577 
 WTPZ44 KNHC 232042
 TCDEP4
 TROPICAL STORM FRANK DISCUSSION NUMBER   9
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP092010
 200 PM PDT MON AUG 23 2010
  
 THE INNER-CORE CONVECTION ASSOCIATED WITH FRANK HAS CONTINUED TO
 ERODE SINCE THE PREVIOUS ADVISORY...ALTHOUGH SOME MODEST CONVECTION
 HAS RECENTLY DEVELOPED OVER AND TO THE SOUTHWEST OF THE CENTER.
 CURRENT INTENSITY ESTIMATES WERE T3.0/45 KT FROM BOTH TAFB AND SAB
 AT 1800 UTC...AND THAT WILL BE THE INTENSITY FOR THIS ADVISORY.
  
 MICROWAVE AND VISIBLE SATELLITE FIX POSITIONS INDICATE FRANK HAS
 BEEN MOVING AT 285/08...AFTER SMOOTHING THROUGH SOME RATHER LARGE
 WOBBLES. THE DEEP-LAYER RIDGE TO THE NORTH OF FRANK IS FORECAST TO
 REMAIN STRONG ENOUGH TO KEEP THE CYCLONE MOVING IN A GENERAL
 WEST-NORTHWESTWARD DIRECTION THROUGHOUT THE FORECAST PERIOD. THIS
 MOTION IS EXPECTED TO KEEP FRANK OFFSHORE AND ON A TRACK PARALLEL
 THE MEXICAN COAST. BY DAY 5...A DECREASE IN FORWARD SPEED AND
 PERHAPS A SLIGHT TURN TOWARD THE NORTHWEST WILL BE POSSIBLE AS THE
 WESTERN EXTENT OF THE RIDGE IS WEAKENED BY A MID-LATITUDE TROUGH
 FORECAST TO DIG SOUTHWARD OFF THE COAST OF BAJA CALIFORNIA. THE
 OFFICIAL FORECAST TRACK IS JUST AN EXTENSION OF THE PREVIOUS
 ADVISORY AND A LITTLE TO THE RIGHT OF THE CONSENSUS MODEL...TVCN.
  
 THE VERTICAL WIND SHEAR ACROSS FRANK IS NOT EXPECTED TO DECREASE
 SIGNIFICANTLY FOR THE NEXT 36-48 HOURS. ALTHOUGH THERE WILL BE
 PERIODIC BURSTS OF DEEP CONVECTION...ESPECIALLY AT NIGHT...THAT
 COULD RESULT IN BRIEF STRENGTHENING OF THE CYCLONE...ANY SUSTAINED
 INTENSIFICATION IS NOT EXPECTED TO OCCUR UNTIL AFTER 48 HOURS WHEN
 THE SHEAR IS FORECAST BY ALL THE GLOBAL MODELS TO DECREASE TO LESS
 THAN 15 KT. HOWEVER...BY 120 HOURS...FRANK IS EXPECTED TO BEGIN
 MOVING OVER SUB-26C SSTS...WHICH SHOULD INITIATE A GRADUAL
 WEAKENING TREND. THE OFFICIAL INTENSITY FORECAST REMAINS A BLEND OF
 THE SHIPS/LGEM AND GFDL/HWRF INTENSITY MODELS THROUGH 36 HOURS...
 AND THEN HIGHER THAN THE MODELS AFTER THAT DUE AN EXPECTED DECREASE
 IN THE SHEAR.
  
 NEARBY SHIP REPORTS CONTINUE TO INDICATE FRANK POSSESSES A SMALL
 WIND FIELD. THEREFORE...NO CHANGES TO THE EXISTING TROPICAL STORM
 WATCH AND WARNING AREAS FOR THE PACIFIC COAST OF MEXICO ARE
 REQUIRED AT THIS TIME.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      23/2100Z 14.9N  99.3W    45 KT
  12HR VT     24/0600Z 15.2N 100.5W    50 KT
  24HR VT     24/1800Z 15.8N 101.9W    50 KT
  36HR VT     25/0600Z 16.5N 103.5W    55 KT
  48HR VT     25/1800Z 17.2N 105.1W    60 KT
  72HR VT     26/1800Z 18.3N 107.8W    65 KT
  96HR VT     27/1800Z 19.5N 110.5W    70 KT
 120HR VT     28/1800Z 20.5N 113.0W    65 KT
  
 $$
 FORECASTER STEWART