Rolex Farr 40 Pre Worlds & Worlds Weather Forecast
Forecast for Thursday, Apr 17, 2008

( Printable Version )
Issued: Thursday, 04/17/2008 at 07:00:52 (Eastern Sum. Time)

NOTICE: The National Weather Service has issued a SMALL CRAFT ADVISORY for very rough seas today. Monitor official National Weather Services forecasts and warnings on NOAA All Hazards Radio via your VHF radio.

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Synopsis: Yesterday’s forecast was on track more or less for the first two races, with gusty left-shifted winds easing and trending right. However, things got more complicated in the afternoon once the wind was from the NE. The cooler air of the early morning was spending more time of the warm Gulf Stream waters, causing increased instability. This instability combined with a weak trough rotating around the western periphery of the low pressure that was located northeast of the Bahamas to produce considerable cloud and some showers/squalls that moved into the course area during the third race. These showers allowed mixing of stronger breeze down to the surface, thus creating the 25 knot winds reported during the third race.

For today, conditions will continue to be a little unstable with the cooler air still overrunning the warmer water. Conditions are trending toward slightly weaker gradients, however there is still support for winds in the low-/mid-teens and a possibility of higher gusts, especially if any heavier cloud or showers approach from the vicinity of the Gulf Stream.

This morning weather map shows the low pressure that was northeast of the Bahamas yesterday is still moving away to the northeast and will pass close to Bermuda today. High pressure that was over the northeastern Gulf of Mexico and southeastern states is consolidating over Georgia this morning while showing signs of moving east. After a land breeze as the coast, NE/ENE gradient over the Gulf Stream will move into the course area by late morning. Winds will gust up at first, then east back during the early afternoon. A second push of gradient is possible in the later afternoon with a slight build in pressure.

Current Conditions: Mainly NW/NNW winds along the beach where the land breeze extends this morning. Offshore, a convergence line of cumulus clouds is over the Gulf Stream and there are a few light showers embedded within that according to the radar. East of the convergence line, winds are NE at 10-15 knots.

Forecast Discussion: NW/N 7-10 knots first thing this morning with land breeze component near the beach. By mid-morning, veering to NE and increasing for a time from late morning to average 12-15 knots. There could be a few briefly stronger gusts, especially behind clouds moving onshore. By mid-day, winds will tend to ease through early afternoon, dropping to 10 knots and possibly less for a time. Then, around mid-afternoon, winds will likely increase again with a possible right shift. Winds will end the day 10-14 knots.

Weather: Mainly clear inland, but cloud offshore and especially over the Gulf Stream. Slight chance of a few light showers offshore through about mid-morning. Then a period of drier weather late morning through early afternoon. Some more showers as possible in the later afternoon.

Maximum Temperature: A cool start around 60F this morning, warming to the mid-/upper-70sF this afternoon.

Seas: Continued very rough seas. 8-11 ft in the Gulf Stream. Between the Gulf Stream and the beach, 4-7ft. A gradual decrease in likely through the day.

Hedge: 1) Forecast Confidence – AVERAGE. There is good agreement among the forecast models on the general features of the forecast, but some spread in how the various models handle the forecast details. Like yesterday, there was significant spread in the wind speed forecast among the forecast models. The forecast table hedges toward the observed gradient winds later this morning, but then comes in line with some of the lighter forecasts for the early afternoon. In the late afternoon, the table follows the higher resolution models closely, but could be over-predicting wind speeds.

2) Keep a keen eye on the clouds offshore once again today. The main convergence line over the Gulf Stream should move to the coast by mid-morning, ushering in the right shift to NE/ENE with additional pressure. Additional clouds will likely move from offshore toward the course through the day.

3) Peak wind potential is not as high as yesterday since the gradient wind is lighter. So it appears less likely that we’ll see any increases similar to those observed with the arrival of showers/squalls yesterday.

Outlook for Tomorrow: High pressure will continue move off the southeast US coast. This will veer the gradient further to the right compared with today. In addition, the gradient will weaken slightly, so lighter winds are forecast for the daily average wind speed.
Weather: Partly cloudy. Slight chance of some showers in the morning and again in the late afternoon.