Tropical Depression NINE-E (Text)

Tropical Depression Nine-E Discussion Number   3
NWS National Hurricane Center Miami FL       EP092021
200 AM PDT Sat Jul 31 2021
The depression remains poorly organized this morning. Deep
convection remains limited, and recent scatterometer data show that
the circulation is elongated from east to west. The initial
intensity is maintained at 25 kt, which could be generous based on
the latest ASCAT data.
As mentioned in the previous advisory, the confidence in the track
and intensity forecast for the depression is quite low due to the
current lack of organization of the system, and the potential for
some interaction with Tropical Storm Hilda located to its
northeast. The ASCAT data was helpful in pinpointing the center
location overnight, and the latest fixes indicate that the cyclone
is moving just south of due west or 265/5 kt. The track guidance
generally agrees on a slow west or west-southwest heading over the
next 12-24 hours followed by a west or west-northwest motion
through 48-60 hours.  After that time, the track guidance begins to
diverge with the GFS showing a binary interaction of the depression
and Hilda by days 4 and 5.  Most of the remainder of the guidance
keeps enough separation between the systems that the depression
continues generally moving westward or west-northwestward through
the end of the forecast period.  The NHC track forecast is once
again close to the various multi-model consensus aids, and is
slightly slower than the previous official forecast.
Although the depression is located over warm water, moderate
easterly shear and dry air entrainment have prevented strengthening
since genesis occurred.  Given the current poor organization of the
system and the marginal environment, only slow strengthening is
indicated over the next few days.  Another plausible scenario is
that the system fails to produce organization deep convection
within the next 12 to 24 hours, and it degenerates into a broad low
pressure area along the ITCZ. Given this uncertainty, the NHC
intensity forecast has been lowered slightly and is in best
agreement with the IVCN intensity aid.
INIT  31/0900Z 12.3N 127.0W   25 KT  30 MPH
 12H  31/1800Z 12.2N 127.5W   25 KT  30 MPH
 24H  01/0600Z 12.1N 128.3W   30 KT  35 MPH
 36H  01/1800Z 12.2N 129.6W   30 KT  35 MPH
 48H  02/0600Z 12.5N 131.3W   35 KT  40 MPH
 60H  02/1800Z 12.8N 132.8W   35 KT  40 MPH
 72H  03/0600Z 13.1N 134.2W   40 KT  45 MPH
 96H  04/0600Z 13.7N 136.5W   45 KT  50 MPH
120H  05/0600Z 14.5N 138.5W   45 KT  50 MPH
Forecaster Brown

Standard version of this page

Alternate Formats
About Alternates - E-Mail Advisories - RSS Feeds

Cyclone Forecasts
Latest Advisory - Past Advisories - About Advisories

Marine Forecasts
Latest Products - About Marine Products

Tools & Data
Satellite Imagery - US Weather Radar - Aircraft Recon - Local Data Archive - Forecast Verification - Deadliest/Costliest/Most Intense

Learn About Hurricanes
Storm Names Wind Scale - Prepare - Climatology - NHC Glossary - NHC Acronyms - Frequently Asked Questions - AOML Hurricane-Research Division

About Us
About NHC - Mission/Vision - Other NCEP Centers - NHC Staff - Visitor Information - NHC Library

Contact Us

NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
Privacy Policy
About Us
Career Opportunities
Page last modified: Friday, 31-Dec-2021 12:09:56 UTC