. >> let's begin with our meteorologist rob mayeda. we cover these fires every year, rob, but the air quality is the other big story tonight. what comes next? >> yeah. it's been getting progressly wor ively worse. the air quality especially around the lore peninsula into the south bay, it's dropped off to the unhealthy range at times. the ash, the plume is still showing up on the radar. that's what you're seeing moving down on the ocean-facing side of the santa cruz mountains. on the other side of the santa cruz mountains, those red dots you see there from redwood city to fremont to san jose, that's beyond spare the air bad. that's unhealthy for all groups. locally at times we've seen that drift to very unhealthy around redwood city and palo alto. the other complex fire in the south bay putting out a lot of smoke. that's another region towards vacaville where we're seeing unhealthy for all groups air quality. much like the north bay fires that led to the highest pollution in the last 20 years. we could be looking at these areas of very

rob mayeda joining us to break it all down.t's a lot. >> the microclimate weather alert you see over my shoulder for red flag warning for lightning, and record heat, another criteria, and earlier this afternoon had unhealthy air quality which is the third thing to trigger the alert. san francisco. pretty view post sunset, had temperatures earlier in the 80s. cooled off nicely. despite climbing to the 80s. wind at 25 miles an hour. dublin is still 87 after high of 106. similar temperatures expected tomorrow and smoke advisory for the tri-valley, and san jose had a high of 100, it's still 80. air quality, localized smoke advisory due to new lightning-sparked fires around the east bay hills, diablo and around san jose and sunol too. we'll see the higher smoke numbers east and south bay. we have to watch closely. towards monday, numbers may come up a bit. livermore and pleasanton were in the red this morning. things have improved with more wind. next round of showers, right now had isolated thunder, starting to cross the coast nort

>> let's bring in jessica and rob mayeda. we do this every year, for the last ten years seemingly, and people might want to start about thinking where to buy their homes, if we are doing it in solano county and in different areas, we may want to think about it year after year because it's not getting any better. >> yeah, we are seeing what appears to be moderate drought across much of the region, coming together to accelerate the wildfires in terms of how fast they are growing and spreading, and let's take you outside to san jose right now. what you are seeing is upper level smoke. the air quality, as chris pointed out, better today, but let's take you to the smoke plume. this is the big towering clouds you see in mt. hamilton. we are seeing the most active

rob mayeda, so hot outside. and even when the temperatures go down next couple of days, it's not that much. >> and that's sea level. just a few degrees of cooling. many of our microclimates we think of location by location but can be also elevation. hills and mountaintops with warmer, drier air at night versus cooler air that sinks to the valleys. seeing a combination of hot, dry conditions and intensities of wildfires building thunderstorm-like structures outside. santa cruz mountains. pyrocumulus top, you need a lot of fire intensity, warm air rising rapidly. gets up, collapses down, leads to wind shifts at surface. and when winds aloft are that strong, seeing so much ash around the bay area, these structures have been with all of the major fires, increasing the rates of spread and transporting ash far downwind. that's the radar scanning there. santa cruz. point to point, upper 80s, mid-90s. humidity down to 15% in solano county and napa county. extreme conditions. more wind tonight. good news for cooling arou

. >>> rob mayeda joining us now. rob, the smoke and the haze from the three fires burning still strong in some areas. when can we see some relief here? >> yeah, probably at thisroblem fire complexes to the north, east, and to the west, depending on how the wind is configured, almost any direction brings us the smoke. but the late day sea breeze did make an impact. still seeing winds inland towards fairfield of 20 miles per hour. as we head towards tomorrow, we'll see a similar pattern develop as the winds lighten up overnight. areas of smoke may fill in once again around thered, the unhealthy air moving towards the east bay valleys and in towards the central valley. i think it will be the inland east bay and the south bay that sees the worst of the air quality. another spare the air day tomorrow and then as we head back to the week, get ready for a warm-up. signs are there that we're going to see high pressure strengthening with mid to upper 90s making a comeback. how this might impact the rest of your weekend coming

. >>> let's bring in meteorologist rob mayeda. rob, we heard one of the fire captains down in santa cruz say that the weather allowed them -- mitigated a little bit some of that fog and allowed them to get a little bit of a handle today. >> and we saw a little bit of that last night at 11:00, how the fire was finally laying down. we had the cooler marine air for elevations below 1,500 feet so that did help on the ocean-facing side of the czu fire there. but this hour typically we scan for raindrops in the skies. what it's finding here as we go to the radar map is ash and embers suspended in the updrafts of this massive fire complex, the scu fire comment plex. when you're seeing that much reflectivity on radar associated with a wildfire, it means there's a lot of material being tossed up into the sky from below. so a very active scene there. temperatures in the 80s and we have winds out of the northwest at 11. 77 degrees near the czu complex. different story in the north bay. 90-degree temperatures and the winds have picked up, arou

meteorologist rob mayeda is here. rob, what are we looking at for the next couple of days? >> well, right now at least the good news, terry did mention it. we're not seeing as much wind as we had earlier today and the lightning that sparked many of these fires has for the most part moved out. temperatures still pretty warm. 79 degrees. the wind is relatively light at both the hennessy fire and the gamble fire, which has burned right down to the edge of lake berryessa. let's give you the time lapse looking back on the hennessy fire. notice that smoke plume being pushed all over the place by strong outflow winds moving away from thunderstorms. that's the reason the fire took off today. you can see the north push of that fire with strong, gusty winds, then back towards the camera as the winds begin to change direction during the day. as the winds have backed off a little tonight and the thunder and lightning have moved out, that is good news short term for firefighters as we shouldn't see any more lightning-sparked fires tomorrow. but the challenging conditions will be the ter

let's bring in our meteorologist rob mayeda. a couple updates from cal fire, significant growth in the past 24 hours. this stood out for us. don't know where the evacuations will lead next, because they're not quite sure where the fire line is going to go. >> yeah, and we were noticing this last night at 11:00, to see the structures on radar, active as they were and in the middle of the night. that was a bad sign but seeing some aggressive growth. growing very tall, like we've been seeing this afternoon, once again around the santa cruz mountains. i want to show you this time lapse. that is a very strong, intense fire. a lot of heat racing into the atmosphere creating that cloud-like top. once that collapses down, that can send wind down in all directions. when you're talking about how to stage evacuations, that's a challenging environment. that's just a 15-minute time lapse. you see how many changes are happening. this is looking down toward where jodi hernandez is. this is a look towards the lightning complex. we're starting t

rob mayeda, nbc bay area news. >>> what's happening with the prison population? the new recommendation from a coalition of lawyers, activists and medical experts says to cut the prison population by half. today, prison reform advocates slammed prison administrators who say they delivered covid-19 to san quinten, when they transferred infected inmates there. that happened may 30th. by august, more than 2500 inmates, guard and staff contracted the virus. the department of corrections is working to reduce the inmate population statewide. >>> let's bring in chief meteorologist jeff ranieri. it's going to be a hot week. >> yeah, we're definitely going to see that heat turned up once we hit friday's forecast. so i wanted to go ahead and take us outside live and show you the changes we had today. a little more lazy off towards the distance as the heat often cooks the pollutants in the atmosphere. you'll see here in concord, as high as 95 degrees today. right now 89 and eventually cooler 60s around midnight. besides the heat, there's something else i wanted to let you kn

rob mayeda, how are things looking right now? we saw walnut creek not too great. how about the rest of the bay area? >> it's the time of day we begin to see the sea breeze push smoke of the smoke of the central bay into contra valley. palo alto above 100 and the sea breeze pushes some of the smoke out. you did see the august complex fire towards the north in mendocino county the smoke is moving down into the north ba o tomorrow morning i think some of that will spill locally south as the hill tops winds headed towards tomorrow morning. the spare the air alerts have been ex-tended all the way through tuesday as we look at more locally unhealthy air at times for the north bay and inland east bay and we'll talk more about air quality changes as we go through the week and mid to upper 90s returning to the seven-day forecast. a look at that coming your way in eight minutes. >>> our free alerts and weather alerts along with up, the race for a vaccine against covid-19. >>> and a major airliner is changing the way it does business. what united will longer charge for. it's

our meteorologist rob mayeda is with us. what's going to happen next, rob, with all of this? not just the heat. there's so many other factors happening. >> yeah. the weather that really started these fires by estimates, 350 lightning-sparked fires in just the last 72 hours. right now it's the heat, dry condition, and the wind which is making for the convergence of some really intense, explosive fire development around the bay area. speaking of the north bay, this is the gamble fire there on the edge of lake berryessa. you can see the plumes of smoke erupting upwards during the mid afternoon heating. it almost looks like a thunderstorm developing. on the tops of these, the pyrocumulus clouds develop when the updraft starts to get very strong. the tops condense over to a cloud and sometimes as though columns collapse back down, that could lead to sudden wind shifts at ground level. look at the conditions in sonoma and napa county. humidity down to 13% or 17%. wind gusts to 20 miles per hour. that's as extreme as wildfire weather can get. you got the triple threat of heat, dry c

heat, lightning and wind and the dry conditions, a lot of questions for our meteorologist, rob mayeda. rob, what are you seeing in the next few hours and overnight going into tomorrow? >> yeah, we're just passing sort of the critical peak heating events of the afternoon. and what you have been seeing all around the bay area from north, east and south is really explosive wildfire development. anytime you see those cumulus cloud tops like you're seeing in the north bay, that lets you know that the fire intensity below is extremely strong, generating its own wind and creating that cloud-like top. let's give you some time lapse. this is on the gamble fire. one-hour time lapse. the pyro cumulus top showing there. more wide angle view coming up. we'll show you those cloud tops, again, if you're far away, that looks like thunderstorms. what that tells us, though, is extreme fire behavior. also casting on radar to ash falling out of the east-southeast moving away from the gamble fire and hennessy fire. look at the temperatures, 90 to 102 degrees. humidity at 12%. winds at 10 to 18 out there i

. >>> let's bring in rob mayeda. rob, areas of concern for this weekend, one, the heat.wo, the air quality. and then of course that's a potential for lightning strikes to be coming inunday oral the t those things. and air quality at least at this hour, we've seen it improve just a little bit. we had that late evening breeze which picked up, actually helped to clear the skies a little bit around san francisco. we'll show you the latest aqi index numbers. this is as good as it gets. but it's still spare the air bad. we saw levels technically three times as high as the standard that would normally trigger a spare the air day. that was in santa cruz and around the tri-valley. tomorrow straight on through the weekend, it is a spare the air weekend. we will see this air pollution likely settling in, draining down from some of the higher elevations down into the valleys for the morning. plan on more of that smoke filling in again for saturday. you can see the worst will be the inland east bay and santa clara valley. slight cooldown in temperatures, you did hear on some of the p

rob mayeda joins us. will we get any relief? >> we will get relief when the sea breeze picks up in san francisco. we saw moderate air quality but it pushed the smoke to concord. notice the banner there, spare the air alert extended to tuesday. what typically happens mid-afternoon and evening. we see the onshore winds pick up. as you look at this time lapse into tomorrow morning, looking at this computer model, the north bay continues to see at times pockets of air while the majority of the really bad smoke from the scu fire east of san jose is heading on of to the central valley. tomorrow morning we're likely to find increased air pollution into the north bay. we're watching for the potential for more heat and less of that marine air influence, which could make things a little tougher in terms of fire danger and could also lead to, perhaps, some heat advisories later this week. we'll have a closer look at the seven-day forecast ahead. >>> let's get you up to the spoo ed on the latest numbers. crews are making progress on the lmu

. >>> rob mayeda, a lot of storms lined up out there. >> yeah, and this particular storm too going from category 1 hurricane to still at 11:00 a tropical storm isaias, which is still off to the west of nassau, moving away from the bahamas. we think at some point overnight it may briefly strengthen back to a category 1 hurricane and head up the florida coast. if the center can manage to stay offshore it might hang on to more intensity as a strong tropical storm or category 1 hurricane as it heads north. eventually up towards jacksonville and perhaps the carolina coast heading into monday morning. here, nothing tropical about that view, a sign of the fog and the low clouds blocking the view around san francisco right now. temperatures in the 50s, mist and drizzle likely in parts of the coast and around san francisco for the morning. around walnut highs around the 90s. notice in the seven-day forecast, temperatures are going to come down quite a bit by the middle part of the creek, including around walnut creek. san jose 62, highs earlier in the 80s. overall tomorrow, similar temperatures

. >> let's bring in rob mayeda. we're talking about wind direction and smoke. even right now in marin county, a lot of that smoke going into mill valley and those communities. what's happening in the east bay and north bay, robbie? >> what we're seeing in san francisco is part of that fire in marin county drift into the west and the bay and into marin county. meantime the fire generating the most smoke is the scu fire east of san jose. one of the signs we've been watching are those big column plumes. the hotspots extending high into the spheatmosphere, and the win inside there can really lift some big pieces of little leaves and ash miles away from the actual fire site. we're taking storm ranger, 86 degrees. a wind shift and the fire is moving a little bit more south than it was over the last 24 hours. cooler temperatures but added wind, still not a good combination in the santa cruz mountaines. in the north bay, winds out of the southwest. the bay area radar, including storm ranger is scanning multip multiple wildfire plumes. after this, that smoke tunnels dow

i think rob mayeda is going to give it auy wind surfing. >> probably not a good idea.bay be doing as a tropical storm is spinning off the coast. let's t latest on isaias. yes, a tropical storm by 5 miles per hour. it's been going a little back and forth with category 1 status to tropical storm status, and that's where it is right now. we do think it's going to approach the coast more or less over the next 24 hours, kind of run parallel to the florida coastline. you see it there briefly, strengthening back to a category 1, offshore west palm beach. and then possibly during the day tomorrow, moving up the coast, passing melbourne and actually close to cape canaveral as the crew dragon now, the splashdown is being plan odd about the gulf of mexico side by florida out there, by pensacola or panama city on the opposite side of florida. we'll still have a tropical storm or maybe category 1 hurricane that is slowly moving up the florida coast this time tomorrow. now closer to home we have our summer microclimates under way. we have numbe good strong sea breeze there. and if you want tempera

and this photo from our weekend meteorologist rob mayeda. incredible shots out there. let's bring in our chief meteorologist jeff ranieri. we were actually communicating via twitter tonight, jeff. it was so cool to see everyone's photos. >> yeah. you got a cool picture from the parking lot out there at our studios. i got some out here at home. it was just phenomenal. we had some subtropical moisture, a little bit of humidity rolling in, and that helped to bring in that cloud cover. that just changed up the day for us. now, thunderstorms are way off to the south, but we have a slight chance of that as we head through tomorrow morning. but the big, big story that's going to impact all of us is the heat. so i wanted to start off tonight. to put it into perspective for you, a look at the hottest all-time temperature in august for livermore. you can see that was 112 degrees set back in 1998. now, are we going to hit that tomorrow? i have increased the daytime high. right now i'm calling for 108. so we'll be close, but i don't think we'll hit an all-time record for august. y

rob mayeda is joining us now to talk about it. >> yes, it really is a day-to-day challenge of our weather forecast. the smoke gets imported into the bay area right now. active fires into the north and how it gets exported out during the afternoon. the sea breeze picks up in the south bay. san francisco, fog or smog at times are back in san francisco. not too much smoke right now. a lot of that got pushed to the east. we'll find some drizzles and mists possible around san francisco in the morning. san jose, hazy skies, 66 degrees. we are in the 70s and 80s. today likely the coolest day we'll see for the next seven, we'll take you over to walnut creek. temperatures starting to cool off. 67 degrees. 89 degrees in the tri-valley today, currently 71. the worse of the air quality is pretty close right there. dublin and livermore and pleasanton. we do get the day breeze sea breeze. that's picking up in the afternoon. but, you may not get a lot of sun. notice the future cast here on the coast around half-moon bay, low clouds around the morning and across the inner bay. that should keep temperatur

. >> let's turn it over to rob mayeda to talk about the next couple of days, just really critical for the next coppuple days and you say maybe more lightning storms? >> that is something that is on the long-term horizon. we may see more tropical sunday. so stay tuned, we'll see that scenario plays out, something to watch closely. tonight, just rough fire conditions across the higher hill tops. temperatures are cooling down. so here's the good news. excessive heat warning is done, that ended at 9:00 tonight. temperatures are reflecting a shift now as a sea breeze picks up. temperatures dropping even towards fairfield. there you see the wind speeds. but the good cooling wind isn't so much higher up. we're seeing dry end there is on the czu complex fire. big towering plume of smoke lit by the fire below. it looks daytime strong. and that's the problem. fires burning with that type of intensity at night have a rapid rate of spread. this particular fire could be heading down to the san lorenzo valley. and to the east, a fire near the summit so with those fires being active as they are, it'