End of an Era: Weather Briefings and Communicating Uncertainty

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 (KSC) as the Launch Team prepares for the 8 July 2011 launch of Atlantis. You can find out more about the 45th Space Wing at their Facebook page.

We had two significant weather briefings Wednesday, 6 July: the 45th Space Wing Launch Readiness Review and the Shuttle Mission Management Team Launch minus 2-day meeting. Both meetings are essential to determine launch readiness, and weather is one piece of the large puzzle of things that must come together for launch. During these meetings, our squadron presents weather forecasts for the rotating service structure retract, tanking, solid rocket booster recovery, launch, plus 24- and 48- hour launch delay forecasts. Spaceflight Meteorology Group also presents the abort landing weather during the Shuttle Mission Management Team meeting. During the briefings, weather threats are highlighted so the Shuttle and Space Wing teams know what to expect. Sometimes NASA managers change the time of a pre-launch operation if the current schedule puts the launch countdown at risk for a weather delay, but the launch window itself is not modified since it is based upon the rendezvous with the International Space Station on-orbit.

After the Mission Management Team meeting, I attend a press conference with the Shuttle Launch Director, Mike Leinbach, and the Shuttle Launch Integration Manager, Mike Moses.  Our squadron Launch Weather Officers interact with them often since weather affects so many Shuttle operations. We provide a weather briefing to Mike Leinbach and his team every weekday morning to plan ground operations around the weather, if necessary. We increase the briefings to a few updates per day when a hurricane threatens the Florida East Coast. Mike Moses and Mike Leinbach have heard so many of my weather briefings that they can tell from the tone of my voice how certain or uncertain I am about a particular weather forecast. One NASA manager called this “Human Capital,” the rapport these managers build with their team which results in the synergy needed during a challenging situation, such as a Shuttle rollback decision.

Another way we describe the forecast confidence in a particular weather situation is through probability forecasts. For launch, we provide the “Probability of KSC Weather Prohibiting Launch,” as opposed to an absolute forecast. We also provide probabilities for constraint violations during ground operations.  In fact, many Shuttle constraints include probabilities, such as for Shuttle rollout, the constraint is “no more than a 10% chance of lightning within 20nm.” If you view our weekly planning forecast, you will see the probability of precipitation and lightning our customers use for planning purposes. These probability forecasts help launch teams make cost/risk decisions.

Speaking of probabilities, Wednesday, we increased our probability of KSC weather prohibiting launch. Weather does not look good for Friday here on the Florida Space Coast! Check out our latest launch forecast.  Hopefully we’ll be able to launch Friday—check out the photo that shows you the view of the Shuttle launch from our building!