Forecast for Friday, May 13

Issued: Thursday, May 12 Launch Weather Officer: Capt. Paul Lucyk, 30th Weather Squadron Synoptic Discussion: High pressure is finally dominating the weather pattern at Vandenberg allowing afternoon winds to ease for Thursday. This pattern will bring warmer temperatures and overnight fog while allowing more cooperative winds for tower roll. The forecast for this afternoon calls for northwesterly winds from 310-340 gusting to 25 knots. The winds are expected to subside to the low teens after 1800L (6 p.m. PDT), and by T-0, expect the direction to become more northerly with maximum gusts of 12 knots. Visibility is expected to decrease to 1 mile with the return of the marine layer stratus and we will have a few cirrus clouds from 26,000 to 30,000 feet during the launch window. The temperature at SLC-2 is forecast in the low to middle 50's. Upper level winds are forecast from the northwest throughout the column with a maximum of 35 knots at 33,000 feet. 24 Hour Scrub Forecast: The forecast for Friday afternoon and Saturday morning calls for high pressure and continued light winds. Expect continued overnight stratus/fog, and reduced visibility. Expect increasing cirrus above the marine layer giving a slight concern for thick clouds. Temperatures at SLC-2 are forecast again in the low 50's as local sea surface temperature has been a very consistent 55F at the Santa Maria buoy. Predominate visibility will be less than 2 miles with fog and upper level winds are forecast to increase to 75 knots at 37,000 feet. Clouds: Stratus at 300 feet with 8/8ths sky coverage tops at 1,100 feet; Cirrus at 26,000 feet with 3/8ths sky coverage tops at 30,000 feet Visibility: 1 mile Launch Pad Winds: Northerly from 330-010 degrees at 8 to 12 knots Temperature: 50 to 55 degrees F Probability of Violating Weather Constraints at T-0: 0 percent Concerns: None

24-hour Delay Forecast

Saturday's Probability of Violating Constraints at T-0: 10 percent Concerns: Thick clouds