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Preliminary Report
Hurricane Madeline
16 - 20 October 1998

Max Mayfield
National Hurricane Center
16 November 1998

Tropical Storm Agatha
Hurricane Blas
Tropical Storm Celia
Hurricane Darby
Hurricane Estelle
Tropical Storm Frank
Hurricane Georgette
Hurricane Howard
Hurricane Isis
Tropical Storm Javier
Hurricane Kay
Hurricane Lester
Hurricane Madeline

[1998 East Pacific Hurricane Season]

a. Synoptic History

Madeline can be traced back to a tropical wave that emerged from the west coast of Africa on 25 September. The wave produced intermittent clusters of convection as it moved across the Atlantic and Caribbean Sea. Cloudiness associated with the wave crossed over Central America on 5 and 6 October. Convection increased in the vicinity of the Gulf of Tehuantepec on 9 October, and Dvorak classifications began on this day. Satellite classifications temporarily ceased on 11 October, although disorganized cloudiness persisted off the southwest coast of Mexico. Classifications resumed on 15 October and the "best track" indicates that a tropical depression formed from the disturbance near 0000 UTC 16 October while centered about 200 n mi west-southwest of Manzanillo, Mexico (Fig. 1 [21K GIF] and Table 1).

Under diffluent conditions aloft, the deep convection became more concentrated and satellite estimates suggest that the depression strengthened into Tropical Storm Madeline at 1200 UTC 16 October while centered about 150 n mi southwest of Cabo Corrientes, Mexico. Banding features became more pronounced and Madeline became a hurricane at 1800 UTC 17 October while centered about 85 n mi west-southwest of Cabo Corrientes. Upper-level outflow remained well-established, and it is estimated that the maximum winds in Madeline reached 75 knots from 1200 UTC 18 October to 0000 UTC 19 October. Satellite pictures showed a hint of an eye on the 18th, and the last report from a reconnaissance aircraft reported that the minimum central pressure was continuing to drop late that day. The best track estimates that the lowest pressure of 979 mb occurred at 0000 UTC 19 October.

Upper-level shear increased during the 19th, and the cloud pattern began looking somewhat ragged. Madeline weakened to a tropical storm by 1200 UTC 19 October, and to a tropical depression twelve hours later, at which time only a swirl of low clouds was left of it midway between the southern tip of Baja California and the mainland of Mexico. The center of the tropical cyclone never crossed the coast, although rainbands moved over portions of southwestern Mexico.

Steering currents surrounding the tropical cyclone were relatively weak throughout its lifetime. In the early stages, Madeline was located near the western edge of an east-west oriented mid-level ridge which resulted in a general northward motion of the cyclone. On the 17th and 18th, a mid-level trough approaching from the west appears to be the reason for a slow northeastward motion. The trough did not move the tropical cyclone far before shearing occurred, however, and the lower-level steering eventually turned the weakening Madeline toward the northwest.

b. Meteorological Statistics

Figures 2 (17K GIF) and 3 (17K GIF) show the curves of minimum central pressure and maximum one-minute wind speed, respectively, versus time, along with the observations on which they are based. As usual for an eastern Pacific tropical cyclone, satellites provided the primary source of observational data. Dvorak technique location and intensity estimates from the satellite data were produced by the Air Force Weather Agency (AFGWC in figures), the NOAA Synoptic Analysis Branch (SAB) and the NOAA Tropical Analysis and Forecast Branch (TAFB). The highest official Dvorak T number was 4.5 (77 knots) from TAFB, SAB and AFGWC.

In addition to the satellite estimates, observations were received from U.S. Air Force "Hurricane Hunter" aircraft. The lowest minimum central pressure reported was 980 mb at 2153 UTC 18 October during the second of two missions into the hurricane. The maximum wind measured was 76 knots from a flight level of 10,000 feet at 2028 UTC on the 18th. A near-surface wind of 73 knots was reported by one of the GPS dropwindsondes near this time.

c. Casualty and Damage Statistics

There were no reports of casualties or damages from Madeline received at the NHC.

d. Forecast and Warning Critique

The NHC average official track forecast errors for Madeline (excluding the tropical depression stage) were 38 (12 cases), 81 (10 cases), 137 (8 cases), 186 (6 cases) and 313 n mi (2 cases), respectively, for the 12-, 24-, 36-, 48- and 72-hour forecast periods. Although the sample size is small, these errors were larger than the 1988-1997 average errors except at 12 hours for which the errors are comparable. The NHC average official track forecast errors were similar to or lower than the averages from most of the operationally available track prediction models through 48 hours. The exception was the UKMI guidance which was 48 n mi lower than the official forecast at 48 hours for a homogeneous sample of five. No meaningful comparisons can be made at 72 hours due to the small number of forecasts made for that time period. The relatively large errors from the official track forecasts as well as the track guidance are not unusual for a northward moving tropical cyclone in the eastern North Pacific. The need for improvement in track forecasts for a hurricane like Madeline near land and in an area of heavy marine traffic is obvious.

The NHC official intensity forecasts showed a negative bias (i.e., intensity was underestimated) while Madeline was strengthening and a distinct positive bias (i.e., intensity was overestimated) while Madeline was weakening. For example, the 48-hour intensity forecast issued about two days before maximum intensity was reached was 40 knots too low. On the other hand, the 12- and 24-hour intensity forecasts issued near the time of maximum intensity were 40 knots too high. These larger than usual short-period intensity forecast errors were the result of the inability to forecast rapid weakening.

Table 2 summarizes the watches and warnings issued for Madeline.

Table 1. Best track, Hurricane Madeline, 16 - 20 October 1998.
Position Pressure
Wind Speed
Lat. (°N)Lon. (°W)
16/000017.8107.6100625tropical depression
120018.9108.0100340tropical storm
120022.2106.998755tropical storm
20/000023.7108.5100425tropical depression
0600    dissipated
19/000021.2106.697975minimum pressure

Table 2. Watch and warning summary, Hurricane Madeline, October 1998.
16/1500tropical storm warning issued Baja California from La Paz southward
hurricane watch issuedBaja California from La Paz southward
17/0900hurricane watch issued Mazatlan to Los Mochis, Mexico
17/1500hurricane warning issued Melaque to Mazatlan, Mexico including the Islas Marias
tropical storm warning discontinuedBaja California from La Paz southward
19/0300hurricane warning discontinued Melaque to just southeast of Cabo Corrientes
hurricane warning extended northwestwardMazatlan to El Dorado, Mexico
19/1500hurricane warning discontinued Cabo Corrientes to San Blas, Mexico
19/1800 hurricane warning downgraded to tropical storm warning north of San Blas to El Dorado, Mexico including the Islas Marias
hurricane watch downgraded to tropical storm watch northwest of El Dorado to Los Mochis,Mexico
hurricane watch downgraded to tropical storm watch Baja California from La Paz southward
20/0000all remaining tropical storm watches and warnings discontinued  

Jack Beven

Last updated May 28, 1999