000
WTPZ45 KNHC 170844
TCDEP5
HURRICANE RICK DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP202009
200 AM PDT SAT OCT 17 2009
 
RICK CONTINUES TO RAPIDLY INTENSIFY. AN EYE BECAME APPARENT
IN CONVENTIONAL SATELLITE IMAGES AROUND 0200 UTC AND HAS GRADUALLY
BECOME MORE CIRCULAR OVER THE PAST FEW HOURS. IN ADDITION...THE
CLOUD PATTERN HAS CONSOLIDATED AND NOW CONSISTS OF A WELL-DEFINED
CDO WITH VERY COLD CLOUD TOPS AROUND THE EYE ALONG WITH SPIRAL OUTER
RAINBANDS. THE INITIAL INTENSITY IS RAISED TO 100 KT...IN AGREEMENT
WITH THE 0600 UTC DATA-T NUMBERS FROM TAFB AND SAB...AND THE LATEST
OBJECTIVE DVORAK CI-NUMBERS FROM UW-CIMSS.
 
ALL OF THE INTENSITY GUIDANCE SUGGESTS ADDITIONAL STRENGTHENING AS
THE ENVIRONMENTAL CONDITIONS REMAIN IDEAL FOR THE NEXT 24 TO 36
HOURS. THE SHIPS MODEL FORECASTS VERTICAL WIND SHEAR TO REMAIN
LIGHT OVER THE NEXT DAY OR SO AS RICK TRAVERSES WATERS AROUND 30C.
THE HWRF IS THE MOST AGGRESSIVE MODEL...BRINGING RICK TO CATEGORY
FIVE INTENSITY IN ABOUT A DAY. THE OFFICIAL FORECAST IS ABOVE THE 
THE INTENSITY CONSENSUS AND SHOWS RICK PEAKING AT CATEGORY 4
STRENGTH AROUND 36 HOURS. HOWEVER...THE NHC INTENSITY PROBABILITY
TABLE SHOWS THAT THERE IS ABOUT A 10 PERCENT CHANCE OF RICK
REACHING CATEGORY FIVE INTENSITY IN ABOUT 36 HOURS. IT IS ALSO
WORTH NOTING THAT INNER CORE DYNAMICS MAY PLAY A ROLE IN THE
INTENSITY OF RICK IN THE NEXT DAY OR TWO...AND THESE FLUCTUATIONS
ARE DIFFICULT TO FORECAST. AT DAY 3 AND BEYOND...WEAKENING IS
EXPECTED DUE TO INCREASING SOUTHERLY TO SOUTHWESTERLY SHEAR AND
COOLER WATERS ALONG THE FORECAST TRACK.
 
THE INITIAL MOTION ESTIMATE IS 290/10...AS RICK IS BEING STEERED BY
A MID-LEVEL RIDGE EXTENDING FROM MEXICO INTO THE EASTERN PACIFIC.
THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF
DAYS.  THEREAFTER...A MID-TO UPPER LEVEL TROUGH CURRENTLY ALONG
160W IS EXPECTED TO AMPLIFY AS IT MOVES INTO THE WESTERN UNITED
STATES. THIS TROUGH WILL ERODE THE RIDGE AND ALLOW RICK TO TURN
NORTHWARD. THE HWRF AND GFDL MODELS REMAIN ON THE RIGHT SIDE OF THE
GUIDANCE ENVELOPE AND ARE MUCH FASTER THAN THE GLOBAL MODELS LATE
IN THE PERIOD. CONVERSELY...THE UKMET IS FAR TO THE LEFT AND IS
CONSIDERED AN OUTLIER AS IT APPEARS TO HAVE AN UNREALISTICALLY
SHALLOW REPRESENTATION OF THE TROPICAL CYCLONE THAT DOES NOT
RESPOND TO THE EROSION OF THE RIDGE.  THE NEW TRACK FORECAST IS
BASICALLY AN UPDATE OF THE PREVIOUS ONE AND LIES CLOSE TO THE MODEL
CONSENSUS.
 
INTERESTS IN THE SOUTHWESTERN COAST OF MEXICO AND BAJA CALIFORNIA
SHOULD CLOSELY MONITOR THE PROGRESS OF THIS DANGEROUS HURRICANE
DURING THE NEXT SEVERAL DAYS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/0900Z 13.9N 102.0W   100 KT
 12HR VT     17/1800Z 14.3N 103.7W   110 KT
 24HR VT     18/0600Z 14.9N 106.1W   120 KT
 36HR VT     18/1800Z 15.7N 108.5W   125 KT
 48HR VT     19/0600Z 16.5N 110.4W   120 KT
 72HR VT     20/0600Z 18.4N 112.7W   110 KT
 96HR VT     21/0600Z 20.5N 113.0W    95 KT
120HR VT     22/0600Z 23.5N 112.0W    80 KT
 
$$
FORECASTER CANGIALOSI/BRENNAN