Daniel was a 110-knot hurricane in the eastern Pacific Ocean basin and then it threatened Hawaii while weakening. Daniel passed just north of Hawaii and produced rough surf conditions there.
a. Synoptic history
Daniel's origin is associated with a tropical wave that moved from Africa to the Atlantic on 8 July. This wave moved westward across the tropical Atlantic, the Caribbean, and Central America without distinction. It was not until 23 July that the wave's weather became well organized. It is estimated from satellite imagery that a tropical depression formed on the 23rd, south of Mexico. The best track listing of center positions, maximum one-minute wind speeds, and minimum central pressures begins at this time and is given in Table 1. Figure 1 is a plot of the best track. Figure 2 and Figure 3 show plots of best-track wind speed and pressure curves as a function of time, along with the data on which they are based. Best track data west of 140° west longitude in the above table and figures were provided by the Central Pacific Hurricane Center at Honolulu.
The track begins 575 n mi south-southeast of Manzanillo, Mexico on 23 July and extends west-northwestward across the eastern and central Pacific basins to just north of Hawaii by 1 August. Daniel was a hurricane from the 24th to the 29th and maximum winds reached 110 knots on the 25th and 26th while still in the eastern Pacific basin. Winds fluctuated from 90 knots on the 27th to 105 knots on the 28 and then weakened to tropical storm levels on the 30th. On the 31st, Daniel turned from west-northwest to northwestward and its center passed parallel to and about 120 n mi north of the Hawaiian island chain over the next two days. Its strongest winds did not affect Hawaii. Daniel weakened to a tropical storm on the 30th, to a depression on the 3rd, and finally dissipated on the 5th about 1000 n mi northwest of Hawaii.
A subtropical ridge anchored to the north was Daniel's controlling steering feature until the track gradually turned from west-northwest to northwestward on the 30th and 31st, into a weakness in the ridge near Hawaii. Daniel's forward speed was generally from 15 to 20 knots, except when it slowed to less than 10 knots while making the turn toward the northwest.
b. Meteorological statistics
Center positions are taken from satellite images and intensity estimates are based on the Dvorak satellite method, except for about 60 hours of Air Force reconnaissance data from the 30th to the 1st. The highest flight level wind speed during this period was 86 knots at 850 millibars. This value was an outlier as all other reconnaissance flight level wind speeds were below 60 knots and is not shown in Fig. 2. QuikSCAT and SSM/I microwave satellite wind fields were used during Daniel's formative stage to help determine the existence of, and to locate, the low level circulation center.
c. Casualty and damage statistics
There were no reports of death or damage. There were reports of rough surf conditions on the big island of Hawaii and on Maui's east-facing coast.
d. Forecast and warning critique
The official average track forecast errors for forecasts issued in the eastern Pacific basin ranged from 50 nautical miles at 24 hours to 79 nautical at 48 hours to 190 nautical miles at 72 hours (21 cases). These errors are 30 to 40 percent smaller than the 1990-99 mean official errors. CLIPER errors for Daniel are also considerably smaller than their 1990-99 mean values. These small errors may be related to the small variation of track heading. The track heading varied from only 275 to 295 degrees during the five days of verification. The bias of the official intensity errors was small...+3.6 knots at 72 hours, compared to the ten-year average of -6.2 knots.
Figure 1. Best track positions for Hurricane Daniel, 23 July - 5 August 2000.
Table 1. Best track for Hurricane Daniel, 23 July - 05 August, 2000. Data west of 140° west longitude provided by the Central Pacific Hurricane Center at Honolulu. Date/Time
(UTC)Position Pressure
(mb)Wind Speed
(kt)Stage Lat. (°N) Lon. (°W) 23/0000 10.1 102.3 1009 25 tropical depression 23/0600 10.3 104.1 1009 30 " 23/1200 10.6 105.9 1007 30 " 23/1800 10.9 107.6 1004 35 tropical storm 24/0000 11.3 109.1 1001 45 " 24/0600 11.8 110.7 997 55 " 24/1200 12.3 112.3 991 65 hurricane 24/1800 12.9 114.1 980 75 " 25/0000 13.4 116.0 970 95 " 25/0600 13.8 117.8 964 100 " 25/1200 14.0 119.4 955 105 " 25/1800 14.3 121.1 954 110 " 26/0000 14.5 122.5 954 110 " 26/0600 14.9 123.9 956 105 " 26/1200 15.3 125.3 959 105 " 26/1800 15.5 127.0 961 105 " 27/0000 15.6 128.5 963 100 " 27/0600 15.7 130.1 964 95 " 27/1200 15.9 131.6 965 90 " 27/1800 16.0 133.2 964 95 " 28/0000 16.4 134.8 962 95 " 28/0600 16.8 136.4 961 105 " 28/1200 17.2 138.2 963 100 " 28/1800 17.5 139.6 968 90 " 29/0000 18.0 141.3 980 80 " 29/0600 18.4 142.9 990 65 " 29/1200 18.7 144.6 990 65 " 29/1800 18.9 146.3 990 65 " 30/0000 19.3 147.7 995 60 tropical storm 30/0600 19.8 148.9 997 55 " 30/1200 20.1 150.0 997 55 " 30/1800 20.5 151.0 995 50 " 31/0000 20.7 151.8 993 55 " 31/0600 20.8 152.5 995 50 " 31/1200 21.0 153.1 998 45 " 31/1800 21.3 153.8 993 60 " 01/0000 21.8 154.5 998 60 " 01/0600 22.3 155.2 1001 50 " 01/1200 22.9 156.1 1004 45 " 01/1800 23.6 157.2 1006 45 " 02/0000 24.2 158.4 1008 40 " 02/0600 25.0 159.6 1006 45 " 02/1200 25.8 160.9 1007 45 " 02/1800 26.9 162.3 1008 45 " 03/0000 27.9 163.7 1010 40 " 03/0600 28.8 165.2 1008 35 " 03/1200 29.8 166.5 1009 30 tropical depression 03/1800 30.5 167.6 1010 30 " 04/0000 31.4 168.6 1012 30 " 04/0600 32.2 169.3 1012 30 " 04/1200 33.0 169.9 1013 25 " 04/1800 33.9 170.3 1015 25 " 05/0000 35.0 170.5 1017 25 " 05/0600 36.1 170.7 1017 25 " 26/0000 14.5 122.4 954 110 minimum pressure
Figure 2. Best track one-min. wind speed curve for Hurricane Daniel, 23 July - 5 August 2000.
Figure 3. Best track minimum central pressure curve for Hurricane Daniel, 23 Jul - 5 August 2000.
