Tropical Cyclone Report

Hurricane Omar

(AL152008)

13-18 October 2008

John L. Beven II and Chris Landsea

National Hurricane Center

3 February 2009

Omar, which directly impacted the Leeward Islands, underwent rapid
intensification (up to a category 4 hurricane on the Saffir-Simpson
Hurricane Scale) and an immediately subsequent rapid weakening.

a.  Synoptic History

    Omar originated from an easterly wave that moved westward off the
    coast of west Africa on 30 September. The wave had a robust
    mid-level circulation and widespread deep convection as it reached
    the eastern Atlantic. However, by 2 October, convection associated
    with this wave diminished. The wave continued westward during the
    next several days with little change in structure. The wave reached
    the Lesser Antilles on 9 October, and deep convection redeveloped
    two days later in the eastern Caribbean Sea. The convective
    structure continued to increase over the next 36 h, and it is
    estimated that the system became a tropical depression around 0600
    UTC 13 October in the central Caribbean Sea, about 165 n mi south of
    the southeastern tip of the Dominican Republic. The westward
    movement of the depression slowed that day as the deep layer
    steering currents weakened. The cyclone was slow to intensify after
    genesis, taking about 18 h to become a tropical storm about 125 n mi
    north-northeast of Aruba. The "best track" chart of the Omar's path
    is given in Fig. 1, with the wind and pressure histories shown in
    Figs. 2 and 3, respectively. The best track positions and
    intensities are listed in Table 1[^1].

    Omar moved slowly in a counter-clockwise turn on 14 October, and
    this motion continued early the next day. Later on 15 October, the
    cyclone began moving toward the northeast under the influence of a
    broad, deep tropospheric trough to Omar's northwest and a mid- to
    low-level ridge to its east. This trough accelerated Omar
    northeastward for the next few days, with the storm reaching a peak
    forward speed of about 30 kt on 17 October.

    After becoming a tropical storm, a central dense overcast developed
    over Omar, and the cyclone underwent an extended period of rapid
    intensification. Omar's intensity increased from 35 kt at 0000 UTC
    14 October to 115 kt at 0600 UTC 16 October. The intensity increased
    30 kt from 0000 14 October to 0000 UTC 15 October, and increased 35
    kt in the 12 h period starting at 1800 UTC 15 October. Omar reached
    hurricane intensity around 0000 UTC 15 October about 115 n mi north
    of Bonaire. Figure 4 shows the evolution of the convective structure
    of Omar on 14-16 October. The first four microwave images depict how
    the deep convection quickly developed banding features and a ragged
    eye on 14 October, with the continued development of symmetric inner
    core convection and a very distinct eye on 15-16 October. This rapid
    intensification occurred while Omar was experiencing moderate to low
    vertical wind shear, a divergent flow aloft, very warm waters with
    high ocean heat content, and a moist low to mid troposphere. One can
    speculate that the impact of the vertical shear during the second
    rapid intensification period was mitigated by Omar\'s motion being
    in the same direction as the shear vector.  However, the importance
    of the relative orientations of the shear and storm motion vectors
    has not been well quantified by the research community.

    Rapid intensification abruptly ended near 0600 UTC 16 October, and
    rapid weakening promptly commenced (a 45-kt decrease in 12 h). The
    final two panels of Figure 4 show that the eye dissipated and the
    deep convection became well removed to the north and east of the
    center. Additionally, visible images on 16 October revealed an
    exposed low-level center. This weakening appeared to be due to a
    combination of strong vertical shear and low to mid-level dry air
    impacting the cyclone's inner core. Omar lost most of its deep
    convection by early on 17 October, and AMSU imagery indicated that
    it had also lost its upper-level warm core.

    Omar briefly re-intensified later that day as the west-southwesterly
    vertical shear decreased while the hurricane still remained over
    warm waters. During this secondary peak in intensity, deep
    convection re-developed around the center, and an eye was
    discernable for a few hours in both geostationary and microwave
    satellite imagery.

    Also on 17 October, the strong trough that caused the rapid
    northeastward motion bypassed the hurricane. Omar began
    decelerating, but continued moving toward the northeast and then the
    east-northeast during the next three days under the influence of a
    mid- to low-level ridge to its south and the mid-latitude westerlies
    to its north.

    Late on 17 October, westerly vertical shear again increased, and the
    hurricane moved over sea surface temperatures below 26^o^C, causing
    a final erosion of Omar's deep convection. The cyclone weakened to a
    tropical storm around 0000 UTC 18 October about 690 n mi east of
    Bermuda. Omar then degenerated into a remnant low 12 h later. The
    low persisted for two days before dissipating around 0600 UTC 21
    October about 700 n mi west of the Azores.

b.  Meteorological Statistics

    Observations in Omar (Figs. 2 and 3) include satellite-based Dvorak
    technique intensity estimates from the Tropical Analysis and
    Forecast Branch (TAFB) and the Satellite Analysis Branch (SAB), as
    well as flight-level, stepped frequency microwave radiometer (SFMR),
    and dropwindsonde observations from flights of the 53^rd^ Weather
    Reconnaissance Squadron of the U. S. Air Force Reserve Command. Data
    and imagery from NOAA polar-orbiting satellites, the NASA Tropical
    Rainfall Measuring Mission (TRMM), the NASA QuikSCAT, Defense
    Meteorological Satellite Program (DMSP), and the EUMETSAT ASCAT
    satellites, among others, as well as the Curacao and San Juan radars
    were also useful in tracking Omar.

    Dvorak classifications by TAFB and SAB began at 2345 UTC 12 October.
    The system was assessed to be a tropical depression the next day
    based upon a combination of Dvorak estimates, radar imagery from
    Curacao, low level cloud drift winds, and surface observations.
    Dvorak estimates, data from the Advanced Dvorak Technique (ADT), and
    a CIMSS AMSU analysis first indicated that the depression became a
    tropical storm on 14 October. An aircraft reconnaissance mission
    later that day showed that Omar was rapidly intensifying and was
    near hurricane force. Nearly continuous aircraft reconnaissance was
    subsequently available while Omar underwent rapid intensification.

    Omar's peak intensity is estimated to be 115 kt at 0600 UTC 16
    October, based upon an SFMR estimate of 113 kt along with 700-mb
    flight-level winds of 132 kt flight-level winds. This intensity is
    higher than the Dvorak-based satellite estimates of about 105 kt at
    that time. It appears the aircraft sampled during the time of the
    peak intensity, as the eye was most apparent in satellite imagery
    around 0600 UTC and a subsequent penetration by the aircraft two
    hours later showed significant filling.

    The minimum central pressure of 958 mb in Omar is analyzed to also
    have occurred around 0600 UTC based upon a GPS dropwindsonde
    sea-level pressure measurement of 959 mb with an observed 14-kt
    surface wind.

    The intensity of Omar during rapid weakening is more uncertain than
    normal. No aircraft data was available, and the system decayed
    faster than the Dvorak technique can accommodate. Intensities at
    those times are based primarily upon the ADT and QuikSCAT data.
    Omar's modest re-intensification on 17 October is based upon the
    depiction of a redeveloping eye in conventional and microwave
    imagery and a 75-kt QuikSCAT wind speed observation.

    No ships reported winds of tropical storm force directly associated
    with Omar. Selected surface observations from land stations and data
    buoys are given in Table 2. The most extreme surface winds observed
    were from St. Barthelemy, which reported a 1-min wind of 53 kt, and
    from the National Ocean Service station at Christiansted Harbor, St.
    Croix, which measured a 6-min mean wind of 52 kt. The peak observed
    gust was 75 kt from an unofficial site at the Buccaneer Resort at
    Christiansted, St. Croix. National Data Buoy Center buoy 42059 in
    the eastern Caribbean measured a peak significant wave height of
    17.7 ft.

    Omar caused a storm surge in portions of the Virgin Islands and
    northern Leeward Islands. On Antigua, the surge was estimated at
    2-3.5 ft accompanied by wave heights of 4.5-7 ft. Surge heights from
    other islands are not currently available.

    Omar caused storm total rainfalls of 2-6 inches across the Virgin
    Islands and northern Leeward Islands, with a maximum of 9.13 inches
    at Antigua.

c.  Casualty and Damage Statistics

There are no known casualties from Omar.

Impacts from Omar were first felt in the Netherland Antilles of Aruba,
Bonaire, and Curacao. Southwesterly winds on the south side of Omar
generated large waves that caused beach erosion and significant damage
to coastal facilities. On all three islands, a considerable number of
houses experienced roof damage, while several trees were uprooted
because of winds near tropical storm intensity. Sections of Aruba
experienced significant flooding from heavy rains.

At the time of peak intensity, Omar was about 50 n mi west of Anguilla
and St. Martin/St. Maarten in the Leeward Islands, and about 30 n mi
southeast of Virgin Gorda in the British Virgin Islands. Fortunately,
the eye of Omar moved through the Anegada Passage, and the core of major
hurricane force winds did not impact any inhabited islands. Sombrero
Island likely experienced the eye of Omar, but this island is
uninhabited.

In the U.S. Virgin Islands, it is estimated that St. Thomas received
tropical-storm conditions, while St. Croix -- especially the eastern end
of the island -- was affected by low-end Category 1 hurricane
conditions. In St. Croix, electrical power was lost due to downed trees,
power lines and utility poles. The east end of St. Croix was hardest hit
by the winds. There were 47 vessels sunk at St. Croix, with 33 in the
Christiansted Harbor, 11 near the St. Croix Yacht Club, one in the
vicinity of Cotton Valley, and two near Salt River. St. Croix
experienced substantial road damage and landslides. Eighty people sought
shelter from the hurricane. Total damage was reported to be about \$5
million. There were no major impacts in the remaining U.S. Virgin
Islands and Puerto Rico.

Omar also affected the Netherland Antilles of Saba, St. Eustatius, and
St. Maarten, which experienced tropical storm conditions that produced
damaging coastal flooding. Widespread damage was experienced to coastal
facilities, buildings and infrastructure.

In Antigua, the storm surge caused damaging flooding with water reaching
near the roofs of some houses in low lying areas.

d.  Forecast and Warning Critique

    The genesis of Omar was well anticipated. The first mention of
    Omar's originating disturbance in the Tropical Weather Outlook was
    at 1200 UTC 9 October. The disturbance was given only a "low" (less
    than 20% chance of tropical cyclone formation within 48 h) chance of
    formation through 1800 UTC 11 October, which was 36 h before
    genesis. A "medium" probability (20-50% chance of tropical cyclone
    formation within 48 h) of formation was predicted from 0000-1800 UTC
    12 October, 12 h before genesis. A "high" probability greater than
    50% chance of tropical cyclone formation within 48 h) was
    operationally assigned from 0000-1200 13 October, with genesis
    occurring (as determined in post-analysis) at 0600 UTC that day.

    A verification of official and guidance model track forecasts is
    given in Table 3. Average official track errors for Omar were 42,
    84, 114, 166, 280, and 472 n mi for the 12, 24, 36, 48, 72, and 96 h
    forecasts, respectively. The number of forecasts ranged from 18 at
    12 h to 4 at 96 h. These errors are greater than the average 5-yr
    official track errors (Table 3). Examination of the along- and
    cross-track official forecast errors (not shown) indicates that the
    absolute errors were due primarily to a significant slow bias
    (along-track) in the predictions. A variety of the track guidance
    models were better than the official forecast across the various
    forecast periods. The consistently available consensus techniques
    (TVCN, TVCC) generally provided improvements over the individual
    models, and the official track errors were quite similar in
    magnitude to these guidance schemes, including the significant
    along-track slow bias. The Florida State University Superensemble
    (FSSE) also lower mean track forecast errors than the official
    forecasts. The best performer amongst the dynamical models was the
    BAMD.

    A verification of official and guidance model intensity forecasts is
    given in Table 4. Average official intensity errors were 12, 15, 19,
    26, 14, and 10 kt for the 12, 24, 36, 48, 72, and 96 h forecasts,
    respectively. For comparison, the average 5-yr official intensity
    errors are: 7, 10, 12, 14, 18, 20, and 22 kt, respectively. These
    larger-than-average errors were due to the combination of a large
    low bias in the forecasts issued on 13-14 October when Omar's rapid
    intensification was not adequately anticipated, and a large high
    bias in the predictions on 15-16 October when Omar did not weaken as
    quickly as forecast. The GHMI and HWFI models had mean intensity
    forecast errors near or smaller than those of the official forecast
    from 24-48 h, as was the case for the consensus models ICON, IVCN,
    and FSSE.

    Omar experienced two periods of rapid intensification, with the
    first starting at 1800 UTC 13 October and the second at 1800 UTC 14
    October. For the first period, none of the statistical techniques
    suggested rapid intensification. However, the 0000 UTC GHMI and the
    0000/0600 UTC HWFI model runs correctly anticipated this
    strengthening. For the second period, the dynamical intensity
    techniques were calling for intensification, but only the 1800 UTC
    DSHP and LGEM models explicitly predicted at least a 30-kt increase
    in winds. The SHIPS Rapid Intensification Index correctly suggested
    a 68% chance of RI at 1800 UTC 14 October (9.3 times the sample mean
    of 8%) and 58% chance at 0000 UTC 15 October.

Watches and warnings associated with Omar are given in Table 5. A
hurricane watch was issued for Puerto Rico and the U.S. Virgin Islands
about 30 h before Omar's closest approach (to St. Croix). A Hurricane
Warning was issued for the U.S. Virgin Islands about 24 h before Omar's
closest approach.

*Acknowledgements*

The San Juan Weather Forecast Office provided their Post Tropical
Cyclone Report with details on key observations and impacts that
occurred in Puerto Rico and the U.S. Virgin Islands. Data from Antigua,
the French West Indies, and the Netherland Antilles were provided by the
meteorological services of those countries.

Table 1. Best track for Hurricane Omar, 13-18 October 2008.

+----------+--------+--------+--------+-------+-----------------------+
| D        | La     | Lon    | Pr     | Wind  | Stage                 |
| ate/Time | titude | gitude | essure | Speed |                       |
|          |        |        |        |       |                       |
| (UTC)    | \(N\)  | \(W\)  | (mb)   | (kt)  |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 13 /     | 15.4   | 69.0   | 1005   | 25    | tropical depression   |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 13 /     | 15.2   | 69.6   | 1005   | 30    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 13 /     | 14.8   | 69.8   | 1004   | 30    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 14 /     | 14.5   | 69.6   | 1001   | 35    | tropical storm        |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 14 /     | 14.3   | 69.3   | 997    | 40    | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 14 /     | 14.2   | 69.1   | 991    | 50    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 14 /     | 13.9   | 68.8   | 983    | 60    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 15 /     | 14.1   | 68.3   | 983    | 65    | hurricane             |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 15 /     | 14.4   | 68.0   | 985    | 70    | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 15 /     | 14.9   | 67.4   | 984    | 75    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 15 /     | 15.6   | 66.5   | 977    | 80    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 16 /     | 16.7   | 65.2   | 970    | 95    | \"                    |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 16 /     | 18.2   | 63.9   | 958    | 115   | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 16 /     | 19.6   | 62.1   | 975    | 90    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 16 /     | 21.1   | 60.4   | 985    | 70    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 17 /     | 22.8   | 58.8   | 986    | 65    | \"                    |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 17 /     | 25.1   | 57.1   | 984    | 70    | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 17 /     | 27.9   | 55.7   | 982    | 75    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 17 /     | 30.1   | 54.4   | 985    | 65    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 18 /     | 31.3   | 53.2   | 988    | 55    | tropical storm        |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 18 /     | 32.4   | 52.1   | 991    | 50    | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 18 /     | 33.0   | 51.3   | 996    | 40    | remnant low           |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 18 /     | 33.5   | 50.5   | 1002   | 35    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 19 /     | 34.0   | 49.7   | 1006   | 30    | \"                    |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 19 /     | 34.5   | 49.0   | 1008   | 30    | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 19 /     | 35.1   | 48.3   | 1012   | 25    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 19 /     | 35.7   | 47.5   | 1012   | 30    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 20 /     | 36.4   | 46.8   | 1013   | 30    | \"                    |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 20 /     | 37.0   | 46.2   | 1014   | 25    | \"                    |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 20 /     | 37.6   | 45.3   | 1015   | 25    | \"                    |
| 1200     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 20 /     | 37.9   | 44.3   | 1016   | 25    | \"                    |
| 1800     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 21 /     | 38.3   | 43.3   | 1016   | 25    | \"                    |
| 0000     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 21 /     |        |        |        |       | dissipated            |
| 0600     |        |        |        |       |                       |
+----------+--------+--------+--------+-------+-----------------------+
| 16 /     | 18.2   | 63.9   | 958    | 115   | minimum pressure &    |
| 0600     |        |        |        |       | maximum wind          |
+----------+--------+--------+--------+-------+-----------------------+

Table 2. Selected surface observations for Hurricane Omar, 13-18 October
2008.

+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| Location        | M   |     | M   |       |     | St  | St  | To  |
|                 | ini |     | axi |       |     | orm | orm | tal |
|                 | mum |     | mum |       |     | su  |     |     |
|                 | Sea |     | S   |       |     | rge | t   | r   |
|                 | Le  |     | urf |       |     |     | ide | ain |
|                 | vel |     | ace |       |     | (   |     |     |
|                 | Pr  |     |     |       |     | ft) | (   | (   |
|                 | ess |     | W   |       |     | ^c^ | ft) | in) |
|                 | ure |     | ind |       |     |     | ^d^ |     |
|                 |     |     | Sp  |       |     |     |     |     |
|                 |     |     | eed |       |     |     |     |     |
+=================+=====+=====+=====+=======+=====+=====+=====+=====+
|                 | Da  | Pre | Da  | Sust  | G   |     |     |     |
|                 | te/ | ss. | te/ | ained | ust |     |     |     |
|                 |     |     |     |       |     |     |     |     |
|                 | t   | (   | t   | (k    | (   |     |     |     |
|                 | ime | mb) | ime | t)^b^ | kt) |     |     |     |
|                 |     |     |     |       |     |     |     |     |
|                 | (U  |     | (U  |       |     |     |     |     |
|                 | TC) |     | TC) |       |     |     |     |     |
|                 |     |     | ^a^ |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **Antigua**     |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TAPA -- Antigua | 1   | 100 | 1   | 35    | 42  | 1   |     | 9   |
|                 | 6/0 | 7.2 | 6/1 |       |     | .8- |     | .13 |
| (17.12^o^N      | 700 |     | 000 |       |     | 3.6 |     |     |
| 61.78^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **French West   |     |     |     |       |     |     |     |     |
| Indies**        |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| St. Barthelemy  | 1   | 100 | 1   | 31    | 64  |     |     |     |
| Airport         | 6/0 | 3.1 | 6/0 |       |     |     |     |     |
|                 | 300 |     | 400 |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| St. Barthelemy  | 1   | 100 | 1   | 53    | 68  |     |     | 1   |
| Gustavia Meteo  | 6/0 | 3.0 | 6/0 |       |     |     |     | .97 |
|                 | 400 |     | 400 |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| St. Martin      | 1   | 100 | 1   | 42    | 70  |     |     | 4   |
| Grand Case      | 6/0 | 1.8 | 6/0 |       |     |     |     | .53 |
| Airport         | 300 |     | 500 |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **Netherland    |     |     |     |       |     |     |     |     |
| Antilles**      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TNCA -- Aruba   |     |     | 1   | 31    | 39  |     |     | 4   |
|                 |     |     | 4/1 |       |     |     |     | .00 |
| (12.50^o^N      |     |     | 014 |       |     |     |     |     |
| 70.02^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TNCB -- Bonaire |     |     | 1   | 34    | 50  |     |     | 1   |
|                 |     |     | 5/0 |       |     |     |     | .60 |
| (12.15^o^N      |     |     | 723 |       |     |     |     |     |
| 68.28^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TNCC -- Curacao |     |     | 1   | 31    | 39  |     |     | 1   |
|                 |     |     | 4/1 |       |     |     |     | .70 |
| (12.20^o^N      |     |     | 626 |       |     |     |     |     |
| 68.97^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TNCE - St.      |     |     | 1   | 36    | 50  |     |     | 4   |
| Eustatius       |     |     | 6/0 |       |     |     |     | .02 |
|                 |     |     | 525 |       |     |     |     |     |
| (17.48^o^N      |     |     |     |       |     |     |     |     |
| 61.98^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TNCM - St.      |     |     | 1   | 46    | 66  |     |     | 5   |
| Maarten         |     |     | 6/0 |       |     |     |     | .49 |
|                 |     |     | 710 |       |     |     |     |     |
| (18.05^o^N      |     |     |     |       |     |     |     |     |
| 63.12^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **Puerto Rico   |     |     |     |       |     |     |     |     |
| and the US      |     |     |     |       |     |     |     |     |
| Virgin          |     |     |     |       |     |     |     |     |
| Islands**       |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TIST - St.      | 1   | 100 | 1   | 29    | 43  |     |     | 2   |
| Thomas Airport, | 6/0 | 3.1 | 6/0 |       |     |     |     | .42 |
| VI (18.33^o^N   | 546 |     | 428 |       |     |     |     |     |
| 64.98^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| TISX - St.      | 1   | 99  | 1   | 42    | 54  |     |     | 5   |
| Croix Airport,  | 6/0 | 3.9 | 6/0 |       |     |     |     | .30 |
| VI (17.70^o^N   | 326 |     | 410 |       |     |     |     |     |
| 64.80^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| Carolina        | 1   | 100 | 1   | 17    | 23  |     |     |     |
| Airport, PR     | 5/2 | 6.4 | 6/0 |       |     |     |     |     |
|                 | 337 |     | 628 |       |     |     |     |     |
|                 |     |     |     |       |     |     |     |     |
|                 | 1   |     |     |       |     |     |     |     |
|                 | 6/0 |     |     |       |     |     |     |     |
|                 | 448 |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| Cotton Valley,  |     |     |     |       |     |     |     | 3   |
| VI              |     |     |     |       |     |     |     | .44 |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **Buoys**       |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| 42059 Eastern   | 1   | 98  | 1   | 50    | 68  |     |     |     |
| Caribbean       | 5/1 | 7.5 | 5/1 |       |     |     |     |     |
|                 | 150 |     | 300 |       |     |     |     |     |
| (15.01^o^N      |     |     |     |       |     |     |     |     |
| 67.50^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **National      |     |     |     |       |     |     |     |     |
| Ocean Service   |     |     |     |       |     |     |     |     |
| (NOS) Sites**   |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| CHSV3 -         | 1   | 99  | 1   | 52    | 68  |     | 2.2 |     |
| Christiansted   | 6/0 | 3.0 | 6/0 |       |     |     |     |     |
| Harbor          | 342 |     | 342 |       |     |     |     |     |
|                 |     |     |     |       |     |     |     |     |
| (17.75^o^N      |     |     |     |       |     |     |     |     |
| 64.72^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| LTBV3 - Lime    | 1   | 99  | 1   | 44    | 65  |     |     |     |
| Tree Bay        | 6/0 | 5.4 | 6/0 |       |     |     |     |     |
|                 | 424 |     | 418 |       |     |     |     |     |
| (17.68^o^N      |     |     |     |       |     |     |     |     |
| 64.75^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **Sites from    |     |     |     |       |     |     |     |     |
| other           |     |     |     |       |     |     |     |     |
| Government      |     |     |     |       |     |     |     |     |
| Agencies**      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| SRBV3 -         |     |     | 1   | 35    |     |     |     |     |
| Integrated      |     |     | 6/0 |       |     |     |     |     |
| Coral Observing |     |     | 130 |       |     |     |     |     |
| Network         |     |     |     |       |     |     |     |     |
|                 |     |     |     |       |     |     |     |     |
| Salt River Bay  |     |     |     |       |     |     |     |     |
|                 |     |     |     |       |     |     |     |     |
| (17.78^o^N      |     |     |     |       |     |     |     |     |
| 64.76^o^W)      |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| **Unofficial US |     |     |     |       |     |     |     |     |
| Virgin          |     |     |     |       |     |     |     |     |
| Islands**       |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
| Buccaneer       | 1   | 99  | 1   |       | 75  |     |     | 9   |
| Resort,         | 6/0 | 2.8 | 6/0 |       |     |     |     | .11 |
| Christiansted,  | 350 |     | 410 |       |     |     |     |     |
| St. Croix       |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+
|                 |     |     |     |       |     |     |     |     |
+-----------------+-----+-----+-----+-------+-----+-----+-----+-----+

^a^ Date/time is for sustained wind when both sustained and gust are
listed.

^b^ Except as noted, sustained wind averaging periods for C-MAN and
land-based ASOS reports are 2 min; buoy averaging periods are 8 min.

^c^ Storm surge is water height above normal astronomical tide level.

^d^ Storm tide is water height above National Geodetic Vertical Datum
(1929 mean sea level).

Table 3. Track forecast evaluation (heterogeneous sample) for Hurricane
Omar, 13 -- 18 October 2008. Forecast errors (n mi) are followed by the
number of forecasts in parentheses. Errors smaller than the NHC official
forecast are shown in boldface type.

+-----------+-------+-------+-------+-------+-------+-------+-------+
| Forecast  | For   |       |       |       |       |       |       |
| Technique | ecast |       |       |       |       |       |       |
|           | P     |       |       |       |       |       |       |
|           | eriod |       |       |       |       |       |       |
|           | (h)   |       |       |       |       |       |       |
+===========+=======+=======+=======+=======+=======+=======+=======+
|           | 12    | 24    | 36    | 48    | 72    | 96    | 120   |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| CLP5      | 83    | 171   | 321   | 529   | 971 ( | 1322  |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFNI      | *     | *     | **    | 181 ( | 348 ( | 715 ( |       |
|           | *37** | *64** | 111** | 7)    | 5)    | 1)    |       |
|           | ( 7)  | ( 7)  | ( 7)  |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFDI      | 50    | 103   | 150   | 195   | **    | **    |       |
|           | (19)  | (17)  | (15)  | (13)  | 240** | 437** |       |
|           |       |       |       |       | ( 9)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| HWFI      | 46    | *     | **    | 177   | 289 ( | **    |       |
|           | (19)  | *74** | 109** | (13)  | 9)    | 400** |       |
|           |       | (17)  | (15)  |       |       | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NAMI      | 88    | 157   | 248   | 358   | 631 ( |       |       |
|           | (18)  | (14)  | (12)  | (11)  | 8)    |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| COAI      | *     | *     | **    | **    |       |       |       |
|           | *30** | *58** | 101** | 135** |       |       |       |
|           | ( 5)  | ( 5)  | ( 5)  | ( 5)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFSI      | 54    | 91    | 121   | **    | **    | **    |       |
|           | (19)  | (17)  | (15)  | 151** | 198** | 447** |       |
|           |       |       |       | (13)  | ( 8)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| AEMI      | 55    | 91    | 116   | **    | 386 ( |       |       |
|           | (19)  | (17)  | (15)  | 158** | 7)    |       |       |
|           |       |       |       | (11)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NGPI      | 55    | 89    | 134   | 191   | 280 ( | 574 ( |       |
|           | (16)  | (14)  | (12)  | (10)  | 7)    | 3)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| UKMI      | 46    | *     | 120   | 178   | 352 ( | 671 ( |       |
|           | (17)  | *80** | (13)  | (11)  | 7)    | 3)    |       |
|           |       | (15)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| EGRI      | 46    | *     | 120   | 180   | 358 ( | 685 ( |       |
|           | (17)  | *78** | (13)  | (11)  | 7)    | 3)    |       |
|           |       | (15)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| EMXI      | 49    | 108   | 158   | 215 ( | 373 ( | 666 ( |       |
|           | (12)  | (11)  | (10)  | 8)    | 6)    | 2)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| JGSI      | 61    | 98    | 128 ( | 177 ( | **    |       |       |
|           | (13)  | (11)  | 9)    | 7)    | 236** |       |       |
|           |       |       |       |       | ( 3)  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMD      | 51    | *     | **    | **    | **    | **    |       |
|           | (19)  | *79** | 108** | 148** | 135** | 238** |       |
|           |       | (17)  | (15)  | (13)  | ( 9)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMM      | 53    | 96    | 129   | 178   | 340 ( | 804 ( |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMS      | 86    | 169   | 238   | 319   | 555 ( | 1116  |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| LBAR      | 60    | 97    | 139   | 185   | **    | **    |       |
|           | (19)  | (17)  | (15)  | (13)  | 249** | 352** |       |
|           |       |       |       |       | ( 9)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| TCON      | 44    | *     | 117   | 179 ( | **    | 515 ( |       |
|           | (14)  | *79** | (10)  | 8)    | 270** | 1)    |       |
|           |       | (12)  |       |       | ( 4)  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| TCCN      | 43    | *     | 116   | 180 ( | 295 ( | 591 ( |       |
|           | (14)  | *77** | (10)  | 8)    | 4)    | 1)    |       |
|           |       | (12)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| TVCN      | 45    | *     | 115   | 159   | **    | **    |       |
|           | (19)  | *82** | (15)  | (13)  | 250** | 436** |       |
|           |       | (17)  |       |       | ( 9)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| TVCC      | 43    | *     | **    | **    | **    | 516 ( |       |
|           | (19)  | *78** | 109** | 152** | 259** | 5)    |       |
|           |       | (17)  | (15)  | (13)  | ( 9)  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GUNA      | 46    | *     | 122   | 180 ( | **    | 543 ( |       |
|           | (14)  | *83** | (10)  | 8)    | 270** | 1)    |       |
|           |       | (12)  |       |       | ( 4)  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| CGUN      | 43    | *     | 124   | 184 ( | 295 ( | 622 ( |       |
|           | (14)  | *83** | (10)  | 8)    | 4)    | 1)    |       |
|           |       | (12)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| FSSE      | 42    | *     | *     | **    | **    |       |       |
|           | (13)  | *63** | *98** | 163** | 242** |       |       |
|           |       | (11)  | ( 9)  | ( 7)  | ( 3)  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OFCL      | 42    | 84    | 114   | 166   | 280 ( | 472 ( |       |
|           | (18)  | (16)  | (14)  | (12)  | 8)    | 4)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NHC       | 34.0  | 58.2  | 82.2  | 106.2 | 154.2 | 207.5 | 272.5 |
| Official  | (     | (     | (     | (     | (996) | (787) | (627) |
|           | 1742) | 1574) | 1407) | 1254) |       |       |       |
| (         |       |       |       |       |       |       |       |
| 2003-2007 |       |       |       |       |       |       |       |
| mean)     |       |       |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+

Table 4. Intensity forecast evaluation (heterogeneous sample) for
Hurricane Omar, 13 -- 18 October 2008. Forecast errors (kt) are followed
by the number of forecasts in parentheses. Errors smaller than the NHC
official forecast are shown in boldface type.

+-----------+-------+-------+-------+-------+-------+-------+-------+
| Forecast  | For   |       |       |       |       |       |       |
| Technique | ecast |       |       |       |       |       |       |
|           | P     |       |       |       |       |       |       |
|           | eriod |       |       |       |       |       |       |
|           | (h)   |       |       |       |       |       |       |
+===========+=======+=======+=======+=======+=======+=======+=======+
|           | 12    | 24    | 36    | 48    | 72    | 96    | 120   |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OCD5      | 17.1  | 19.4  | 21.9  | 28.1  | 29.4  | 17.6  |       |
|           | (19)  | (17)  | (15)  | (13)  | ( 9)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GHMI      | 13.1  | **1   | **1   | **1   | 20.9  | 25.6  |       |
|           | (19)  | 4.9** | 4.5** | 8.3** | ( 9)  | ( 5)  |       |
|           |       | (17)  | (15)  | (13)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFNI      | 16.3  | 16.0  | **1   | **2   | 16.6  | 20.0  |       |
|           | ( 7)  | ( 7)  | 2.1** | 0.0** | ( 5)  | ( 1)  |       |
|           |       |       | ( 7)  | ( 7)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| HWFI      | 13.4  | 15.1  | **1   | **1   | 17.7  | 25.2  |       |
|           | (19)  | (17)  | 3.9** | 6.0** | ( 9)  | ( 5)  |       |
|           |       |       | (15)  | (13)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| LGEM      | 18.4  | 20.8  | 21.7  | 30.5  | 30.4  | 21.8  |       |
|           | (19)  | (17)  | (15)  | (13)  | ( 9)  | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| DSHP      | 16.1  | 18.2  | 20.4  | 26.7  | 23.8  | **    |       |
|           | (19)  | (17)  | (15)  | (13)  | ( 9)  | 8.8** |       |
|           |       |       |       |       |       | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| FSSE      | 15.4  | 15.7  | **1   | **1   | **1   |       |       |
|           | (13)  | (11)  | 4.4** | 3.9** | 3.7** |       |       |
|           |       |       | ( 9)  | ( 7)  | ( 3)  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| ICON      | 14.7  | 15.2  | **1   | **2   | 17.4  | **    |       |
|           | (19)  | (17)  | 5.7** | 0.6** | ( 9)  | 7.8** |       |
|           |       |       | (15)  | (13)  |       | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| IVCN      | 14.8  | **1   | **1   | **2   | 17.3  | **    |       |
|           | (19)  | 4.9** | 5.1** | 0.5** | ( 9)  | 8.2** |       |
|           |       | (17)  | (15)  | (13)  |       | ( 5)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OFCL      | 12.2  | 15.0  | 19.3  | 26.3  | 14.4  | 10.0  |       |
|           | (18)  | (16)  | (14)  | (12)  | ( 8)  | ( 4)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NHC       | 6.7   | 10.0  | 12.3  | 14.3  | 18.2  | 19.7  | 21.8  |
| Official  | (     | (     | (     | (     | (996) | (787) | (627) |
|           | 1742) | 1574) | 1407) | 1254) |       |       |       |
| (         |       |       |       |       |       |       |       |
| 2003-2007 |       |       |       |       |       |       |       |
| mean)     |       |       |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+

Table 5. Watch and warning summary for Hurricane Omar, 13-18 October
2008.

  ----------- ------------------------------ -------------------------------
  Date/Time   Action                         Location
  (UTC)                                      

  13 / 2100   Tropical Storm Watch issued    Puerto Rico, US Virgin Islands,
                                             Vieques, and Culebra,
                                             andBritish Virgin Islands

  13 / 2100   Tropical Storm Watch issued    Dominican Republic from Isla
                                             Saona to Cabo Engano

  14 / 2100   Tropical Storm Watch changed   Puerto Rico, US Virgin Islands,
              to Tropical Storm Warning/     Vieques, and Culebra, and
              Hurricane Watch                British Virgin Islands

  14 / 2100   Tropical Storm Watch           Dominican Republic from Isla
              discontinued                   Saona to Cabo Engano

  14 / 2100   Tropical Storm Watch issued    Montserrat

  14 / 2100   Tropical Storm Warning/        Anguilla, St. Kitts, Nevis,
              Hurricane Watch issued         Saba, St. Eustatius, St.
                                             Maarten, St. Martin, and St.
                                             Barthelemy

  15 / 0300   Tropical Storm Warning/        US Virgin Islands, Vieques, and
              Hurricane Watch changed to     Culebra
              Hurricane Warning              

  15 / 0300   Tropical Storm Warning/        British Virgin Islands,
              Hurricane Watch changed to     Anguilla, St. Kitts, Nevis,
              Hurricane Warning              Saba, St. Eustatius, St.
                                             Maarten, St. Martin, and St.
                                             Barthelemy

  15 / 0300   Tropical Storm Warning issued  Antigua and Barbuda

  15 / 0300   Tropical Storm Watch changed   Montserrat
              to Tropical Storm Warning      

  15 / 1800   Hurricane Warning changed to   St. Kitts and Nevis
              Tropical Storm Warning/        
              Hurricane Watch                

  16 / 0700   All warnings discontinued      Puerto Rico

  16 / 0900   All warnings discontinued      US Virgin Islands, Vieques, and
                                             Culebra, British Virgin Islands

  16 / 1200   All warnings discontinued      St. Kitts, Nevis, Antigua,
                                             Barbuda, St. Martin, St.
                                             Maarten, St. Eustatius, St.
                                             Barthelemy, Saba, Anguilla, and
                                             Montserrat
  ----------- ------------------------------ -------------------------------

![](media/image1.jpeg){width="8.216666666666667in"
height="6.102777777777778in"}

Figure 1. Best track positions for Hurricane Omar, 13-18 October 2008.
Track during the remnant low stage is based on analyses from the NOAA
Ocean Prediction Center.

![](media/image2.wmf){width="7.361111111111111in"
height="5.098611111111111in"}

Figure 2. Selected wind observations and best track maximum sustained
surface wind speed curve for Hurricane Omar, 13 -- 18 October 2008.
Aircraft observations have been adjusted for elevation using 90%, 80%,
and 75% adjustment factors for observations from 700 mb, 850 mb, and 925
mb, respectively. Dropwindsonde observations are surface wind estimates
derived from the mean wind over the lowest 150 m of the wind sounding
(LLM). Objective Dvorak estimates represent linear averages over a
three-hour period centered on the nominal observation time. CIMSS AMSU
intensity estimates are included when the estimated radius of maximum
winds was at least 25 n mi. Dashed vertical lines correspond to 0000
UTC.

![](media/image3.wmf){width="8.191666666666666in"
height="5.701388888888889in"}

Figure 3. Selected pressure observations and best track minimum central
pressure curve for 13 -- 18 October 2008. Objective Dvorak estimates
represent linear averages over a three-hour period centered on the
nominal observation time. CIMSS AMSU intensity estimates are included
when the estimated radius of maximum winds was at least 25 n mi. Dashed
vertical lines correspond to 0000 UTC.

![](media/image4.jpeg){width="2.8in" height="2.8in"}
![](media/image5.png){width="2.8in" height="2.8in"}
![](media/image6.png){width="2.8in" height="2.8in"}

![](media/image7.png){width="2.8in" height="2.8in"}
![](media/image8.png){width="2.8in" height="2.8in"}
![](media/image9.png){width="2.8in" height="2.8in"}

Figure 4. Microwave imagery depicting the rapid evolution of Omar's
convective structure during a 40 h period: (from top left to bottom
right) 0608 UTC on 14 October (intensity 40 kt), 2306 UTC on 14 October
(intensity 65 kt), 1149 UTC on 15 October (intensity 75 kt), 0554 UTC on
16 October (intensity 115 kt), 1135 UTC on 16 October (intensity 90 kt),
and 2150 UTC on 16 October (intensity 70 kt). Images courtesy NRL
Monterey, CA.

[^1]: A digital record of the complete best track, including wind radii,
    can be found on line at <ftp://ftp.nhc.noaa.gov/atcf>. Data for the
    current year's storms are located in the *btk* directory, while
    previous years' data are located in the *archive* directory.