Tropical Storm RICHARD

ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
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
 
NNNN