The National Weather Service in San Francisco has provided an update on the weather forecast for the region, highlighting dry conditions with cool mornings and warm afternoons set to continue. According to their Area Forecast Discussion, we're looking at a repetition of the previous day's weather, with the main subtle change being the marine stratus peeling off the coast due to a robust offshore flow.
"The SFO-WMC gradient is -12.3 mb, quite a bit stronger than most models have it analyzed," the NWS San Francisco described, noting that winds at Mt. St. Helena were gusting as high as 47 mph. The forecast suggests this offshore gradient will continue to weaken over the next 36 hours, with a slight moderation of minimum and maximum temperatures due to incoming high clouds. Despite these variations, it's expected to feel very similar to the day before.
The NWS San Francisco also gives a nod to the long-term outlook, stating, "Sunday will be a rinse and repeat of Saturday," and predicting that the strong ridging trend will hold steady through the week. There's a little possibility of light rain towards the end of the week, but it mainly seems to be a cloud-making affair. However, the pattern is anticipated to change, potentially bringing wet weather back before January ends. "The 00Z ECMWF ensemble IQR has between 1.0-2.5" of rain from the 27th to the 31st at SFO," the report added.
On the aviation front, the NWS foresees VFR conditions at most TAF sites throughout the TAF period, with some morning and nighttime fog expected at STS and APC. The winds are projected to remain light with variable directions. "VFR through the TAF period. Expect mostly light and variable winds through much of the day before winds turn northeasterly in the late afternoon," according to the NWS San Francisco for the vicinity of SFO.
