Forecast for Thursday, April 20

Issued: Sunday, April 16 Launch Weather Officer: 45th Weather Squadron Synoptic Discussion: "The Central peninsula will remain under high pressure through Monday with high pressure suppressed to the South resulting in Westerly surface winds. Expect winds at 230 feet from the West gusting to 15 knots Sunday becoming Easterly gusting to 15 knots late afternoon as the sea breeze attempts to set up, although pinned to the coast. Winds increase Monday afternoon gusting to 25 kts and increase to 30 kts Tuesday from the WNW. Winds remain gusty for 24 to 36 hours as a cold front approaches the Florida peninsula. The weak cold front is expected to stall in South Florida Tuesday evening with a gradual decline in wind speeds gusting to 20 knots. Although dry, there is a small chance of an isolated thunderstorm with the boundary on Tuesday afternoon and evening. Weak high pressure remains off the coast on Wednesday into launch day with a broad area of low pressure and disturbed weather to the North in South Georgia/North Florida. "For launch day, winds become Southeasterly gusting to 20 knots with a chance of isolated showers associated with low pressure in North Florida. The primary concerns for launch day are thick clouds and disturbed weather associated with the disturbance to the North. Proton flux for 10 MeV energetic particles is forecast marginal through 19 Apr. "Conditions remain similar in the event of a 24 hour delay with thick clouds and disturbed weather the principle concerns." Clouds: Strato-Cumulus Scattered at 2,500 feet with tops at 4,500 feet; and Cirrus Scattered at 24,000 feet with tops at 26,000 feet Visibility: 7 miles Launch Pad Winds: Southeasterly from 130 degrees at 14 to 20 knots Temperature: 76-78 degrees F Relative Humidity: 70 percent Weather: Isolated Showers Solar Activity: Moderate Probability of Violating Weather Constraints: 30 percent Concerns: Thick clouds associated with isolated showers

Forecast for 24-hour delay

Friday's Probability of Violating Constraints: 30 percent Concerns: Thick clouds associated with isolated showers

Times of note

Thursday's launch window: 4:27-7:16 p.m. EDT (2027-2316 GMT) Friday's launch window: 4:22-7:16 p.m. EDT (2022-2316 GMT)