Tropical Storm Alex 1998

Preliminary Report
Tropical Storm Alex
27 July - 02 August 1998


Tropical Storm Alex (TS)
Hurricane Bonnie (3)
Tropical Storm Charley (TS)
Hurricane Danielle (2)
Hurricane Earl (2)
Tropical Storm Frances (TS)
Hurricane Georges (4)
Tropical Storm Hermine (TS)
Hurricane Ivan (1)
Hurricane Jeanne (2)
Hurricane Karl (2)
Hurricane Lisa (1)
Hurricane Mitch (5)
Hurricane Nicole (1)

Alex was the first tropical cyclone of the 1998 season and remained over the open waters of the tropical Atlantic throughout its lifetime.


a. Synoptic History

A well-organized tropical wave emerged from the west coast of Africa on 26 July and moved westward at 17 to 23 mph. Early on 27th, ship reports and satellite scatterometer winds supported the presence of a surface circulation in association with the wave. On this basis, it is estimated that the system attained tropical depression status around 1200 UTC 27 July while located about 300 nautical miles south-southwest of the Cape Verde Islands.

The depression changed little in organization on 27 July and most of the 28th, with minimal deep convection near the center, while moving on a general west-northwestward track at 17 to 23 mph. During this period, satellite imagery characterized the depression as a large and elongated circulation which was still involved with the Intertropical Convergence Zone. By the evening of the 28th, deep convection increased near the center and meteorologists from both the Tropical Analysis and Forecast Branch (TAFB) at the Tropical Prediction Center and the Satellite Analysis Branch (SAB) from the National Environmental Satellite, Data, and Information Service assigned Dvorak T-numbers of 2.5, i.e., 40 mph. Consequently, the system was upgraded to Tropical Storm Alex at 0000 UTC 29 July.

Alex continued to move on a general west to west-northwest course at 12 to 17 mph in response to a deep-layer ridge over the tropical eastern Atlantic. During the next several days, Alex's development was hampered by a mid- to upper-level trough, and attendant cyclonic circulation, located to its north and west. By 30 July, satellite imagery indicated that Alex was experiencing southerly vertical wind shear. During the evening of the 30th, satellite imagery showed a burst of deep convection just east of the center. It is estimated that Alex reached a peak intensity of 52 mph from 1800 UTC 30 July to 0600 UTC 31 July, and a minimum central pressure of 1002 mb near 0000 UTC 31 July. Shortly thereafter, increased southerly vertical wind shear induced by the mid- to upper-level tropospheric trough to the west of Alex curtailed further strengthening.

Over the next few days the vertical wind shear took its toll with the low-level center of Alex becoming fully exposed south of the remaining deep convection on 1 August. Alex turned toward the northwest later that day and continued to gradually weaken. Alex was downgraded to a depression by midday on the 2nd. Later that afternoon, data from an Air Force Reserve Hurricane Hunter reconnaissance aircraft showed that the system no longer had a closed low-level circulation, and the system dissipated.

b. Meteorological Statistics

There were no surface observations of tropical storm force winds in association with Alex.

c. Casualty and Damage Statistics

Alex is not known to have caused any casualties or damages.

Maximum Intensity For Tropical Storm Alex
27 July - 02 August, 1998

Position Pressure
Wind Speed
Lat. (°N) Lon. (°W)
31/0000 15.4 47.1 1002 50 Tropical Storm