The above map appears to total rainfall for the previous day. So the Sunday 1-17-2010 map appears to show precipitation for Saturday. Thus the annotated date 1-17-2010 that is Sunday show "Sat". Note I am no meterologist, just a long time keen weather follower. My decades of chasing fresh powder skiing about Tahoe and photog landscape work otherwise has a lot to do with that. I'm offering others this unique graphical look of precipitation results back into this week of storms plus some terse comments and digs at media forecasters. I'm expecting there are other weather data types like this person on the board.
By Friday January 15 media had finally caught wind of the coming big storms and weather forecast I'd first noted in the terse discussion earlier in the week. Some tv stations with new modeling tools were showing how much precip was going to occur with each of the 5 storms and when it would occur during the day. Even though forecasting is much better this decade, I doubted it would play out so neatly as modeled and media predicted and that came to pass. Historically here in California, the larger a storm series, the more likely forecasters usually get the way it plays out rather incorrect.
Per forecasts Thursday and Friday, Saturday 1-16 storm #1, was supposed to be the first day of light showers with considerable cloudiness over all the SF Bay Area. The map for that day only shows precip for north of the SF peninsula. It was mostly sunny across much of our area. Generally the system stalled moving against the fair weather ridge on land and vectored more north.
Sunday 1-17, storm #2 was forecast for moderate temperature rain of about a quarter to half an inch here in the Santa Clara Valley and an inch or so in the north bay. We only received about half of that advertised. It was moist and drissly all day and the forecast was accurate further north. There was a large area of the front so it managed to spread all the way down to Los Angeles, especially in the Coast and Transverse Ranges.
Monday 11-18, storm #3 on the was forecast to be a large storm with mildly cooler temperatures and indeed it was, especially north of the SF Bay Area as the map shows. Note the major rains along the North Coast and Shasta. It was the first day to really impact the Sierra Nevada with snows across the full range and there were numerous problems with those returning from Tahoe holiday skiing.
Tuesday 11-19, storm #4 was much more intense in our area than #3 with high daqmaging winds as the brunt passed into the Santa Cruz and Santa Lucia Mountains and Santa Clara Valley. Rains were very heavy and temps colder during the water-planing commute here in Silicon Valley. However the storm was more compact and after pushing strong rains into the Sacramento Valley, strangely hardly pushed across the Sierra and instead while the barometric core moved due north along the coast, heavy rain bands in the valley also pushed due north towards Shasta. Thus did not much impact areas of the central and southern Sierra or areas in Southern California as much as the broader storm #3. So forecasters were correct that it was not a large a storm as #3 or #5 but missed that it would be as intense as it was in our area.
As forecast, storm #5 on Wednesday 11-20 was overall the largest of the series as the peak jetstream rammed into the Southland. In our area a cold core moist cumulus flow lasted all day and night which had not been forecast. So there wasn't much of an expected lull into Thursday. The previous Friday it had been forecast to be the the most intense. However it was not as intense at least in our area. It pushed good rains into Southern California even more than #3 and seemed to linger for hours in the San Diego mountains and western Sonora Desert. Even noticed rare periods of rain on Las Vegas radar further north over Death Valley.
For the Southern California desert areas, as I expected, it was storm #6 on Thursday 1-21 behind the front of storm #5 with lots of cold air cumulus build ups moving across in the powerful trough that brought rare heavy rains to those areas. Very similar to February 2005. What was really amazing were the major rains that intensified over Arizona causing considerable flash flooding. Maybe some of you that live in the Southland have some more insighteful comments about #5 and #6 than I could offer.
