Tropical Cyclone Report

Tropical Depression Fifteen

(AL152007)

11 -- 12 October 2007

Jack Beven

National Hurricane Center

22 November 2007

A large and complex area of disturbed weather extended from the
northwestern Caribbean Sea into the western Atlantic beginning on 4
October. A surface low pressure system formed near the eastern end of
the area on 8 October about 150 n mi northeast of the Turks and Caicos
Islands. The associated convection gradually increased as the low moved
east-northeastward, and by 1200 UTC 11 October there was sufficient
organized convection to designate the system as a tropical depression
while it was centered about 645 n mi east-southeast of Bermuda. The best
track positions and intensities for Tropical Depression 15 are listed in
Table 1.

The depression turned eastward after genesis and its forward motion
slowed. This was followed by a slow northward drift on 12 October. An
upper-level trough moved over the depression late on 11 October, with
strong northerly vertical wind shear developing over the cyclone in the
wake of the trough. This shear caused the associated convection to
dissipate, and the depression degenerated to a remnant low late on 12
October about 790 n mi east of Bermuda.

The remnant low moved northwestward on 13 October, then turned
northeastward and merged with a frontal zone on 14 October. The
resulting extratropical low developed gale-force winds on 16 October and
maintained them until it was absorbed by a larger extratropical low on
17 October north of the Azores Islands.

Table 1. Best track for Tropical Depression Fifteen, 11 -- 12 October
2007.

+----------+---------+---------+--------+---------+-----------------+
| D        | L       | Lo      | Pr     | Wind    | Stage           |
| ate/Time | atitude | ngitude | essure | Speed   |                 |
|          |         |         |        |         |                 |
| (UTC)    | \(N\)   | \(W\)   | (mb)   | (kt)    |                 |
+----------+---------+---------+--------+---------+-----------------+
| 11 /     | 29.5    | 52.6    | 1011   | 30      | tropical        |
| 1200     |         |         |        |         | depression      |
+----------+---------+---------+--------+---------+-----------------+
| 11 /     | 30.1    | 51.0    | 1011   | 30      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 12 /     | 30.0    | 50.0    | 1011   | 30      | \"              |
| 0000     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 12 /     | 30.1    | 49.6    | 1011   | 30      | \"              |
| 0600     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 12 /     | 30.2    | 49.4    | 1011   | 25      | \"              |
| 1200     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 12 /     | 30.5    | 49.4    | 1012   | 25      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 13 /     | 30.9    | 49.9    | 1012   | 25      | remnant low     |
| 0000     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 13 /     | 31.3    | 50.3    | 1012   | 25      | \"              |
| 0600     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 13 /     | 31.8    | 50.3    | 1013   | 25      | \"              |
| 1200     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 13 /     | 32.5    | 50.0    | 1012   | 25      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 14 /     | 33.1    | 49.2    | 1012   | 25      | \"              |
| 0000     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 14 /     | 33.7    | 48.3    | 1012   | 25      | \"              |
| 0600     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 14 /     | 34.6    | 46.8    | 1010   | 25      | extratropical   |
| 1200     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 14 /     | 35.6    | 44.7    | 1010   | 25      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 15 /     | 36.0    | 43.0    | 1009   | 25      | \"              |
| 0000     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 15 /     | 36.1    | 41.4    | 1006   | 30      | \"              |
| 0600     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 15 /     | 36.1    | 39.9    | 1005   | 30      | \"              |
| 1200     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 15 /     | 36.3    | 38.8    | 1004   | 30      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 16 /     | 37.4    | 37.0    | 1003   | 30      | \"              |
| 0000     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 16 /     | 38.6    | 35.2    | 1000   | 30      | \"              |
| 0600     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 16 /     | 39.8    | 33.5    | 999    | 35      | \"              |
| 1200     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 16 /     | 40.8    | 31.8    | 996    | 40      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 17 /     | 41.9    | 30.1    | 996    | 45      | \"              |
| 0000     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 17 /     | 43.7    | 28.4    | 997    | 45      | \"              |
| 0600     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 17 /     | 45.8    | 26.7    | 998    | 45      | \"              |
| 1200     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 17 /     | 48.7    | 25.2    | 999    | 40      | \"              |
| 1800     |         |         |        |         |                 |
+----------+---------+---------+--------+---------+-----------------+
| 18 /     |         |         |        |         | absorbed by     |
| 0000     |         |         |        |         | larger          |
|          |         |         |        |         | extratropical   |
|          |         |         |        |         | low             |
+----------+---------+---------+--------+---------+-----------------+
| 11 /     | 29.5    | 52.6    | 1011   | 30      | minimum         |
| 1200     |         |         |        |         | pressure as a   |
|          |         |         |        |         | tropical        |
|          |         |         |        |         | cyclone         |
+----------+---------+---------+--------+---------+-----------------+