Tropical Storm JULIA

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM JULIA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122010
1100 PM AST SUN SEP 12 2010
 
INFRARED AND MICROWAVE SATELLITE IMAGERY SHOW THAT THE CENTER OF
THE CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF A CURVED BAND OF
CONVECTION THAT WRAPS AROUND THE WESTERN SEMICIRCLE OF THE SYSTEM.
SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE 35 KT FROM TAFB AND 30 KT
FROM SAB.  OBJECTIVE DVORAK ESTIMATES FROM UW/CIMMS ARE SLIGHTLY
HIGHER.  A BLEND OF THESE ESTIMATES SUPPORT AN UPGRADE OF THE
DEPRESSION TO A 35-KT TROPICAL STORM...THE TENTH OF THE 2010 
ATLANTIC HURRICANE SEASON.
 
THE EASTERLY SHEAR IS EXPECTED TO WEAKEN DURING THE NEXT 12 HOURS
AND IS FORECAST TO REMAIN LIGHT OVER THE NEXT COUPLE OF DAYS.
DURING THAT TIME JULIA WILL BE TRAVERSING WARM WATER AND AS A
RESULT...STEADY STRENGTHENING IS ANTICIPATED.  THE SHIPS...LGEM...
AND GFDL MODELS ALL BRING JULIA TO HURRICANE STATUS WITHIN TWO DAYS
AND THE NHC FORECAST IS IN GOOD AGREEMENT.  THEREAFTER...JULIA WILL
BE MOVING OVER SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND INTO AN
AREA OF INCREASING SOUTHWESTERLY SHEAR TO THE EAST OF AN
UPPER-LEVEL LOW/TROUGH BETWEEN 30W AND 40W.  IT IS A BIT SURPRISING
GIVEN THESE NEGATIVE FACTORS THAT THE INTENSITY GUIDANCE SHOWS
LITTLE...IF ANY...WEAKENING.  BECAUSE OF THAT...THE OFFICIAL
FORECAST WILL KEEP JULIA AT 65 KT AT DAYS 3-5 FOR NOW.
 
THE CENTER OF JULIA WAS RELOCATED A LITTLE EAST OF THE PREVIOUS
ADVISORY POSITION BASED ON THE EARLIER MICROWAVE DATA.  THE INITIAL
MOTION ESTIMATE IS 285/10.  THE TRACK FORECAST REASONING REMAINS
THE SAME AS THE PREVIOUS ADVISORY.  JULIA IS FORECAST TO MOVE
WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN SIDE OF A MID-LEVEL
RIDGE THAT EXTENDS FROM AFRICA WESTWARD INTO THE EASTERN ATLANTIC. 
IN A COUPLE OF DAYS...THE CYCLONE IS FORECAST TO TURN NORTHWESTWARD
TOWARD A WEAKNESS IN THE RIDGE.  MOST OF THE GUIDANCE INDICATES A
TURN BACK TOWARD THE WEST-NORTHWEST LATE IN THE PERIOD AS JULIA
MOVES AROUND THE NORTH SIDE OF AN UPPER-LEVEL LOW THAT CUTS OFF
NEAR 40W.  THE OFFICIAL FORECAST TRACK IS GOOD AGREEMENT WITH THE
PREVIOUS ADVISORY AND A BLEND OF THE LATEST RUNS OF THE GFS...
UKMET...GFDL...HWRF...AND ECMWF MODELS.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/0300Z 13.5N  23.5W    35 KT
 12HR VT     13/1200Z 14.0N  25.3W    45 KT
 24HR VT     14/0000Z 14.9N  27.6W    50 KT
 36HR VT     14/1200Z 15.9N  29.5W    55 KT
 48HR VT     15/0000Z 17.1N  31.1W    65 KT
 72HR VT     16/0000Z 20.9N  35.1W    65 KT
 96HR VT     17/0000Z 24.5N  41.0W    65 KT
120HR VT     18/0000Z 27.5N  46.5W    65 KT
 
$$
FORECASTER BROWN
 
NNNN