Tropical Storm IVO

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TROPICAL STORM IVO DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092013
800 AM PDT SAT AUG 24 2013

EVEN WITH THE HELP OF MICROWAVE DATA...THE CENTER OF IVO HAS BEEN
DIFFICULT TO LOCATE THIS MORNING.  OSCAT SCATTEROMETER DATA DURING
THE NIGHT INDICATED THAT THE CENTER WAS ELONGATED FROM NORTH TO
SOUTH...AND A RECENT SSM/I OVERPASS SUGGESTED THAT MULTIPLE
LOW-LEVEL VORTICITY CENTERS WERE PRESENT. FIRST LIGHT VISIBLE
IMAGERY SUPPORTS A CENTER WEST OF THE PREVIOUS ADVISORY...NEAR THE
NORTHERNMOST OF THE TWO MAIN CONVECTIVE MASSES.  THERE IS NO CHANGE
TO ANY OF THE INTENSITY ESTIMATES...SO THE INITIAL INTENSITY
REMAINS 40 KT.
 
THE INITIAL MOTION IS AN UNCERTAIN 340/10.  THERE IS NO CHANGE TO
THE FORECAST PHILOSOPHY DESPITE THE UNCERTAINTIES IN THE CENTER
POSITION AND INITIAL MOTION.  IVO SHOULD CONTINUE TO MOVE GENERALLY
NORTH-NORTHWESTWARD ON THE WEST SIDE OF A SUBTROPICAL RIDGE LOCATED
OVER MEXICO FOR THE NEXT DAY OR SO.  AFTER THAT...THE DYNAMICAL
MODELS ARE NOW IN MUCH BETTER AGREEMENT THAT THE CYCLONE WILL SHEAR
APART IN 24-48 HR...WITH THE MID/UPPER-LEVEL PORTION CONTINUING
NORTHWARD AND THE LOW-LEVEL CENTER STALLING WEST OF THE BAJA
CALIFORNIA PENINSULA.  THE NEW FORECAST TRACK FOLLOWS THIS
SCENARIO...AND IT IS SHIFTED A LITTLE TO THE WEST OF THE PREVIOUS
TRACK BASED ON THE INITIAL POSITION.
 
IVO SHOULD START WEAKENING WITHIN 12-24 HOURS AS IT MOVES OVER THE
COLDER WATER WEST OF THE BAJA CALIFORNIA PENINSULA.  THE CYCLONE IS
EXPECTED TO DEGENERATE INTO A REMNANT LOW BY 36 HR AND DISSIPATE
COMPLETELY BY 96 HR.
 
RAIN ASSOCIATED WITH IVO IS SPREADING OVER THE SOUTHERN AND CENTRAL
BAJA CALIFORNIA PENINSULA.  MOISTURE FROM THE CYCLONE IS EXPECTED
TO SPREAD NORTHWARD ACROSS THE REMAINDER OF THE BAJA CALIFORNIA
PENINSULA...NORTHWESTERN MEXICO...AND THE SOUTHWESTERN UNITED
STATES...AND CAUSE LOCALLY HEAVY RAINS AND FLASH FLOODING DURING
THE NEXT COUPLE OF DAYS.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 22.5N 113.4W   40 KT  45 MPH
 12H  25/0000Z 23.8N 114.1W   40 KT  45 MPH
 24H  25/1200Z 25.4N 115.0W   35 KT  40 MPH
 36H  26/0000Z 26.6N 115.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 48H  26/1200Z 27.0N 116.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  27/1200Z 27.5N 116.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  28/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN
 
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