Number range CHAPTERTropical Cyclone Report

Tropical Storm Lowell

(EP132008)

6 -- 11 September 2008

Robbie Berg

National Hurricane Center

2 December 2008

Lowell was a tropical storm that moved northwestward well off the coast
of Mexico before turning northeastward and affecting the southern Baja
California peninsula as a tropical depression. The remnants of Lowell
caused heavy rainfall and flooding across the Mexican states of Sonora
and Sinaloa.

a.  Synoptic History

    Lowell's formation resulted from a complex interaction of a surface
    trough off the coast of Mexico and a westward-moving tropical wave.
    The tropical wave initially moved off the coast of Africa on 19
    August and propagated across the Atlantic for the next 10 days.
    Hurricane Hanna developed from the northern portion of the wave axis
    on 28 August as it moved north of the Greater Antilles, but the
    southern portion of the wave continued to move westward across the
    Caribbean Sea and crossed Central America on 27 and 28 August. By
    that time, strong southwesterly low-level flow and a surface trough
    had developed off the coast of southern Mexico. The tropical wave
    moved very slowly westward through the larger cyclonic circulation
    associated with the trough and induced a gradual increase in deep
    convection. As the wave reached the western edge of the gyre, a
    smaller embedded circulation developed and eventually detached from
    the larger circulation. It is estimated that the resulting tropical
    depression formed at 1200 UTC 6 September when it was centered about
    255 n mi south of Manzanillo, Mexico. A prominent convective band
    formed that day, and the depression strengthened into a tropical
    storm at 0000 UTC 7 September about 225 n mi south-southwest of
    Manzanillo. The "best track" chart of Lowell'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].

A deep-layer anticyclone over Mexico steered Lowell northwestward during
the next couple of days. However, strong upper-level winds on the south
side of the anticyclone produced about 20 kt of northeasterly to
easterly shear over the cyclone for several days, and the low-level
center of Lowell remained exposed to the northeast of the deep
convection. Lowell reached and then maintained a peak intensity of 45 kt
from 1200 UTC 7 September through 0600 UTC 8 September as it moved very
close to Socorro Island. Fig. 4 depicts an infrared and microwave image
of Lowell near its peak intensity.

Vertical shear lessened over Lowell by 9 September as the cyclone
reached the western periphery of the subtropical ridge. However, the
tropical storm had already begun ingesting drier, more stable air
originating from west of Baja California, and organized deep convection
was never able to fully redevelop. The circulation began to slowly spin
down, and QuikSCAT data indicate that Lowell weakened to a tropical
depression at 0600 UTC 10 September as it was moving north-northeastward
about 180 n mi west-southwest of the southern tip of Baja California.
The depression produced intermittent thunderstorm activity in a ring
around the low-level center and in a burst of deep convection to the
north of the center on 10 September. However, the mid-level center and
the thunderstorm activity was sheared northeastward across southern Baja
California and into northwestern mainland Mexico ahead of an upper-level
trough. Lowell then turned to the east-northeast and made landfall near
Cabo San Lucas at 0900 UTC 11 September as a 30-kt depression. By 1800
UTC, satellite imagery and surface observations indicate that the
circulation of Lowell opened up into an elongated surface trough that
extended across the southern Gulf of California. A squall line developed
along and to the south of the trough and moved quickly eastward towards
the mainland Mexican coast of Sinaloa and Nayarit later that day.

b.  Meteorological Statistics

    Observations in Lowell (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). Data
    and imagery from NOAA polar-orbiting satellites, Defense
    Meteorological Satellite Program (DMSP) satellites, National
    Aeronautics and Space Administration (NASA) satellites, including
    the Tropical Rainfall Measuring Mission (TRMM), QuikSCAT, and Aqua,
    and the U.S. Navy WindSat were also useful in tracking Lowell.

    Lowell's peak intensity of 45 kt is based on a combination of
    satellite intensity estimates as well as two QuikSCAT passes at 1320
    UTC 7 September and 0147 UTC 8 September. Each of the QuikSCAT
    passes showed a few wind barbs of 50 kt, but these were rain-flagged
    within deep convection and located well to the southwest of the
    center of circulation. In addition, objective and subjective
    satellite intensity estimates at the time supported an intensity
    between 35 and 45 kt. The landfall intensity of 30 kt on the
    southern tip of Baja California is based on a 1317 UTC QuikSCAT pass
    on 11 September and satellite intensity estimates at 1200 UTC.

    There were no surface land station or ship reports of winds of
    tropical storm force associated with Lowell. However, two unofficial
    stations in Cabo San Lucas reported minimum pressures of 998.5 mb
    (IBAJACAL9) and 1000.6 mb (IBAJACAL12) at 0915 UTC and 0925 UTC,
    respectively, as the center of Lowell moved over the area. These
    were the lowest reported pressures in southern Baja California and
    agree with geostationary and microwave satellite imagery, indicating
    that the low-level center moved over the southern tip of the
    peninsula.

c.  Casualty and Damage Statistics

    Heavy rainfall from the remnants of Lowell caused streams and canals
    to overflow in the Mexican states of Sonora and Sinaloa, leaving
    more than 26,500 people homeless. The cities of Navojoa, Benito
    Juarez, Huatabampo, and Etchojoa were most affected. The government
    of Sonora has estimated the damage in that state at 200 million
    pesos (about 15.5 million US dollars).

    The remnants of Lowell later merged with a frontal boundary over the
    central United States and caused heavy rainfall and flooding one to
    two days before the remnants of Hurricane Ike passed through the
    region. Fig. 5 shows the swath of heaviest rain, which fell from
    Kansas to northern Illinois and Indiana. Wichita, Kansas, measured a
    daily record 10.31 inches of rain on 12 September and broke the
    24-hour rainfall record of 7.99 inches that had been held
    since 1911. Chicago, Illinois, reported 6.64 inches at O'Hare
    International Airport, the highest one-day total since records began
    in 1871. This amount broke the previous daily record of 6.49 inches
    set in 1987. Numerous people were rescued from stranded vehicles as
    rainfall flooded city streets.

d.  Forecast and Warning Critique

    The genesis of Lowell was not well forecast. The large area of
    disturbed weather from which Lowell eventually emerged was first
    mentioned in the Tropical Weather Outlook (TWO) and given a medium
    chance of development (20-50%) approximately 12 h before the system
    became a tropical depression. The possibility of formation of a
    tropical depression was first mentioned in the TWO at 1200 UTC 6
    September, but a post-analysis of Lowell's history suggests that the
    system had already become a tropical depression by that time.

    A verification of official and guidance model track forecasts is
    given in Table 2. Average official track errors for Lowell were 30,
    41, 58, 75, 129, and 278 n mi for the 12, 24, 36, 48, 72, and 96 h
    forecasts, respectively. The number of forecasts ranged from 17 at
    12 h to 3 at 96 h. These errors are lower than the average long-term
    official track errors through 72 h but are higher than average
    long-term errors at 96 h (Table 2). However, only three forecasts
    were made for the 96 h period, and a comprehensive comparison is not
    valid. Of the individual track models, only the ECMWF model (EMXI)
    consistently performed better than the official forecast at 36
    through 96 h.

    Average official intensity errors were 5, 7, 10, 13, 19, and 15 kt
    for the 12, 24, 36, 48, 72, and 96 h forecasts, respectively (Table
    3). For comparison, the average long-term official intensity errors
    are 6, 10, 14, 16, 19, and 19 kt, respectively. The official
    forecast intensity errors were lower than the average long-term
    errors for all forecast times except the 72 h period, when they were
    nearly equal. Even though the official forecasts showed skill over
    the long-term averages, they did not show as much skill as most of
    the available model guidance, especially from 36 through 96 h. In
    particular, the Florida State Superensemble (FSSE) and Decay SHIPS
    (DSHP) had lower errors than the official forecast at all forecast
    times. The intensity consensus (ICON) had lower errors at all
    forecast times except the 12 h period.

Watches and warnings associated with Lowell are listed in Table 4. A
tropical storm watch was issued for a portion of the southwest coast of
Baja California despite the fact that the official forecast indicated
Lowell would reach the coast as a tropical depression. Wind speed
probabilities at the time indicated that there was still a 26% chance
that Lowell could reach the coast as a tropical storm.

Number range CHAPTERTable 1. Best track for Tropical Storm Lowell, 6 --
11 September 2008.

+----------+--------+--------+---------+---------+------------------+
| D        | La     | Lon    | P       | Wind    | Stage            |
| ate/Time | titude | gitude | ressure | Speed   |                  |
|          |        |        |         |         |                  |
| (UTC)    | (°N)   | (°W)   | (mb)    | (kt)    |                  |
+----------+--------+--------+---------+---------+------------------+
| 06 /     | 14.9   | 104.3  | 1004    | 25      | tropical         |
| 1200     |        |        |         |         | depression       |
+----------+--------+--------+---------+---------+------------------+
| 06 /     | 15.2   | 105.2  | 1003    | 30      | \"               |
| 1800     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 07 /     | 15.7   | 106.0  | 1002    | 35      | tropical storm   |
| 0000     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 07 /     | 16.3   | 106.7  | 1000    | 40      | \"               |
| 0600     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 07 /     | 16.9   | 107.5  | 998     | 45      | \"               |
| 1200     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 07 /     | 17.4   | 108.4  | 998     | 45      | \"               |
| 1800     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 08 /     | 17.8   | 109.2  | 998     | 45      | \"               |
| 0000     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 08 /     | 18.3   | 110.0  | 998     | 45      | \"               |
| 0600     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 08 /     | 18.8   | 110.6  | 1000    | 40      | \"               |
| 1200     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 08 /     | 19.3   | 111.3  | 1000    | 40      | \"               |
| 1800     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 09 /     | 19.6   | 112.0  | 1000    | 40      | \"               |
| 0000     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 09 /     | 19.9   | 112.6  | 1000    | 40      | \"               |
| 0600     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 09 /     | 20.3   | 113.0  | 1000    | 40      | \"               |
| 1200     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 09 /     | 20.7   | 113.1  | 1000    | 40      | \"               |
| 1800     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 10 /     | 21.1   | 113.1  | 1002    | 35      | \"               |
| 0000     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 10 /     | 21.6   | 112.9  | 1002    | 30      | tropical         |
| 0600     |        |        |         |         | depression       |
+----------+--------+--------+---------+---------+------------------+
| 10 /     | 22.0   | 112.6  | 1002    | 30      | \"               |
| 1200     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 10 /     | 22.4   | 112.1  | 1002    | 30      | \"               |
| 1800     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 11 /     | 22.7   | 111.4  | 1002    | 30      | \"               |
| 0000     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 11 /     | 22.9   | 110.6  | 1001    | 30      | \"               |
| 0600     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 11 /     | 23.0   | 109.7  | 1000    | 30      | \"               |
| 1200     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 11 /     |        |        |         |         | dissipated       |
| 1800     |        |        |         |         |                  |
+----------+--------+--------+---------+---------+------------------+
| 07 /     | 16.9   | 107.5  | 998     | 45      | minimum pressure |
| 1200     |        |        |         |         | and maximum wind |
+----------+--------+--------+---------+---------+------------------+
| 11 /     | 23.0   | 110.1  | 1000    | 30      | landfall near    |
| 0900     |        |        |         |         | Cabo San Lucas,  |
|          |        |        |         |         | Mexico           |
+----------+--------+--------+---------+---------+------------------+

Number range CHAPTERNumber range CHAPTERNumber range CHAPTERTable 2.
Track forecast evaluation (heterogeneous sample) for Tropical Storm
Lowell, 6 -- 11 September 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.

+-----------+-------+-------+-------+-------+-------+-------+-------+
| Number    | For   |       |       |       |       |       |       |
| range     | ecast |       |       |       |       |       |       |
| CHAPTE    | P     |       |       |       |       |       |       |
| RForecast | eriod |       |       |       |       |       |       |
| Technique | (h)   |       |       |       |       |       |       |
+===========+=======+=======+=======+=======+=======+=======+=======+
|           | 12    | 24    | 36    | 48    | 72    | 96    | 120   |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| CLP5      | 51    | 93    | 149   | 203   | 258 ( | 285 ( |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFNI      | 32    | 62    | 99    | 128 ( | 216 ( |       |       |
|           | (11)  | (11)  | (10)  | 8)    | 4)    |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFDI      | **28  | 50    | 78    | 108   | **110 | **101 |       |
|           | (     | (17)  | (15)  | (13)  | (     | (     |       |
|           | 19)** |       |       |       | 8)**  | 2)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| HWFI      | 37    | 63    | 94    | 146   | 265 ( | 360 ( |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GFSI      | 47    | 82    | 110   | 135   | 182 ( | 327 ( |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| AEMI      | 46    | 77    | 100   | 111   | 130 ( | **246 |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | (     |       |
|           |       |       |       |       |       | 5)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NGPI      | 45    | 63    | 73    | 115   | 212 ( | 335 ( |       |
|           | (17)  | (15)  | (13)  | (11)  | 7)    | 3)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| UKMI      | 53    | 83    | 123   | 135   | 199 ( | **166 |       |
|           | (16)  | (14)  | (12)  | (10)  | 6)    | (     |       |
|           |       |       |       |       |       | 2)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| EGRI      | 52    | 82    | 123   | 135   | 201 ( | **166 |       |
|           | (16)  | (14)  | (12)  | (10)  | 6)    | (     |       |
|           |       |       |       |       |       | 2)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| EMXI      | 31    | 44    | **48  | **62  | **87  | **172 |       |
|           | (12)  | (11)  | (     | (     | (     | (     |       |
|           |       |       | 10)** | 9)**  | 6)**  | 3)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMD      | 53    | 91    | 135   | 177   | 277 ( | 412 ( |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMM      | 42    | 70    | 107   | 148   | 260 ( | 372 ( |       |
|           | (19)  | (17)  | (15)  | (13)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| BAMS      | 32    | 45    | 58    | 86    | 199 ( | 327 ( |       |
|           | (18)  | (16)  | (14)  | (12)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| LBAR      | 46    | 84    | 123   | 169   | 284 ( | 504 ( |       |
|           | (18)  | (16)  | (14)  | (12)  | 9)    | 5)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| TVCN      | **28  | 41    | 62    | 84    | **123 | **240 |       |
|           | (     | (17)  | (15)  | (13)  | (     | (     |       |
|           | 19)** |       |       |       | 9)**  | 5)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GUNA      | **29  | **37  | 58    | 88 (  | 133 ( |       |       |
|           | (     | (     | (10)  | 8)    | 4)    |       |       |
|           | 14)** | 12)** |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| FSSE      | **23  | 41    | 67    | 88    | **75  | **103 |       |
|           | (     | (13)  | (12)  | (10)  | (     | (     |       |
|           | 13)** |       |       |       | 6)**  | 2)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OFCL      | 30    | 41    | 58    | 75    | 129 ( | 278 ( |       |
|           | (17)  | (15)  | (13)  | (11)  | 7)    | 3)    |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NHC       | 31.9  | 55.1  | 77.4  | 97.9  | 136.2 | 180.1 | 226.1 |
| Official  | (     | (     | (979) | (849) | (620) | (439) | (293) |
|           | 1282) | 1129) |       |       |       |       |       |
| (         |       |       |       |       |       |       |       |
| 2003-2007 |       |       |       |       |       |       |       |
| mean)     |       |       |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+

Table 3. Intensity forecast evaluation (heterogeneous sample) for
Tropical Storm Lowell,\
6 -- 11 September 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.

+-----------+-------+-------+-------+-------+-------+-------+-------+
| Number    | For   |       |       |       |       |       |       |
| range     | ecast |       |       |       |       |       |       |
| CHAPTE    | P     |       |       |       |       |       |       |
| RForecast | eriod |       |       |       |       |       |       |
| Technique | (h)   |       |       |       |       |       |       |
+===========+=======+=======+=======+=======+=======+=======+=======+
|           | 12    | 24    | 36    | 48    | 72    | 96    | 120   |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OCD5      | 5.3   | 8.0   | *     | *     | 21.0  | 24.2  |       |
|           | (19)  | (17)  | *10.0 | *12.1 | ( 9)  | ( 5)  |       |
|           |       |       | (     | (     |       |       |       |
|           |       |       | 15)** | 13)** |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| GHMI      | 6.3   | 7.9   | **7.9 | **8.2 | **6.6 | **2.5 |       |
|           | (19)  | (17)  | (     | (     | (     | (     |       |
|           |       |       | 15)** | 13)** | 8)**  | 2)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| HWFI      | 6.3   | 9.5   | 11.3  | *     | *     | 15.0  |       |
|           | (19)  | (17)  | (15)  | *12.6 | *15.1 | ( 5)  |       |
|           |       |       |       | (     | (     |       |       |
|           |       |       |       | 13)** | 9)**  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| LGEM      | 5.7   | 8.1   | **7.7 | **8.6 | *     | **7.0 |       |
|           | (19)  | (17)  | (     | (     | *10.8 | (     |       |
|           |       |       | 15)** | 13)** | (     | 5)**  |       |
|           |       |       |       |       | 9)**  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| DSHP      | **3.8 | **5.8 | **5.4 | **7.8 | *     | *     |       |
|           | (     | (     | (     | (     | *12.2 | *11.6 |       |
|           | 19)** | 17)** | 15)** | 13)** | (     | (     |       |
|           |       |       |       |       | 9)**  | 5)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| FSSE      | **4.6 | **6.2 | **8.2 | **8.8 | *     | **2.0 |       |
|           | (     | (     | (     | (     | *13.3 | (     |       |
|           | 13)** | 13)** | 12)** | 10)** | (     | 2)**  |       |
|           |       |       |       |       | 6)**  |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| ICON      | 5.3   | **7.1 | **6.9 | **6.9 | **9.1 | **9.5 |       |
|           | (19)  | (     | (     | (     | (     | (     |       |
|           |       | 17)** | 15)** | 13)** | 8)**  | 2)**  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| OFCL      | 4.7   | 7.3   | 10.4  | 12.7  | 18.6  | 15.0  |       |
|           | (17)  | (15)  | (13)  | (11)  | ( 7)  | ( 3)  |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+
| NHC       | 6.2   | 10.4  | 13.9  | 16.3  | 18.7  | 19.2  | 19.1  |
| Official  | (     | (     | (979) | (848) | (620) | (439) | (293) |
|           | 1282) | 1129) |       |       |       |       |       |
| (         |       |       |       |       |       |       |       |
| 2003-2007 |       |       |       |       |       |       |       |
| mean)     |       |       |       |       |       |       |       |
+-----------+-------+-------+-------+-------+-------+-------+-------+

Number range CHAPTERTable 4. Watch and warning summary for Tropical
Storm Lowell, 6 -- 11 September 2008.

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

  9 / 2100    Tropical Storm Watch issued    Bahia Magdalena to Cabo San
                                             Lucas

  11 / 0900   Tropical Storm Watch           All
              discontinued                   
  ----------- ------------------------------ ------------------------------

![](media/image1.jpeg){width="7.886805555555555in"
height="6.094444444444444in"}

Number range CHAPTERFigure 1. Best track positions for Tropical Storm
Lowell, 6 -- 11 September 2008.

![](media/image2.wmf){width="8.000694444444445in"
height="5.476388888888889in"}

Number range CHAPTERFigure 2. Selected wind observations and best track
maximum sustained surface wind speed curve for Tropical Storm Lowell, 6
-- 11 September 2008. Objective Dvorak estimates represent linear
averages over a three-hour period centered on the nominal observation
time. Dashed vertical lines correspond to 0000 UTC. Thick vertical line
depicts landfall.

![](media/image3.wmf){width="8.000694444444445in"
height="5.476388888888889in"}

Number range CHAPTERFigure 3. Selected pressure observations and best
track minimum central pressure curve for Tropical Storm Lowell, 6 -- 11
September 2008. Objective Dvorak estimates represent linear averages
over a three-hour period centered on the nominal observation time.
Dashed vertical lines correspond to 0000 UTC. Thick vertical line
depicts landfall.

![](media/image4.jpeg){width="4.2444444444444445in"
height="3.8631944444444444in"}

Number range CHAPTERFigure 4. An infrared satellite image from GOES-W at
1500 UTC 7 September when Lowell was at its peak intensity of 45 kt
(left) and a corresponding 91 GHz image from SSMIS at 1448 UTC 7
September (right). Note that the low cloud lines in the SSMIS image
indicate that the low-level center (marked by an **X**) is exposed to
the northeast of the deep convection. Images courtesy of the Fleet
Numerical Meteorology and Oceanography Center.

![](media/image6.png){width="7.346527777777778in" height="5.5375in"}

Number range CHAPTERFigure 5. Radar/gauge composite analysis of 24-hour
rainfall accumulation between 1200 UTC 12 September and 1200 UTC 13
September, showing the swath of heavy rain that occurred over the U.S.
Central Plains when the remnants of Lowell merged with a frontal
boundary. Data courtesy of the National Weather Service National
Precipitation Verification Unit.

[^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.