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Issued at 200 AM PDT Mon Aug 11 2025 000 WTPZ44 KNHC 110847 TCDEP4 Tropical Depression Ivo Discussion Number 19 NWS National Hurricane Center Miami FL EP092025 200 AM PDT Mon Aug 11 2025 Ivo has become devoid of deep convection as it moves over increasingly cooler waters and into a drier air mass. The current intensity estimate is 30 kt which could be a bit generous based on partial scatterometer overpasses. The motion continues west-northwestward, or around 295/9 kt. Ivo should remain embedded in low-level easterly flow for the next day or two. The track forecast is similar to that from the previous advisory and very close to the latest corrected consensus, HCCA, solution. Since the system is expected to traverse even cooler waters during the next 36 hours or so, it is unlikely to regenerate significant deep convection. Thus the cyclone will likely become a post-tropical remnant low very soon. The global models depict the system opening up into a trough within 48 hours and this is reflected in the official forecast. FORECAST POSITIONS AND MAX WINDS INIT 11/0900Z 22.7N 118.7W 30 KT 35 MPH 12H 11/1800Z 23.0N 120.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 12/0600Z 23.0N 122.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 12/1800Z 23.0N 125.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 13/0600Z...DISSIPATED $$ Forecaster Pasch

Issued at 0900 UTC MON AUG 11 2025 000 FOPZ14 KNHC 110847 PWSEP4 TROPICAL DEPRESSION IVO WIND SPEED PROBABILITIES NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 0900 UTC MON AUG 11 2025 AT 0900Z THE CENTER OF TROPICAL DEPRESSION IVO WAS LOCATED NEAR LATITUDE 22.7 NORTH...LONGITUDE 118.7 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 30 KTS...35 MPH...55 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 06Z MON 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 06Z MON 18Z MON 06Z TUE 18Z TUE 06Z WED 06Z THU 06Z FRI PERIODS TO TO TO TO TO TO TO 18Z MON 06Z TUE 18Z TUE 06Z WED 06Z THU 06Z FRI 06Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER PASCH

Issued at 200 AM PDT Mon Aug 11 2025 000 WTPZ34 KNHC 110847 TCPEP4 BULLETIN Tropical Depression Ivo Advisory Number 19 NWS National Hurricane Center Miami FL EP092025 200 AM PDT Mon Aug 11 2025 ...IVO LIKELY TO BECOME A REMNANT LOW LATER TODAY... SUMMARY OF 200 AM PDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...22.7N 118.7W ABOUT 560 MI...900 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...WNW OR 295 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 200 AM PDT (0900 UTC), the center of Tropical Depression Ivo was located near latitude 22.7 North, longitude 118.7 West. The depression is moving toward the west-northwest near 10 mph. A west-northwestward and then westward motion at a similar forward speed is expected during the next day or two. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Weakening is forecast, and Ivo is expected to become a remnant low later this morning. The remnant low is forecast to dissipate on Tuesday. The estimated minimum central pressure is 1007 mb (29.74 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 800 AM PDT. $$ Forecaster Pasch

...IVO LIKELY TO BECOME A REMNANT LOW LATER TODAY... As of 2:00 AM PDT Mon Aug 11 the center of Ivo was located near 22.7, -118.7 with movement WNW at 10 mph. The minimum central pressure was 1007 mb with maximum sustained winds of about 35 mph.

Issued at 0900 UTC MON AUG 11 2025 000 WTPZ24 KNHC 110846 TCMEP4 TROPICAL DEPRESSION IVO FORECAST/ADVISORY NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 0900 UTC MON AUG 11 2025 TROPICAL DEPRESSION CENTER LOCATED NEAR 22.7N 118.7W AT 11/0900Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1007 MB MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT. 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 22.7N 118.7W AT 11/0900Z AT 11/0600Z CENTER WAS LOCATED NEAR 22.6N 118.2W FORECAST VALID 11/1800Z 23.0N 120.3W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 12/0600Z 23.0N 122.6W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 12/1800Z 23.0N 125.0W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 13/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 22.7N 118.7W NEXT ADVISORY AT 11/1500Z $$ FORECASTER PASCH

Issued at 0900 UTC MON AUG 11 2025 ZCZC MIATCMEP4 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION IVO FORECAST/ADVISORY NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 0900 UTC MON AUG 11 2025 TROPICAL DEPRESSION CENTER LOCATED NEAR 22.7N 118.7W AT 11/0900Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1007 MB MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT. 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 22.7N 118.7W AT 11/0900Z AT 11/0600Z CENTER WAS LOCATED NEAR 22.6N 118.2W FORECAST VALID 11/1800Z 23.0N 120.3W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 12/0600Z 23.0N 122.6W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 12/1800Z 23.0N 125.0W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 13/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 22.7N 118.7W NEXT ADVISORY AT 11/1500Z $$ FORECASTER PASCH NNNN

WW 0587 Status Updates
STATUS REPORT ON WW 587 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SW AVK TO 25 WSW P28 TO 25 E P28 TO 25 SSW HUT TO 35 NW HUT. ..LEITMAN..08/11/25 ATTN...WFO...DDC...ICT...OUN...TSA... STATUS REPORT FOR WS 587 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC007-015-019-035-049-073-077-079-095-125-155-173-191-110940- KS . KANSAS COUNTIES INCLUDED ARE BARBER BUTLER CHAUTAUQUA COWLEY ELK GREENWOOD HARPER HARVEY KINGMAN MONTGOMERY RENO SEDGWICK SUMNER OKC003-047-053-071-093-103-105-113-117-147-151-110940- OK . OKLAHOMA COUNTIES INCLUDED ARE ALFALFA GARFIELD GRANT KAY MAJOR NOBLE NOWATA OSAGE PAWNEE WASHINGTON WOODS THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more

WW 0587 Status Updates
STATUS REPORT ON WW 587 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SSE DDC TO 25 WNW P28 TO 30 S RSL. ..LEITMAN..08/11/25 ATTN...WFO...DDC...ICT...OUN...TSA... STATUS REPORT FOR WS 587 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC007-015-019-033-035-049-073-077-079-095-125-151-155-173-185- 191-110840- KS . KANSAS COUNTIES INCLUDED ARE BARBER BUTLER CHAUTAUQUA COMANCHE COWLEY ELK GREENWOOD HARPER HARVEY KINGMAN MONTGOMERY PRATT RENO SEDGWICK STAFFORD SUMNER OKC003-045-047-053-059-071-093-103-105-113-117-147-151-153- 110840- OK . OKLAHOMA COUNTIES INCLUDED ARE ALFALFA ELLIS GARFIELD GRANT HARPER KAY MAJOR NOBLE NOWATA OSAGE PAWNEE WASHINGTON WOODS WOODWARD Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Mon Aug 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS... ...SUMMARY... At least isolated severe hail and wind will be possible late Wednesday afternoon and evening over parts of the Dakotas. ...Synopsis and Discussion... A large upper trough will move across eastern Canada on Wednesday with rising heights over the Great Lakes and a temporary upper ridge over the Plains. Meanwhile, a low-amplitude trough will develop over the Pacific Northwest and move into the northern Rockies. At the surface, high pressure will exist over the mid to upper MS Valley and Great Lakes in the wake of the ejecting Canadian wave. West of there, low pressure will develop over the northern High Plains in advance of the developing northwestern trough. Southerly winds will increase across the northern Plains as a result of this pressure gradient, with moisture return commencing. Despite the initially meager moisture, lapse rates will be steep by late in the day, and scattered storms are expected to develop near the MT/ND border around 00Z. Increasing winds aloft combined with over 2000 J/kg MUCAPE and veering winds with height suggest a few cells producing hail will spread east across the Dakotas. An increasing nocturnal low-level jet and eventual outflow could also yield bowing structures with strong gusts as well. ..Jewell.. 08/11/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Mon Aug 11 2025 Valid 121200Z - 131200Z ...Synopsis... Isolated dry thunderstorms will remain the primary fire weather concern for Tuesday across the country. Latest forecast guidance hints that a deeply-mixed, but adequately buoyant, environment will remain in place across central AZ on the northern fringe of deeper monsoonal moisture. Forcing for ascent will be fairly weak and largely driven by orographic ascent along the Mogollon Rim. However, several deterministic CAM and recent HREF guidance hints at the potential for at least a few thunderstorms. This thermodynamic environment has yielded a mixture of wet and dry thunderstorms over the past 24 hours, so a similar combination appears probable for Tuesday. Fine fuels largely remain dry across the region, and recent lightning-caused fires hint that the fuel environment should support at least some fire starts. ...Pacific Northwest... A weak mid-level trough is forecast to move across the Pacific Northwest on Tuesday. While flow aloft will be fairly modest, the zonal flow over the Cascades and northern Sierra Nevada will likely induce a downslope flow regime within an antecedent dry environment with receptive fuels. Ensemble support was too limited to warrant additional highlights, but localized elevated fire weather conditions appear possible across far northwest NV, eastern OR, and southern WA Tuesday afternoon. ..Moore.. 08/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more