Tropical Cyclone Report

Tropical Storm Jerry (AL112007)

23-24 September 2007

Lixion A. Avila

National Hurricane Center

24 October 2007

Jerry was a short-lived tropical cyclone over the far northeastern
Atlantic.

a.  Synoptic History

    A non-tropical low formed in the central North Atlantic on 21
    September and meandered for a few days, while gradually developing
    deep convection. The thunderstorm activity became better organized
    and eventually wrapped around the low. Since the system was still
    well-involved with an upper--level low and the strongest winds were
    well removed from the center, it is estimated that the depression
    that formed at 0000 UTC 23 September was subtropical in nature. The
    cyclone lacked a well-defined inner core, and there were multiple
    low-cloud swirls near the estimated center, but when both satellite
    estimates and QuikScat data indicated that the maximum winds
    increased to 35 knots, the cyclone became a subtropical storm. Jerry
    became a tropical storm at 0000 UTC 24 September, with a peak
    intensity of 35 knots and a minimum pressure of 1003 mb, when deep
    convection developed near the center and the radius of maximum winds
    decreased. Thereafter, Jerry moved slowly toward the northeast over
    cooler waters and began to weaken. A strong cold front approached
    the area and Jerry accelerated northeastward ahead of the front. By
    0000 UTC 25 September, the circulation of Jerry had opened up into a
    sharp trough and dissipated.

    The "best track" chart of the tropical 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.

b.  Meteorological Statistics

    Observations in Jerry (Figs. 2 and 3) include satellite intensity
    estimates from the Tropical Analysis and Forecast Branch (TAFB) and
    the Satellite Analysis Branch (SAB). Data and imagery from NOAA
    polar-orbiting satellites, the NASA Tropical Rainfall Measuring
    Mission (TRMM), and the NASA QuikSCAT, among others, were also
    useful in tracking Jerry. Data from QuikScat played an important
    role in determining the transformation of Jerry from a subtropical
    storm to a tropical storm.

c.  Casualty and Damage Statistics

    There are no reports of casualties or damage associated with Jerry.

d.  Forecast and Warning Critique

    The description of the non-tropical low from which Jerry originated
    was included in Tropical Weather Outlook (TWO) products beginning on
    20 August. However, the possibility of tropical or subtropical
    cyclone formation was not included in the TWO until 2130 UTC 22
    September, only a couple of hours prior to genesis.

    Jerry was a short-lived cyclone and there were only a few forecasts.
    Average official track errors for Jerry were 28, 52 and 101 n mi for
    the 12, 24 and 36 h forecasts, respectively. The official 5-yr
    period (2002-2006) average errors are 35, 61 and 86 n mi for these
    three forecast periods, respectively.

    Average official intensity errors were 3, 10 and 10 kt for the 12,
    24 and 36 h forecasts, respectively. For comparison, the average
    official intensity errors over the 5-yr period 2002-2006 are 6, 10
    and 12 kt, respectively.

    Table 1. Best track for Tropical Storm Jerry, 23-24 September 2007.

+-----------+---------+---------+---------+--------+-----------------+
| Date/Time | L       | Lo      | P       | Wind   | Stage           |
|           | atitude | ngitude | ressure | Speed  |                 |
| (UTC)     |         |         |         |        |                 |
|           | (°N)    | (°W)    | (mb)    | (kt)   |                 |
+-----------+---------+---------+---------+--------+-----------------+
| 23 / 0000 | 36.2    | 46.1    | 1008    | 30     | subtropical     |
|           |         |         |         |        | depression      |
+-----------+---------+---------+---------+--------+-----------------+
| 23 / 0600 | 36.2    | 46.1    | 1007    | 35     | subtropical     |
|           |         |         |         |        | storm           |
+-----------+---------+---------+---------+--------+-----------------+
| 23 / 1200 | 36.0    | 46.3    | 1004    | 35     | \"              |
+-----------+---------+---------+---------+--------+-----------------+
| 23 / 1800 | 36.5    | 46.3    | 1004    | 35     | \"              |
+-----------+---------+---------+---------+--------+-----------------+
| 24 / 0000 | 37.1    | 46.3    | 1003    | 35     | tropical storm  |
+-----------+---------+---------+---------+--------+-----------------+
| 24 / 0600 | 38.1    | 45.9    | 1004    | 35     | \"              |
+-----------+---------+---------+---------+--------+-----------------+
| 24 / 1200 | 39.3    | 44.7    | 1004    | 35     | \"              |
+-----------+---------+---------+---------+--------+-----------------+
| 24 / 1800 | 41.0    | 43.5    | 1004    | 30     | tropical        |
|           |         |         |         |        | depression      |
+-----------+---------+---------+---------+--------+-----------------+
| 25 / 0000 |         |         |         |        | dissipated      |
+-----------+---------+---------+---------+--------+-----------------+
| 24 / 0000 | 37.1    | 46.3    | 1003    | 35     | minimum         |
|           |         |         |         |        | pressure        |
+-----------+---------+---------+---------+--------+-----------------+

![](media/image1.wmf){width="6.498611111111111in"
height="5.000694444444444in"}

Figure 1. Best track positions for Tropical Storm Jerry, 23-24 September
2007.

![](media/image2.wmf){width="6.49375in" height="4.409722222222222in"}

Figure 2. Selected wind observations and best track maximum sustained
surface wind speed curve for Tropical Storm Jerry, 23-24 September 2007.

![](media/image3.wmf){width="6.49375in" height="4.409722222222222in"}

Figure 3. Selected pressure observations and best track minimum central
pressure curve for Tropical Storm Jerry, 23-24 September 2007.