000
WTPZ43 KNHC 241441
TCDEP3
 
TROPICAL STORM COSME DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032013
800 AM PDT MON JUN 24 2013
 
A LARGE BURST OF CONVECTION NEAR THE CENTER OF COSME BEGAN JUST
AFTER 0600 UTC AND HAS PERSISTED SINCE THAT TIME.  SOME NORTHERLY
TO NORTHWESTERLY VERTICAL SHEAR STILL APPEARS TO BE AFFECTING THE
CYCLONE...YET TAFB AND SAB BOTH PROVIDED INTENSITY ESTIMATES OF 45
KT.  THE OBJECTIVE UW-CIMSS ADT ESTIMATE IS EVEN HIGHER AT 50 KT.
EITHER WAY...COSME IS STRENGTHENING...AND THE INITIAL INTENSITY IS
BEING SET AT 45 KT ON THIS ADVISORY.
 
THE CENTER HAS JUST RECENTLY BECOME EASIER TO LOCATE BASED ON A 1241
UTC SSMIS OVERPASS AND THE FIRST FEW VISIBLE IMAGES.  THE BLOW-UP
OF CONVECTION APPEARS TO HAVE CAUSED THE LOW-LEVEL CENTER TO JUMP
TO THE NORTH-NORTHWEST...BUT SMOOTHING THE TRACK YIELDS A 12-HOUR
MOTION OF 315/11 KT.  THE CYCLONE IS CURRENTLY LOCATED ALONG THE
SOUTHWESTERN EDGE OF A MID-LEVEL RIDGE THAT EXTENDS WESTWARD ACROSS
NORTHERN MEXICO.  ANOMALOUSLY STRONG MID-LEVEL HIGH PRESSURE IS
FORECAST TO DEVELOP OVER THE WESTERN U.S. IN 2-3 DAYS...WHICH WILL
TEND TO STEER COSME WEST-NORTHWESTWARD AND THEN WESTWARD OVER THE
NEXT 3 TO 4 DAYS.  THERE IS VERY LITTLE SPREAD AMONG THE TRACK
MODELS...AND THE NEW NHC FORECAST IS ESSENTIALLY JUST AN UPDATE OF
THE PREVIOUS ONE.
 
THE GLOBAL MODEL FIELDS SUGGEST THAT THE UPPER-LEVEL ENVIRONMENT
AROUND COSME SHOULD BE SUFFICIENTLY CONDUCIVE FOR THE CYCLONE TO
CONTINUE STRENGTHENING DURING THE NEXT 36 TO 48 HOURS.  THIS PERIOD
ALSO HAPPENS TO COINCIDE WITH THE TIME THAT THE CYCLONE IS OVER
WATER WARMER THAN 26C.  THE OFFICIAL FORECAST INTENSITIES HAVE BEEN
INCREASED DURING THE FIRST 72 HOURS MAINLY TO ACCOUNT FOR THE
RECENT STRENGTHENING...AND THEY ARE VERY SIMILAR TO THE FORECAST
SHOWN BY THE LGEM.  WEAKENING SHOULD STILL BEGIN BY 72 HOURS...WITH
THE CYCLONE LIKELY DEGENERATING TO A REMNANT LOW BY DAY 5. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 14.1N 105.8W   45 KT  50 MPH
 12H  25/0000Z 15.0N 107.8W   55 KT  65 MPH
 24H  25/1200Z 16.0N 110.2W   65 KT  75 MPH
 36H  26/0000Z 16.7N 112.5W   70 KT  80 MPH
 48H  26/1200Z 17.5N 114.7W   70 KT  80 MPH
 72H  27/1200Z 19.0N 120.0W   55 KT  65 MPH
 96H  28/1200Z 20.0N 125.5W   35 KT  40 MPH
120H  29/1200Z 20.0N 130.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BERG