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ABPZ20 KNHC 091116
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sat Aug 9 2025

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

Active Systems:
The National Hurricane Center is issuing advisories on recently
redesignated Tropical Depression Henriette, located in the Central
Pacific basin several hundred miles east of the Hawaiian Islands.
The National Hurricane Center is also issuing advisories on
Tropical Storm Ivo, located over the Eastern Pacific basin a couple
of hundred miles southwest of the southern tip of the Baja
California peninsula.

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

$$
Forecaster Berg

WW 0580 Status Updates
STATUS FOR WATCH 0580 HAS NOT BEEN ISSUED YET Read more

WW 0580 Status Updates
STATUS FOR WATCH 0580 HAS NOT BEEN ISSUED YET Read more

WW 0580 Status Updates
STATUS FOR WATCH 0580 HAS NOT BEEN ISSUED YET Read more

MD 1909 CONCERNING SEVERE THUNDERSTORM WATCH 579... FOR PORTIONS OF EASTERN NE AND FAR SOUTHWEST IA
Mesoscale Discussion 1909 NWS Storm Prediction Center Norman OK 0428 AM CDT Sat Aug 09 2025 Areas affected...portions of eastern NE and far southwest IA Concerning...Severe Thunderstorm Watch 579... Valid 090928Z - 091100Z The severe weather threat for Severe Thunderstorm Watch 579 continues. SUMMARY...A risk for potentially significant wind gusts will accompany an intense supercell as it tracks east/northeast toward the NE/IA border over the next couple of hours. DISCUSSION...A hybrid supercell/small bow has been producing severe/damaging gusts over the past 1-2 hours across southeast NE. Radar presentation shows very strong outbound velocities aloft coincident with damage reports, and most recently a 91 mph measured gust in Fillmore County. This activity is occurring in a strongly unstable airmass, with MUCAPE near 4000 J/kg in a corridor ahead of a southeastward-sagging cold front. Convection will likely persist at least another couple of hours, and given the favorable downstream thermodynamic environment, severe gusts, some greater than 75 mph, are expected to continue as the storm approaches the Missouri River vicinity by 11z. ..Leitman.. 08/09/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OAX...GID... LAT...LON 40689811 41169785 41439747 41559703 41589618 41559586 41449568 41219557 40729574 40439614 40339738 40289790 40529810 40689811 MOST PROBABLE PEAK WIND GUST...75-90 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

WW 0579 Status Updates
STATUS REPORT ON WW 579 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 W BIE TO 15 S OLU TO 25 SW SUX. ..LEITMAN..08/09/25 ATTN...WFO...OAX...GID... STATUS REPORT FOR WS 579 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC085-129-133-155-165-091140- IA . IOWA COUNTIES INCLUDED ARE HARRISON MILLS MONONA POTTAWATTAMIE SHELBY NEC021-023-025-037-039-053-055-067-095-097-109-131-151-153-155- 159-177-091140- NE . NEBRASKA COUNTIES INCLUDED ARE BURT BUTLER CASS COLFAX CUMING DODGE DOUGLAS GAGE JEFFERSON JOHNSON LANCASTER OTOE SALINE SARPY SAUNDERS SEWARD WASHINGTON THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more

5-Day Uncertainty Track last updated Sat, 09 Aug 2025 08:41:08 GMT


Wind Speed Probabilities last updated Sat, 09 Aug 2025 09:26:40 GMT

5-Day Uncertainty Track last updated Sat, 09 Aug 2025 08:41:08 GMT


Wind Speed Probabilities last updated Sat, 09 Aug 2025 08:41:08 GMT

WW 0579 Status Updates
STATUS REPORT ON WW 579 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SSW HSI TO 15 SW GRI TO 35 WNW OLU. ..LEITMAN..08/09/25 ATTN...WFO...OAX...GID... STATUS REPORT FOR WS 579 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC085-129-133-155-165-090940- IA . IOWA COUNTIES INCLUDED ARE HARRISON MILLS MONONA POTTAWATTAMIE SHELBY NEC001-021-023-025-035-037-039-053-055-059-081-109-121-125-129- 141-143-151-153-155-159-167-169-177-181-185-090940- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BURT BUTLER CASS CLAY COLFAX CUMING DODGE DOUGLAS FILLMORE HAMILTON LANCASTER MERRICK NANCE NUCKOLLS PLATTE POLK SALINE SARPY SAUNDERS SEWARD STANTON THAYER WASHINGTON WEBSTER YORK Read more

WW 0579 Status Updates
STATUS REPORT ON WW 579 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SSW HSI TO 15 SW GRI TO 35 WNW OLU. ..LEITMAN..08/09/25 ATTN...WFO...OAX...GID... STATUS REPORT FOR WS 579 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC085-129-133-155-165-090940- IA . IOWA COUNTIES INCLUDED ARE HARRISON MILLS MONONA POTTAWATTAMIE SHELBY NEC001-021-023-025-035-037-039-053-055-059-081-109-121-125-129- 141-143-151-153-155-159-167-169-177-181-185-090940- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BURT BUTLER CASS CLAY COLFAX CUMING DODGE DOUGLAS FILLMORE HAMILTON LANCASTER MERRICK NANCE NUCKOLLS PLATTE POLK SALINE SARPY SAUNDERS SEWARD STANTON THAYER WASHINGTON WEBSTER YORK Read more

MD 1908 CONCERNING SEVERE THUNDERSTORM WATCH 578... FOR PORTIONS OF MN INTO NORTHWEST WI AND IA
Mesoscale Discussion 1908 NWS Storm Prediction Center Norman OK 0240 AM CDT Sat Aug 09 2025 Areas affected...portions of MN into northwest WI and IA Concerning...Severe Thunderstorm Watch 578... Valid 090740Z - 090915Z The severe weather threat for Severe Thunderstorm Watch 578 continues. SUMMARY...Isolated to widely scattered storms may produce strong to severe wind gusts into early morning across eastern portions of Minnesota, northwest Wisconsin, and portions of northern Iowa. DISCUSSION...Storms have modestly increased in coverage/intensity over the past 1-2 hours ahead of the east/southeast-advancing cold front. A very moist airmass beneath steep midlevel lapse rates is supporting a corridor of strong instability greater than 2500 J/kg. Stronger vertical shear lags somewhat behind the front across IA into southeast MN/northwest WI, but a 30-40 kt low-level jet is evident across the region. Convection has been somewhat slow to increase/organize, but will likely persist in the favorable thermodynamic environment as large-scale ascent continues to slowly overspread the Mid-MO/Upper MS Valleys into early morning. Damaging wind gusts will be the main hazard with this activity, though isolated large hail is possible with any more discrete cellular activity. Severe Thunderstorm Watch 578 is set to expire at 09z. Given convection is likely to persist, a local watch extension or a new watch issuance is possible for parts of the MCD area. ..Leitman.. 08/09/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...DMX...FSD... LAT...LON 42509608 48589323 48238987 45549139 42559354 42509608 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

Issued at 200 AM MST Sat Aug 09 2025 023 WTPZ44 KNHC 090839 TCDEP4 Tropical Storm Ivo Discussion Number 11 NWS National Hurricane Center Miami FL EP092025 200 AM MST Sat Aug 09 2025 Ivo is having intermittent bursts of deep convection since the last advisory. An ASCAT pass from 0412 UTC showed the center of the small circulation near the northeastern edge of the CDO. Subjective and objective satellite intensity estimates have generally decreased in recent hours and the initial intensity is lowered to 50 kt for this cycle. The storm is moving westward at 8 kt. A general westward to west-northwestward motion is anticipated through the forecast period while Ivo is steered along the southern side of a ridge positioned to its north. The track guidance has shifted poleward this cycle, and the latest official forecast lies on the southern side of the envelope between the ECMWF to its south and the simple consensus aid TVCE to its north. Ivo is currently crossing a cooling gradient of sea surface temperatures and moving towards a dry and stable airmass. The storm is expected to gradually weaken through the weekend, until it becomes a post-tropical cyclone sometime Sunday night or Monday morning. The NHC intensity forecast has been adjusted lower based on the decrease in initial intensity and is in the middle of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 20.6N 112.4W 50 KT 60 MPH 12H 09/1800Z 20.9N 113.4W 45 KT 50 MPH 24H 10/0600Z 21.3N 115.1W 45 KT 50 MPH 36H 10/1800Z 21.7N 117.1W 40 KT 45 MPH 48H 11/0600Z 22.0N 119.3W 35 KT 40 MPH...POST-TROPICAL 60H 11/1800Z 22.1N 121.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 12/0600Z 22.2N 123.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 13/0600Z...DISSIPATED $$ Forecaster Bucci

Issued at 0900 UTC SAT AUG 09 2025 522 FOPZ14 KNHC 090839 PWSEP4 TROPICAL STORM IVO WIND SPEED PROBABILITIES NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 0900 UTC SAT AUG 09 2025 AT 0900Z THE CENTER OF TROPICAL STORM IVO WAS LOCATED NEAR LATITUDE 20.6 NORTH...LONGITUDE 112.4 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 50 KTS...60 MPH...95 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 SAT 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 SAT 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED PERIODS TO TO TO TO TO TO TO 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED 06Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 20N 115W 34 X 5( 5) 1( 6) X( 6) X( 6) X( 6) X( 6) $$ FORECASTER BUCCI

Issued at 200 AM MST Sat Aug 09 2025 219 WTPZ34 KNHC 090839 TCPEP4 BULLETIN Tropical Storm Ivo Advisory Number 11 NWS National Hurricane Center Miami FL EP092025 200 AM MST Sat Aug 09 2025 ...IVO HEADING WESTWARD... SUMMARY OF 200 AM MST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...20.6N 112.4W ABOUT 225 MI...365 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 200 AM MST (0900 UTC), the center of Tropical Storm Ivo was located near latitude 20.6 North, longitude 112.4 West. Ivo is moving toward the west near 9 mph (15 km/h). A westward to west-northwestward motion is expected during the next few days. Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Gradual weakening is forecast for the next few days and Ivo is expected to become post-tropical by Sunday night. Tropical-storm-force winds extend outward up to 35 miles (55 km) from the center. The estimated minimum central pressure is 1001 mb (29.56 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Ivo will continue to affect the southern portion of the Baja California peninsula during the next day or so. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 800 AM MST. $$ Forecaster Bucci

...IVO HEADING WESTWARD... As of 2:00 AM MST Sat Aug 09 the center of Ivo was located near 20.6, -112.4 with movement W at 9 mph. The minimum central pressure was 1001 mb with maximum sustained winds of about 60 mph.

Issued at 0900 UTC SAT AUG 09 2025 213 WTPZ24 KNHC 090838 TCMEP4 TROPICAL STORM IVO FORECAST/ADVISORY NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092025 0900 UTC SAT AUG 09 2025 TROPICAL STORM CENTER LOCATED NEAR 20.6N 112.4W AT 09/0900Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1001 MB MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT. 50 KT....... 15NE 0SE 0SW 15NW. 34 KT....... 30NE 30SE 20SW 30NW. 4 M SEAS.... 60NE 30SE 30SW 60NW. 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 20.6N 112.4W AT 09/0900Z AT 09/0600Z CENTER WAS LOCATED NEAR 20.5N 112.1W FORECAST VALID 09/1800Z 20.9N 113.4W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 30NE 30SE 20SW 30NW. FORECAST VALID 10/0600Z 21.3N 115.1W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 30NE 20SE 20SW 30NW. FORECAST VALID 10/1800Z 21.7N 117.1W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 30NE 20SE 10SW 30NW. FORECAST VALID 11/0600Z 22.0N 119.3W...POST-TROPICAL MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 20NE 0SE 0SW 20NW. FORECAST VALID 11/1800Z 22.1N 121.5W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 12/0600Z 22.2N 123.7W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 13/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.6N 112.4W NEXT ADVISORY AT 09/1500Z $$ FORECASTER BUCCI

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0317 AM CDT Sat Aug 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... A shortwave trough will move from the northern Plains into the Northeast during the Tuesday/D4 to Wednesday/D5 time frame, with an initial push of drier air southward across the Midwest/Great Lakes. Stronger instability is forecast to redevelop by Thursday/D6 and beyond as a low-amplitude upper trough moves across the northern Rockies and Plains and increasing southerly low-level winds bring dewpoints into the mid 70s F northward across the Mid MO/Upper MS Valleys. This may yield one or more severe events across parts of the northern Plains to upper MS Valley, but confidence is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0317 AM CDT Sat Aug 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... A shortwave trough will move from the northern Plains into the Northeast during the Tuesday/D4 to Wednesday/D5 time frame, with an initial push of drier air southward across the Midwest/Great Lakes. Stronger instability is forecast to redevelop by Thursday/D6 and beyond as a low-amplitude upper trough moves across the northern Rockies and Plains and increasing southerly low-level winds bring dewpoints into the mid 70s F northward across the Mid MO/Upper MS Valleys. This may yield one or more severe events across parts of the northern Plains to upper MS Valley, but confidence is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0317 AM CDT Sat Aug 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... A shortwave trough will move from the northern Plains into the Northeast during the Tuesday/D4 to Wednesday/D5 time frame, with an initial push of drier air southward across the Midwest/Great Lakes. Stronger instability is forecast to redevelop by Thursday/D6 and beyond as a low-amplitude upper trough moves across the northern Rockies and Plains and increasing southerly low-level winds bring dewpoints into the mid 70s F northward across the Mid MO/Upper MS Valleys. This may yield one or more severe events across parts of the northern Plains to upper MS Valley, but confidence is low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0317 AM CDT Sat Aug 09 2025 Valid 121200Z - 171200Z ...DISCUSSION... A shortwave trough will move from the northern Plains into the Northeast during the Tuesday/D4 to Wednesday/D5 time frame, with an initial push of drier air southward across the Midwest/Great Lakes. Stronger instability is forecast to redevelop by Thursday/D6 and beyond as a low-amplitude upper trough moves across the northern Rockies and Plains and increasing southerly low-level winds bring dewpoints into the mid 70s F northward across the Mid MO/Upper MS Valleys. This may yield one or more severe events across parts of the northern Plains to upper MS Valley, but confidence is low. Read more