Eastern North Pacific Tropical Weather Outlook
000
ABPZ20 KNHC 251754
TWOEP
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Tue Aug 25 2026
For the eastern and central North Pacific east of 180 longitude:
Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Lala, located several hundred miles north of Pearl and Hermes
Atoll, on Tropical Storm Iselle, located several hundred miles
west of the southern tip of the Baja California Peninsula, and on
Tropical Storm Julio, located well west-southwest of the southern
tip of Baja California Peninsula.
Central East Pacific:
A tropical wave located well to the south of southern Mexico is
producing a large area of showers and thunderstorms. This system
has become become better organized since yesterday, and
environmental conditions appear favorable for further development.
A tropical depression is expected to form in a few days while it
moves generally west-northwestward at 10 to 15 mph, well offshore
of Mexico.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...high...90 percent.
Western East Pacific:
A trough of low pressure located well to the east-southeast of the
Hawaiian Islands is producing some disorganized showers and
thunderstorms. An area of low pressure is forecast to form along the
trough during the next couple of days, and environmental conditions
appear conducive for some gradual development thereafter. A tropical
depression is likely to form during the latter part of the week or
early this weekend while the system drifts northeastward, then
turns to the west-northwest.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...high...70 percent.
Well Offshore of Southern Mexico:
An area of low pressure could form well offshore of Central America
late this week or this weekend. Environmental conditions should
support some gradual development of this system, and a tropical
depression could form late this weekend or early next week while it
moves westward to west-northwestward at 10 to 15 mph well offshore
of southern Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.
Central Pacific:
An area of low pressure could form well south of the Hawaiian
Islands late this week. Some gradual development is possible by
the weekend into early next week while the system moves slowly to
the west or west-northwest, well south-southwest of the Hawaiian
Islands.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.
$$
Forecaster Blake
Summary for Tropical Storm Iselle (EP4/EP092026)
...ISELLE LIKELY TO FURTHER WEAKEN THIS WEEK... As of 2:00 PM PDT Tue Aug 25 the center of Iselle was located near 21.0, -121.8 with movement WNW at 9 mph. The minimum central pressure was 994 mb with maximum sustained winds of about 60 mph.
Tropical Storm Iselle Public Advisory Number 10
Issued at 200 PM PDT Tue Aug 25 2026000 WTPZ34 KNHC 252040 TCPEP4 BULLETIN Tropical Storm Iselle Advisory Number 10 NWS National Hurricane Center Miami FL EP092026 200 PM PDT Tue Aug 25 2026 ...ISELLE LIKELY TO FURTHER WEAKEN THIS WEEK... SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...21.0N 121.8W ABOUT 775 MI...1245 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...994 MB...29.36 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 Iselle was located near latitude 21.0 North, longitude 121.8 West. Iselle is moving toward the west-northwest near 9 mph (15 km/h), and this general motion is expected for the next couple of days, with a turn towards the west possible late on Wednesday. Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Weakening is forecast, and Iselle could become a post-tropical cyclone on Wednesday. Tropical-storm-force winds extend outward up to 230 miles (370 km) from the center. The estimated minimum central pressure is 994 mb (29.36 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Iselle are affecting the west coast of the Baja California Peninsula, and will continue for a couple more days. 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 PM PDT. $$ Forecaster Blake/Evans
Tropical Storm Iselle Forecast Advisory Number 10
Issued at 2100 UTC TUE AUG 25 2026000 WTPZ24 KNHC 252040 TCMEP4 TROPICAL STORM ISELLE FORECAST/ADVISORY NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092026 2100 UTC TUE AUG 25 2026 TROPICAL STORM CENTER LOCATED NEAR 21.0N 121.8W AT 25/2100Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 994 MB MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT. 50 KT....... 90NE 0SE 0SW 90NW. 34 KT.......200NE 170SE 60SW 120NW. 4 M SEAS....210NE 200SE 120SW 180NW. 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 21.0N 121.8W AT 25/2100Z AT 25/1800Z CENTER WAS LOCATED NEAR 20.9N 121.4W FORECAST VALID 26/0600Z 21.3N 123.0W MAX WIND 40 KT...GUSTS 50 KT. 34 KT...170NE 140SE 40SW 90NW. FORECAST VALID 26/1800Z 21.8N 124.7W MAX WIND 35 KT...GUSTS 45 KT. 34 KT...100NE 60SE 20SW 70NW. FORECAST VALID 27/0600Z 22.4N 126.6W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 27/1800Z 23.0N 128.7W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 28/0600Z 23.5N 130.6W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 28/1800Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.0N 121.8W NEXT ADVISORY AT 26/0300Z $$ FORECASTER BLAKE/EVANS
Tropical Storm Iselle Forecast Discussion Number 10
Issued at 200 PM PDT Tue Aug 25 2026000 WTPZ44 KNHC 252041 TCDEP4 Tropical Storm Iselle Discussion Number 10 NWS National Hurricane Center Miami FL EP092026 200 PM PDT Tue Aug 25 2026 The structure of Iselle has significantly degraded during the past several hours, with the low-level circulation further detaching from the mid-level center located well to the northeast. This change has caused any deep convection to be located well away from the center near the old mid-level center and is representative of a weakening cyclone. A recent ASCAT scatterometer pass showed peak winds of about 45 kt, so the initial intensity is set to 50 kt, consistent with the low bias of the instrument. Further weakening is anticipated due to continued shear, progressively cooler water and dry air entrainment near the core of the cyclone. Perhaps because of the poor initial structure, Iselle isn't expected to be a particularly resilient cyclone, and no model shows organized deep convection beyond 36 hours. The new NHC intensity forecast is lower than the last one, keeping the same general rate of weakening, but it shows a much earlier transition into a remnant low. Satellite fixes show that the storm continues to move to the west-northwest, and little change in track is anticipated for the next couple of days due to ridging extending from the southern United States. As the storm weakens, it should turn more westward by Thursday due to the cyclone becoming steered more by the low-level flow. The guidance is shifting southward, consistent with a decaying system, so the new forecast is shifted equatorward, closest to the Google DeepMind ensemble mean. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 21.0N 121.8W 50 KT 60 MPH 12H 26/0600Z 21.3N 123.0W 40 KT 45 MPH 24H 26/1800Z 21.8N 124.7W 35 KT 40 MPH 36H 27/0600Z 22.4N 126.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 27/1800Z 23.0N 128.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 28/0600Z 23.5N 130.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 28/1800Z...DISSIPATED $$ Forecaster Blake/Evans
Tropical Storm Iselle Wind Speed Probabilities Number 10
Issued at 2100 UTC TUE AUG 25 2026 000
FOPZ14 KNHC 252041
PWSEP4
TROPICAL STORM ISELLE WIND SPEED PROBABILITIES NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092026
2100 UTC TUE AUG 25 2026
AT 2100Z THE CENTER OF TROPICAL STORM ISELLE WAS LOCATED NEAR
LATITUDE 21.0 NORTH...LONGITUDE 121.8 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
18Z TUE 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 TUE 06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT
PERIODS TO TO TO TO TO TO TO
06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT 18Z SUN
FORECAST HOUR (12) (24) (36) (48) (72) (96) (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
LOCATION KT
20N 120W 34 99 X(99) X(99) X(99) X(99) X(99) X(99)
20N 125W 34 1 3( 4) X( 4) X( 4) X( 4) X( 4) X( 4)
25N 130W 34 X X( X) X( X) 2( 2) 3( 5) X( 5) X( 5)
$$
FORECASTER BLAKE
Tropical Storm Iselle Graphics
Wind Speed Probabilities last updated Tue, 25 Aug 2026 20:59:00 GMT
Summary for Remnants of Julio (EP5/EP102026)
...JULIO DISSIPATES... ...THIS IS THE LAST ADVISORY... As of 2:00 PM PDT Tue Aug 25 the center of Julio was located near 21.0, -119.5 with movement N at 25 mph. The minimum central pressure was 1003 mb with maximum sustained winds of about 45 mph.
Remnants of Julio Public Advisory Number 5
Issued at 200 PM PDT Tue Aug 25 2026312 WTPZ35 KNHC 252038 TCPEP5 BULLETIN Remnants Of Julio Advisory Number 5 NWS National Hurricane Center Miami FL EP102026 200 PM PDT Tue Aug 25 2026 ...JULIO DISSIPATES... ...THIS IS THE LAST ADVISORY... SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...21.0N 119.5W ABOUT 630 MI...1010 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...N OR 350 DEGREES AT 25 MPH...41 KM/H MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 200 PM PDT (2100 UTC), the remnants of Julio were located near latitude 21.0 North, longitude 119.5 West. The remnants are moving toward the north near 25 mph (41 km/h) and are expected to move northwestward into the circulation of Iselle tonight. Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Weakening is expected as the remnants decay tonight. Tropical-storm-force winds extend outward up to 90 miles (150 km) from the center. The estimated minimum central pressure is 1003 mb (29.62 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- This is the last public advisory issued by the National Hurricane Center on this system. For additional information on the remnants of Julio, please see High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFEPI, WMO header FZPN01 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php $$ Forecaster Blake/Evans
Remnants of Julio Forecast Advisory Number 5
Issued at 2100 UTC TUE AUG 25 2026311 WTPZ25 KNHC 252038 TCMEP5 REMNANTS OF JULIO FORECAST/ADVISORY NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102026 2100 UTC TUE AUG 25 2026 REMNANTS OF CENTER LOCATED NEAR 21.0N 119.5W AT 25/2100Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTH OR 350 DEGREES AT 22 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1003 MB MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT. 34 KT....... 80NE 60SE 0SW 0NW. 4 M SEAS.... 90NE 120SE 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 21.0N 119.5W AT 25/2100Z AT 25/1800Z CENTER WAS LOCATED NEAR 19.5N 118.8W FORECAST VALID 26/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.0N 119.5W THIS IS THE LAST FORECAST/ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM. FOR ADDITIONAL INFORMATION ON THE REMNANTS OF JULIO PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFEPI AND WMO HEADER FZPN01 KWBC. $$ FORECASTER BLAKE/EVANS
Remnants of Julio Forecast Discussion Number 5
Issued at 200 PM PDT Tue Aug 25 2026000 WTPZ45 KNHC 252040 TCDEP5 Remnants Of Julio Discussion Number 5 NWS National Hurricane Center Miami FL EP102026 200 PM PDT Tue Aug 25 2026 Satellite and microwave data indicate that the circulation of Julio has opened up into a trough of low pressure. Thus, it is no longer a tropical cyclone, and this is the last NHC advisory. The initial wind speed is set to 40 kt, consistent with the ASCAT-B pass from a few hours ago. The remnant vorticity should wrap into the circulation of Tropical Storm Iselle and totally lose any identity soon. For additional information on the remnants please see High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFEPI, WMO header FZPN01 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 21.0N 119.5W 40 KT 45 MPH...REMNANTS OF 12H 26/0600Z...DISSIPATED $$ Forecaster Blake/Evans
Remnants of Julio Wind Speed Probabilities Number 5
Issued at 2100 UTC TUE AUG 25 2026 448
FOPZ15 KNHC 252039
PWSEP5
REMNANTS OF JULIO WIND SPEED PROBABILITIES NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102026
2100 UTC TUE AUG 25 2026
AT 2100Z THE REMNANTS OF JULIO WERE LOCATED NEAR LATITUDE 21.0 NORTH
...LONGITUDE 119.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 40 KTS...
45 MPH...75 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 TUE 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 TUE 06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT
PERIODS TO TO TO TO TO TO TO
06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT 18Z SUN
FORECAST HOUR (12) (24) (36) (48) (72) (96) (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
LOCATION KT
$$
FORECASTER BLAKE/EVANS
Remnants of Julio Graphics
Wind Speed Probabilities last updated Tue, 25 Aug 2026 20:41:37 GMT