TROPICAL STORM RICHARD DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL192010
1100 PM EDT THU OCT 21 2010

DATA FROM AN AIR FORCE RESERVE UNIT AIRCRAFT INDICATE THAT RICHARD
HAS CHANGED LITTLE IN ORGANIZATION SINCE EARLIER TODAY. THE
MAXIMUM FLIGHT-LEVEL WINDS HAVE BEEN AROUND 30 KT AND SURFACE WINDS
FROM THE SFMR ARE AROUND 35 KT...WITH A MINIMUM PRESSURE OF 1007
MB. BASED UPON THESE MEASUREMENTS...THE INITIAL INTENSITY FOR THIS
ADVISORY IS BEING HELD AT 35 KT. SATELLITE IMAGES REINFORCE THIS
ASSESSMENT OF THE INTENSITY. THEY SHOW THE CONVECTIVE ORGANIZATION
OF THE CYCLONE IS SOMEWHAT LINEAR AND THE CLOUD PATTERN HAS BECOME
SOMEWHAT RAGGED...WITH THE SURFACE CENTER LOCATED TO THE WEST OF
THE COLDEST CLOUD TOPS.

RECON FIXES YIELD AN INITIAL MOTION ESTIMATE OF 160/02. RICHARD IS
MEANDERING IN A REGION OF WEAK STEERING LOCATED AT THE BASE OF A
TROUGH LIFTING OUT OF THE EASTERN UNITED STATES/WESTERN ATLANTIC.
GLOBAL MODELS INDICATE THAT RIDGING OVER THE WESTERN GULF OF MEXICO
WILL BUILD EASTWARD DURING THE NEXT SEVERAL DAYS AND PUSH THE
CYCLONE ON A GENERALLY WESTWARD TO WEST-NORTHWESTWARD COURSE WITH
SOME INCREASE IN FORWARD SPEED. THE TRACK GUIDANCE HAS SHIFTED
SOUTHWARD THIS CYCLE AND HAS COME INTO SOMEWHAT BETTER AGREEMENT AT
LATER TIMES...WITH THE GFDL/HWRF SOLUTIONS NOW CLOSER TO THE MORE
CONSISTENT GLOBAL MODELS. HOWEVER...SPREAD CONTINUES IN THE
SOLUTIONS EVEN IN THE EARLY PART OF THE FORECAST. THE OFFICIAL NHC
TRACK FORECAST IS ADJUSTED TO THE LEFT BASED UPON THE TREND IN THE
GUIDANCE BUT NOT AS FAR LEFT AS THE MULTI-MODEL CONSENSUS. THE NEW
TRACK IS ON THE NORTHERN SIDE OF THE GUIDANCE ENVELOPE.

VARIOUS ANALYSES INDICATE A CONTINUATION OF AROUND 10 KT OF
SOUTHERLY TO SOUTHWESTERLY VERTICAL WIND SHEAR OVER RICHARD. THE
CYCLONE IS ALSO ENTRAINING DRY AIR PUSHED INTO THE AREA BY THE U.
S. TROUGH. BOTH OF THESE FACTORS APPEAR TO BE PREVENTING
INTENSIFICATION AT THE MOMENT. AFTER ABOUT 24 HOURS...THE SHIPS
MODEL OUTPUT SHOWS THE SHEAR DECREASING...AND THE CYCLONE GRADUALLY
BECOMING EMBEDDED IN A MORE MOIST ENVIRONMENT OVER THE WARM WATERS
OF THE NORTHWESTERN CARIBBEAN SEA. AS A RESULT OF THIS
EVOLUTION...RICHARD IS FORECAST TO BEGIN STRENGTHENING. THE ONE
CAVEAT TO THE INTENSITY FORECAST IS THE POTENTIAL INTERACTION
OF THE CYCLONE WITH LAND WHICH COULD OCCUR EARLIER IF THE SYSTEM
MOVES SOUTH OF THE FORECAST TRACK. THE OFFICIAL NHC INTENSITY
FORECAST IS LARGELY UNCHANGED AND IS IN GOOD AGREEMENT WITH
LGEM/MULTI-MODEL INTENSITY CONSENSUS IVCN.
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