5am Hurricane Olivia Update
Olivia is still slowly weakening, with a continued erosion of the
eyewall convection in the northwestern quadrant. The various
subjective and objective satellite intensity estimates are now in
the 90-100 kt range, and the initial intensity is reduced to 95 kt
given the decay in the cloud pattern since the previous advisory.
Olivia is currently experiencing moderate easterly shear, but the
guidance suggests this should decrease during the next 12-24 h.
Therefore, the major influences on the intensity should be gradually
decreasing sea surface temperatures along the forecast track and
entrainment of dry air. The intensity guidance is in good agreement
that Olivia should weaken through the forecast period, and based on
this the new intensity forecast is an update of the previous
forecast. There is a chance that Olivia could weaken faster than
currently forecast during the first 24 h if the current convective
trend continues.
The initial motion is 280/11. There is no change to the forecast
philosophy from the previous advisory, and there are only minor
adjustments to the forecast track. A building subtropical ridge
over the eastern Pacific to the north of Olivia should induce a
general west-northwestward motion with increasing forward speed
during the next several days. Toward the end of the forecast
period, global models continue to show a stronger ridge that would
turn Olivia back to a westward motion. The track guidance is in
good agreement with this scenario, although the UKMET and the UKMET
ensemble mean show a motion to the north of the other models.
