Image Department Meteorology
Meteorology_Home Weather_Server News/Seminars
People
Research
Academics Application Contact_Us

Hawaiian_Weather
US_Mainland_Weather
Tropical_Weather
Satellite_Imagery
Radar_Imagery
Marine
Numerical_Models
LAPS
Forecasts
Observations
Archive
Links Disclaimer
Space
SOEST_Home
University_of_Hawaii_Home

 934 
 WTPZ42 KNHC 070903 CCA
 TCDEP2
 
 Hurricane Olivia Discussion Number  27...Corrected
 NWS National Hurricane Center Miami FL       EP172018
 200 AM PDT Fri Sep 07 2018
 
 Corrected second paragraph about previous category-4 strength
 
 Olivia's overall cloud structure in infrared and passive microwave
 satellite imagery has changed little since the previous advisory,
 except that the cloud tops have warmed significantly around the
 well-defined, 20-nmi-diameter eye. As a result, both subjective and
 objective intensity estimates have decreased markedly since Olivia
 briefly gained category-4 strength on the previous advisory.
 However, microwave imagery indicates that Olivia has evolved into an
 annular hurricane, with only inner-core convection present and no
 banding features. As a result, the initial intensity only been
 decreased to 110 kt, which is a typical slower rate of weakening for
 annular hurricanes.
 
 The initial motion estimate is 290/13 kt. There is no significant
 change to the previous forecast track or reasoning. Olivia is
 expected to continue moving west-northwestward for the next 24-36
 hours, followed by a westward motion as the hurricane nudges up
 against a strong deep-layer subtropical ridge that stretches from
 Mexico and the southwestern U.S. westward into the central Pacific.
 The new NHC forecast track is essentially just an extension of the
 previous advisory track and is down the middle of the very tightly
 packed model guidance, closest to the speed of the TVCN consensus
 track model.
 
 As mentioned in the previous advisory discussion, the current
 annular pattern indicates that Hurricane Olivia should weaken more
 slowly than indicated by guidance, even though the cyclone will be
 moving over slightly cooler SSTS of about 25.5 deg C by 36 h. The
 low shear environment that the cyclone will be embedded in should
 help to offset some of the negative effects of the cooler waters.
 After that time, Olivia will move back over slightly warmer
 waters and remain in a low shear environment, so a little leveling
 off in the weakening process is forecast until 96 hours. On day 5,
 however, southwesterly vertical wind shear of 15-20 kt is expected
 to induce more significant weakening at that time. The official
 intensity forecast is similar to, but higher than, the consensus
 models, and more closely follows a blend of the dynamical models
 HWRF and HMON.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  07/0900Z 19.6N 131.2W  110 KT 125 MPH
  12H  07/1800Z 20.2N 133.1W  100 KT 115 MPH
  24H  08/0600Z 20.9N 135.7W   90 KT 105 MPH
  36H  08/1800Z 21.4N 138.3W   80 KT  90 MPH
  48H  09/0600Z 21.7N 140.9W   75 KT  85 MPH
  72H  10/0600Z 22.0N 145.6W   70 KT  80 MPH
  96H  11/0600Z 21.9N 149.6W   65 KT  75 MPH
 120H  12/0600Z 21.0N 153.5W   55 KT  65 MPH
 
 $$
 Forecaster Stewart
 
 
Return to the Tropical Systems Page for OLIVIA

Back to main Tropical Weather page




This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students.
It was last modified on: Thu, Jul 23 2020 - 2003 UTC
Send comments to: Ryan Lyman