000 WTPZ45 KNHC 080841 TCDEP5 TROPICAL STORM LINDA DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152009 200 AM PDT TUE SEP 08 2009 INFRARED SATELLITE IMAGERY SUGGESTS THAT THE APPEARANCE OF LINDA TYPIFIES THAT OF A TROPICAL CYCLONE UNDERGOING WESTERLY SHEAR. DEEP CONVECTIVE CLOUDS WERE DISPLACED TO THE EAST OF THE CENTER EARLIER THIS EVENING...BUT RECENT SATELLITE PICTURES SHOW A RESURGENCE OF CONVECTION IN A MORE SYMMETRIC SHAPE AROUND THE CENTER. OVERALL... HOWEVER...THERE HAS BEEN NO SIGNIFICANT CHANGE TO THE CLOUD PATTERN SINCE EARLIER THIS AFTERNOON. SATELLITE-BASED INTENSITY ESTIMATES ARE AT 3.0 FROM SAB AND TAFB AND ARE USED AS A BASIS TO MAINTAIN THE INITIAL INTENSITY AT 50 KT THIS ADVISORY. AN 0413 UTC SSMIS PASS WAS USEFUL IN LOCATING THE CENTER. THAT PASS ALONG WITH RECENT SATELLITE FIXES SUGGEST AN INITIAL MOTION OF 265/07. LINDA REMAINS IN A WEAK-STEERING ENVIRONMENT...DOMINATED BY WEAK RIDGING TO THE EAST AND A DEVELOPING WEAKNESS IN THE RIDGE EXTENDING FROM THE BAJA PENINSULA SOUTHWESTWARD TO 130W. AS THE RIDGE WEAKENS FURTHER DURING THE NEXT 24 TO 36 HOURS...LINDA SHOULD TURN MORE WEST-NORTHWESTWARD AND THEN NORTHWESTWARD. THEREAFTER... MODEL GUIDANCE DIVERGES...WITH THE GFS/HWRF/GFDL/ECMWF INDICATING EITHER A WEAKER RIDGE/MORE ROBUST TROUGH OR A STRONGER LINDA...AND THEREFORE TURN LINDA MORE NORTHWARD EARLIER. THE UKMET/NOGAPS/ CANADIAN MODELS DIFFER BY SHOWING A WEAKER TROUGH AND STRONGER RIDGING...WHICH LEADS TO A MORE WESTWARD TRACK. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ONE BUT ADJUSTED SIGNIFICANTLY TO LEFT DUE TO PERSISTENCE IN THE SHORT-TERM AND THEN TO THE RIGHT LATER IN THE PERIOD...FOLLOWING THE MODEL CONSENSUS. ALTHOUGH LINDA WAS DEVELOPING AT A MORE RAPID PACE EARLIER...THE CYCLONE APPEARS TO BE EXPERIENCING A PERIOD OF ARRESTED DEVELOPMENT AS A RESULT OF SEVERAL FACTORS. THE SHIPS MODEL GUIDANCE INDICATES MODERATE WESTERLY WIND SHEAR...A STABLE BOUNDARY LAYER...AND WARMING TEMPERATURES ALOFT AS NEGATIVE INFLUENCES ON FURTHER INTENSIFICATION. THE COMBINATION OF THESE FACTORS SEEMS ENOUGH TO PREVENT MUCH ADDITIONAL INTENSIFICATION...AND THE OFFICIAL FORECAST IS ADJUSTED DOWNWARD AWAY FROM THE MORE AGGRESSIVE GFDL/HWRF PREDICTIONS AND MORE CLOSELY MATCHING THE SHIPS GUIDANCE. FORECAST POSITIONS AND MAX WINDS INITIAL 08/0900Z 15.1N 128.4W 50 KT 12HR VT 08/1800Z 15.2N 128.9W 50 KT 24HR VT 09/0600Z 15.9N 129.4W 55 KT 36HR VT 09/1800Z 16.7N 130.0W 60 KT 48HR VT 10/0600Z 17.8N 130.7W 60 KT 72HR VT 11/0600Z 20.0N 132.0W 45 KT 96HR VT 12/0600Z 22.0N 133.0W 25 KT 120HR VT 13/0600Z 24.0N 133.5W 20 KT...REMNANT LOW $$ FORECASTER KIMBERLAIN