The precursor of Hurricane Cesar was a tropical wave
which passed Dakar, Africa on 17 July and moved westward for a few days
without development. The wave was accompanied by a large 200-mb
anticyclone which suggested a very favorable upper-level
environment for development. Cloudiness and showers began to
increase when the wave was about 900 n mi east of the southern
Windward Islands on 22 July. When the wave neared these islands,
the 24-hour surface pressure changes were of the order of -3.0 mb,
(which is the threshold value that forecasters have typically found
to be associated with a developing system) and a surface
circulation center began to develop. The incipient center of circulation
moved over Trinidad and
Tobago early on 24 July. This system produced rains and gusty winds through a
large portion of the Lesser Antilles. A post-analysis of the surface data and
satellite images indicate that a
tropical depression
formed from the disturbed weather at 1800 UTC 24 July when the circulation
center was moving just to the north of the island of Margarita
along the north coast of Venezuela.
The depression moved westward through the southern Caribbean
Sea and reached tropical storm
status at 1200 UTC 25 July in the vicinity of Curacao.
A well defined
upper-level anticyclone (200mb) accompanied the tropical cyclone at that
time as well as an above-normal surface pressure located to the north of the
tropical cyclone from the Bahamas westward into the Gulf of Mexico. The
latter probably reflects
an anomalously strong and persistent high pressure system which
forced Cesar to move westward and even south of due west for
several days. In addition, this dipole in the pressure field is
operationally recognized as a favorable pattern for
disturbances to develop and strengthen.
Cesar continued its general westward track very close to the
coast of South America and gradually intensified. However, the
development was inhibited by the close proximity to land and it was
not until 1200 UTC 27 July that Cesar reached
hurricane
status over the open waters of the southwestern Caribbean Sea. Cesar
began strengthening more rapidly prior to landfall just north of
Bluefields, Nicaragua, and it reached its maximum intensity of 75
knots and minimum pressure of 985 mb near landfall at 0400 UTC 28
July. Rapid intensification of tropical cyclones near landfall has
been observed in the past; e.g., Hurricanes
Andrew and
Cleo over
south Florida in August 1992 and September 1964.
Cesar crossed Nicaragua and moved into the eastern North Pacific where it
reintensified and became Hurricane Douglas. The most recent hurricane to
hit Nicaragua before Cesar was
Joan, a category 4 hurricane on the
Saffir-Simpson Hurricane Scale,
in October 1988. Joan also redeveloped over the eastern Pacific and
became Tropical Storm Miriam.
Cesar was upgraded to tropical storm status based on a 40-knot 1-minute sustained wind and gusts to 50 knots observed in Curacao at 1155 UTC 25 July. The central pressure in the best track associated with Cesar while moving near the coast of Colombia is estimated to be 1 or 2 mb lower that reported by the reconnaissance plane at that time because the storm's close proximity to land prevented the plane from reaching the pressure center. Ship observations and the Hurricane Research Division (HRD) surface wind analysis indicate that 34-knot winds extended northward from the center for about 240 n mi. San Andres experienced calm winds at 2128 UTC followed by 64-knot gusts marking the passage of a portion of Cesar's center. The strengthening just prior to landfall is supported observations from the reconnaissance plane just before it departed the storm center. Data indicate the formation of an eye at 0050 UTC 28 July, a closed eyewall of 15 n mi diameter at 0256 UTC and a drop in the surface pressure of 3 mb in 1 hour. Satellite images confirmed the strengthening at landfall by showing an embedded center within cold tops between -54 to -63C corresponding to a T-number of 4.5 on the Dvorak scale.
Cesar was responsible for at least 51 deaths on its trek through the Caribbean Sea and Central America. Most of the deaths were attributed to heavy rainfall which caused flash flooding and mudslides. The death total includes 26 people in Costa Rica which was not in the direct path of the hurricane but was hit by floods and mud slides.