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TROPICAL STORM JULIETTE DISCUSSION NUMBER 6
NATIONAL WEATHER SERVICE MIAMI FL
2 PM PDT SAT SEP 22 2001
DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB WERE BOTH 45 KT. SINCE
THEN...THERE HAS BEEN A BURST OF DEEP CONVECTION OVER THE CENTER.
YESTERDAY RECON INDICATED THIS CYCLONE HAD WINDS IN EXCESS OF
SATELLITE ESTIMATES...SO THE INITIAL INTENSITY IS SET TO 55 KT. A
MICROWAVE PASS AT 13Z SHOWED A WELL DEFINED INNER CORE...AND I WOULD
NOT BE AT ALL SURPRISED TO SEE AN EYE DEVELOP WITHIN THE NEXT 12
HOURS. WITH LIGHT SHEAR AND VERY WARM WATER AHEAD...CONTINUED
STRENGTHENING IS EXPECTED.
THE INITIAL MOTION IS STILL WESTWARD...BUT THE FORWARD SPEED HAS
SLOWED CONSIDERABLY...265/9. THE GFDL CONTINUES TO BE THE
OUTLIER...SHOWING A SHARP TURN BACK TO THE COAST AFTER 36 HOURS.
EXAMINATION OF THE GFDL FIELDS SHOWS A BINARY INTERACTION WITH A
MID-LEVEL VORTEX ANALYZED IN THE NEAR STORM ENVIRONMENT. ALL THE
REMAINING GUIDANCE TAKES JULIETTE ON A GENTLY CURVING TRACK ROUGHLY
PARALLEL TO THE COAST. GIVEN THE HISTORICAL BIAS OF THE GFDL IN
THIS BASIN...IT IS HARD TO BELIEVE THAT IT ALONE HAS THE ANSWER.
MORE LIKELY THE GFDL TRACK IS RELATED TO A PROBLEM WITH THE FLOW
DECOMPOSITION OF THE SMALL TROPICAL CYCLONE VORTEX IN THE MODEL.
THE OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS FORECAST...AND
INDICATIONS ARE THAT A SIGNIFICANT TROPICAL CYCLONE WILL BE
APPROACHING BAJA CALIFORNIA BY MID-WEEK.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 22/2100Z 13.5N 100.1W 55 KTS
12HR VT 23/0600Z 13.5N 101.1W 65 KTS
24HR VT 23/1800Z 13.7N 102.3W 70 KTS
36HR VT 24/0600Z 14.2N 103.4W 75 KTS
48HR VT 24/1800Z 15.0N 104.5W 85 KTS
72HR VT 25/1800Z 17.0N 106.0W 90 KTS
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