The 1987 Gulf Coast tropical storm caused flooding along the Gulf Coast of the United States. The second tropical cyclone and first tropical storm of the 1987 Atlantic hurricane season, it originated from a tropical wave in the Gulf of Mexico, southeast of Texas, on August 9. Initially a tropical depression, the cyclone moved north-northwestward and slightly intensified into a tropical storm later that day. By August 10, it made landfall between Galveston and Beaumont. The system weakened after moving inland and turned towards the east and later southeast. Briefly reemerging over the Gulf on August 15, the depression moved onshore a second time in Florida, before dissipating over eastern Georgia on August 17.
Tropical Storm Two
Tropical storm (SSHWS/NWS)
The unnamed storm weakening over Texas on August 10
Due to the relatively weak nature of the system, it caused relatively little damage. However, the system dropped heavy rainfall, peaking at 21.05 inches (535 mm) in southern Mississippi. This resulted in flooding, which forced more than 400 people to evacuate their homes, some of which had 2 to 4 feet (0.61 to 1.22 m) of water. Flash flooding was reported in a few others states, including Alabama, Florida, and Louisiana. In all, losses from the unnamed storm reached $7.4 million (1987 USD) and one person was reported missing after being thrown overboard a boat in rough seas.
On July 29, 1987, a tropical wave emerged off the west coast of Africa into the Atlantic Ocean. Tracking westward along the southern edge of the Saharan Air Layer, a feature associated with large masses of dry air, little convective development took place over the following several days. Once near the Lesser Antilles in early August, atmospheric conditions became more favorable for development. Traveling across the Caribbean, the system became increasingly organized and a mid-level circulation formed shortly before the wave moved inland over Central America on August 7. The following day, the northern portion of the wave interacted with a cold-core low over the Gulf of Mexico, resulting in the formation of a low-level circulation, exhibiting tropical characteristics, on August 9. Over the following two days, the system tracked in a general north-northwest direction towards the Texas coastline. Aided by an anticyclone aloft, outflow became pronounced and convection increased in coverage and intensity. Around 1200 UTC, the National Hurricane Center (NHC) estimated that the system developed into a tropical depression while located about 145 miles (235 km) south-southeast of Galveston, Texas.[1]
Hours after being classified a tropical depression, the convective structure of the system deteriorated, a sign of a weakening storm; however, nearby oil rigs indicated a gradual increase in winds. Later on August 9, several rigs reported tropical storm-force winds – winds greater than 39 mph (63 km/h) – and the NHC estimated that the depression strengthened into a tropical storm. Operationally, however, these winds were considered to be related to local convective activity rather than the storm itself and it was not considered to be a tropical storm until post-storm analysis.[1] As such, it was not named and is officially classified as "Unnamed Tropical Storm." Additionally, the strongest winds were located well away from the center of circulation, a signature of subtropical cyclones.[2]
Remaining relatively weak, the unnamed system attained peak winds of 45 mph (75 km/h) before making landfall along the Texas coastline between Galveston and Beaumont at 0600 UTC on August 10.[3] Once over land, the storm weakened to a tropical depression as it neared the Texas-Louisiana border and began a gradual turn towards the east-southeast.[2] On August 12, while over central Mississippi, the cyclone attained its lowest barometric pressure of 1,007 mbar (29.7 inHg).[3] On August 15, the low emerged back over the Gulf of Mexico after crossing the Florida Panhandle. No redevelopment took place during its brief time back over water before making its final landfall near St. Marks, Florida the following day. The depression gradually diminished before losing its identity over eastern Georgia on August 17.[2]
Preparations and impact
Rain totals across the southeastern United States from the Unnamed Tropical Storm
Due to the system's proximity to land upon being declared a tropical depression and subsequent intensity uncertainties, the unnamed storm posed several challenges to forecasters that "vividly illustrated limitations that are of major concern at the National Hurricane Center."[4] With operational forecasters noting the possibility of intensification, the first-ever tropical storm warning was issued along the northern Gulf Coast between Matagorda, Texas and Morgan City, Louisiana on August 9.[3] Prior to 1987, gale warnings were issued in areas where winds above 39 mph (63 km/h) were anticipated.[1] This warning was later discontinued on August 10 once the system moved inland and weakened.[3] The United States Coast Guard advised ships to seek harbor to avoid large swells associated with the cyclone. Additionally, some non-essential workers were evacuated from offshore rigs.[5] By August 13, several flash flood watches were in place over portions of Mississippi, Alabama and Florida as remnants of the unnamed system slowly moved through the region.[6]
Throughout the United States, damage from the tropical storm amounted to $7.4 million, the majority of which resulted from flooding.[7] Offshore, a woman was reported missing after she was thrown off her boat amidst rough seas produced by the storm.[8] The system produced rainfall across a large swath of the southern states, with many areas recording more than 5 in (130 mm).[4] Though it made landfall in Texas, the system's asymmetric structure led to relatively little rain falling in the state, peaking at 4.25 in (108 mm) in Umbarger.[9] In parts of Louisiana, many streets were left impassable by high waters, creating widespread traffic delays.[10] The most significant impact took place in southern Mississippi where rainfall in excess of 12 in (300 mm), peaking at 21.06 in (535 mm) in Vancleave,[9] caused significant flash flooding, especially along the Biloxi and Tchoutacabouffa Rivers. The former of these experienced a record crest of 16.8 ft (5.1 m). More than 400 people were forced to evacuate due to rising water across the region as several homes were inundated with 2 to 4 ft (0.61 to 1.22 m) of water.[4] In Columbia, 12.2 in (310 mm) of rain fell in just eight hours, triggering flash floods that washed away a portion of a small dam. Further east in Baldwin County, Alabama and Pensacola, Florida, many roads ere closed or left impassable due to high water.[11] Additionally, the system spawned a brief tornado in Mobile County but no damage resulted from it.[12][13]
^ abcHarold P. Gerrish (November 18, 1987). Preliminary Report: Unnamed Tropical Storm 9 to 17 August 1987. National Hurricane Center (Report). Miami, Florida: National Oceanic and Atmospheric Administration. p. 2. Retrieved July 15, 2011.
^ abcdHarold P. Gerrish (November 18, 1987). Preliminary Best Track, Unnamed Tropical Storm, 9–17 August, 1987. National Hurricane Center (Report). Miami, Florida: National Oceanic and Atmospheric Administration. p. 5. Retrieved July 15, 2011.
^ abcHarold P. Gerrish (November 18, 1987). Forecast and Warning Technique. National Hurricane Center (Report). Miami, Florida: National Oceanic and Atmospheric Administration. p. 3. Retrieved March 24, 2013.
^Peter Rowe (August 10, 1987). "Tropical storm weakens in Gulf". The Bryan Times. p. 3. Retrieved July 16, 2011.
^ abDavid M. Roth (2012). (Report). College Park, Maryland: Weather Prediction Center. Archived from the original on July 21, 2011. Retrieved March 24, 2013.
^Unattributed (August 12, 1987). "Heavy rains flood many EBR streets". The Advocate. Baton Rouge, Louisiana. Retrieved July 16, 2011.
^Unattributed (August 14, 1987). "Rains flood several states". The Gainesville Sun. p. 2A. Retrieved July 16, 2011.
^Tom Grazulis and Bill McCaul (2008). List of Known Tropical Cyclones Which Have Spawned Tornadoes (Report). The Tornado Project. from the original on June 3, 2011. Retrieved May 28, 2011.
^J. D. Ziemianski and S. C. Lackey. Storm Data and Unusual Weather Phenomena: August 1987 (PDF). National Climatic Data Center (Report). Asheville, North Carolina: National Oceanic and Atmospheric Administration. p. 22. Retrieved March 24, 2013.[permanent dead link]
External links
Preliminary Report for the Unnamed Tropical Storm
January 07, 2023
1987, gulf, coast, tropical, storm, caused, flooding, along, gulf, coast, united, states, second, tropical, cyclone, first, tropical, storm, 1987, atlantic, hurricane, season, originated, from, tropical, wave, gulf, mexico, southeast, texas, august, initially,. The 1987 Gulf Coast tropical storm caused flooding along the Gulf Coast of the United States The second tropical cyclone and first tropical storm of the 1987 Atlantic hurricane season it originated from a tropical wave in the Gulf of Mexico southeast of Texas on August 9 Initially a tropical depression the cyclone moved north northwestward and slightly intensified into a tropical storm later that day By August 10 it made landfall between Galveston and Beaumont The system weakened after moving inland and turned towards the east and later southeast Briefly reemerging over the Gulf on August 15 the depression moved onshore a second time in Florida before dissipating over eastern Georgia on August 17 Tropical Storm TwoTropical storm SSHWS NWS The unnamed storm weakening over Texas on August 10FormedAugust 9 1987DissipatedAugust 17 1987Highest winds1 minute sustained 45 mph 75 km h Lowest pressure1007 mbar hPa 29 74 inHgFatalities1 reported missingDamage 7 4 million 1987 USD Areas affectedGulf Coast of the United StatesPart of the 1987 Atlantic hurricane seasonDue to the relatively weak nature of the system it caused relatively little damage However the system dropped heavy rainfall peaking at 21 05 inches 535 mm in southern Mississippi This resulted in flooding which forced more than 400 people to evacuate their homes some of which had 2 to 4 feet 0 61 to 1 22 m of water Flash flooding was reported in a few others states including Alabama Florida and Louisiana In all losses from the unnamed storm reached 7 4 million 1987 USD and one person was reported missing after being thrown overboard a boat in rough seas Contents 1 Meteorological history 2 Preparations and impact 3 See also 4 References 5 External linksMeteorological history Edit Map plotting the storm s track and intensity according to the Saffir Simpson scaleMap keySaffir Simpson scale Tropical depression 38 mph 62 km h Tropical storm 39 73 mph 63 118 km h Category 1 74 95 mph 119 153 km h Category 2 96 110 mph 154 177 km h Category 3 111 129 mph 178 208 km h Category 4 130 156 mph 209 251 km h Category 5 157 mph 252 km h Unknown Storm type Tropical cyclone Subtropical cyclone Extratropical cyclone Remnant low Tropical disturbance Monsoon depression On July 29 1987 a tropical wave emerged off the west coast of Africa into the Atlantic Ocean Tracking westward along the southern edge of the Saharan Air Layer a feature associated with large masses of dry air little convective development took place over the following several days Once near the Lesser Antilles in early August atmospheric conditions became more favorable for development Traveling across the Caribbean the system became increasingly organized and a mid level circulation formed shortly before the wave moved inland over Central America on August 7 The following day the northern portion of the wave interacted with a cold core low over the Gulf of Mexico resulting in the formation of a low level circulation exhibiting tropical characteristics on August 9 Over the following two days the system tracked in a general north northwest direction towards the Texas coastline Aided by an anticyclone aloft outflow became pronounced and convection increased in coverage and intensity Around 1200 UTC the National Hurricane Center NHC estimated that the system developed into a tropical depression while located about 145 miles 235 km south southeast of Galveston Texas 1 Hours after being classified a tropical depression the convective structure of the system deteriorated a sign of a weakening storm however nearby oil rigs indicated a gradual increase in winds Later on August 9 several rigs reported tropical storm force winds winds greater than 39 mph 63 km h and the NHC estimated that the depression strengthened into a tropical storm Operationally however these winds were considered to be related to local convective activity rather than the storm itself and it was not considered to be a tropical storm until post storm analysis 1 As such it was not named and is officially classified as Unnamed Tropical Storm Additionally the strongest winds were located well away from the center of circulation a signature of subtropical cyclones 2 Remaining relatively weak the unnamed system attained peak winds of 45 mph 75 km h before making landfall along the Texas coastline between Galveston and Beaumont at 0600 UTC on August 10 3 Once over land the storm weakened to a tropical depression as it neared the Texas Louisiana border and began a gradual turn towards the east southeast 2 On August 12 while over central Mississippi the cyclone attained its lowest barometric pressure of 1 007 mbar 29 7 inHg 3 On August 15 the low emerged back over the Gulf of Mexico after crossing the Florida Panhandle No redevelopment took place during its brief time back over water before making its final landfall near St Marks Florida the following day The depression gradually diminished before losing its identity over eastern Georgia on August 17 2 Preparations and impact Edit Rain totals across the southeastern United States from the Unnamed Tropical Storm Due to the system s proximity to land upon being declared a tropical depression and subsequent intensity uncertainties the unnamed storm posed several challenges to forecasters that vividly illustrated limitations that are of major concern at the National Hurricane Center 4 With operational forecasters noting the possibility of intensification the first ever tropical storm warning was issued along the northern Gulf Coast between Matagorda Texas and Morgan City Louisiana on August 9 3 Prior to 1987 gale warnings were issued in areas where winds above 39 mph 63 km h were anticipated 1 This warning was later discontinued on August 10 once the system moved inland and weakened 3 The United States Coast Guard advised ships to seek harbor to avoid large swells associated with the cyclone Additionally some non essential workers were evacuated from offshore rigs 5 By August 13 several flash flood watches were in place over portions of Mississippi Alabama and Florida as remnants of the unnamed system slowly moved through the region 6 Throughout the United States damage from the tropical storm amounted to 7 4 million the majority of which resulted from flooding 7 Offshore a woman was reported missing after she was thrown off her boat amidst rough seas produced by the storm 8 The system produced rainfall across a large swath of the southern states with many areas recording more than 5 in 130 mm 4 Though it made landfall in Texas the system s asymmetric structure led to relatively little rain falling in the state peaking at 4 25 in 108 mm in Umbarger 9 In parts of Louisiana many streets were left impassable by high waters creating widespread traffic delays 10 The most significant impact took place in southern Mississippi where rainfall in excess of 12 in 300 mm peaking at 21 06 in 535 mm in Vancleave 9 caused significant flash flooding especially along the Biloxi and Tchoutacabouffa Rivers The former of these experienced a record crest of 16 8 ft 5 1 m More than 400 people were forced to evacuate due to rising water across the region as several homes were inundated with 2 to 4 ft 0 61 to 1 22 m of water 4 In Columbia 12 2 in 310 mm of rain fell in just eight hours triggering flash floods that washed away a portion of a small dam Further east in Baldwin County Alabama and Pensacola Florida many roads ere closed or left impassable due to high water 11 Additionally the system spawned a brief tornado in Mobile County but no damage resulted from it 12 13 See also Edit Tropical cyclones portalTropical cyclone List of tropical cyclones List of Atlantic hurricanes List of North Carolina hurricanes 1980 present References Edit a b c Harold P Gerrish November 18 1987 Preliminary Report Unnamed Tropical Storm 9 to 17 August 1987 National Hurricane Center Report Miami Florida National Oceanic and Atmospheric Administration p 1 Retrieved July 15 2011 a b c Harold P Gerrish November 18 1987 Preliminary Report Unnamed Tropical Storm 9 to 17 August 1987 National Hurricane Center Report Miami Florida National Oceanic and Atmospheric Administration p 2 Retrieved July 15 2011 a b c d Harold P Gerrish November 18 1987 Preliminary Best Track Unnamed Tropical Storm 9 17 August 1987 National Hurricane Center Report Miami Florida National Oceanic and Atmospheric Administration p 5 Retrieved July 15 2011 a b c Harold P Gerrish November 18 1987 Forecast and Warning Technique National Hurricane Center Report Miami Florida National Oceanic and Atmospheric Administration p 3 Retrieved March 24 2013 Year s first tropical storm sighted Milwaukee Journal Sentinel Miami Florida Associated Press August 10 1987 p 2 Retrieved March 24 2013 Weather Nation Mohave Daily Miner United Press International August 13 1987 p 12 Retrieved July 16 2011 Robert A Case and Harold P Gerrish April 1988 Atlantic Hurricane Season of 1987 PDF Monthly Weather Review Miami Florida Atlantic Oceanographic and Meteorological Laboratory 116 4 939 949 Bibcode 1988MWRv 116 939C doi 10 1175 1520 0493 1988 116 lt 0939 AHSO gt 2 0 CO 2 Retrieved March 24 2013 Peter Rowe August 10 1987 Tropical storm weakens in Gulf The Bryan Times p 3 Retrieved July 16 2011 a b David M Roth 2012 Tropical Cyclone Rainfall for the Gulf Coast Report College Park Maryland Weather Prediction Center Archived from the original on July 21 2011 Retrieved March 24 2013 Unattributed August 12 1987 Heavy rains flood many EBR streets The Advocate Baton Rouge Louisiana Retrieved July 16 2011 Unattributed August 14 1987 Rains flood several states The Gainesville Sun p 2A Retrieved July 16 2011 Tom Grazulis and Bill McCaul 2008 List of Known Tropical Cyclones Which Have Spawned Tornadoes Report The Tornado Project Archived from the original on June 3 2011 Retrieved May 28 2011 J D Ziemianski and S C Lackey Storm Data and Unusual Weather Phenomena August 1987 PDF National Climatic Data Center Report Asheville North Carolina National Oceanic and Atmospheric Administration p 22 Retrieved March 24 2013 permanent dead link External links EditPreliminary Report for the Unnamed Tropical Storm Retrieved from https en wikipedia org w index php title 1987 Gulf Coast tropical storm amp oldid 1054451532, wikipedia, wiki, book, books, library,
