2018 Hurricane Season: extra weather balloon launches for Hurricane Florence

I have blogged about the upper air data gathered by the National Weather Service (NWS) from weather balloons known as the upper air observation program. There are about 90 NWS Weather Forecast Offices (WFO) that join other sites around the world in the upper air observation program by launching weather balloons with a radiosonde with sensors that record some weather data as the balloon ascends into the upper atmosphere. These "weather balloons" are launched per international agreement at the same time, at midnight and noon UTC. One of the important uses of this upper air data is that it is fed into the weather models that the NWS meteorologists and meteorologists from around the world use to come up with their weather forecasts.

I have written elsewhere about how NWS incident meteorologists will sometimes launch balloons for upper air observations to aid their fire weather forecasting.The data gathered by these balloon launches is also used by the National Hurricane Center in their hurricane forecast models.

Every so often when a large storm is threatening the U.S. the National Weather Service adds two extra weather balloon launches at 6AM and 6PM UTC, making for four balloon launches six hours apart. This was done in January 2016 for a large snow storm/blizzard that hit the east coast, see my January 2016 post on weather balloons. This week, many NWS WFOs in the upper air observation program, most but not all in the eastern half of the country, launched two additional weather balloons (one every six hours) to provide additional data for the NHC hurricane models. The NWS WFO Buffalo NY has a nice twitter post explaining balloon launches, with some nice graphics and photos.

I have two videos to share with you on upper air balloon launches. One shows a fairly typical balloon launch on a day that is not too windy.


Direct link to video from the City of Tampa

The second video is very short video from the NWS WFO Newport/Morehead NC, shared on their facebook page, go here to see the short video. The balloon launch was on or about September 13th. Note that because of the windy conditions, two people are holding on to the balloon as they exit the upper air building prior to launching the balloon.

I understand from a friend at the NWS WFO Norman Oklahoma that WFOs in Texas and Oklahoma stopped launching the two extra balloons as of today, September 14th, but WFOs to the east are continuing with the two extra balloon launches.