Tropical Cyclone Report

Tropical Storm Josephine

Josephine was a short-lived, high latitude tropical storm well out at sea.

a. Synoptic History

Josephine was of non-tropical origin. Surface data indicated that a weak low pressure system formed along a dissipating, nearly stationary frontal zone about 750 n mi east of Bermuda on 16 September. Over the next day, as the low moved slowly westward, a small area of deep convection formed near the low-level circulation center and the system's cloud pattern changed from one that resembled a non-tropical cyclone to that of a tropical cyclone. It is estimated that the system became a tropical depression around 1200 UTC 17 September, while centered about 620 n mi east of Bermuda. The tropical cyclone moved slowly north-northwestward to northward for about a day. Deep convection associated with the system was intermittent and at times the low-level center became exposed. However, the cyclone strengthened slightly and is estimated to have become a tropical storm by 0600 UTC 18 September. Soon thereafter, Josephine accelerated northeastward in the flow ahead of a deep-layer mid-latitude trough. The system lost its tropical characteristics around 1200 UTC 19 September, at which time a ship report indicated that the cyclone had strengthened into an storm with winds near 50 kt well removed from the center. Soon thereafter, the storm merged with a larger extratropical low and frontal system. The "best track" chart of Josephine's path is displayed in Figure 1, with the wind and pressure histories shown in Figure 2 and Figure 3, respectively. The best track positions and intensities are listed in Table 1.

b. Meteorological Statistics

Observations in Josephine (Figure 2 and Figure 3) include satellite-based Dvorak technique intensity estimates from the Tropical Analysis and Forecast Branch (TAFB), the Satellite Analysis Branch (SAB) and the U. S. Air Force Weather Agency (AFWA). Additionally, there was a report of 37 kt winds from a ship (see Table 2) as well as QuikSCAT and SSM/I winds near 35 kt around 0600 UTC 18 September. When Josephine became extratropical at 1200 UTC 19 September, a ship with call sign C6LV3 reported 50 kt winds about 76 n mi southeast of the center.

c. Casualty and Damage Statistics

There were no reports of damages or casualties associated with Josephine.

d. Forecast and Warning Critique

Josephine was a tropical storm for only about a day, so there are no meaningful forecast statistics. In general, the official forecasts correctly anticipated that the cyclone would accelerate northeastward, and that it would not strengthen significantly as a tropical cyclone. Watches or warnings were not required for Josephine.

Figure 1: Best track positions for Tropical Storm Josephine, 17-19 September 2002. Minimum pressure (mb) at arrowhead.

Figure 2: Best track maximum sustained surface wind speed curve and satellite-derived intensity estimates for Tropical Storm Josephine, 17-19 September 2002.

Figure 3: Best track minimum central pressure curve and satellite-derived pressure estimates for Tropical Storm Josephine, 17-19 September 2002.