HOME	ARCHIVES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
HURRICANE OLGA DISCUSSION NUMBER  18
NATIONAL WEATHER SERVICE MIAMI FL
10 PM EST WED NOV 28 2001

VERTICAL SHEAR...DUE TO UPPER-LEVEL NORTHERLIES...IS IMPACTING OLGA.
THE LOW-CLOUD CIRCULATION IS BECOMING MORE EXPOSED OVER THE NORTHERN
SEMICIRCLE OF THE SYSTEM...AND THE EYE IS BECOMING POORLY DEFINED.
SUBSIDENCE ON THE WEST SIDE OF THE LARGE UPPER-LEVEL TROUGH...THAT
OLGA HAS BEEN EMBEDDED IN...MAY ALSO BE CONTRIBUTING TO THE
WEAKENING.  THE CURRENT INTENSITY...65 KNOTS...IS CONSISTENT WITH
SATELLITE-BASED ESTIMATES FROM TAFB MIAMI...SAB WASHINGTON...AND THE
AIR FORCE WEATHER AGENCY.  A STEADY DECREASE IN INTENSITY IS
FORECAST...AT ABOUT THE SAME RATE AS SHOWN IN THE PREVIOUS ADVISORY.
NUMERICAL GUIDANCE...IN PARTICULAR THE SHIPS MODEL...DOES NOT WEAKEN
OLGA AS FAST AS SHOWN HERE.  SHOULD THE VERTICAL SHEAR DIMINISH FOR
SOME REASON...THE WEAKENING TREND COULD BE REVERSED SINCE THE
CYCLONE IS MOVING OVER WARMER WATERS.  HOWEVER...IF THE SYSTEM
CONTINUES TO DECLINE AS IT IS DOING AT THE MOMENT...OLGA WOULD
WEAKEN FASTER THAN INDICATED HERE.

INITIAL MOTION IS ESTIMATED TO BE 220/11 AS THE CYCLONE IS BEING 
STEERED BY THE FLOW ON THE SOUTHEAST SIDE OF A MID-LEVEL RIDGE.  A 
GRADUAL TURN TO THE RIGHT IS FORECAST OVER THE NEXT FEW DAYS.  THIS 
IS JUST SLIGHTLY SOUTH OF AND FASTER THAN THE TRACK SHOWN IN THE 
PREVIOUS ADVISORY...AND ABOUT IN THE MIDDLE OF THE CURRENT NUMERICAL 
GUIDANCE SUITE.

FORECASTER PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     29/0300Z 29.9N  58.1W    65 KTS
12HR VT     29/1200Z 28.7N  59.5W    60 KTS
24HR VT     30/0000Z 27.5N  61.5W    55 KTS
36HR VT     30/1200Z 26.5N  63.7W    50 KTS
48HR VT     01/0000Z 26.0N  66.0W    45 KTS
72HR VT     02/0000Z 25.5N  70.0W    35 KTS
 
 
NNNN