Skip Navigation Links   
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
National Hurricane Center
Local forecast by
"City, St" or "ZIP"

Alternate Formats
   Text     |   Mobile
   Email   |   RSS XML/RSS logo
   About Alternates
Cyclone Forecasts
   Latest Advisory
   Past Advisories
   About Advisories
Marine Forecasts
   Atlantic & E Pacific
   Gridded Marine
   About Marine
Tools & Data
   Satellite | Radar
   Analysis Tools
   Aircraft Recon
   GIS Datasets
   Data Archive
   Forecast Accuracy
Outreach & Education
   Storm Surge
   About Cyclones
   Cyclone Names
   Wind Scale
   Most Extreme
   Forecast Models
   Glossary | Acronyms
   Frequent Questions
Our Organization
   About NHC
   Mission & Vision
   Staff | Q&A
   Visitors | Virtual Tour
   Library Branch
   NCEP | Newsletter
Contact Us
Follow the National Hurricane Center on Facebook Follow the National Hurricane Center on Twitter
Subscribe the National Hurricane Center on YouTube Read the National Hurricane Center Inside the Eye blog on WordPress is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Tropical Storm ISELLE Forecast Discussion

Home   Public Adv   Fcst Adv   Discussion   Wind Probs   Graphics   Archive  

WTPZ44 KNHC 010226

800 PM PDT THU JUL 31 2014

The satellite presentation of Iselle features an area of cold
convective tops mainly to the north and east of the estimated center
position, and the poleward outflow has been enhanced somewhat due to
an upper-level trough to the northwest. The initial intensity has
been raised to 40 kt based on a blend of the TAFB Dvorak estimate
and the latest ADT from UW-CIMSS. Conditions appear favorable for
steady intensification during the next couple of days. In fact,
rapid strengthening is a possibility during the next 24 hours with
the SHIPS RI index showing a 40 percent chance of a 25-kt increase
in the next 24 hours. After 72 hours SSTs cool somewhat along the
forecast track, which should result in gradual weakening. The NHC
intensity forecast has been adjusted upward a little from the
previous advisory and is close to or just below the SHIPS model
through the period and above the intensity consensus.

The initial motion estimate is a somewhat uncertain 290/10 given the
recent formation of the cyclone, and the initial position is a
little to the south and west of previous estimates. Overall the
track forecast reasoning has not changed, as Iselle will be steered
generally west-northwestward south of the subtropical ridge for the
next 72 hours or so. After that time, the ridge weakens as a
mid/upper-level trough digs equatorward along 135W, which should
result is a slower westward motion late in the period. The track
guidance envelope remains tightly clustered for the first 48 hours
and the only change to the NHC track during that time is a westward
adjustment due to the initial position and motion. Late in the
period the spread of the guidance increases a little, and the
envelope has shifted northward this cycle. At days 3 through 5 the
NHC track has been adjusted northward and westward, but still lies
south of the TVCE multi-model consensus.


INIT  01/0300Z 13.2N 123.9W   40 KT  45 MPH
 12H  01/1200Z 13.8N 125.1W   50 KT  60 MPH
 24H  02/0000Z 14.6N 126.7W   60 KT  70 MPH
 36H  02/1200Z 15.2N 128.3W   65 KT  75 MPH
 48H  03/0000Z 15.6N 130.1W   70 KT  80 MPH
 72H  04/0000Z 16.5N 134.0W   70 KT  80 MPH
 96H  05/0000Z 16.5N 136.5W   60 KT  70 MPH
120H  06/0000Z 16.5N 140.0W   55 KT  65 MPH

Forecaster Brennan

Quick Navigation Links:
Tropical Cyclone Forecasts  -  Tropical Marine Forecasts  -  Data Archive
Outreach  -  Prepare  -  About Cyclones  -  About NHC  -  Contact Us

NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida 33165-2149 USA
Information Quality
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities
Page last modified: Friday, 01-Aug-2014 02:26:48 UTC