000
WTPZ45 KNHC 010836
TCDEP5
 
TROPICAL STORM EUGENE DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP052011
200 AM PDT MON AUG 01 2011
 
SINCE THE LAST ADVISORY...CONVECTIVE BANDING ASSOCIATED WITH EUGENE
HAS INCREASED MARKEDLY...AND THE LOW-LEVEL CENTER NOW APPEARS
COMPLETELY EMBEDDED BENEATH THE CENTRAL DENSE OVERCAST.  DVORAK
INTENSITY ESTIMATES FROM TAFB AND SAB WERE BOTH 45 KT AT 0000
UTC...BUT THE BANDING HAS INCREASED FURTHER SINCE THAT TIME.  THE
ADT ESTIMATE FROM UW-CIMSS IS NOW T3.5 SO THE INITIAL INTENSITY IS
RAISED TO A COMPROMISE OF 50 KT.
 
THE INITIAL MOTION IS NOW 290/10.  A STRONG MID-LEVEL HIGH CENTERED
OVER KANSAS AND OKLAHOMA EXTENDS SOUTH AND SOUTHWEST ACROSS MUCH OF
MEXICO...AND THIS FEATURE IS EXPECTED TO DRIVE EUGENE ON A
CONSISTENT WEST-NORTHWESTWARD TRACK THROUGH AT LEAST THE NEXT 96
HOURS.  MYSTERIOUSLY...THE GFDL AND HWRF CONTINUE TO SHOW THE
PORTION OF THE RIDGE OVER THE SOUTHWESTERN UNITED STATES
DISINTEGRATING BY 72 HOURS AND CONSEQUENTLY ALLOW EUGENE TO TURN
NORTHWARD TOWARDS THE MOUTH OF THE GULF OF CALIFORNIA.  THE NHC
TRACK FORECAST DISREGARDS THESE MODELS AND IS CLOSE TO A CONSENSUS
OF THE GFS...ECMWF...AND UKMET.  THIS NEW FORECAST IS JUST A LITTLE
FASTER THAN THE PREVIOUS ONE FROM 36 TO 72 HOURS BUT COMES BACK IN
LINE BY 120 HOURS.
 
EUGENE SO FAR HAS BEEN ABLE TO STRENGTHEN WITHIN MODERATE EASTERLY
SHEAR...AND THERE IS NO REASON TO EXPECT ANY IMMEDIATE CHANGE IN
THIS TREND.  GRADUAL STRENGTHENING IS ANTICIPATED OVER THE NEXT 72
HOURS WHILE THE CYCLONE REMAINS OVER WARM WATER.  THE NEW OFFICIAL
INTENSITY FORECAST IS AT THE UPPER BOUND OF THE GUIDANCE FOR THE
FIRST 24 HOURS GIVEN THE RECENT SHORT-TERM STRENGTHENING TREND AND
IS A BLEND OF THE SHIPS AND LGEM THEREAFTER.

THE 34-KT WIND RADII HAVE BEEN ADJUSTED BASED ON A 0347 UTC ASCAT
PASS.

FORECAST POSITIONS AND MAX WINDS
 
INIT  01/0900Z 11.6N 103.2W   50 KT  60 MPH
 12H  01/1800Z 12.2N 104.7W   55 KT  65 MPH
 24H  02/0600Z 12.9N 106.9W   60 KT  70 MPH
 36H  02/1800Z 13.6N 108.9W   65 KT  75 MPH
 48H  03/0600Z 14.2N 110.7W   65 KT  75 MPH
 72H  04/0600Z 15.5N 114.0W   70 KT  80 MPH
 96H  05/0600Z 17.0N 117.0W   65 KT  75 MPH
120H  06/0600Z 18.5N 119.5W   45 KT  50 MPH
 
$$
FORECASTER BERG