Lake Lopez Wind Forecasting

[buczacz]

As an AARP member, I seek gentle sailing sites. This summer I have favored Lake Lopez over Lake Isabella as it has delivered very good wind on most occasions, but I've still gotten skunked. Given that it is a 3+ hour drive from my home in Los Angeles, I'm looking for good odds of good sailing.

Primarily I look to temperature forecasts for Arroyo Grande and Paso Robles. Normally if Arroyo Grande is cool (70's oF) and Paso is hot (90's oF) you get wind. Then there are days like today when there is a relatively small 8 oF differential, and it is blowing nearly 20 mph.

Anyone have suggestions as to better forecast Lopez wind.

[MalibuGuru]

Fast warmup with little fog on the coast seems to work best.

[bprice]

Use Oceano, not AG, as your coastal thermal comparison location. Today you would have seen around 70 for Oceano and over 100 in Paso. Also, notice the coast had some cool NW wind around 15mph... just right. Too much more and it can cause Lopez to turn SW and gusty. Fog is great too unless it pushes far into the inland areas... not a problem today. I spend about 30 minutes a day looking at forecast tools just to improve my odds... not always right, but it helps.

The result: today had solid, steady, shore to shore, warm, dry winds into the low twentys. Only a few of us out on small stuff (90L, 5.3, 190#s), no boats, jet skis or other craft to mess up the smooth water and some nice swell for jumping and carving.

[buczacz]

It would seem to me that forecasts for Arroyo Grande, Oceano and Grover's Beach would be substantially the same, but I'll monitor them in the future. Per you suggestion, I'll also start to monitor wind direction. Do you know of site that has Arroy Grande's historical weather data tabulated, so it might be correlated with Lopez wind?

Wednesday, at Lopez there was barely enough wind to plane even with big sails. Yesterday, Thursday, 9/8/2011, all wind-push factors must of been aligned as 5 meter sails were way too big for nearly everyone. If you believe the iWindsurf wind speed reports, the wind velocity on Wednesday should of been adequate, but conditions were mostly marginal. Perhaps it was the lower density of the warmer air, but I would think that a 5% change in air density, from 70 oF to 90 oF would be inadequate to explain the change.

Bottom line ... I had a day of high adventure sailing at Lopez on Thursday.

[buczacz]

Bprice say to look to Oceano for coastal temperature guidance. Today on CNN, Oceano and Arroyo Grande forecasts are identical.

Normally I look to the projected temperature differential between Arroyo Grande and Paso Robles to forecast Lake Lopez wind. Today the temp. differential is only moderate 87 - 76 = 11 oF , and yet the wind is averaging nearly 18 mph today. Last Thursday there was a similar temperature delta, 85 - 71 = 14 oF, yet the was no significant wind. I suspect the other factor may be the wind, yet today both Arroyo Grande and Paso Robles are shown as having calm (<3 mph) winds. I have still not identified the other key factor driving Lake Lopez winds. SUGGESTIONS would be welcome.

On i-windsurf, below the wind chart is a table of projected winds. Does any one know how to use it to aid in the forecasting. Every time I look at it, it seems to be way off. For example, right now, Monday afternoon at 1:17PM, it says that they'll be 5 - 6 mph winds, yet chart says winds are running in the high teens. Other days it projects winds of 11 to 12 mph, and you get nothing. IS CHART OF ANY USE?

[bprice]

I would not use CNN for weather data in SLO... try Weather.com and you would see Paso was forecast today to be upper 90's and Oceano to be 70 with heavy morning fog giving a temp difference of about 30. Also check todays local NWS marine forecast and you would see this statement: DENSE FOG WITH VSBY 1 NM OR LESS IN THE MORNING. I also use local webcams to check fog levels and surface pressure charts to understand larger weather systems which influence local thermals. Last week I knew to skip Wednesday thru Saturday because I used these quick tools. Yesterday and today I returned to Lopez and sailed 6.0 and 5.3 because the data showed a good chance for decent wind. The rest of this week shows good potential too, so I'll be there unless something changes. By late next weekend, it looks to cool off inland and not be good again... Paso back in the low 80's... Time to make other plans.

IWindsurf does not do human forecasts for Lopez area and the models are useless.

[buczacz]

to: bprice, let's talk more if you make it to Lopez tomorrow, Wed., 9/21/2011. I'm the skinny AARP guy on the 15 year old Mistral Screamer with the blue-grey Subaru SW. You were right about last week; Thursday was a total bust.

[rhawkins]

Use Weatherunderground for any forecasting