Tropical Storm Grace - August 30-September 4, 2003

A strong tropical wave, accompanied by a vigorous low pressure system, moved off the west coast of Africa on
August 19th. Both conventional satellite data and QuikSCAT microwave wind data indicated that the wave came close
 several times over the next few days to developing into a tropical cyclone. Convection became most pronounced on the
 21st when some outer banding features and a circular cirrus outflow pattern briefly developed. The rapid westward
 motion, exceeding 20 mph at times, may have disrupted the low-level circulation enough to prevent  the convection from
 becoming concentrated near the center. The system also moved through a mid- to upper-level region of very dry air over
 the central tropical Atlantic, and by late on 22 August nearly all of the convection had dissipated.

As the pre-Grace wave continued its westward trek, a second convective development phase occurred  when the system
 slowed as it moved across the Lesser Antilles on 24th and 25th. However, southwesterly upper-level shear ahead of a large
 upper-level trough located to the west disrupted development. Devoid of significant thunderstorm activity, the wave moved
 west-northwestward at under 10 mph until it reached the northwestern Caribbean Sea on the 28th, when deep convection
 redeveloped along the wave axis. When the tropical wave crossed the northern Yucatan Peninsula on the 29th, a broad
 low pressure area redeveloped along the wave axis as it turned northwestward toward the Texas coast. While there was
 an abundance of deep convection associated with this system, the disturbance remained poorly organized until later
 that day.

Convective organization continued to improve during the early morning hours of the 30th, and surface observations in
 conjunction with satellite intensity estimates indicated that tropical Depression Eleven had formed about 290 n mi east-
southeast of Corpus Christi, Texas.  The depression initially showed some signs of interaction with an upper-level
 cold low,  but this was short-lived and subsequent reconnaissance flights indicated that the cyclone was mostly tropical
 in  nature. More specifically, a reconnaissance flight during the afternoon of the 30th indicated the depression had likely
 strengthened into Tropical Storm Grace about 245 n mi east-southeast of Corpus Christi, Texas. The upper-low situated
 a few hundred miles to the west of Grace created persistent southerly to southwesterly upper-level shear which prevented
 the deep convection from organizing around the low-level circulation. While remaining broad and somewhat disorganized,
 Grace moved northwestward on the 31st at a faster forward speed of about 15 mph.

A large surface high located over the southeastern United States strengthened the pressure gradient and the low-level wind
 field for several hundred miles northeast of the center. The long fetch of southeasterly winds and cyclonic shear, in conjunction
 with several bursts of deep convection east of the original low-level center, caused the spin up of a new center about 100 n mi
 farther to the north of the former center. This new circulation center of Grace moved inland near San Luis Pass, Texas
 on the southwestern tip of Galveston Island during the morning of the 31st as a weak tropical storm. The original circulation
 weakened and eventually dissipated before it made landfall. Grace continued to move northwestward and quickly weakened
 back to a tropical depression shortly after making landfall. Tropical Depression Grace turned northward over northeastern
 Texas on 1 September and merged with a frontal zone near the Arkansas-Oklahoma border early on 2 September.
Below is its track provided by the National Hurricane Center

Grace 2003 track

The storm total rainfall maps below were constructed using data from data provided by the National
Climatic Data Center, the Harris County Office of Emergency Management, and Jefferson County/
Texas Drainage District 6 ALERT data.

Tropical Storm Grace (2003) Rainfall Grace (2003) Filled Contour Rainfall on Black Background
Grace (2003) Filled Contour Rainfall on White Background

Below are the calendar for Daily Precipitation Maps.  Note that the 24-hour periods end
at 12z that morning.

Sun Mon Tue Wed Thu Fri Sat