000
WTPZ44 KNHC 230831
TCDEP4
TROPICAL STORM FRANK DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP092010
200 AM PDT MON AUG 23 2010
 
THERE CONTINUES TO BE LITTLE CHANGE IN THE OVERALL ORGANIZATION OF
FRANK.  THE SYSTEM IS EXHIBITING A CDO-TYPE PATTERN WITH VERY
COLD-TOPPED CONVECTIVE CLOUDS NEAR AND JUST WEST OF THE ESTIMATED
CENTER POSITION.  DVORAK INTENSITY ESTIMATES FROM BOTH TAFB AND SAB
ARE UNCHANGED...AND THE ADVISORY WIND SPEED IS HELD AT 50 KT.
EASTERLY SHEAR OVER FRANK IS LIKELY TO INCREASE TO OVER 20 KT AS AN
UPPER-TROPOSPHERIC RIDGE TO THE NORTH OF THE STORM IS DEPICTED BY
THE GLOBAL MODELS TO STRENGTHEN OVER THE NEXT COUPLE OF DAYS.
NEVERTHELESS...OTHER ENVIRONMENTAL FACTORS APPEAR CONDUCIVE FOR
INTENSIFICATION SO FRANK IS ANTICIPATED TO BECOME A HURRICANE
WITHIN 24 HOURS.  THE OFFICIAL INTENSITY FORECAST IS SLIGHTLY LOWER
THAN THE PREVIOUS ONE BUT IS ABOVE MOST OF THE NUMERICAL GUIDANCE.
 
BASED ON CENTER POSITION ESTIMATES FROM GEOSTATIONARY AND MICROWAVE
IMAGERY...THE MOTION CONTINUES JUST NORTH OF WEST AT NEAR 7 KT.  A
MID-TROPOSPHERIC RIDGE OVER THE SOUTHWESTERN U.S. AND NORTHERN
MEXICO IS FORECAST TO REMAIN IN PLACE THROUGH 72 HOURS.  THIS FLOW
PATTERN SHOULD PRODUCE A WEST-NORTHWESTWARD TRACK FOR FRANK OVER
THE NEXT FEW DAYS.  LATE IN THE FORECAST PERIOD...THE RIDGE TO THE
NORTH OF THE TROPICAL CYCLONE IS FORECAST TO WEAKEN AND A SLOWING
OF THE FORWARD SPEED IS PREDICTED BY DAYS 4 TO 5.  THE GFDL/HWRF/
GFS MODELS TAKE FRANK QUITE CLOSE TO THE SOUTHWEST COAST OF MEXICO
IN ABOUT 3 DAYS...WHEREAS THE MODEL CONSENSUS IS FARTHER OFFSHORE.
THE OFFICIAL FORECAST IS SIMILAR TO...BUT JUST A TAD TO THE NORTH
OF...THE PREVIOUS ONE.
 
BASED ON THE UPDATED FORECAST TRACK...THE TROPICAL STORM WARNING AND
WATCH ARE EXTENDED FARTHER WEST ALONG THE COAST OF MEXICO.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/0900Z 14.3N  97.5W    50 KT
 12HR VT     23/1800Z 14.5N  98.5W    60 KT
 24HR VT     24/0600Z 15.0N 100.0W    65 KT
 36HR VT     24/1800Z 15.7N 101.4W    70 KT
 48HR VT     25/0600Z 16.4N 102.8W    70 KT
 72HR VT     26/0600Z 17.5N 105.5W    70 KT
 96HR VT     27/0600Z 18.5N 108.0W    70 KT
120HR VT     28/0600Z 19.5N 110.5W    70 KT
 
$$
FORECASTER PASCH