Skip Navigation Links weather.gov   
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
   Audio/Podcasts
   About Advisories
Marine Forecasts
   Atlantic & E Pacific
   Gridded Marine
   About Marine
Tools & Data
   Satellite | Radar
   Analysis Tools
   Aircraft Recon
   GIS Datasets
   Data Archive
Development
   Experimental
   Research
   Forecast Accuracy
Outreach & Education
   Prepare
   Storm Surge
   About Cyclones
   Cyclone Names
   Wind Scale
   Most Extreme
   Forecast Models
   Breakpoints
   Resources
   Glossary | Acronyms
   Frequent Questions
Our Organization
   About NHC
   Mission & Vision
   Staff | Q&A
   Visitors | Virtual Tour
   Library Branch
   NCEP | Newsletter
Contact Us
   Comments
Follow the National Hurricane Cent
er on Facebook Follow the National Hurricane Center on Twitter
FirstGov.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.
 
 

Tropical Depression NINE


ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
 
TROPICAL DEPRESSION NINE DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092013
500 PM AST SUN SEP 08 2013
 
SATELLITE IMAGES INDICATE THAT THE LOW PRESSURE SYSTEM BETWEEN THE
CAPE VERDE ISLANDS AND THE WEST COAST OF AFRICA HAS DEVELOPED
ENOUGH CONVECTIVE ORGANIZATION TO BE DESIGNATED AS A TROPICAL
DEPRESSION.  THE INITIAL INTENSITY IS SET AT 25 KT BASED ON DVORAK
ESTIMATES OF T2.0 FROM TAFB AND T1.5 FROM SAB.  THE LOW-LEVEL
CENTER APPEARS TO BE ON THE EASTERN EDGE OF THE DEEP CONVECTION DUE
TO A LITTLE BIT OF NORTHEASTERLY SHEAR.
 
THE INITIAL MOTION ESTIMATE IS 270/9 KT.  THE DEPRESSION IS LOCATED
TO THE SOUTH OF A LARGE MID-TROPOSPHERIC ANTICYCLONE CENTERED NEAR
THE AZORES...AND THE CURRENT WESTWARD MOTION IS EXPECTED TO
CONTINUE FOR ANOTHER 36 HOURS OR SO.  AFTER THAT TIME...THE
ANTICYCLONE IS FORECAST TO WEAKEN WHILE A CLOSED MID/UPPER-LEVEL
LOW DEVELOPS NEAR THE CANARY ISLANDS AND A RIDGE BUILDS WESTWARD
FROM AFRICA.  THIS PATTERN WILL ALLOW THE DEPRESSION TO TURN RATHER
SHARPLY TO THE NORTH-NORTHWEST AFTER 48 HOURS AND CONTINUE THAT
TRAJECTORY THROUGH THE END OF THE FORECAST PERIOD.  SURPRISINGLY...
THE LARGEST SPREAD AMONG THE TRACK GUIDANCE OCCURS WITHIN THE FIRST
48 HOURS OR SO...BUT THE MODELS SEEMS TO CONVERGE BY 72 HOURS.  THE
NHC OFFICIAL TRACK FORECAST IS CLOSE TO THE MODEL CONSENSUS FOR
MUCH OF THE FORECAST.
 
A MOIST AIR MASS...WARM WATERS...AND RELATIVELY LIGHT SHEAR SHOULD
ALLOW THE DEPRESSION TO STRENGTHEN AT LEAST GRADUALLY DURING THE
NEXT FEW DAYS.  HOWEVER...SOME OF THE MODELS...MAINLY THE
STATISTICAL-DYNAMICAL GUIDANCE...ARE FAIRLY AGGRESSIVE WITH THE
INTENSIFICATION RATE AFTER 24 HOURS.  SHIPS AND LGEM HAVE TENDED TO
HAVE A HIGH BIAS THIS HURRICANE SEASON...SO THE OFFICIAL FORECAST
IS KEPT A BIT LOWER.  THE FORECAST DOES...HOWEVER...ANTICIPATE THE
CYCLONE BECOMING A HURRICANE BY 72 HOURS.
 
GIVEN THE FORECAST...AND THE UNCERTAINTY WITH HOW BIG THE WIND FIELD
WILL GET ONCE THE DEPRESSION BECOMES A TROPICAL STORM...A TROPICAL
STORM WARNING HAS BEEN ISSUED FOR THE SOUTHERN CAPE VERDE ISLANDS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/2100Z 13.1N  20.7W   25 KT  30 MPH
 12H  09/0600Z 13.2N  22.1W   30 KT  35 MPH
 24H  09/1800Z 13.5N  24.3W   35 KT  40 MPH
 36H  10/0600Z 13.9N  26.5W   40 KT  45 MPH
 48H  10/1800Z 14.5N  27.9W   55 KT  65 MPH
 72H  11/1800Z 17.5N  29.5W   70 KT  80 MPH
 96H  12/1800Z 21.0N  31.0W   70 KT  80 MPH
120H  13/1800Z 23.5N  32.5W   65 KT  75 MPH
 
$$
FORECASTER BERG
 
NNNN


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
nhcwebmaster@noaa.gov
Disclaimer
Credits
Information Quality
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities
Page last modified: Monday, 07-Apr-2014 23:29:01 UTC