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TROPICAL STORM BARRY DISCUSSION NUMBER   3
NATIONAL WEATHER SERVICE MIAMI FL
10 PM CDT THU AUG 02 2001
 
BARRY HAS BECOME A BATCH OF MIXED SIGNALS THIS EVENING.  FIXES
FROM THE HURRICANE HUNTER AIRCRAFT INDICATED THE CENTER WAS MOVING
WEST OR WEST-NORTHWEST ABOUT 10 KT.  HOWEVER...SATELLITE FIXES FROM 
TAFB...SAB...AND AFWA...INCLUDING SOME APPARENTLY GOOD VISIBLE
FIXES...SUGGEST THE CENTER IS MOVING NORTH OR EVEN EAST OF NORTH. 
THE AIRCRAFT IS SUPPORTED BY DATA FROM BUOY 42003...WHILE THE
SATELLITE IS SUPPORTED BY THE TAMPA WSR-88D.  IT IS POSSIBLE THAT
THE CENTER IS TILTED DUE TO SOUTHWESTERLY VERTICAL SHEAR...AND THAT
THE SATELLITE AND RADAR ARE TRACKING THE UPPER LEVEL CENTER.  GIVEN
THE  SPREAD OF THE FIXES...THE SYNOPTIC POSITION WILL BE A
COMPROMISE BETWEEN THE VARIOUS PLATFORMS.  THIS WILL MAINTAIN SOME
CONTINUITY FROM THE PREVIOUS TRACK...AS WELL AS GUARD AGAINST THE
POSSIBILITY THAT THE CENTER MAY RE-FORM TO THE NORTHEAST CLOSER TO
THE PRIMARY CONVECTION.

THE BEST ESTIMATE OF THE INITIAL MOTION IS 305/5.  WATER VAPOR
IMAGERY...RAWINSONDES...AND DATA FROM THE NOAA G-IV JET INDICATE
BARRY IS EMBEDDED IN A MID/UPPER LEVEL TROUGH BETWEEN STRONG RIDGES
OVER THE CENTRAL UNITED STATES AND THE NORTHWESTERN CARIBBEAN.  
ADDITIONALLY...A STRONG UPPER LEVEL CYCLONIC SHEAR AXIS EXTENDS
FROM AN UPPER LEVEL LOW JUST SOUTH OF CAPE HATTERAS ACROSS THE
WESTERN FLORIDA PANHANDLE TO NEAR BROWNSVILLE TEXAS.  THIS SYNOPTIC
PATTERN SUGGESTS THAT BARRY WILL GO NOWHERE FAST...AND NHC HURRICANE
GUIDANCE AGREES ON THAT POINT.  HOWEVER...THERE IS OTHERWISE A
CONSIDERABLE SPREAD IN THE GUIDANCE...RANGING FROM THE NHC98
TAKING BARRY NORTH TOWARD THE FLORIDA PANHANDLE TO THE WESTWARD
TRACKS OF THE GFDL...UKMET...AND NOGAPS.  OTHER MODELS SUGGEST AN
ERRATIC LOOPING MOTION OF THE SORT SEEN IN THE 18Z AVN RUN.  THE
STRONG U.S. RIDGE STILL LOOKS LIKE THE FEATURE MOST LIKELY TO STEER
BARRY.  THUS THE OFFICIAL FORECAST WILL CONTINUE THE TREND OF THE
PREVIOUS FORECAST...SLOWLY TOWARD TO WEST-NORTHWEST AND THEN WEST.

THE MINIMUM CENTRAL PRESSURE WAS 1007 MB ON THE LAST 3 RECON FIXES.
HOWEVER...FLIGHT LEVEL WINDS WERE BELOW 50 KT DURING THAT TIME.
THUS...THE INITIAL INTENSITY WILL REMAIN 40 KT FOR THIS PACKAGE.
THE FIX SPREAD SUGGESTS THAT THE LOW LEVEL CENTER MAY BE BECOMING
DECOUPLED FROM THE SMALL UPPER LOW THAT WAS OVER THE LOW LEVEL
CENTER...AND IF THE SYSTEM IS MOVING AS INDICATED BY THE AIRCRAFT
THEN IT IS BECOMING RATHER DISORGANIZED.  HOWEVER...LARGE-SCALE
MODELS INDICATE THAT THE CURRENT 15-25 KT UPPER-LEVEL WEST-
SOUTHWESTERLY FLOW SHOULD DIMINISH AS UPPER LEVEL RIDGING DEVELOPS
OVER THE WESTERN GULF.  THIS WOULD ALLOW FOR FUTURE STRENGTHENING.
THE INTENSITY FORECAST WILL BE AN UPDATE OF THE PREVIOUS PACKAGE...
AND A COMPROMISE BETWEEN THE STRONGER STORM FORECAST BY THE SHIPS
AND GFDL MODELS AND THE WEAKER STORM INDICATED BY CURRENT TRENDS.
 
WIND RADII HAVE BEEN REVISED ON THE BASIS OF AIRCRAFT DATA...AND
12 FT SEAS RADII HAVE BEEN REVISED ON THE BASIS OF BUOY DATA.
 
DUE TO THE UNCERTAINTY OF THE FORECAST TRACK AND INTENSITY...WATCHES
OR WARNINGS MAY BE REQUIRED ON FRIDAY FOR PORTIONS OF THE NORTH
CENTRAL GULF COAST.
 
FORECASTER BEVEN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     03/0300Z 26.8N  85.6W    40 KTS
12HR VT     03/1200Z 27.2N  86.2W    45 KTS
24HR VT     04/0000Z 27.5N  87.0W    50 KTS
36HR VT     04/1200Z 27.7N  87.9W    55 KTS
48HR VT     05/0000Z 27.9N  88.9W    60 KTS
72HR VT     06/0000Z 28.0N  91.0W    65 KTS
 
 
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