Issued: Friday, April 21, 2000
Valid: Monday, April 24, 2000

KSC Contact: George Diller

Synopsis: An upper level low pressure disturbance over the Gulf of Mexico is
expected to produce thunderstorms over the eastern Gulf. Westerly upper level
winds will bring the threat of anvil clouds over eastern Florida. Surface high
pressure will be located to the east of Cape Canaveral.

At the 4:15 p.m. launch time:

Clouds: 3/8 scattered cumulus at 4,000 – 7,000 feet

5/8 broken cirrus at 25,000 – 31,000 feet

Visibility: 7+ miles

Wind at Launch Pad 39-A: East at 10-15 knots

Temperature: 77 degrees

Relative Humidity: 45%

Weather Concerns: Potential thunderstorm anvil clouds

Probability of weather conditions prohibiting launch: 30%

Probability of violation with 24-hour delay: 30%

Solid Rocket Booster Recovery Area:

Winds: SE/7-10 knots

Seas: 2-3 feet

Water Temperature: 74 degrees

Sunrise on Monday: 6:48 a.m.

Sunset: 7:53 p.m.

Forecast by USAF 45th Weather Squadron, Cape Canaveral Air Force Station