Forecast (0000 UTC 20 February)
Current Conditions: Temperatures are still hanging out in the lower-mid 70s for the forecast period, and likely the next few days. Current conditions look to be mostly cloudy; by satellite, I’d estimate this at ~75%. Winds are hard to estimate since you are currently between ASCAT satellite passes, but eyeballing the other passes and examining the models would lead me to estimate winds of about 18-20 knots from the NE. Waves are 2-3m from the NE and currents are weak or ambiguous.
Short-term Forecast: Temperatures should remain in the lower to mid 70s over the forecast period. At around 12z on 2/20, 2-3m waves are likely to shift direction, and start coming from the NW. Winds should remain from the ENE for the day. They may decrease in strength to 15-18 knots from 12z-18z, but will strengthen again to 18-23 knots by 0UTC on the 21st. Cloud cover at the start of the forecast period may be ~50-75% but will generally decrease during the day to ~30-40%. You may experience some occasional drizzle through the day. Currents according to RTOFS should remain weak and ambiguous.
The forecasters think we might have an answer for your dawn and dusk shifting winds: atmospheric tides. Unlike ocean tides which are forced by gravitational attraction with the moon, atmospheric tides are forced by absorption of sunlight in the upper troposphere and stratosphere. This absorption creates waves, some of which travel down to the surface and are felt as an oscillation in pressure and wind, and sometimes clouds and rain too. Because sunlight is a very “square” thing (it’s either on or it’s off), it can create waves with “harmonic” frequencies. This means you might experience these thermal tides with periods of both the forcing (sunlight: 24-hours) and its largest harmonic (24/2 = 12-hours). As a bit of historical background, the cause of atmospheric tides was a huge puzzle to scientists for the first half of the 20th century, and it wasn’t until 1967 that scientists (specifically, Richard Lindzen) came up with this correct theory of thermal forcing. We’ll let you know if we come up with another idea, or if we decide that this definitely what you’re experiencing.
Longer-term Forecast: As mentioned previously, a low pressure center currently off the coast of North America will increase you wave heights to 3-4m from the NW on Thursday morning, so do watch out. Current model runs indicate that waves will return to 2-3m around 12UTC on Friday (2/22). The waves may decrease further to 1.5-2m from the NNW over the weekend. Although currents are pretty ambiguous/weak now, there is a huge eddy (2.5-4 knots in strength near ) to your west that you’ll hit next week sometime. Even better, it’s going your way: from 17N to 19N and -41W to -37W, currents are moving to the west. Partly cloud conditions (25-50%) should continue through Friday, so you should see a bit of sun from time to time. Winds should remain from the ENE and from 18-23 knots on Wednesday, and will likely decrease to 15-18 knots from the ENE mid-day on Thursday. On Friday, the winds will decrease further, perhaps down to 10 knots; however, due to the location of the next low pressure system, winds will shift direction and start coming from the E or ESE depending on your location at the time.
Next 12 hours (0000-1200 UTC 20 February)
Winds: 18-23kts from the ENE, descreasing
Waves: 2-3m from of the NE, shifting near 12UTC to the NW
Currents: weak
Clouds: 40-60%
12-18 hours (1200-1800 UTC 20 February)
Winds: 15-18kts from the ENE
Waves: 2-3m from the NW
Currents: weak
Clouds: decreasing to 30-40%
18-24 hours (1800 UTC 20 February – 0000 UTC 21 February)
Winds: 18-23kts from the ENE, increasing
Waves: 2-3m from the NW, increasing to 3-4m from the NW
Currents: weak
Clouds: 40-60%
Forecaster Maroon