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Preliminary Report
Tropical Storm Marty
12 - 16 September 1997

Richard J. Pasch
National Hurricane Center
12 December 1997

Tropical Storm Andres
Tropical Storm Blanca
Tropical Depression 3-E
Tropical Storm Carlos
Tropical Depression 5-E
Hurricane Dolores
Hurricane Enrique
Hurricane Felicia
Hurricane Guillermo
Tropical Storm Hilda
Tropical Storm Ignacio
Hurricane Jimena
Tropical Storm Kevin
Hurricane Linda
Tropical Storm Marty
Hurricane Nora
Tropical Storm Olaf
Hurricane Pauline
Hurricane Rick

[1997 EPAC Hurricane Season]

a. Synoptic History

Marty's origins could be associated with two westward-traveling tropical waves, one which crossed Central America around the end of August, and another which entered the eastern Pacific about three days later. These two waves appeared to contribute to an area of disturbed weather which was located in the vicinity of 129°W early on 10 September. Meteorologists at the Tropical Prediction Center's Tropical Analysis and Forecast Branch (TAFB) began to locate and "classify" the disturbance on that date. Deep convection associated with the system increased in a "bursting"-type event on the 11th, but there was no significant increase in organization until the following day, when curved cloud bands became readily apparent. The system is estimated to have become Tropical Depression Fifteen-E at 1800 UTC 12 September, at which time Dvorak T-numbers were up to T2.0 from both TAFB and the Synoptic Analysis Branch (SAB). The depression was centered about 1300 n mi east-southeast of the island of Hawaii at that time. Figure 1 (12K GIF) shows the best track and Table 1 lists the positions and intensities every six hours.

Steering currents in the vicinity of this tropical cyclone remained fairly weak, and the system never moved faster than 5 or 6 knots throughout its lifetime. The depression moved a little south of due westward on the 12th and 13th, and, after strengthening into Tropical Storm Marty around 0000 UTC on the 14th, it turned southwestward and then southward. Marty's forward speed slowed to a crawl on the 15th, and it weakened back to a depression that day. The weakening was apparently caused by vertical shear due to upper-level southeasterly flow over the area, with the low-cloud center becoming clearly exposed. Strong shearing continued, weakening the slow-moving Marty to dissipation around 1800 UTC 16 September.

b. Meteorological Statistics

Figures 2 (13K GIF) and 3 (13K GIF) depict the curves of minimum central sea-level pressure and maximum one-minute average "surface" (10 meters above ground level) wind speed, respectively, as a function of time for Tropical Storm Marty. Also plotted are the observations on which the curves are based, consisting of Dvorak-technique estimates (from the TAFB, the SAB, and the U.S. Air Force Global Weather Center [AFGWC]) using geostationary and polar-orbiting satellite imagery.

c. Casualty and Damage Statistics

No reports of casualties or damage due to Marty have been received at the National Hurricane Center and, since the storm remained at sea, nothing was likely damaged and probably no one was hurt.

d. Forecast and Warning Critique

Marty was a tropical storm for only about 30 hours. Therefore, no meaningful forecast statistics are available. However, the official forecasts never called for the cyclone to move very fast or to strengthen much. This turned out to be generally correct.

Marty did not threaten land, and watches and/or warnings were not required.

Table 1. Best track, Tropical Storm Marty, 12 -16 September, 1997.
Position Pressure
Wind Speed
Lat. (°N)Lon. (°W)
12/180014.3133.1100625 tropical depression
14/000013.9135.5100435 tropical storm
120011.9136.2100630 tropical depression
16/1800     dissipated
14/120013.3135.8100240 minimum pressure

Brian Maher
Jack Beven

Last updated December 26, 1998