1000km Alert - Mojave Desert to Reno & SW Nevada - for Sunday 07/13/2014

Ladies and gentlemen,

A great summer soaring pattern for long cross country and triangle flights is developing late this weekend. Sunday looks fantastic with just a taste of scattered cu 15500 to 18000 and light E-SE low to mid level flow for early thermal starts.

Monday will be too late... as monsoon moisture sweeps into the Mojave and Southern Sierras Mon afternoon with mid cloud cover and thunderstorms.

A strong 500mb high will build over Nevada between Ely and Reno Sunday. Circulation around the high brings drier airmass in a northerly flow over Utah, turning to E-SE over the Mojave Deserts and Southern Sierra. This is my "classic" 1000km triangle pattern because the flow sweeps in steep lapse rates to the Western edge of the Mojave Desert (Tehachapi for example) for early starts (say 1030am Double Mtn). Late finishes up to 7 or 8pm looks reasonable as the low level westerlies will be shallow and only favor triggering of convergence zone 25-40 miles out of Tehachapi. Easterly flow around the high will begin bringing monsoon moisture to the Eastern Mojave and lower deserts late afternoon and evening perhaps triggering scattered thunderstorms Barstow-Daggett Big Bear area. More cloud cover, moisture and showers should spread into the lower deserts 9pm to after midnight.

For Sunday XCSkies is showing high cloud cu bases on the Sierras around 17.5-19.0 msl, with somewhat lower bases say 16.5 over the Inyos and 15.5 Barstow region.

My plans were to fly out of Inyokern with the Southern Sierra group, but because of the large number of private owners turning up, I might change to Tehachapi if there is a 2nd tow plane available. A 750km triangle is my goal.... unless it looks spectacular... then I might go for a 1000km triangle.

More to follow tonight or Saturday morning... with graphics and illustrations.

Walt Rogers WX

PS - Jane... what's the likelihood of a 2nd tow plane for Sunday?