HOME	ARCHIVES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
HURRICANE ALMA DISCUSSION NUMBER  17
NATIONAL WEATHER SERVICE MIAMI FL
2 PM PDT TUE MAY 28 2002
 
SATELLITE INTENSITY ESTIMATES ARE 65 KT FROM BOTH TAFB AND 
SAB...WHICH MEANS THAT THERE IS A 50-50 CHANCE THAT ALMA IS A 
HURRICANE.  VISIBLE IMAGERY SUGGESTS A RAGGED EYE IS TRYING TO 
FORM...AND SO ALMA IS UPGRADED.

THE INITIAL MOTION IS 285/10.  WATER VAPOR IMAGERY SHOWS A MID- TO 
UPPER-LEVEL LOW BEGINNING TO CUT OFF WEST OF BAJA CALIFORNIA.  THIS 
CUTOFF WILL BE ERODING THE RIDGE TO THE NORTH OF ALMA...WHICH SHOULD 
RESULT IN A WEAKENING OF THE STEERING FLOW OVER THE NEXT 24-36 
HOURS.  MODEL GUIDANCE IS HIGHLY DIVERGENT ON THE ISSUE OF 
RECURVATURE...BUT IN GENERAL TENDS TO DOWNPLAY THE INTERACTION 
BETWEEN THE CUTOFF LOW AND THE TROPICAL CYCLONE.  AS ALMA BEGINS TO 
MOVE OVER COOLER WATERS IN A DAY OR TWO...IT MAY NOT BE STRONG 
ENOUGH TO BE ACCELERATED NORTHEASTWARD...BUT INSTEAD COULD SIMPLY 
SHEAR OFF AND SPIN DOWN...AS INDICATED BY THE GFS.  THE OFFICIAL 
FORECAST IS A LITTLE SLOWER THAN THE PREVIOUS ADVISORY...BUT IS 
STILL FASTER THAN NEARLY ALL OF THE GUIDANCE.

THERE IS STILL TIME...PERHAPS ANOTHER DAY OR SO...FOR ALMA TO 
STRENGTHEN SOME MORE.  HOWEVER...ALMA IS APPROACHING A STABLE AIR 
MASS TO ITS WEST...AND BOTH COOLER WATER AND INCREASING SHEAR AWAITS 
AFTER 24-36 HOURS...SO ONLY MODEST STRENGTHENING IS EXPECTED.

FORECASTER FRANKLIN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     28/2100Z 12.2N 113.8W    65 KTS
12HR VT     29/0600Z 12.9N 115.0W    75 KTS
24HR VT     29/1800Z 13.7N 116.1W    75 KTS
36HR VT     30/0600Z 15.0N 116.6W    70 KTS
48HR VT     30/1800Z 16.0N 116.5W    65 KTS
72HR VT     31/1800Z 18.0N 116.0W    50 KTS
 
 
NNNN