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Tropical Storm Iris was the twelfth tropical cyclone as well as the ninth named storm of the 1989 Atlantic hurricane season. Iris formed from a tropical wave that moved off the coast of northwestern Africa on September 12. It managed to peak as a strong tropical storm while to the northeast of the Lesser Antilles. The storm did this before outflow from Hurricane Hugo caused unfavorable conditions. In the wake of Hurricane Hugo, strong upper level wind shear was present as a result of outflow. This caused Iris to greatly weaken and ultimately dissipate on September 21. The only affects known on land from Tropical Storm Iris were a few inches of rain of the northern Leeward Islands. No measurements of wave heights were reported because ship were still out of the area after vacating from Hurricane Hugo.
A tropical wave moved off the coast of northwest Africa on September 12. It did not show signs of organization until September 15. This tropical wave would take almost same path as the wave that spawned Hurricane Hugo did. At 1800 UTC on September 16, the National Hurricane Center classified it as Tropical Depression Twelve. It slowly strengthened despite being in the close vicinity of Hugo. Tropical Depression Twelve was upgraded to a tropical storm at 0000 UTC on September 18, it had received the name Iris. Iris was upgraded while roughly Template:Convert/LoffAnoneDbSoff to the south-southeast of Barbados. Tropical Storm Iris began to turn to the north-northwest shortly after reaching tropical storm status.
This movement also caused it to parallel the Leeward Islands. Tropical Storm Iris quickly reached peak intensity; sustained winds were at Template:Convert/mph and the minimum central pressure was at 1001 mbar. Iris was located about Template:Convert/LoffAnoneDbSoff to the northeast of Barbuda at the time. Wind shear generated from the outflow of Hurricane Hugo began to increase because Hurricane Hugo was strengthening and growing larger. It quickly weakened back, being only a relatively weak tropical storm only 12 hours later. Shortly thereafter, it was briefly maintaining minimal tropical storm status. At 0000 UTC on September 21, it was downgraded to a tropical depression after winds had ceased maintaining tropical storm status. 24 hours later, the center had become completely exposed due to wind shear, therefore it was declared dissipated at 0000 UTC on September 22. The remnants headed for Florida before dissipating.
Forecasting errors were large in association with Tropical Storm Iris were high. This was because some predicted a much greater interaction with Hurricane Hugo, such as a fujiwhara interaction which would have resulted in a path over the Leeward or the Virgin Islands. Some of the computer models predicted a close approach to the Leeward and Virgin Islands. Many residents were in fear because Hurricane Hugo devastated those Islands just days before.
On St. Johns and in the Virgin Islands, rainfall was recorded at Template:Convert/-. There were no reports of damage or fatalities in association with Tropical Storm Iris. However, there were some unofficial reports of flooding in the Virgin Islands. Also, there were no tropical storm watches or warning issued in association with Tropical Storm Iris.
- ↑ 1.0 1.1 1.2 1.3 Gerrish, Harold (November 20, 1989). "Tropical Storm Iris Preliminary Report". National Hurricane Center. http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1989-prelim/iris/prelim01.gif. Retrieved 17 February 2010.
- ↑ Gerrish, Harold (November 20, 1989). "Tropical Storm Iris Preliminary Report". National Hurricane Center. http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1989-prelim/iris/prelim03.gif. Retrieved 17 February 2010.
- ↑ 3.0 3.1 Gerrish, Harold (November 20, 1989). "Tropical Storm Iris Preliminary Report". National Hurricane Center. http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1989-prelim/iris/prelim02.gif. Retrieved 18 February 2010.