The End of an Era: Atlantis Launch Weather Outlook

By Carla Voorhees

Kathy Winters is an Air Force Civilian Meteorologist at the 45th Weather Squadron at Cape Canaveral Air Force Station. She is the Space Shuttle Launch Weather Officer providing weather support to the Space Shuttle Program at Kennedy Space Center as the Launch Team prepares for the 29 April 2011 launch of Endeavour. You can find out more about the 45th Space Wing at their Facebook page.

It’s launch week and we are issuing our weather forecasts for the last Space Shuttle launch Friday, 8 July 2011.  The weather situation is interesting. A tropical wave located over the Turks and Caicos Islands is moving west-northwest toward Florida. These waves are typical this time of year, and as they move into Florida, they bring scattered showers and isolated thunderstorms behind them. We expect this wave to move into Florida on Thursday, the day prior to launch, as it rotates around the western side of the high pressure ridge north of the Central Florida area.  A tropical wave near the Turks and Caicos Islands will bring scattered showers and isolated thunderstorms to Florida Thursday. You can follow the development of the tropical wave in the Caribbean on the National Hurricane Center’s web site, tropical discussion.

Lingering moisture from the wave will still be prevalent in our atmosphere Friday providing ingredients for weather to develop as the sea breeze forms. The sea breeze will likely set up along the coast between 1000EDT and 1100EDT, early enough for weather to become an issue by the 1121EDT opening of the launch window. We expect cumulus clouds, showers, and even possibly a thunderstorm to develop which could violate our launch commit criteria or flight weather rules.  Given this situation, there is a 60% chance of Kennedy Space Center weather prohibiting launch Friday.  The primary concerns are showers or thunderstorms within 20 nautical miles of the Shuttle Landing Facility and cumulus clouds within 10 nautical miles (nm) of the launch pad.

Another weather phenomenon we have potential for this week is an offshore waterspout. On summertime mornings when we have a south-southeasterly flow with very weak winds through a moist atmosphere, waterspouts sometimes develop offshore of the Kennedy Space Center coast. These waterspouts are not damaging like tornadoes and usually have winds 30-45 knots. You wouldn’t want to drive your boat through one of these, but we issue weather advisories for these types of waterspouts (as opposed to a tornado warning) so the personnel at Kennedy Space Center know they are not a threat to life and property like a classic tornado.  Although there are no launch commit criteria or flight rules associated with waterspouts, the cumulus clouds above them might be a concern! You can learn more about Florida waterspouts from NOAA.