EPAC: TROPICAL DEPRESSION MARTY (16E)

[HURAKAN]

940
WTPZ41 KNHC 190232
TCDEP1
TROPICAL STORM MARTY DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP162009
800 PM PDT FRI SEP 18 2009

SATELLITE IMAGERY INDICATES THAT MARTY HAS BECOME A SWIRL OF LOW- TO
MID-LEVEL CLOUDS...WITH INTERMITTENT BURSTS OF DEEP CONVECTION
LIMITED TO A SMALL AREA NORTHEAST OF THE CENTER. ALTHOUGH DVORAK
CI-NUMBERS ARE 30 KT FROM BOTH TAFB AND SAB AT 0000 UTC...IT IS
ASSUMED THAT HIGHER WINDS COULD BE OCCURRING IN THE CURRENT...
IMPRESSIVE CONVECTIVE BURST. ON THIS BASIS...THE INITIAL INTENSITY
IS HELD AT 35 KT. UW CIMSS ANALYSES SUGGEST NEARLY 20 KT OF
SOUTHWESTERLY SHEAR OVER THE CYCLONE...WHICH HAS PROVEN ENOUGH TO
WEAKEN MARTY IN SPITE OF ITS TRACK OVER MARGINALLY WARM WATERS.
ACCORDING TO THE SHIPS MODEL...MARTY IS LIKELY TO ENCOUNTER EVEN
STRONGER SHEAR BEYOND 12 HOURS...NOT TO MENTION PROGRESSIVELY
COOLER WATERS. THESE FACTORS SHOULD LEAD TO MARTY BECOMING A
REMNANT LOW WITHIN 36 HOURS...IF NOT SOONER.

RECENT 0000 UTC FIXES YIELD AN INITIAL MOTION OF 315/08...SLIGHTLY
FASTER THAN BEFORE. THE OFFICIAL TRACK FORECAST IS LARGELY
UNCHANGED. AS MARTY STEADILY WEAKENS AND BECOME A MORE SHALLOW
SYSTEM...THE CYCLONE SHOULD TURN MORE WEST-NORTHWESTWARD AND THEN
WESTWARD WITHIN THE LOW-LEVEL FLOW SOUTH OF A SURFACE RIDGE. THE
OFFICIAL TRACK IS ADJUSTED SLIGHTLY NORTH OF THE PREVIOUS PACKAGE
DUE TO THE SLIGHTLY FASTER INITIAL MOTION BUT REMAINS CLOSE TO THE
MODEL CONSENSUS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 19/0300Z 21.9N 115.9W 35 KT
12HR VT 19/1200Z 22.5N 117.1W 30 KT
24HR VT 20/0000Z 22.9N 118.8W 25 KT
36HR VT 20/1200Z 23.0N 120.7W 20 KT...REMNANT LOW
48HR VT 21/0000Z 22.9N 122.7W 20 KT...REMNANT LOW
72HR VT 22/0000Z...DISSIPATED

$$
FORECASTER KIMBERLAIN

[HURAKAN]

775
WTPZ41 KNHC 192043
TCDEP1
TROPICAL DEPRESSION MARTY DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP162009
200 PM PDT SAT SEP 19 2009

MARTY HAS BEEN VOID OF ORGANIZED DEEP CONVECTION SINCE AROUND 0500
UTC...AND THEREFORE IS BEING DECLARED A REMNANT LOW. MARTY STILL HAS
A WELL-DEFINED LOW-LEVEL CIRCULATION THAT SHOULD PERSIST FOR A
COUPLE OF DAYS...AND MAY PRODUCE INTERMITTENT BURSTS OF CONVECTION.
THE INITIAL INTENSITY IS HELD AT 25 KT...AND A SLOW WEAKENING IS
EXPECTED THROUGH DISSIPATION.

THE INITIAL MOTION ESTIMATE IS 290/10. AS MARTY MOVES TO THE SOUTH
OF THE LOW-LEVEL RIDGE OVER THE EASTERN PACIFIC...A TURN TOWARD THE
WEST AND EVENTUALLY SOUTH OF DUE WEST IS EXPECTED UNTIL THE LOW
DISSIPATES. THE NEW OFFICIAL FORECAST IS A BLEND OF THE PREVIOUS
FORECAST AND THE TVCN MODEL CONSENSUS.

THIS IS THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON
MARTY. FOR ADDITIONAL INFORMATION ON THE REMNANT LOW PLEASE SEE
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER
AWIPS HEADER NFDHSFEPI AND WMO HEADER FZPN02 KWBC.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/2100Z 22.9N 119.0W 25 KT...REMNANT LOW
12HR VT 20/0600Z 23.1N 120.5W 25 KT...REMNANT LOW
24HR VT 20/1800Z 23.2N 122.6W 20 KT...REMNANT LOW
36HR VT 21/0600Z 23.1N 124.8W 20 KT...REMNANT LOW
48HR VT 21/1800Z 22.8N 127.0W 20 KT...REMNANT LOW
72HR VT 22/1800Z...DISSIPATED

$$
FORECASTER BRENNAN