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 GUILLERMO Forecast Discussion

Home   Public Adv   Fcst Adv   Discussion   Wind Probs   Graphics   Archive  

WTPZ44 KNHC 302032

200 PM PDT THU JUL 30 2015

Guillermo is quickly becoming better organized, and both microwave
and visible imagery suggest that the cyclone is developing a ring
of inner core convection.  Dvorak classifications at 1800 UTC were
T3.0/45 kt from both TAFB and SAB, but given the quickly improving
convective structure, the advisory intensity is set at 50 kt.  This
is close to the latest UW-CIMSS ADT estimate of T3.4/53 kt.

The upper-level outflow of Guillermo continues to expand, and the
storm is over very warm waters of around 29 degrees Celsius.  Global
model guidance indicates that Guillermo should remain in a
light-shear environment for at least another 3 days, while also
remaining over warm water and in a moisture-laden atmosphere.
Therefore, continued strengthening is likely for the next 48 hours,
and Guillermo could become a hurricane within the next 12-24 hours.
Gradual weakening is forecast from day 3 through 5 due to stronger
upper-level westerly winds which could affect the cyclone.  The
statistical-dynamical guidance continues to show only modest
strengthening--barely taking Guillermo to hurricane status--but
this scenario seems low given the seemingly favorable environment.
The NHC official intensity forecast remains closer to the higher
dynamical guidance and is largely unchanged from the previous

The subtropical ridge is steering Guillermo west-northwestward, or
295/12 kt.  The ridge is forecast to strengthen slightly, causing
Guillermo to accelerate during the next 36 hours.  After that time,
a mid- to upper-level low well west of California is expected to
produce a break in the ridge, which should cause the cyclone to
slow down and turn northwestward by day 5.  The latest track
guidance ended up lying to the west of the previous official
forecast track, and the updated NHC track has therefore been
shifted a bit to the left, especially after 48 hours.


INIT  30/2100Z  9.8N 128.4W   50 KT  60 MPH
 12H  31/0600Z 10.6N 130.6W   60 KT  70 MPH
 24H  31/1800Z 11.5N 133.7W   70 KT  80 MPH
 36H  01/0600Z 12.4N 136.8W   75 KT  85 MPH
 48H  01/1800Z 13.2N 139.4W   80 KT  90 MPH
 72H  02/1800Z 14.9N 143.3W   75 KT  85 MPH
 96H  03/1800Z 16.5N 146.0W   65 KT  75 MPH
120H  04/1800Z 18.0N 148.5W   55 KT  65 MPH

Forecaster Berg

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 USA
Information Quality
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities
Page last modified: Thursday, 30-Jul-2015 20:32:09 UTC