From SSCA FB
Marine Weather Forecaster Chris Parker of the Marine Weather Center had so generously provided us with the following update on the projected drift of the unmanned S/V DAGNY which went adrift from West End, Bahamas on December 22, 2015.
Please share this information to fellow cruisers transiting the coastal waters of Northern Florida and Georgia. Please report any sighting to the United States Coast Guard (USCG) and Seven Seas Cruising Association (SSCA) Radio Station “KPK” at KPK@ssca.org
or telephone 941-456-5070.
Glenn Tuttle - Moderator
Cruisers Network Online
SSCA Radio Station “KPK”
Daily 8.104 @ 1145 hrs UTC
Here was the analysis I provided Sat26:
The vessel drifted about 25 miles in a direction of 320T in 24 hours. This makes sense, and confirms the roughly 1k speed of drift. My guess was between 1k and 1.5k speed of drift due to wind. Assuming there were no tidal currents, the speed of drift may be closer to 1k in wind of 15k, which is slightly less than I was estimating.
So the vessel started drifting from 26-40N/79W at about 5:30pm EST on Tue22.
Was sighted 27-04N/79-16W at 5:20pm on Wed23.
At 5pm on Thu24, I estimate position 28-12N/79-45W, based on drift from wind 30 miles, in direction 320T & set from current 48 miles in direction 355T.
At 5pm on Fri25, I estimate position 29-30N/80-10W, based on drift from wind 25 miles, in direction 310T & set from current 45 miles in direction 348T.
At 5pm today (Sat26), I estimate position 30N/80-30W, based on drift from wind 22 miles, in direction 320T & current about 10 miles in direction 345T.
From the current location there's little GulfStream current (and tidal currents should cancel themselves out over a 24hr period), so drift should be due exclusively to wind, and should be about 18 miles in a direction of 330T Sat26 night-Sun27 (yielding a 5pm Sun27 location of 30-15N/80-40W)...
and 22 miles in a direction 340T Sun27 night-Mon28 (yielding a Mon28 evening location of 30-36N/80-48W).
and 25mi in a direction 360T Mon28 night-Tue29 (yielding a 5pm Tue29 position 30-51N/80-48W).
Of course, all of the above is only an educated guess, and the possible errors compound over time...cheers...Chris.
Let's assume this was correct:
At 5pm on Fri25, I estimate position 29-30N/80-10W
Here's the revision: At 5pm on Sat26, I now estimate Dagny might lie near 29-53N/80-30W, based on drift from wind of 20mi, in direction 310T & set from current about 10 miles in direction 345T.
At 5pm on Sun27, I now estimate Dagny might lie near 30-08N/80-45W, based on drift from wind of 20mi, in direction 320T
At 5pm Mon28, I now estimate Dagny might lie near 30-21N/80-56W, based on drift from wind of 16mi, in direction 325T.
At 5pm on Tue29, I now estimate Dagny might lie near 30-36N/80-59W, based on drift from wind of 15mi, in direction 350T.
At 5pm on Wed30, I now estimate Dagny might lie near 30-50N/80-56W, based on drift from wind of 15mi, in direction 010T.
At 5pm on Thu31, I now estimate Dagny might lie near 30-59N/80-50W, based on drift from wind of 10mi, in direction 030T.
I'll reiterate: Of course, all of the above is only an educated guess, and the possible errors compound over time...cheers...Chris.
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