Tropical Storm Iba Discussion Number 13
Wiki-Hurricanes Forecast Center
06:00 PM AST Tue Mar 26 2019
The convective activity that grew this morning near Iba's center of circulation has since abated, leaving the center of circulation once again exposed as strong westerly upper-level winds quickly shear any new convection eastwards. New convectie growth this evening is currently limited to a banded region well east of the center, and it appears that a continued local streak in these strong upper-level winds will maintain an unfavorable environment over Iba. SAB estimates have fallen to T2.5/35kt. A blend of the 1212z ASCAT-B scatterometer data and the velocity of the low-level cloud lines supports maintaining the intensity tentatively at 35 kt for this advisory.
There are no changes to either the track or intensity philosophy for this advisory. The system is expected to continue drifting towards the southeast towards a weakeness between two subtropical ridges over the South Atlantic and Uruguay. The impinging subtropical jet jet during this time will continue to shear the system and advect dry air, weakening the tropical storm. The divergent region of the subtropical jet streak may develop a broad trough in the vicinity of Iba's remnants that will likely elongate whatever remains of Iba's circulation are left.
FORECAST MAX WINDS
INIT 26/2100Z 35 KT 40 MPH
12H 27/0600Z 30 KT 35 MPH
24H 27/1800Z 30 KT 40 MPH
36H 28/0600Z 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 28/1800Z 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 29/1800Z 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 30/1800Z...ABSORBED BY TROUGH