STS-99 Launch Weather Forecast

George Diller

Kennedy Space Center

ISSUED: Friday, January 28, 2000

VALID: Monday, January 31, 2000

Synopsis: A cold front will move through the Cape Canaveral vicinity on
Sunday night and will be followed by high pressure. Compared to the
weekend, this will bring cooler, drier conditions. There will also be a
west-southwesterly flow aloft creating a slight chance of thick mid-level
or high clouds.

During the launch window of 12:47 p.m. – 2:49 p.m. EST :

Clouds:

3/8 scattered stratocumulus 3,000-6,000 feet

4/8 scattered altocumulus 10,000 – 14,000 feet

6/8 broken cirrostratus 25,000 – 30,000 feet

Visibility: 7 miles

Wind at Launch Pad 39-B: NW/12-18 knots

Temperature: 60 degrees Dewpoint: 44 degrees

Relative Humidity: 55%

Weather concern: chance of thick clouds in violation of triggered lightning
rule

Probability of weather conditions at KSC prohibiting launch: 30%

Probability of violation w/24-hour delay: 0%

Solid Rocket Booster Recovery Area

Winds: NW/15-20 knots Seas: 3-5 feet Water Temperature: 71 degrees

Sunrise: 7:11 a.m. Sunset: 6:01 p.m.

Forecast by USAF45th Weather Squadron, Cape Canaveral Air Station