| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

Tropical Storm GUILLERMO (Text)


ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
 
Tropical Storm Guillermo Discussion Number   2
NWS National Hurricane Center Miami FL       EP072021
300 PM MDT Sat Jul 17 2021
 
Fragmented convective banding has gradually increased since the 
previous advisory, with a very tight low-level vortex having become 
evident over the center in high-resolution visible satellite 
imagery. Low-cloud motion vectors in the inner-core region have 
been around 45 kt, which equals approximately 34-kt surface winds if 
the cloud motions represent the 925-mb level. Satellite current 
intensity (CI) estimates remain T2.5/35 kt from TAFB and and SAB. 
The latest UW-CIMSS ADT estimate is T2.2/32 kt, with the raw and 
adjusted T-numbers at 37 kt and 36 kt, respectively. Based on these 
data, the intensity has been increased to 35 kt, making the cyclone 
Tropical Storm Guillermo.

The initial motion estimate is 295/12 kt. There are no significant 
changes to the previous track forecast or reasoning. The global and 
regional models remain in very good agreement on Guillermo moving 
west-northwestward today, and then turning toward the west later 
tonight or early Sunday, with a general westward motion continuing 
through day 3. By days 4 and 5, the deep-layer ridge to the north of 
Guillermo is forecast by the models to gradually build southward, 
forcing the tropical storm west-southwestward. The latest NHC model 
guidance has converged tightly around the previous forecast track 
through 96 h, so no adjustments were made. The new official forecast 
track lies close to the tightly packed consensus models, which are 
about midway between the stronger GFS track forecast on the right 
side of the guidance envelope and the weaker ECMWF solution on the 
left or south side.
 
Guillermo is expected to remain within a low vertical wind shear 
regime and a moist mid-level environment, and over sea-surface 
temperatures (SST) of at least 27C for the next 48 hours or so. 
These favorable conditions should allow for at least modest 
strengthening to occur during that time, with the only hindering 
factor being Guillermo's large circulation. By 60 hours and beyond, 
the cyclone will be moving over sub-26C SSTs, which should induce 
gradual weakening despite the low vertical wind shear pattern. The 
new NHC intensity forecast is similar to the previous advisory, and 
closely follows the NOAA-HCCA corrected consensus model, which is 
above most of the available intensity guidance.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  17/2100Z 17.1N 110.1W   35 KT  40 MPH
 12H  18/0600Z 17.6N 111.7W   45 KT  50 MPH
 24H  18/1800Z 18.0N 113.9W   50 KT  60 MPH
 36H  19/0600Z 18.3N 116.2W   55 KT  65 MPH
 48H  19/1800Z 18.4N 118.7W   55 KT  65 MPH
 60H  20/0600Z 18.5N 121.2W   50 KT  60 MPH
 72H  20/1800Z 18.4N 123.8W   45 KT  50 MPH
 96H  21/1800Z 18.1N 128.9W   35 KT  40 MPH
120H  22/1800Z 17.8N 134.1W   30 KT  35 MPH
 
$$
Forecaster Stewart
 
NNNN

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
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Friday, 31-Dec-2021 12:09:53 UTC