Tropical Storm Iselle

EP092026 Eastern Pacific

Current Conditions

As of Aug 27, 03:00 AM UTC

Position
23.0°N 125.9°W
Intensity
30 kt
Pressure
1002.0 mb
Classification
Post-Tropical Cyclone
Movement
300° at 8 kt

Track & cone

Best track Forecast track Cone
Intensity: D TD TS Cat 1 Cat 2 Cat 3 Cat 4 Cat 5 L Post-tropical / low Radii: 34 50 64 kt · click points for detail
NHC Advisory 015 Aug 27, 02:33 AM UTC
000
WTPZ44 KNHC 270233
TCDEP4
 
Post-Tropical Cyclone Iselle Discussion Number  15
NWS National Hurricane Center Miami FL       EP092026
800 PM PDT Wed Aug 26 2026

Iselle continues to have no deep convective organization this 
evening with the low-level center still fully exposed due to dry air 
and moderate wind shear. With the lack of convection occuring, 
Iselle is now considered to have become a Post-Tropical Cyclone. The 
most recent TAFB Dvorak fix has 1.5/25 kt and the objective 
satellite intensity estimates are in the range of 25-43 kt. Based on 
that data, the current NHC initial intensity has been set to 30 kt.

Iselle should continue to move west-northwestward over the next 
couple of days, steered by a mid-level ridge to the north of the 
cyclone. Increasing wind shear, cooler sea surface temperatures, and 
a drier air mass will continue to weaken the system. The 
post-tropical remnant low is expected to gradually spin down 
and open into a trough in about 2 to 3 days. However, it still 
remains possible that the cyclone could spin down even sooner. Very 
minor adjustments were made to the previous NHC track and intensity 
forecasts.

For additional information on the remnant low 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  27/0300Z 23.0N 125.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 12H  27/1200Z 23.6N 127.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  28/0000Z 24.3N 128.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 36H  28/1200Z 24.8N 130.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  29/0000Z 25.3N 131.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
 60H  29/1200Z...DISSIPATED
 
$$
Forecaster Katz/Hagen/Papin
 

Track

Time Position Intensity Pressure Class
Observed · best track
Aug 25, 12:00 AM UTC 19.6°N 118.2°W 60 kt 988.0 mb Tropical Storm
Aug 25, 06:00 AM UTC 20.4°N 119.6°W 60 kt 988.0 mb Tropical Storm
Aug 25, 12:00 PM UTC 20.8°N 120.7°W 60 kt 988.0 mb Tropical Storm
Aug 25, 06:00 PM UTC 20.9°N 121.4°W 50 kt 994.0 mb Tropical Storm
Aug 26, 12:00 AM UTC 21.1°N 122.1°W 45 kt 996.0 mb Tropical Storm
Aug 26, 06:00 AM UTC 21.7°N 122.7°W 40 kt 999.0 mb Tropical Storm
Aug 26, 12:00 PM UTC 21.9°N 123.6°W 40 kt 999.0 mb Tropical Storm
Aug 26, 06:00 PM UTC 22.5°N 124.5°W 40 kt 1000.0 mb Tropical Storm
Aug 27, 12:00 AM UTC 22.8°N 125.5°W 30 kt 1002.0 mb Tropical Depression
Aug 27, 03:00 AM UTC 23.0°N 125.9°W 30 kt 1002.0 mb Post-Tropical Cyclone
Forecast NHC official · issued Aug 27, 12:00 AM UTC
Aug 27, 12:00 PM UTC +12h 23.6°N 127.2°W 25 kt — Low
Aug 28, 12:00 AM UTC +24h 24.3°N 128.8°W 20 kt — Low
Aug 28, 12:00 PM UTC +36h 24.8°N 130.2°W 20 kt — Low
Aug 29, 12:00 AM UTC +48h 25.3°N 131.6°W 20 kt — Low

Recon & fixes

Latest fix

Microwave

Newest observation of any type. No aircraft fix received for this storm.

Aug 26, 09:56 PM UTC 61 d ago
Pressure
999.0 mb measured
Wind
36 kt surface
Reference position
22.6°N 125.1°W

CIMSS ADT/AiDT/DPRINT CIMSS SSMIS/DMINT

Time Source Position Wind Pressure Notes
Aug 26, 09:56 PM UTC Microwave 22.6°N 125.1°W ref 36 kt 999.0 mb meas CIMS · CIMSS ADT/AiDT/DPRINT CIMSS SSMIS/DMINT
Aug 26, 09:00 PM UTC Dvorak (subjective) 22.8°N 125.1°W — — TAFB
Aug 26, 09:00 PM UTC Microwave 22.5°N 124.9°W ref 35 kt 1000.0 mb meas CIMS · CIMSS ADT/AiDT/DPRINT CIMSS SSMIS/DMINT
Aug 26, 08:40 PM UTC Dvorak (objective) 22.5°N 124.9°W ref 25 kt 1003.0 mb CIMS
Aug 26, 06:25 PM UTC Scatterometer 22.4°N 124.6°W — — KNHC · 33 kt max wind. Used 32 kt vectors for 34 kt radii
Aug 26, 06:01 PM UTC Scatterometer 22.4°N 124.7°W 34 kt — NHC · ASCAT-B
Aug 26, 06:00 PM UTC Dvorak (subjective) 22.5°N 124.5°W 30 kt 1009.0 mb TAFB · DT agrees with Pattern T. MET a 2.0. Rules seem to b
Aug 26, 05:40 PM UTC Dvorak (objective) 22.3°N 124.4°W ref 25 kt 999.0 mb CIMS
Aug 26, 03:00 PM UTC Dvorak (subjective) 22.4°N 124.0°W — — TAFB
Aug 26, 02:40 PM UTC Dvorak (objective) 22.2°N 124.0°W ref 25 kt 999.0 mb CIMS
Aug 26, 12:00 PM UTC Dvorak (subjective) 21.8°N 123.6°W 35 kt 1005.0 mb TAFB
Aug 26, 11:40 AM UTC Dvorak (objective) 22.0°N 123.9°W ref 25 kt 999.0 mb CIMS

95 observations · 17 ATCF working-record analysis records not shown
Observed fixes from NHC's ATCF fix deck. Operational data, subject to later revision.