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 Storm IRWIN


ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
 
TROPICAL STORM IRWIN DISCUSSION NUMBER  24
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112011
800 PM PDT TUE OCT 11 2011
 
THE CONVECTIVE PATTERN OF IRWIN HAS CHANGED CONSIDERABLY DURING THE
LAST SEVERAL HOURS. AROUND 1800 UTC...A FAIRLY CIRCULAR AREA OF
CONVECTION EXISTED NEAR THE ESTIMATED LOW-LEVEL CENTER.  SINCE THAT
TIME...THE CONVECTION HAS BECOME MUCH MORE SPREAD OUT WITH THE MAIN
AREA IN A RAGGED-LOOKING CLUSTER TO THE NORTH OF THE CENTER. THE
INITIAL WIND SPEED IS HELD AT 40 KT...WHICH IS IN AGREEMENT WITH
THE DVORAK CI NUMBERS FROM TAFB AND SAB...AND ADT ESTIMATES FROM
UW-CIMSS.
 
IRWIN CONTINUES TO MOVE JUST SOUTH OF DUE EAST...AND THE INITIAL
MOTION ESTIMATE IS ABOUT THE SAME AS BEFORE...095/8. WATER VAPOR
IMAGERY INDICATES THAT THE ADVERTISED MID-LEVEL LOW IS BEGINNING TO
DEVELOP A FEW HUNDRED MILES TO THE SOUTHWEST OF THE BAJA PENINSULA.
THIS FEATURE IS EXPECTED TO CAUSE IRWIN TO TURN EAST-NORTHEASTWARD
WITH SOME INCREASE IN FORWARD SPEED DURING THE NEXT 36 TO 48 HOURS.
BEYOND THAT TIME...IRWIN IS FORECAST TO SLOW DOWN AND MAKE A
CLOCKWISE LOOP AS A LOW- TO MID-LEVEL RIDGE BUILDS TO THE NORTH OF
THE CYCLONE. THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ONE
AND LIES NEAR THE MULTI-MODEL CONSENSUS.
 
THE ENVIRONMENT AHEAD OF IRWIN IS NOT FAVORABLE FOR STRENGTHENING.
THE INTERACTION WITH THE AFOREMENTIONED MID-LEVEL LOW AND THE
EXPECTED SIGNIFICANT INCREASE IN EASTERLY SHEAR BY THE END OF THE
FORECAST PERIOD SHOULD LIMIT THE STORM FROM INTENSIFYING MUCH...IF
AT ALL. THEREFORE...THE OFFICIAL FORECAST GENERALLY SHOWS LITTLE
CHANGE IN STRENGTH FOR THE NEXT 36 HOURS...FOLLOWED BY GRADUAL
WEAKENING. THIS FORECAST IS A LITTLE LOWER THAN THE PREVIOUS ONE
AND IS IN BEST AGREEMENT WITH THE LGEM GUIDANCE.

FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0300Z 14.8N 113.3W   40 KT  45 MPH
 12H  12/1200Z 15.5N 111.8W   40 KT  45 MPH
 24H  13/0000Z 16.5N 109.8W   45 KT  50 MPH
 36H  13/1200Z 17.1N 107.9W   40 KT  45 MPH
 48H  14/0000Z 17.1N 106.2W   35 KT  40 MPH
 72H  15/0000Z 16.2N 104.2W   30 KT  35 MPH
 96H  16/0000Z 15.5N 105.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  17/0000Z 15.5N 107.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER CANGIALOSI
 
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: Tuesday, 17-Jul-2012 13:44:19 UTC