Wednesday evening First Alert weather forecast with Paul Heggen - 1/17/24

OK, let's check in with first alert. Chief meologist Paul Hagan and some more. I guess mushroom weather is headed our way right now. I mean, we laugh about it, but it is. It can be dangerous. Absolutely, and we've seen how quickly they can sprout up after just one storm. And what an ominous name. The Western destroying angel. I don't know who came up with that one, but I'm not going near it. Yeah, kudos to them for a very descriptive title. Let's take a look at the weather pattern is going to cause those favorable growing conditions for all sorts of fungus as we look at a beautiful sunset this evening. Looking towards downtown San Francisco. Just a little high cloud cover reflecting those last rays of sunlight. We're going to see some locally dense fog developing tonight through the first half of Thursday. That's going to be tough to shake until about late morning. Early afternoon at the latest, that fog should finally lift and then we'll see a lot of cloud cover farther up in the atmosphere. Those clouds will yield some showers beginning on Friday. In fact, a wave of heavier rain is going to be moving through the Bay Area Friday often on showers Saturday, including for the Niners game. As we talked about earlier, Saturday evening and then more heavy rain in the forecast by Friday, so let's take a look at all of those various factors, beginning with the fog that is going to be spreading out as we head through the rest of tonight. The really dense fog is going to be once again through the Central Valley, but there's going to be some of that streaming through the delta into the inland valleys of the East Bay and the North Main, even some fog surrounding the Bay itself. Gradually that is going to lift, but you still see plenty of the duller shade of gray here on the map that indicates the clouds that are farther up in the atmosphere, and those are going to be pretty tough to shake. It's going to be a little higher up during the sunshine Thursday afternoon. Then here's our chance of showers approaching the coast already. Friday morning, more likely that the widespread rain is going to move in Friday afternoon, continuing Friday evening. I think the Friday afternoon and evening commute is going to be pretty sloppy with some heavier downpours in that time frame, but it's unlikely to last long enough to lead to any significant flooding threat. We're going to see those showers lingering on Saturday, but it's a lighter shade of green for most of the Bay Area Saturday, indicating that often on shower activity, not a complete washout, but still any outdoor plans this weekend. Be very flexible with those. Have an indoor alternative in mind, or make sure you bring the rain gear. As we look ahead to the Niners game Saturday evening, and then this next wave of heavier rain is going to be moving in on Sunday. How much rain are we talking about? The first one anywhere from a little over a quarter inch of rain to over one inch of rain for parts of the North Bay that falls Friday into Friday night. But with those subsequent waves of rain headed through by the time we get to late Monday, we're talking about between an inch and a half and four inches of rain on a widespread basis across the Bay Area, and some of the mountainous terrain. Could easily pick up more than six inches of rain, and that's enough that the weather prediction center, while it's only outlined a marginal risk of excessive rainfall, basically categorizing the flooding threat. That's for Friday in that first system, with more rain falling on already wet ground, that goes up to a slight risk. One category higher, especially for the North Bay by Sunday, with that threat likely continuing into Monday and that Sunday and Monday system is going to be associated with an atmospheric river, but towards the low end of the scale. AR1 on our one to five scale, which means for the most part, it doesn't bring any significant threat of widespread flooding, but we're talking about several days of rain that does ramp up just a little bit. Looking outside from the Mark Hopkins Hotel right now, we're waiting on the rain to arrive. Temperatures are mostly in the 50s, but it's still 60 degrees in San Jose. It's only about 49 degrees right now in Santa Rosa. We're going to see temperatures dropping down to the low to mid 40s by early tomorrow morning, just a little bit above average for those inland spots because of the influence of the cloud cover. High temperatures tomorrow going to warm up to at least a few degrees. Above average, the warm spots are going to be in the Santa Clara Valley. You're going to be well above normal into the mid 60s by tomorrow afternoon. Not nearly that warm inland in the East Bay because the fog is going to be more of a factor. Keeping your temperatures in the 50s. By the way, we're talking about a lot of low to mid 60s across most of the Bay Area, but only a 10 degree difference between the coolest spots on the map and the warmest locations in the Santa Clara Valley temperatures in the North Bay should be warmer than today. Again, I think the fog is going to lift as we head towards about midday, and even that filtered sunshine should be able to warm us up a little bit. Let's check out the seven day forecast, which includes a lot of rain chances farther down the line, beginning Friday and then off and on showers on Saturday with more rain. Continuing Sunday and Monday at this point, we're optimistically forecasting a little dry break to take hold by Tuesday and Wednesday of next week, but it's a long way down the line. It's very possible the rainy pattern even lingers towards midweek next week.