592
WTPZ44 KNHC 260838
TCDEP4
TROPICAL STORM ISELLE DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092026
200 AM PDT WED AUG 26 2026
MODERATE NORTHERLY WIND SHEAR AND DRY AIR ENTRAINMENT ARE AFFECTING
ISELLE THIS MORNING. AN EARLIER GPM MICROWAVE PASS INDICATED THAT
THE CIRCULATION IS BETTER ESTABLISHED TO THE NORTH AND EAST OF THE
CENTER, WITH LESS DEFINITION ON THE SOUTHERN AND WESTERN SIDES. THIS
STRUCTURE IS CONSISTENT WITH INFRARED SATELLITE IMAGERY, WHICH SHOWS
SHOWER AND THUNDERSTORM ACTIVITY CONCENTRATED PRIMARILY NORTHEAST OF
THE CENTER. HOWEVER, A RECENT ASCAT SCATTEROMETER PASS INDICATED
THAT WINDS OF 40-45 KT REMAIN PRESENT IN THE NORTHEASTERN QUADRANT.
THE 0600 UTC DVORAK INTENSITY ESTIMATE FROM TAFB WAS 3.0/45 KT,
WHILE OBJECTIVE INTENSITY ESTIMATES FROM UW-CIMSS RANGE FROM 26-44
KT. GIVEN THE SCATTEROMETER DATA AND SUBJECTIVE DVORAK ESTIMATE,
THE INTENSITY IS SET AT 45 KT FOR THIS ADVISORY.
ISELLE WILL CONTINUE ON A WEST-NORTHWESTWARD HEADING OVER THE NEXT
COUPLE OF DAYS AS A RIDGE BUILDS TO THE NORTH OF THE CYCLONE.
INCREASING WIND SHEAR, COOLER SEA SURFACE TEMPERATURES AND DRIER
MID-LEVEL AIR WILL PROMOTE GRADUAL WEAKENING THROUGH LATE THIS WEEK,
AND ISELLE MAY STRUGGLE TO MAINTAIN ORGANIZED CONVECTION AS EARLY AS
TONIGHT. THE LATEST NHC FORECAST CALLS FOR ISELLE TO BECOME
POST-TROPICAL BY 24 H AND DEGENERATE TO A REMNANT LOW BY 36 H. ONLY
MINOR ADJUSTMENTS WERE MADE TO THE TRACK AND INTENSITY FORECASTS FOR
THIS ADVISORY CYCLE.
FORECAST POSITIONS AND MAX WINDS
INIT 26/0900Z 21.8N 123.5W 45 KT 50 MPH
12H 26/1800Z 22.2N 124.6W 40 KT 45 MPH
24H 27/0600Z 22.8N 126.4W 35 KT 40 MPH...POST-TROPICAL
36H 27/1800Z 23.5N 128.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 28/0600Z 23.8N 130.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 28/1800Z 24.3N 132.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 29/0600Z...DISSIPATED
FORECASTER ADAMS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page