Preliminary Report
Hurricane Chantal
30 July - 03 August 1989

1989 PRELIMINARY REPORTS

Tropical Storm Allison (TS)
Tropical Storm Barry (TS)
Hurricane Chantal (1)
Hurricane Dean (2)
Hurricane Erin (2)
Hurricane Felix (1)
Hurricane Gabrielle (4)
Hurricane Hugo (5)
Tropical Storm Iris (TS)
Hurricane Jerry (1)
Tropical Storm Karen (TS)

Hurricane Chantal was the first hurricane of the 1989 Atlantic Season. Although Chantal was not a strong hurricane, it thoroughly tested preparedness efforts along the upper Texas coast while making landfall near High Island, Texas, between Galveston and Sea Rim State Park, on 1 August 1989.

 

a. Synoptic History

The system that provided the embryo for Chantal could not be traced back to Africa as a tropical wave, but first appeared on 24 July as an ITCZ disturbance near Trinidad just off the coast of South America. The system moved westward across the Caribbean with little development until approaching Honduras on the 27th. Beginning on the 27th, NHC highlighted the the wave in the Tropical Weather Discussions (TWD), the Satellite Interpretation Messages (SIM), and in the Tropical Weather Outlooks (TWO). Even though the outflow was impressive on satellite imagery on the 27th, there was some uncertainty about the potential for development due to close proximity to land. Thus, the TWO's indicated that development if any would be slow.

By 1800 UTC on the 28th, synoptic reports indicated the possibility of a surface low near Belize City. However, during the next 24 hours the system was disorganized while over the Yucatan Peninsula. Beginning at 0230 UTC on the 30th, NHC indicated in the TWO's that there was some potential for development as the system was in the process of emerging off the coast near Merida, Mexico.

Satellite pictures at 0900 UTC on the 30th indicated that although the center was still close to the Yucatan Peninsula, the cloud pattern was becoming better organized. Ship data and satellite imagery confirmed that a tropical depression had formed and the first advisory on Tropical Depression Four was issued at 1900 UTC on the 30th. After the fact, it is estimated that the tropical depression likely formed in the south central Gulf of Mexico about 80 nautical miles north of the Yucatan Peninsula as early as 1200 UTC on the 30th.

Based on estimates by satellite analysts using the Dvorak technique, Tropical Storm Chantal likely formed 310 nautical miles southeast of Galveston, Texas at 0600 UTC on the 31st. However, interpretation of infrared satellite imagery during the night can be misleading and the NHC decided to wait for reconnaissance confirmation before formally upgrading the system. When the first Air Force reconnaissance plane arrived in the system at 1224 UTC on the 31st, the pressure was already down to 994 mb and the estimated surface winds were 52 mph. Ship HZZB located 150 nautical miles east northeast of the center reported 58 mph winds at 1200 UTC. NHC issued a special advisory at 1300 UTC on the 31st upgrading the depression to a tropical storm. Outflow conditions favoured continued strengthening and hurricane warnings were issued at that time from Freeport, Texas to Morgan City, Louisiana based on the anticipated motion of the center.

Normally the rate of development of a tropical system is one T number per day using the Dvorak technique. NHC satellite meteorologists classified the system as a T 1.5 at 1800 UTC on the 30th, a 2.5 at 0600 UTC on the 31st, and a 3.5 at 1800 UTC on the 31st. Thus the rate of development during that 24 hour period was two T numbers per day which is rapid.

Strengthening Tropical Storm Chantal moved toward the northwest at 12 mph in responce to weak ridging extending westward across Florida. During the afternoon of the 31st, an Air Force reconnaissance plane found 91 mph winds at 1500 feet and satellite pictures were showing better organization. Thus Chantal was formally upgraded to hurricane at 2200 UTC.

Hurricane Chantal passed between oil rigs T81 and WC 459A, between W76 and P95, and to the west of P12 on its trek toward the upper Texas coast. At 0439 UTC on the 1st, WC 459A reported sustained winds of 70 mph with gusts to 79 mph at an elevation of 80 feet and a surface pressure of 994 mb. The hurricane was under continuous surveillance by both the Galveston and the Lake Charles radars when within about 100 nautical miles of the coast. Small scale fluctuations were noted in the radar positions but generally they were within about 10 nautical miles of the best track.

Chantal continued strengthening while approaching the Texas coast and at 1050 UTC reconnaissance reports were showing flight level winds of 94 mph at 850 millibars and the minimum pressure extrapolated to the surface was 984 mb. At 1156 UTC, about one hour prior to landfall, the pressure was 986 mb. Thus, Chantal reached its peak intensity just prior to the center making landfall at High Island, Texas near 1300 UTC as a Category 1 hurricane on the Saffir/Simpson Hurricane Scale.

The center of Chantal continued moving northwestward passing close to Dayton, Conroe, just northeast of College Station, and just east of Waco before turning north northwestward to just west of Cleburne and east of Mineral Wells before dissipating in southwestern Oklahoma by 0600 UTC on 3 August 1989. Although the system could not be tracked at the surface beyond then, satellite pictures showed that the cloud shield traveled to eastern Kansas, eastern Iowa, Michigan, New York, and eventually joined cloudiness associated with a trough over New England. That combined cloudiness passed over Newfoundland early on 7 August ahead of Hurricane Dean.

b. Meteorological Statistics

The center of Hurricane Chantal crossed the upper Texas coast at High Island near 1300 UTC on 01 August with sustained winds estimated at 81 mph and a minimum pressure of 986 mb. The highest winds reported at a costal location were at Galveston where a sustained wind of 69 mph and a gust of 82 mph were observed. The highest sustained wind at Sea Rim State park was 54 mph with a gust to 62 mph. Sea Rim State Park had about 7 continuous hours with sustained winds of tropical storm force. The minimum pressure at Sea Rim State Park occurred at 1200 UTC, about one hour prior to landfall, when the surface winds were from the east southeast. At 1300 UTC, the wind was from the south southeast and the pressure was 2.3 mb higher. The lowest pressure reported at a land station was 994 mb at Houston Intercontinental Airport at 1700 UTC.

1. Storm Surge Data

Tides at High Island were 7 feet MSL. Kemah reported 3.8 feet MSL and Galveston Flagship Pier had 3.5 feet MSL. Tides at Sabine Pass were 4 feet MSL. There was extensive beach erosion from High Island to Sea Rim State Park.

2. Rainfall Data

Rainfall associated with Chantal varied considerably. Houston's Hobby Airport reported 7.14 inches in 6 hours and 8.58 inches in 24 hours, whereas Houston International Airport had only 1.21 inches in 6 hours and 2.05 inches in 24 hours. Unofficially, Friendwood, southeast of Hobby had a storm total of 20 inches and Clear Lake, northeast of Alvin, had 16 inches.

3. Tornadoes

One confirmed torando was reported on Crystal Beach (Galveston County) causing total destruction to a boat shed. A tornado touched down near Iota, LA uprooting several trees and moving a mobile home off its foundation.

c. Casualty and Damage Statistics

There were 13 deaths attributed to Chantal; 2 in Texas and 11 in Louisiana.

The main effects from Chantal were from flooding by torrential rains and beach erosion. Wind effects were relatively light. However, numerous trees, powerlines, fences and signs were blown down. There was some roof damage to homes, carports and mobile homes. About 3000 homes in Texas had either water or wind damage. Total damage is estimated to be near $100 Million.

Thirteen deaths are attributed to Chantal. Two teenage boys drowned in College Station (Brazos County) when their raft on which they were riding capsized in flood waters and they were swept into a drainage pipe. Two others on the raft managed to make it to safety. A 48 year old man drowned about 100 miles south of New Orleans as he attempted to leave an oil rig. A 74 foot "lift boat" , Avco 5, capsized in the Gulf about 20 nautical miles off the coast south of Morgan City, Louisiana. Four men were rescued about 10 others were trapped in the oil service vessel, of which 7 are known drowned and three are missing and presumed drowned. (According to: The Times Picayune, "a lift boat is equipped with three extendable legs allowing it to work in up to 65 feet of water. When a crew reaches a work site, the legs are lowered to the sea floor and the vessel's hull is jacked up above above the waves to provide a steady platform for pipeline construction and maintenance chores. The Avco 5 overturned while heading for Safety") There were 18 persons rescued by U.S. Coast Guard helicopters and rescue boats. Most of these were fishermen whose boats capsized near the Bolivar Peninsula. Several of the rescued were near the jetties at Sabine Pass. A man was injured while evacuating a dredge barge in the coastal waters south of Lafayette, Louisiana. Hundreds of persons were evacuated by airboats and high water vehicles in flooded areas in Texas.