Tropical Cyclone Report

Tropical Storm Laura

(AL122008)

29 September-1 October 2008

Richard J. Pasch

National Hurricane Center

4 February 2009

Short-lived Laura remained well out at sea over the North Atlantic.

a.  Synoptic History

    Laura originated from a non-tropical source. On 26 September, a low
    pressure system formed along a quasi-stationary front a few hundred
    miles west of the Azores. During the ensuing day or so, the cyclone
    intensified, apparently due to baroclinic energy sources, and
    acquired hurricane force (70 kt) winds on 27 September. Over the
    next couple of days the extratropical cyclone moved westward while
    the associated frontal features gradually dissipated, and rather
    unorganized deep convection developed within the system's
    circulation. The cyclone's maximum winds had decreased to near 50 kt
    by 28 September. By early on 29 September, a prominent band of deep
    convection formed over the southeastern semicircle of the cyclone;
    however, deep cloudiness was not concentrated near or over the
    center, and the system was essentially collocated with an
    upper-tropospheric low pressure area. It is estimated that the
    system had transformed into a 50-kt subtropical storm by 0600 UTC 29
    September, centered about 650 n mi south-southeast of Cape Race,
    Newfoundland.

    The "best track" chart of the cyclone'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]. Laura turned from a west-northwestward to a
    north-northwestward heading as it moved between an area of high
    pressure to the north of the Azores and an extratropical cyclone
    (the remnants of Hurricane Kyle) over the Canadian Maritimes. By
    early on 30 September Laura was moving northward while maintaining
    an intensity of near 50 kt. Although the system had acquired some
    warm-core structure, it had minimal deep convection and was still
    too coincident with the upper-tropospheric low to be considered a
    tropical cyclone. A little later on 30 September, the upper-level
    low became stretched and offset from the center of Laura, the radius
    of maximum winds contracted somewhat to near 60 n mi, and moderately
    deep convection became more organized and concentrated near the
    center of circulation. Based on these events, it is estimated that
    the system became a tropical storm around 1200 UTC 30 September.
    Maximum winds remained near 50 kt as Laura traversed marginal sea
    surface temperatures of around 26ºC. By early on 1 October, the
    system began a gradual weakening trend as it moved over cooler
    waters. Laura weakened to 40 kt by 1200 UTC 1 October, and its deep
    convection had diminished to the point that it could no longer be
    designated a tropical cyclone. There was little evidence of frontal
    structure within the system at that time, indicating that Laura had
    become a remnant low. The low accelerated northward, and surface
    analyses suggest that the system became embedded within a front by
    0600 UTC 2 October, marking a transformation into an extratropical
    cyclone. Around 0600 UTC 3 October, the cyclone turned eastward and
    slowed its forward motion while intensifying again to hurricane
    force. The system then accelerated eastward while gradually
    weakening, and finally became absorbed within a larger extratropical
    low pressure system several hundred n mi west of the British Isles
    on 4 October.

b.  Meteorological Statistics

    Observations in Laura (Figs. 2 and 3) include satellite-based Dvorak
    and Hebert-Poteat technique intensity estimates from the Tropical
    Analysis and Forecast Branch (TAFB) and the Satellite Analysis
    Branch (SAB) as well as surface ship and fixed platform observations
    over the North Atlantic. Data and imagery from NOAA polar-orbiting
    satellites, the NASA Tropical Rainfall Measuring Mission (TRMM), the
    NASA QuikSCAT, and Defense Meteorological Satellite Program (DMSP)
    satellites, among others, were also useful in tracking Laura. The
    estimated peak intensity of Laura, 50 kt, is based on both satellite
    classifications and QuikSCAT measurements.

    Ship and stationary platform reports of winds of tropical storm
    force associated with Laura are given in Table 2.

c.  Casualty and Damage Statistics

    There were no reports of damage or casualties associated with Laura.

d.  Forecast and Warning Critique

    The first mention in the Tropical Weather Outlook (TWO) of the
    extratropical cyclone that would eventually become Laura was made 36
    h prior to subtropical cyclogenesis. At that time, the TWO indicated
    the potential for the system to slowly acquire subtropical or
    tropical characteristics, and the experimental genesis probability
    was set in the "low" category (less than 20%). The genesis
    probabilities increased to the "medium" category (20% to 50%) within
    24 h of genesis, but were not in the "high" category (greater than
    50%) until 6 h before the formation of the subtropical cyclone.

    A verification of official and guidance model track forecasts is
    given in Table 3. Average official track errors for Laura were 19,
    30, 33 and 48 n mi for the 12, 24, 36, and 48 h forecasts,
    respectively. There were no official forecasts to verify at 72 h or
    longer forecast intervals. The number of forecasts ranged from 8 at
    12 h to just 2 at 48 h. These errors are fairly low in comparison to
    the average 5-yr official track errors (also shown in Table 3), but
    for such a small sample of forecasts, the comparisons are not very
    meaningful.

    A verification of official and guidance model intensity forecasts is
    given in Table 4. Average official intensity errors were 3, 8, 10,
    and 13 kt for the 12, 24, 36, and 48 h forecasts, respectively. For
    comparison, the average 5-yr official intensity errors are 7, 10,
    12, and 14 kt, respectively. The mean official intensity forecasts
    had a positive bias that ranged from 3 kt at 12 h to 13 kt at 48 h;
    every official forecast had a positive bias.

Watches and/or warnings were not required for Laura.

Table 1. Best track for Tropical Storm Laura, 29 September-1 October
2008.

+---------+-----------+---------+---------+---------+----------------+
| Da      | Latitude  | Lo      | P       | Wind    | Stage          |
| te/Time |           | ngitude | ressure | Speed   |                |
|         | \(N\)     |         |         |         |                |
| (UTC)   |           | \(W\)   | (mb)    | (kt)    |                |
+---------+-----------+---------+---------+---------+----------------+
| 26 /    | 39.0      | 35.0    | 1011    | 40      | extratropical  |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 26 /    | 37.9      | 35.0    | 1010    | 45      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 26 /    | 37.0      | 35.5    | 1009    | 50      | \"             |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 26 /    | 36.5      | 36.0    | 1007    | 55      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 27 /    | 37.0      | 36.5    | 1004    | 60      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 27 /    | 37.4      | 37.2    | 998     | 65      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 27 /    | 37.5      | 38.0    | 992     | 70      | \"             |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 27 /    | 37.4      | 39.0    | 992     | 70      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 28 /    | 37.3      | 40.0    | 994     | 60      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 28 /    | 37.2      | 41.2    | 994     | 55      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 28 /    | 37.0      | 42.5    | 995     | 50      | \"             |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 28 /    | 36.8      | 44.1    | 995     | 50      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 29 /    | 36.7      | 45.7    | 995     | 50      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 29 /    | 37.0      | 47.0    | 995     | 50      | subtropical    |
| 0600    |           |         |         |         | storm          |
+---------+-----------+---------+---------+---------+----------------+
| 29 /    | 37.2      | 47.7    | 995     | 50      | \"             |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 29 /    | 37.8      | 48.2    | 995     | 50      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 30 /    | 38.6      | 48.5    | 996     | 50      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 30 /    | 39.6      | 48.8    | 996     | 50      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 30 /    | 40.6      | 48.9    | 996     | 50      | tropical storm |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 30 /    | 41.7      | 48.8    | 994     | 50      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 01 /    | 42.9      | 48.3    | 995     | 45      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 01 /    | 44.2      | 47.7    | 995     | 45      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 01 /    | 45.7      | 46.9    | 995     | 40      | low            |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 01 /    | 47.5      | 46.3    | 995     | 40      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 02 /    | 49.5      | 46.0    | 997     | 35      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 02 /    | 51.5      | 46.0    | 996     | 35      | extratropical  |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 02 /    | 53.5      | 46.0    | 992     | 40      | \"             |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 02 /    | 55.6      | 45.5    | 992     | 40      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 03 /    | 56.9      | 44.0    | 991     | 50      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 03 /    | 57.0      | 42.0    | 990     | 65      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 03 /    | 57.0      | 40.0    | 992     | 60      | \"             |
| 1200    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 03 /    | 57.0      | 37.0    | 994     | 55      | \"             |
| 1800    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 04 /    | 56.5      | 31.4    | 996     | 45      | \"             |
| 0000    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 04 /    | 56.0      | 26.0    | 997     | 40      | \"             |
| 0600    |           |         |         |         |                |
+---------+-----------+---------+---------+---------+----------------+
| 04 /    |           |         |         |         | merged with    |
| 1200    |           |         |         |         | extratropical  |
|         |           |         |         |         | low            |
+---------+-----------+---------+---------+---------+----------------+
| 30 /    | 41.7      | 48.8    | 994     | 50      | minimum        |
| 1800    |           |         |         |         | pressure (as a |
|         |           |         |         |         | tropical or    |
|         |           |         |         |         | subtropical    |
|         |           |         |         |         | cyclone)       |
+---------+-----------+---------+---------+---------+----------------+

Table 2. Selected ship and fixed platform reports with winds of at least
34 kt for Tropical Storm Laura, 29 September-1 October 2008.

+-----------+-----------+-----------+-----------+-----------+-----------+
| Date/Time | Ship call | Latitude  | Longitude | Wind      | Pressure  |
| (UTC)     | sign      |           |           |           |           |
|           |           | \(N\)     | \(W\)     | dir/speed | (mb)      |
|           |           |           |           | (kt)      |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 29 / 1800 | C6QK      | 36.8      | 44.3      | 160 / 35  | 1008.9    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 29 / 2100 | C6QK      | 36.4      | 44.6      | 160 / 35  | 1008.8    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 30 / 0000 | C6QK      | 36.0      | 45.1      | 180 / 37  | 1009.6    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0000 | VEP717    | 46.7      | 48.7      | 080 / 36  | 1008.7    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0300 | S6TS      | 40.9      | 47.9      | 250 / 35  | 1006.5    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0300 | VCXF      | 46.4      | 48.4      | 090 / 36  | 1005.3    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0300 | VEP717    | 46.7      | 48.7      | 070 / 47  | 1004.6    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0300 | YJUF7     | 46.7      | 48.0      | 100 / 39  | 1005.8    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0600 | V2OH3     | 46.1      | 44.4      | 090 / 40  | 1006.2    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0600 | VEP717    | 46.7      | 48.7      | 110 / 45  | 1002.1    |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 01 / 0600 | YJUF7     | 46.7      | 48.0      | 110 / 41  | 1002.8    |
+-----------+-----------+-----------+-----------+-----------+-----------+

Table 3. Track forecast evaluation (heterogeneous sample) for Tropical
Storm Laura, 29 September-1 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      | 38 (  | 99 (  | 217 ( | 350 ( |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFNI      | 27 (  | 42 (  | 53 (  |       |       |       |       |
|           | 5)    | 3)    | 1)    |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFDI      | 27 (  | 45 (  | *     | *     |       |       |       |
|           | 8)    | 6)    | *26** | *35** |       |       |       |
|           |       |       | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| HWFI      | 26 (  | 60 (  | 101 ( | 129 ( |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFSI      | 20 (  | 45 (  | 55 (  | 72 (  |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| AEMI      | 27 (  | 56 (  | 68 (  | 121 ( |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NGPI      | 24 (  | 45 (  | 63 (  |       |       |       |       |
|           | 6)    | 4)    | 2)    |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| UKMI      | 20 (  | *     | *     |       |       |       |       |
|           | 6)    | *18** | *21** |       |       |       |       |
|           |       | ( 4)  | ( 2)  |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| EGRI      | 20 (  | *     | 38 (  |       |       |       |       |
|           | 6)    | *18** | 2)    |       |       |       |       |
|           |       | ( 4)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| EMXI      | *     | *     | 63 (  |       |       |       |       |
|           | *17** | *22** | 2)    |       |       |       |       |
|           | ( 6)  | ( 4)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMD      | 39 (  | 70 (  | 99 (  | 177 ( |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMM      | 32 (  | 43 (  | 63 (  | 123 ( |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMS      | 37 (  | 66 (  | 99 (  | 80 (  |       |       |       |
|           | 7)    | 5)    | 3)    | 1)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| LBAR      | 31 (  | 69 (  | 154 ( | 366 ( |       |       |       |
|           | 7)    | 5)    | 3)    | 1)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| TVCN      | 20 (  | 33 (  | 40 (  | 72 (  |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GUNA      | *     | 30 (  | *     |       |       |       |       |
|           | *16** | 4)    | *21** |       |       |       |       |
|           | ( 6)  |       | ( 2)  |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| FSSE      | *     | 34 (  | 34 (  | *     |       |       |       |
|           | *17** | 5)    | 3)    | *47** |       |       |       |
|           | ( 7)  |       |       | ( 1)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OFCL      | 19 (  | 30 (  | 33 (  | 48 (  |       |       |       |
|           | 8)    | 6)    | 4)    | 2)    |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| 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
Tropical Storm Laura, 29 September-1 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      | **    | **    | 11.5  | 18.0  |       |       |       |
|           | 2.9** | 5.0** | ( 4)  | ( 2)  |       |       |       |
|           | ( 8)  | ( 6)  |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GHMI      | **    | 7.8 ( | **    | **    |       |       |       |
|           | 3.0** | 6)    | 7.8** | 6.0** |       |       |       |
|           | ( 8)  |       | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| HWFI      | 4.8 ( | **    | **    | **    |       |       |       |
|           | 8)    | 5.5** | 4.3** | 9.5** |       |       |       |
|           |       | ( 6)  | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| LGEM      | 3.4 ( | 7.5 ( | 12.3  | 15.5  |       |       |       |
|           | 8)    | 6)    | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| DSHP      | 3.5 ( | 8.3 ( | 14.3  | 20.5  |       |       |       |
|           | 8)    | 6)    | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| FSSE      | **    | **    | **    | 13.0  |       |       |       |
|           | 2.4** | 2.4** | 7.3** | ( 1)  |       |       |       |
|           | ( 7)  | ( 5)  | ( 3)  |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| ICON      | **    | **    | **    | **    |       |       |       |
|           | 1.9** | 1.2** | 3.8** | 7.5** |       |       |       |
|           | ( 8)  | ( 6)  | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OFCL      | 3.1 ( | 7.5 ( | 10.0  | 12.5  |       |       |       |
|           | 8)    | 6)    | ( 4)  | ( 2)  |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| 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)     |       |       |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+

![](media/image1.jpeg){width="7.7659722222222225in"
height="6.000694444444444in"}

Figure 1. Best track positions for Tropical Storm Laura, 29 September-1
October 2008. Track during the extratropical stage is based partially on
analyses from the NOAA Ocean Prediction Center.

![](media/image2.wmf){width="7.111111111111111in"
height="4.819444444444445in"}

Figure 2. Selected wind observations and best track maximum sustained
surface wind speed curve for Tropical Storm Laura, 29 September-1
October 2008. Estimates during the extratropical stage are based
partially on analyses from the NOAA Ocean Prediction Center. Dashed
vertical lines correspond to 0000 UTC.

![](media/image3.wmf){width="6.930555555555555in"
height="4.819444444444445in"}

Figure 3. Selected pressure observations and best track minimum central
pressure curve for Tropical Storm Laura, 29 September-1 October 2008.
Estimates during the extratropical stage are based partially on analyses
from the NOAA Ocean Prediction Center. Dashed vertical lines correspond
to 0000 UTC.

[^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.