What is
the white dome used for?
Please click picture for a larger image
Over the past few weeks, several residents
have asked us what the strange structure is behind the new National
Weather Service Forecast Office building is, and most notably the new
white dome on top.
The building serves several functions, and is built to withstand the
winds and storm surge of category 5 hurricanes. First, it will
house the new forecast office's electric generator at a safe elevation
above most hurricane storm
surge levels. The generator will help the National Weather
Service staff continue
operations during severe weather conditions, should commercial power
fail. It also will enclose the facility's trash container,
keeping it
enclosed so that our future neighbors won't have to worry about bad
smells or storms making loose trash blow...or float...off the
property. There will also be
storage space for large items that will keep larger items protected and
out of view, keeping the property looking neat and orderly.
One important function of the National Weather Service Key West is to conduct
weather balloon launches. Launched twice daily, and more often when
the weather is rapidly changing (such as before severe thunderstorms and hurricanes),
weather balloons are attached to small instrument packages to obtain a lot
of information about temperature, humidity and winds above the ground.
This data is input into computer forecast models, and is also used right away
by our office to determine the potential for strong thunderstorms, cloud ceilings
that affect local pilots, and numerous other weather phenomena. Without
this information, computer models would not be very helpful about predicting
future weather. The balloons will be launched from the tower-structure
on the main weather office facility. After we relocate to this new facility,
weather balloons will be launched from a tower attached the the main forecast
office building. You can see the balloon launch tower in the picture
above, behind and to the left of the dome building in the foreground
(Please click here to see a larger image).
This is where the dome comes in!
As the weather balloon instrument sends a weak radio signal to report its
observed data, a receiver dish protected inside the dome at the National Weather
Service Key West will track the balloon's position and report this data to
a computer inside the forecast office. No signals will be transmitted
from the dish; it will only "listen" to the incoming signals from the weather
instruments attached to the balloon while the balloon is in flight, and track
the balloon's position to obtain valuable wind data from the ground through
about 17 miles into the atmosphere. The dish (see a picture of one here) will be roughly 6 feet across
and will have to turn in any direction the weather balloon travels.
Therefore, the dome is sufficiently large enough to allow the dish to turn
safely and for our dedicated electronics technicians to perform maintenance.
While similar in appearance, the new dome at our future White Street
location should not be confused with our National Weather Service
Doppler Radar unit, which will remain in its current location on
non-residential ground on U.S. Navy
property, on Boca Chica Key. We will continue to operate and use
the doppler
radar's information remotely
for the preparation of warnings for the
safety of life and property in the Keys, just as we currently do from
the Key West International Airport.
For additional information, feel free to contact us, your local
National Weather Service Forecast Office in Key West, at
295-1316.