Hurricane Center Miami FL EP092025 200 PM PDT Sun Aug 10 2025 ...IVO RESILIENTLY MAINTAINING SHOWERS AND THUNDERSTORMS OVER COOL WATER... ...STILL EXPECTED TO BECOME A REMNANT LOW ON MONDAY... SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...22.1N 117.2W ABOUT 470 MI...755 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 200 PM PDT (2100 UTC), the center of Tropical Storm Ivo was located near latitude 22.1 North, longitude 117.2 West. Ivo is moving toward the west-northwest near 12 mph (19 km/h). A west-northwestward and then westward motion at a similar forward speed is expected during the next couple of days. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Weakening is forecast, and Ivo is expected to become a remnant low on Monday. The remnant low is forecast to dissipate on Tuesday. Tropical-storm-force winds extend outward up to 35 miles (55 km) from the center. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 800 PM PDT. $$ Forecaster Berg

...IVO RESILIENTLY MAINTAINING SHOWERS AND THUNDERSTORMS OVER COOL WATER... ...STILL EXPECTED TO BECOME A REMNANT LOW ON MONDAY... As of 2:00 PM PDT Sun Aug 10 the center of Ivo was located near 22.1, -117.2 with movement WNW at 12 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 40 mph.

Issued at 2100 UTC SUN AUG 10 2025 465 WTPZ24 KNHC 102031 TCMEP4 TROPICAL STORM IVO FORECAST/ADVISORY NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 2100 UTC SUN AUG 10 2025 TROPICAL STORM CENTER LOCATED NEAR 22.1N 117.2W AT 10/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT. 34 KT....... 30NE 0SE 0SW 30NW. 4 M SEAS.... 45NE 0SE 0SW 0NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 22.1N 117.2W AT 10/2100Z AT 10/1800Z CENTER WAS LOCATED NEAR 21.9N 116.7W FORECAST VALID 11/0600Z 22.5N 118.6W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 11/1800Z 22.8N 120.7W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 12/0600Z 22.9N 123.0W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 12/1800Z 22.9N 125.3W...POST-TROP/REMNT LOW MAX WIND 15 KT...GUSTS 20 KT. FORECAST VALID 13/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 22.1N 117.2W NEXT ADVISORY AT 11/0300Z $$ FORECASTER BERG

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sun Aug 10 2025 Valid 102000Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the central/southern Plains through tonight, with large hail and damaging winds the main threats. ...20z Update Front Range... Initial thunderstorms should continue to develop over the higher terrain of eastern CO and the Front Range as a broad upper trough shifts eastward and low-level upslope flow continues this afternoon. 1500 J/kg of MLCAPE and westerly flow aloft around 35-45 kt will support supercells. Steep mid-level lapse rates and cooler mid-level temperatures will favor an initial risk for hail before upscale growth results in an MCS tonight. Damaging gusts are possible into parts of the southern Plains. Have expanded the Slight Risk farther north/east where development is possible closer to the WY/CO border. ...Mid Mississippi Valley... Diurnal heating ahead of the weak cold front over the Midwest will continue to support moderate destabilization this afternoon. Ongoing thunderstorm clusters should gradually expand eastward as cold pools deepen. While vertical shear will not be strong, (generally less than 20 kt) an occasional damaging gust remains possible over parts of IL, MO and WI. Have expanded the Marginal risk eastward to cover the low-end risk. Otherwise, see the prior outlook for additional info. ..Lyons.. 08/10/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Sun Aug 10 2025/ ...CO/KS... Morning water vapor loop shows a vigorous shortwave trough digging southeastward into central CO. Large scale forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms along the foothills of central CO by early afternoon, with storms spreading eastward through the afternoon/evening. Ample low-level moisture and CAPE are present over eastern CO/western KS to promote a few intense cells, with favorable westerly flow aloft for supercell structures. Large hail is the main concern, with an increasing risk of damaging winds with eastward extent this evening. A tornado or two is possible as storms interact with a remnant outflow boundary that extends across the TX Panhandle and northwest OK. ...MO/IL/WI... A corridor of strong heating will encourage scattered thunderstorm development this afternoon from southern MO into central/northeast IL. Weak winds aloft and considerable mid-level moisture will limit overall downdraft potential. Nevertheless, gusty/damaging winds could occur with the strongest cells. ...Southeast AZ... Similar to yesterday, scattered high-based afternoon/evening thunderstorm development is expected over southeast AZ in a hot/unstable environment. The strongest cells may produce locally damaging wind gusts. Read more