Dudley's plan of action was to proceed direct to the Van Nuys VOR, then to the Fillmore vortac via V186. Heading along the coast toward Santa Barbara, he'd take V386 to the San Marcus vortac, and then V25 to the Paso Robles vortac. He'd miss seeing the coastline, but he would also miss some military operations areas and restricted airspace that way, too. From Paso Robles, it was a straight shot up V113 north to the Priest VOR and then the Panoche vortac. From there, the final leg on V107 led right into Hayward. The sculpted hills of central California were beautiful to behold, but the terrain along several segments of his route rose up to 3,000 or 4,000 feet, so Dudley planned to fly this one at 8,500 msl.
Dudley, being as thorough as always, did his homework before venturing out into the unknown. Dudley had recently discovered a gold mine! It was a book called Flying America's Weather: A Pilot's Tour of Our Nation's Weather Regions, by Thomas A. Horne, and published by ASA (800/ASA-2-FLY). In its pages were the results of years of research associated with the author's hundreds of magazine articles on aviation weather, as well as formal university study in meteorology. In Flying America's Weather, Dudley learned that California has many different geological features in close proximity. The large semi-permanent area of high pressure 1,000 miles off the central California coast contributes to the upwelling of cool water offshore, which accentuates the onshore flow of moisture-laden marine air into the coastal lowlands, mountains, and valleys. In Southern California, coastal fog is common, as is the smog in the Los Angeles basin, which is trapped by surrounding mountain ranges and inversions of warm air aloft. The smaller (by 3 or 4 degrees) temperature-dewpoint spread in cooler Northern California is just enough to turn that onshore moist flow into a fog machine, often drawing a white blanket through gaps in the coastal terrain around the San Francisco Bay area. Hmmm...from smog to fog.
Moist onshore flow notwithstanding, the weather here along the central California coast had been nothing short of glorious! Any occasional fog had usually burned off by mid-morning. Just about every day was a good flying day-at least while Dudley had been in the area. As it happened, when Dudley awoke a little after 7 a.m. on this particular Thursday morning, there was a weak trough inland and significant amounts of fog along most of his route. Going first to the "Live Wx" section, he looked at the 14Z Weather Depiction chart. There were low ceilings and instrument weather conditions along significant stretches of his route. The best he was likely to encounter was marginal VFR. He'd hope for a better outlook in a couple of hours. In the meantime, he had a quick look at the National IR Satellite/Radar Composite image, which updated every 30 minutes. This combined visual and infrared information gave Dudley a good picture both of the probable extent of cloud cover as well as tops. If he were instrument-rated, it would be a simple matter of flying "VFR on top." For someone not yet inducted into that fraternity, however, it would not be a wise move. Even if he could find enough holes to climb through the clouds, he couldn't guarantee that he'd find enough breaks to land at his destination.
Moving over to the forecast area next, Dudley looked at the 12-hour surface forecast. The sunny skies in the forecast were good news. But now it was time to get down to the details. Looking next at the "AvCast" area, Dudley was impressed with the textual version that had terminal area forecasts, winds aloft, pilot reports, and many other familiar products. He was even more impressed by the graphical "AvCast Pro" version, which combines a map with the text route briefing input and regional Nexrad images as well as many other types of graphical data.
Wanting to look first at some plain, old-fashioned text data, Dudley went to the route briefing section and pulled down details for several points along his intended route.
Looking at the output in much the same way as a standard weather briefing, he noted the airmet for instrument flight conditions, which basically covered the entire coast of California until 1 p.m. His route did head toward the coast at Santa Barbara (to avoid mountainous terrain to the north), and that station was reporting a ceiling of 700 overcast. The temperature-dewpoint spreads were very small at most places near his starting point. The funny thing was that, contrary to what he'd been expecting, fog or low clouds did not seem to be a problem away from the Los Angeles area. Of course, his route was mostly inland after Santa Barbara, but even San Jose and Hayward were now VFR. Also, a half-hour-old pilot report near Santa Barbara put the tops at 1,700 feet, which gave Dudley a vivid picture of what the cloud cover must be like: a low, but thin stratus layer. The forecasts from earlier in the morning all predicted VFR conditions after local noon. Time to relax for a couple of hours, and check back later.
Well, the forecasts weren't far off, as it turned out. Dudley waited until almost noon before checking back. The Los Angeles area had some clouds at around 1,000 feet. Santa Barbara, the previous choke point for Dudley with regard to cloud cover, now had 1,300 scattered and 5,000 broken. (Even if it stayed that way-not that it was predicted to-Dudley could drop down underneath to 4,500 feet until he passed clear.) The new forecasts all said VFR until about 8 p.m. local time, when things would cool down and this would start all over again.
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