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 SIX


ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION SIX DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT THU JUL 21 2005
 
AIR FORCE RECON AIRCRAFT HAS BEEN INVESTIGATING THE STRONG TROPICAL
WAVE JUST EAST OF THE BAHAMAS AND HAVE FOUND WINDS THAT SUPPORT AT
LEAST A 30-KT TROPICAL DEPRESSION...AND ADVISORIES HAVE BEEN
INITIATED ON TD-6. CONVECTION HAS DECREASED SOMEWHAT NEAR THE
CENTER OVER THE PAST COUPLE OF HOURS...BUT THIS IS TYPICAL FOR THIS
TIME OF THE DAY. UPPER-LEVEL OUTFLOW HAS CONTINUED TO IMPROVE
DURING THE DAY...INCLUDING THE RESTRICTED SOUTHWEST QUADRANT.

THE INITIAL MOTION ESTIMATE IS 300/11...BASED ON THE PAST 3 HOURS OF
SATELLITE POSITIONS. THE FORECAST TRACK IS SOMEWHAT PROBLEMATIC.
THE GLOBAL MODELS TAKE THE SURFACE TO 850 MB CIRCULATION NORTHWARD
AND THEN RECURVE IT NORTHEASTWARD THROUGH THE SUBTROPICAL RIDGE.
HOWEVER...ALL OF THE MODELS GENERALLY AGREE THAT THE MID-LEVEL/500
MB CIRCULATION WILL MOVE INTO THE RIDGE AXIS AND STALL IN ABOUT 48
HOURS AS A SHORTWAVE TROUGH MOVES NORTHEAST OF THE DEPRESSION AND
ALLOWS THE RIDGE TO BUILD BACK IN TO THE WEST. AFTER THAT...SOME OF
THE MODELS MEANDER THE SYSTEM SLOWLY EAST OR SOUTHWARD...WHILE THE
GFS AND GFDL MODELS TAKE THE MID-LEVEL CIRCULATION SOUTHWESTWARD
TOWARD FLORIDA. THE MEDIUM AND DEEP BAM MODELS ACTUALLY TAKE THE
DEPRESSION SLOWLY WESTWARD AFTER 48 HOURS ACROSS CENTRAL FLORIDA.
GIVEN THE LARGE SPREAD IN THE MODEL GUIDANCE...WHICH TYPICALLY
SUGGESTS SLOW MOTION...THE FORECAST TRACK SHOWS A GRADUAL TURN TO
THE NORTH AFTER 24 HOURS AND THEN TURNS THE CYCLONE SLOWLY EASTWARD
AND MAKING A SMALL CLOCKWISE LOOP WELL EAST OF THE CENTRAL FLORIDA
COAST.

THE WATER AHEAD OF THE DEPRESSION IS QUITE WARM...AROUND 29C...AND
THE SHEAR IS FORECAST REMAIN LOW WITH A FAVORABLE OUTFLOW PATTERN
FOR THE NEXT 36 TO 48 HOURS. THEREFORE...THE DEPRESSION COULD REACH
HURRICANE STRENGTH WITHIN 48 TO 72 HOURS. NOTE...THE AIRCRAFT HAS
JUST REPORTED AT 2114Z FLIGHT-LEVEL WINDS OF 48 KT...WHICH WOULD
NORMALLY SUPPORT UPGRADING THE DEPRESSION TO A TROPICAL STORM.
HOWEVER...CONVECTION HAS BEEN WEAKENING AND WE WOULD PREFER TO SEE
DEEP CONVECTION PERSIST BEFORE UPGRADING THIS SYSTEM TO A TROPICAL
STORM.

FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/2100Z 25.3N  75.4W    30 KT
 12HR VT     22/0600Z 26.3N  76.8W    35 KT
 24HR VT     22/1800Z 27.5N  77.5W    40 KT
 36HR VT     23/0600Z 28.5N  77.6W    45 KT
 48HR VT     23/1800Z 29.0N  77.0W    50 KT
 72HR VT     24/1800Z 29.0N  76.5W    60 KT
 96HR VT     25/1800Z 28.5N  76.0W    60 KT
120HR VT     26/1800Z 28.0N  76.5W    60 KT
  
$$
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: Thursday, 21-Jul-2005 21:40:03 UTC