000 WTNT44 KNHC 212034 TCDAT4 TROPICAL STORM RICHARD DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL192010 500 PM EDT THU OCT 21 2010 THERE HAS NOT BEEN A LOT OF CHANGE WITH RICHARD DURING THE PAST FEW HOURS. THE LOW-LEVEL CENTER IS DIFFICULT TO FIND...BUT APPEARS TO BE JUST WEST OF A PERSISTENT BALL OF CONVECTION. THE WESTERN SIDE OF THE SYSTEM REMAINS WITHOUT SIGNIFICANT CONVECTION...A SIGN OF THE DRIER AIR IN THAT VICINITY. ALTHOUGH SATELLITE ESTIMATES HAVE INCREASED...OVERALL THE SYSTEM LOOKS A LITTLE STRETCHED AND THE INITIAL INTENSITY WILL REMAIN 35 KT FOR THIS ADVISORY. AN AIR FORCE RESERVE AIRCRAFT WILL BE IN THE AREA THIS EVENING...WHICH WILL PROVIDE A BETTER ASSESSMENT OF THE STRENGTH OF THE SYSTEM. THE BEST ESTIMATE OF CURRENT MOTION IS ABOUT 155/3. A TROUGH OVER THE WESTERN ATLANTIC AND NORTHWESTERN CARIBBEAN HAS BEEN STEERING THE SYSTEM SLOWLY SOUTHEASTWARD DURING THE PAST DAY OR SO. HOWEVER... THIS TROUGH IS IN THE PROCESS OF LIFTING OUT OF THE AREA...WHICH WILL ALLOW A RIDGE TO BUILD OVER THE GULF OF MEXICO. WHILE THE MODELS ARE IN REASONABLE AGREEMENT ON THE STORM EVENTUALLY TURNING BACK TOWARD THE WEST IN A DAY OR SO...THEY ARE IN RATHER POOR AGREEMENT AFTER THAT TIME DUE TO VARYING RIDGE STRENGTHS OVER THE GULF OF MEXICO. ALL OF THE FORECAST GUIDANCE HAS SHIFTED WELL TOWARD THE LEFT...AFTER MOVING TOWARD THE RIGHT OVERNIGHT. GIVEN THE ERRATIC BEHAVIOR OF THE MODEL GUIDANCE...A LUXURY THE OFFICIAL FORECAST DOES NOT HAVE...THIS IS A LOW CONFIDENCE TRACK FORECAST. THE MODEL CONSENSUS IS ACTUALLY NOW IN GOOD AGREEMENT WITH THE PREVIOUS NHC TRACK...AND LITTLE CHANGE WILL BE MADE TO THE NHC FORECAST. THE NEW 48-HOUR FORECAST POINT IS CLOSE ENOUGH TO HONDURAS TO WARRANT A TROPICAL STORM WATCH. CONVECTION HAS BEEN GRADUALLY CONSOLIDATING NEAR THE CENTER....WITH CIRRUS BEGINNING TO FAN OUT IN MOST QUADRANTS. THE MAIN INHIBITOR TO FURTHER STRENGTHENING IS PROBABLY THE VERY DRY AIR ALOFT SEEN TO THE NORTHWEST OF RICHARD. HOWEVER...MORE FAVORABLE ENVIRONMENTAL CONDITIONS ARE EXPECTED WITHIN A DAY OR TWO AS MOIST EASTERLY MID-LEVEL FLOW BECOMES ESTABLISHED SOUTH OF THE RIDGE AND THE CYCLONE MOVES INTO WEAKER SHEAR CONDITIONS. SIGNIFICANT INTENSIFICATION IS POSSIBLE IF THE SYSTEM REMAINS FAR ENOUGH AWAY FROM LAND...AND THE GFDL AND HWRF MODELS STILL STRENGTHEN THIS SYSTEM INTO A MAJOR HURRICANE IN A FEW DAYS. THE NHC FORECAST WILL REMAIN CLOSE TO THE PREVIOUS ONE...MOSTLY BECAUSE OF THE TRACK UNCERTAINTY AND THE HIGHER POSSIBILITY OF EARLIER LAND INTERACTION. FORECAST POSITIONS AND MAX WINDS INITIAL 21/2100Z 16.0N 80.4W 35 KT 12HR VT 22/0600Z 15.8N 80.6W 45 KT 24HR VT 22/1800Z 15.7N 81.1W 50 KT 36HR VT 23/0600Z 15.9N 81.9W 60 KT 48HR VT 23/1800Z 16.3N 83.0W 65 KT 72HR VT 24/1800Z 17.5N 86.0W 80 KT 96HR VT 25/1800Z 19.5N 88.5W 40 KT...INLAND 120HR VT 26/1800Z 21.5N 89.0W 35 KT...OVER WATER $$ FORECASTER BLAKE