Tropical Depression MARTY
ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION MARTY DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP162009
200 AM PDT SAT SEP 19 2009
THE THUNDERSTORM ACTIVITY HAS DIMINISHED SIGNIFICANTLY AFTER THE
LAST CONVECTIVE BURST A FEW HOURS AGO. MARTY HAS BECOME A SWIRL
OF LOW CLOUDS WITH ONE RELATIVELY SMALL AREA OF THUNDERSTORMS NEAR
THE CENTER. BASED ON T-NUMBERS WHICH HAVE DECREASED TO 1.0 ON THE
DVORAK SCALE...MARTY IS BEING DOWNGRADED TO A 30-KNOT TROPICAL
DEPRESSION AT THIS TIME. THE CIRCULATION IS ALREADY OVER COOLER
WATERS AND EMBEDDED WITHIN A STRONG SHEAR. THEREFORE...A CONTINUED
WEAKENING IS FORECAST...AND MARTY SHOULD BECOME A REMNANT LOW IN
24 HOUR OR SO. SOME PATCHES OF DEEP CONVECTION COULD DEVELOP
INTERMITTENTLY.
THE DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT
8 KNOTS. SINCE MARTY IS A SHALLOW SYSTEM...IT SHOULD TURN MORE TO
THE WEST AS IT BECOMES STEERED BY THE LOW LEVEL FLOW.
FORECAST POSITIONS AND MAX WINDS
INITIAL 19/0900Z 22.2N 116.8W 30 KT
12HR VT 19/1800Z 22.6N 118.0W 25 KT
24HR VT 20/0600Z 23.0N 120.0W 25 KT...REMNANT LOW
36HR VT 20/1800Z 23.0N 122.0W 20 KT...REMNANT LOW
48HR VT 21/0600Z...REMNANT LOW
$$
FORECASTER AVILA
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