613 
 WTPZ45 KNHC 210859
 TCDEP5
 TROPICAL STORM RICK DISCUSSION NUMBER  24
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP202009
 200 AM PDT WED OCT 21 2009
  
 INFRARED SATELLITE IMAGERY INDICATES THAT THE CLOUD PATTERN
 ASSOCIATED WITH RICK HAS CHANGED LITTLE DURING THE LAST FEW HOURS.
 THE CYCLONE CONTINUES TO CONSIST OF A SHIELD OF PULSATING DEEP
 CONVECTION ORGANIZED IN A BANDING FEATURE OVER THE NORTHWEST
 SEMICIRCLE...WITH A DISTINCT MID-LEVEL CIRCULATION CENTER EVIDENT
 TO ITS SOUTHEAST. DVORAK T-NUMBERS AT 0600 UTC WERE 3.0 AND 3.5
 FROM SAB AND TAFB...RESPECTIVELY...AND AGREE FAIRLY WELL WITH A
 0148 UTC QUIKSCAT PASS THAT SUGGESTED A MAX INTENSITY OF AT LEAST
 55 KT. ON THIS BASIS...THE INITIAL INTENSITY IS HELD AT 55 KT.
 UW-CIMSS ANALYSES CURRENTLY INDICATE NEARLY 25 KT OF SOUTHWESTERLY
 SHEAR OVER RICK...AND THE SHIPS MODEL OUTPUT SUGGESTS A FURTHER
 INCREASE IN THE SHEAR DURING THE NEXT 12-24 HOURS. THE
 PROHIBITIVELY HIGH VALUES OF SHEAR SHOULD RESULT IN WEAKENING PRIOR
 TO LANDFALL IN SPITE OF SSTS WARMING ALONG THE FORECAST TRACK.
 DISSIPATION IS LIKELY IN 24-36 HOURS ONCE THE CENTER QUICKLY MOVES
 WELL INLAND OVER THE RUGGED TERRAIN OF THE SIERRA MADRE MOUNTAINS.
  
 THE CENTER REMAINS EXCEEDINGLY DIFFICULT TO FIND...EVEN WITH
 MICROWAVE AND SCATTEROMETER PASSES...BUT THE FORWARD MOTION APPEARS
 TO HAVE INCREASED AND IS ESTIMATED AT 050/12. AN AMPLIFIED MID- TO
 UPPER-LEVEL TROUGH PROGRESSING THROUGH THE SOUTHERN ROCKIES AND
 NORTHERN MEXICO DURING THE NEXT 24 HOURS SHOULD STEER RICK ON A
 CONTINUED NORTHEASTWARD COURSE WITH INCREASING FORWARD SPEED...AT
 LEAST UNTIL LANDFALL...WHEN SOME OF THE GUIDANCE INDICATES THAT
 RICK WILL SHEAR APART.   
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      21/0900Z 21.8N 108.2W    55 KT
  12HR VT     21/1800Z 23.1N 106.7W    50 KT
  24HR VT     22/0600Z 24.3N 104.7W    20 KT...REMNANT LOW INLAND
  36HR VT     22/1800Z...DISSIPATED
  
 $$
 FORECASTER KIMBERLAIN/FRANKLIN