Opti Forecast 7/23

Sailing Weather Forecast

Optimist Nationals

Lake Minnetonka, MN

Issued: 0700LT Monday, 23 JULY 2007

 

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WEATHER RISKS: There are no active weather warnings or advisories for the sailing area.

Please tune your VHF to NOAA Weather Radio for the latest official warnings and advisories.

 

Synopsis: Despite a few minor instances yesterdays forecast remained on track in what was a challenging weather environment. As predicted the wind was southerly through the day, building to the forecasted 09-12 kts during mid afternoon. Unanticipated was a slight left hand shift to the SSW from 1130-1300 and gusts a few knots above the forecasted 17 kt limit. There was also a brief lull in the wind speed near 1430 as thunderstorm passed to the northeast.  

 

Today’s forecast is complicated as the Lake Minnetonka area remains on the periphery of high pressure centered over the southeastern Great Lakes. The distant high will be unable to prevent small disturbances from developing in the unstable air over Minnesota. Several of these very small areas of low pressure will cross the state today and this means shifty winds and some clouds but it should remain dry.    

 

Current Conditions: A S-SSW breeze at 06-09 kts has been in place since midnight and at 0630 this continues to be the case at the MYC weather station, Minneapolis, and Flying cloud.

 

Satellite images depict an area of broken clouds across central and southern Minnesota including the Lake Minnetonka area. These clouds are moving southwest and slowly dissipating in converge. Rain and thunderstorms associated with these clouds is indicated by radar over the far southeastern portion of the state. Surface observations report unrestricted visibility at 10 miles or greater away from areas of rain.   

 

Forecast Discussion: A southerly wind at 06-09 kts will continue this morning over Lake Minnetonka. Approaching 1300 the wind builds slightly to 07-11 kts with gusts to 15 kts and a slight right hand shift to the SSE is likely. Late in the afternoon, near 1700, a continued right shift to the SE is probable as wind speeds ease to 05-09 kts.     

 

Weather: The broken clouds currently overhead remain for several hours before clearing to mostly sunny conditions ensues near 1100. Temperatures gradually rise this morning to an afternoon high of 89 F and the high humidity will make it feel quite sticky. Once the sunshine breaks through the clouds the UV index rises to a high 9-10 so put that sunscreen on.  

 

Seas: Light winds today mean relatively calm waters so only a slight chop is expected on Lake Minnetonka today.

 

Detailed Wind Forecast for Today (07/23/2007):

Time(LT)  Wind Speed    Wind Direction 

1000      06-09         SSW-S

1100      06-10         S           …slight build in speed underway

1200      07-10         S          

1300      07-11         S-SSE       …small right shift     

1400      07-11         SSE         …max winds of the day, gusts to 15 kts

1500      07-11         SSE        

1600      06-10         SSE  

1700      05-09         SSE-SE      …continued right shift, declining winds

1800      05-09         SE

 

Hedge: 1) Forecast confidence is BELOW AVERAGE for wind direction and AVERAGE for wind speed today. Lake Minnetonka will reside near several wind shifts today. Significant changes in wind direction are expected to remain west of the area. However, there is a possibility that a significant change in wind direction occurs at the lake today. If this happens the most likely scenario would be a quick and significant right shift to the E-ENE around 1200 and then a return to the SE late in the afternoon.  

 

2) Breaking clouds this morning should provide an opportunity for pockets of increased wind speed. This means that winds may be stronger, but shiftier, along the edge of clouds and weaker, but less shifty, beneath the clouds.    

 

Tuesday (24 JULY 2007): A greater confidence exists in tomorrows forecast as a steady southerly flow returns to Lake Minnetonka. A light S wind at 03-06 kts is expected at sunrise and though the morning hours. Winds remain out of the S at midday and during the afternoon but by 1200 they should increase to 05-09 kts with gusts to 13 kts. A slight right shift to the SSE occurs near 1700 as winds relax to 04-08 kts.  

 

Detailed Wind Forecast for Tuesday (07/24/2007):

Time(LT)  Wind Speed    Wind Direction

1000      03-06         S

1200      05-09         S

1400      05-09         S

1600      04-08         S-SSE

1800      04-08         SSE

 

Weather: High pressure builds weakly into the area tomorrow but enough to keep skies mostly sunny. The bright sunshine sends temperatures to a toasty high of 91 F and it will feel very humid.

 

LONG RANGE OUTLOOK

 

Wednesday (25 JULY 2007): A SSE wind at 04-09 kts in the morning becomes S and increase to 06-11 kts by 1200. Blazing hot sunshine with a high of 93 F.

 

Thursday (26 JULY 2007):  Wind SSE in the morning at 02-05 kts, building to 05-09 and turning left to the SE by 1300. A continued build in speed to 07-11 kts and shift to the ESE late in the day. Sunshine with building afternoon clouds and evening showers, high of 89 F.

 

Friday (27 JULY 2007): Expect a NNW wind to start the day at 03-06 kts. Turning N near noontime and then shifting left to the NNE at 05-10 kts through the afternoon. Sunshine mixed with clouds and high near 85 F.