Preliminary Report
Tropical Storm Ernesto
21 - 26 September 1994

1994 PRELIMINARY REPORTS

Tropical Storm Alberto (TS)
Tropical Storm Beryl (TS)
Hurricane Chris (1)
Tropical Storm Debby (TS)
Tropical Storm Ernesto (TS)
Hurricane Florence (2)
Hurricane Gordon (1)

Ernesto was a relatively short-lived tropical storm which spent its existence over the open waters of the eastern Atlantic Ocean. Since 1886, only three other tropical storms formed farther east in the Atlantic as late or later in the season.

 

a. Synoptic History

Ernesto developed from a tropical wave that moved off the coast of western Africa on 18 September. It is interesting to note that this was one of several strong-looking (in terms of amount and organization of deep convection) waves to appear over the extreme eastern tropical Atlantic in the latter part of September. These waves came after a period of quietude (i.e., weak-looking systems) during the climatological "peak" of the Atlantic hurricane season, late August to early September. Meteorologists at the NHC's Tropical Satellite Analysis and Forecast (TSAF) unit began giving position estimates for a possible low-level circulation center at 2300 UTC on the 20th, when the wave was nearing 30°W longitude. The initial Dvorak classification was done by the TSAF unit and the NESDIS Synoptic Analysis Branch (SAB) were assigning a T-number of 1.5 on the Dvorak scale, and it is estimated that the tropical depression stage of Ernesto began at that time. When it formed, the tropical cyclone was centered about 500 nautical miles southwest of the Cape Verde Islands, and was moving slowly northwestward.

At upper-tropospheric levels, a southwesterly flow prevailed in the environment of the depression. However, the vertical shear was apparently just weak enough to permit the system to strengthen. While the depression was developing, a mid-tropospheric trough dominated the east-central subtropical Atlantic. This created a southerly steering flow over the tropical cyclone. The cyclone turned northward, and, based on satellite-derived estimates, became a tropical storm around 1200 UTC 22 September. Additional strengthening occurred on the 22nd and (based on post-analysis of satellite imagery) Ernesto reached its peak intensity, estimated near 58 mph, around 0000 UTC 23 September.

As the storm moved farther north, it entered a region of stronger upper-troposperic flow and stronger shear. Steady weaking began on the 23rd. Most of the deep convection associated with Ernesto was gone by 1200 UTC on the 24th, and Ernesto diminished to a tropical depression around that time. Moving very slowly, the system (a swirl of low clouds with isolated thunderstorms) turned northwestward, then westward by the 25th. By about 0000 UTC, the cyclonic circulation inferred from the cloud pattern was very weak and Ernesto was dissipating. Notwithstanding, a remnant disturbance was steered west-southwestward to westward by the lower-tropospheric winds for several days, occasionally generating deep convection. In fact, there was a Dvorak classification of the disturbance by the SAB at 0000 UTC 29 September. The remnant disturbance was last identifiable about 775 nautical miles to the east of the Leeward Islands on 29 September at 1800 UTC.

b. Meteorological Statistics

There were no ship reports received at the NHC of tropical storm force winds associated with with Ernesto.

c. Casualty and Damage Statistics

There were no reports of casualties or damage due to Ernesto.