Forecast for Wednesday, May 11

Issued: Monday, May 9 Launch Weather Officer: Capt. Paul Lucyk, 30th Weather Squadron Synoptic Discussion: Vandenberg is currently under the influence of a weak frontal system which will continue to move through the area Monday afternoon. Expect continued isolated showers this morning with partial clearing by afternoon and evening. By Tuesday morning expect high pressure to build in from the west. As this occurs, expect a tightening pressure gradient bringing northerly wind gusts throughout Tuesday afternoon and evening with a maximum of 35 knots at SLC-2. This will present a significant challenge for tower roll/exposure and subsequent launch preparations. By T-0, expect the winds to subside slightly, but we will still see northwesterly gusts in the 20-25 knot range. Visibility is expected to remain above 7 miles and we will have scattered stratocumulus from 1,000 to 4,000 feet during the launch window. The temperature at SLC-2 is forecast in the lower 50's and upper level winds are forecast from the northwest throughout the column with a maximum of 90 knots at 40,000 feet. 24 Hour Scrub Forecast: The forecast for Wednesday afternoon and Thursday morning brings continued gusty winds through sunset with maximum gusts from the north at 32 knots followed by 18-22 knots by T-0. This will present yet another challenging day for tower roll/exposure and booster preparations. Expect some cirrus and a possibility of radiation fog in low lying areas by T-0. Predominate visibility will be unrestricted and temperature is forecast in the low 50's. Upper level winds are forecast to decrease to 65 knots at 35,000 feet. Clouds: Stratocumulus at 1,000 feet with 4/8ths sky coverage tops at 4,000 feet Visibility: 7 miles Launch Pad Winds: Northwesterly from 320-350 degrees at 20 to 25 knots Temperature: 50 to 55 degrees F Probability of Violating Weather Constraints at T-0: 40 percent Concerns: Launch pad winds as measured at 102-foot level

24-hour Delay Forecast

Thursday's Probability of Violating Constraints at T-0: 20 percent Concerns: Launch pad winds as measured at 102-foot level