Latest news with #Crimmins
Yahoo
02-06-2025
- Climate
- Yahoo
When does the Arizona monsoon season start, and how much rain will the Phoenix area see?
Arizona's monsoon season starts in June and goes through the end of September, but that doesn't guarantee storms will pop up immediately. Most experts agree that there's no way to know exactly when black clouds, streaks of lightning and walls of dust will appear. Forecasting the monsoon is notoriously difficult. The June date is more for public awareness than a definitive arrival time for monsoon storms. 'We're really flying blind,' said Michael Crimmins, a climatologist at the University of Arizona. 'This feels like we could be two weeks out from the monsoon and still have no idea how it's going to turn out.' Every monsoon is different, and forecasting can be hit or miss. After a disappointing 2024 monsoon and an abnormally dry winter that deepened drought conditions, experts say Arizona needs rain. Here's what to expect for hopefully a more fruitful 2025 monsoon. The monsoon officially starts June 15 and goes until Sept. 30. Climatologists have studied the monsoon and variables that can influence a season's severity for decades, but correlations in the research are weak or inconsistent, according to Crimmins. For example, some research shows dry winters can be followed by wet summers. 'It's a weak correlation,' Crimmins said. 'We're not sure of the mechanism, and it's not stable over the last hundred years. There have been decades where that worked, decades where it hasn't.' There are also weak correlations between the monsoon and El Niño-Southern Oscillation, or ENSO, which is a natural cycle that reflects the relationship between ocean temperatures and atmospheric conditions stemming from the Pacific Ocean. El Niño, La Niña and a neutral period are ENSO cycles that can have a big effect on the weather, and these events provide some of the best insights for seasonal outlooks for the U.S. La Niña was present over the winter, which was partly responsible for abnormally warm and dry weather in the Southwest, but conditions have transitioned back to neutral heading into the summer. 'When you don't have either El Niño or La Niña with a neutral pattern, which is what we're at right now, we don't have much to go on,' Crimmins said. There is some evidence that El Niño can delay the onset of the monsoon, while a strong La Niña can trigger an earlier start. 'What I've seen in the climate models so far is they're shrugging,' Crimmins said. 'They're not leaning in either direction, so we're going to be week-by-week looking through June looking for a start.' Even when the monsoon arrives, predicting day-to-day storms and overall activity throughout the season is tricky. The season starts when a ridge of high pressure settles over the Four Corners region. The winds reverse, transitioning from westerly to southeasterly winds, pulling moisture into the Southwest from the Gulf of California, the eastern Pacific Ocean and sometimes the Gulf of Mexico. This high-pressure subtropical ridge slowly travels north during May and June, bringing heat and humidity as it moves toward the Four Corners. Meteorologists also watch hurricane and tropical storm activity in the eastern Pacific and warming surface temperatures in the Gulf of California, which can provide moisture for monsoon storms. Even when the monsoon ridge is positioned over the Four Corners, it doesn't guarantee storms, and forecasting is still complex. 'The monsoon doesn't mean we're going to get rain every day,' said Erinanne Saffell, Arizona State's climatologist. 'We can look a few days ahead, but it's a better understanding looking at the morning forecast and getting a sense of whether we have warm air rising, is there enough moisture in the atmosphere to create clouds and will the clouds get big enough to drop moisture?' Thunderstorms are created from warm air rising, or convection, while there is moisture in the atmosphere. Meteorologists will look at dew point temperatures to gauge how much water is in the air. If there is enough water in the atmosphere, clouds will begin to form. Moisture, warm air rising and instability in the atmosphere are the three main ingredients of a monsoon storm. But even if those conditions are present, storms may not leave the mountains. For monsoon storms to reach places like Phoenix or Tucson, weather systems in the mountains must push out air, forming new thunderstorms. Some storms die out before they hit the metro areas. In terms of actual rainfall, Arizona could see roughly two inches in lower deserts, including the Phoenix area, and up to 16 inches in mountain ranges. Metro Phoenix typically experiences about 10 days with measurable rainfall during the monsoon, while the higher mountainous areas see roughly 30 to 50 days of rainfall. The weather service projected Phoenix with a 43% chance of above normal precipitation during the monsoon, a 33% chance of near normal precipitation and a 24% chance of having below normal precipitation. For context, Phoenix had an average of 2.43 inches of rainfall during monsoon seasons from 1991 through 2020, according to the weather service. Other cities that leaned toward having above normal rain included Tucson, Flagstaff, Prescott, Kingman and Show Low, among others. The weather service recommended people check their local forecasts before going out and ensure they're signed up to receive weather warnings. This article originally appeared on Arizona Republic: Arizona monsoon season starts in June and goes through September
USA Today
23-03-2025
- Climate
- USA Today
Is springtime early or late in your area? Maps track flowers and birds.
Is springtime early or late in your area? Maps track flowers and birds. Show Caption Hide Caption How you can prepare now for spring gardening It might not be time yet to plant in your region, but there's still a lot of preparation that can be done in March. The calendar may say spring is here, but what is nature telling us? Bright new leaves on trees and spring flowers are arriving in waves across the U.S., and the birds are right behind them with early season migrants on the move over the last few weeks. Nationally, spring leaf out continues to spread north across the country, the USA National Phenology Network reported this week. In the eastern half of the country, spring is coming in fits and starts, arriving later than a long-term average in some areas and earlier in others, the Network said. Specifically, the classic signs of spring have been appearing for weeks across the South and are gradually inching northward on a map the Network uses to represent the very beginning of biological activity in the spring. Spring actually arrived a little later than usual in many locations across much of the southern half of the nation, where spring arrives first, said Theresa Crimmins, an associate professor at the University of Arizona and the network's director. 'Only little chunks of the country have had an early season,' she said, while places like Texas and North Florida have spring signals arriving a little later. However, Crimmins expects that to change over the next couple of weeks. They're watching the leading edge of the spring conditions moving northward into Illinois, Indiana and Pennsylvania, and she said it looks like the more northward locations are ahead of schedule. Spring indicators in southern Nebraska, the southern half of Iowa and creeping into northern Illinois, Indiana, Ohio and southern Pennsylvania, are starting next week and it will be ahead of schedule by a week to two weeks, she said. Leaves are budding out on red maples and silver maples, she said. In addition, sumac species have flower buds, and the lilacs are starting to wake up. At the Biltmore Estate in Asheville, North Carolina, spring blooms are a welcome sight after months of recovery from Hurricane Helene. The gardens are "bursting with color," according to the estate's latest bloom report and the daffodils are "especially brilliant." They're seeing one of the earliest blooming azaleas, the Cornell Pink Rhodendron, put on "a dazzling display." Overall, spring is a great time to get outside, and the center offers activities to get people on the move, Crimmins said. 'Getting outside and looking at plants and animals is good for physical and mental health.' Migrating birds on the move 'At this rather early stage of spring migration – numbers are close to the last 10 years' average,' said Andrew Farnsworth, a migration ecologist at Cornell University's Cornell Lab of Ornithology. The university hosts the BirdCast Migration Dashboard. In recent nocturnal migration metrics, Farnsworth said they've seen about 37 million birds move through Texas and 13-14 million move through Florida. So far the biggest nights across the U.S. have been March 13-14, with about 65 million birds aloft mostly in the upper Mississippi River valley and Midwest. March 17-18 and March 18-19 were also big nights, with "each seeing about 30-40 million birds migrating at night, mostly in the central and eastern U.S.,' he said. Coming soon to a sky near you: 500 million birds Waterfowl are also on the move, he said. 'So people will be seeing lots of geese and ducks moving generally north, as well as the arrival of great egrets and great blue herons,' he said. In Chicago, the last few weeks have been that odd time of year, said Matt Igleski, executive director of the Chicago Bird Alliance. Some birds that spend winters haven't left yet, but other new birds are arriving as they migrate through the region. It seems like this year's migration is arriving 'about on time,' Igleski said. Last week he visited a little forest area and saw his first fox sparrow of the season. On Wednesday, 'I had my first brown-headed cowbird singing outside the office,' he said. 'The red-winged blackbirds also are showing up. When you see those, you know that spring is showing up. We've been seeing them at the backyard feeders.' During a warm spell last week, the area had big pushes of sandhill cranes migrating through, he said. 'In the next few weeks, we'll see Eastern phoebes and golden-crowned kinglets.' See spring's arrival around the country Photo galleries from USA Network newspapers show the earliest spring arrivals in all their glory. Sheboygan, Wisconsin Stockton, California Cape Cod, Massachusetts Wilmington, North Carolina
Yahoo
22-03-2025
- Climate
- Yahoo
Is springtime early or late in your area? Maps track flowers and birds.
The calendar may say spring is here, but what is nature telling us? Bright new leaves on trees and spring flowers are arriving in waves across the U.S., and the birds are right behind them with early season migrants on the move over the last few weeks. Nationally, spring leaf out continues to spread north across the country, the USA National Phenology Network reported this week. In the eastern half of the country, spring is coming in fits and starts, arriving later than a long-term average in some areas and earlier in others, the Network said. Specifically, the classic signs of spring have been appearing for weeks across the South and are gradually inching northward on a map the Network uses to represent the very beginning of biological activity in the spring. Spring actually arrived a little later than usual in many locations across much of the southern half of the nation, where spring arrives first, said Theresa Crimmins, an associate professor at the University of Arizona and the network's director. 'Only little chunks of the country have had an early season,' she said, while places like Texas and North Florida have spring signals arriving a little later. However, Crimmins expects that to change over the next couple of weeks. They're watching the leading edge of the spring conditions moving northward into Illinois, Indiana and Pennsylvania, and she said it looks like the more northward locations are ahead of schedule. Spring indicators in southern Nebraska, the southern half of Iowa and creeping into northern Illinois, Indiana, Ohio and southern Pennsylvania, are starting next week and it will be ahead of schedule by a week to two weeks, she said. Leaves are budding out on red maples and silver maples, she said. In addition, sumac species have flower buds, and the lilacs are starting to wake up. At the Biltmore Estate in Asheville, North Carolina, spring blooms are a welcome sight after months of recovery from Hurricane Helene. The gardens are "bursting with color," according to the estate's latest bloom report and the daffodils are "especially brilliant." They're seeing one of the earliest blooming azaleas, the Cornell Pink Rhodendron, put on "a dazzling display." Overall, spring is a great time to get outside, and the center offers activities to get people on the move, Crimmins said. 'Getting outside and looking at plants and animals is good for physical and mental health.' 'At this rather early stage of spring migration – numbers are close to the last 10 years' average,' said Andrew Farnsworth, a migration ecologist at Cornell University's Cornell Lab of Ornithology. The university hosts the BirdCast Migration Dashboard. In recent nocturnal migration metrics, Farnsworth said they've seen about 37 million birds move through Texas and 13-14 million move through Florida. So far the biggest nights across the U.S. have been March 13-14, with about 65 million birds aloft mostly in the upper Mississippi River valley and Midwest. March 17-18 and March 18-19 were also big nights, with "each seeing about 30-40 million birds migrating at night, mostly in the central and eastern U.S.,' he said. Coming soon to a sky near you: 500 million birds Waterfowl are also on the move, he said. 'So people will be seeing lots of geese and ducks moving generally north, as well as the arrival of great egrets and great blue herons,' he said. In Chicago, the last few weeks have been that odd time of year, said Matt Igleski, executive director of the Chicago Bird Alliance. Some birds that spend winters haven't left yet, but other new birds are arriving as they migrate through the region. It seems like this year's migration is arriving 'about on time,' Igleski said. Last week he visited a little forest area and saw his first fox sparrow of the season. On Wednesday, 'I had my first brown-headed cowbird singing outside the office,' he said. 'The red-winged blackbirds also are showing up. When you see those, you know that spring is showing up. We've been seeing them at the backyard feeders.' During a warm spell last week, the area had big pushes of sandhill cranes migrating through, he said. 'In the next few weeks, we'll see Eastern phoebes and golden-crowned kinglets.' Photo galleries from USA Network newspapers show the earliest spring arrivals in all their glory. Sheboygan, Wisconsin Stockton, California Cape Cod, Massachusetts Wilmington, North Carolina This article originally appeared on USA TODAY: Early or late spring? Maps track flowers and birds.
New York Times
12-03-2025
- Science
- New York Times
Is It Spring Yet?
I'm micro-dosing my way through this wintry moment in American history, with the simple act of looking closely for each tiny hint of spring-to-be as my drug of choice. The nature-infused prescription was laid out for me in the new book 'Phenology' by Theresa Crimmins, a primer on the why and how of taking sharper notice of what happens when. 'I invite you to weave a practice of observing seasonal cycles of plants and animals into your life to contribute to science as well as soothe your soul,' writes Dr. Crimmins, director of the USA National Phenology Network, a plant ecologist and an associate professor at the University of Arizona, where the network is based. Her ask: Become an 'everyday phenologist.' After a focused look around outside at particular plants, sign in to the network's community science app, Nature's Notebook, and answer some questions about what you just saw. I could easily get hooked on missions like going to check for signs of life in the beds of ferns and bloodroot (Sanguinaria canadensis), or among the branches of the flowering dogwood (Cornus florida) or pussy willow (Salix discolor). Both the soothing part and the idea of making a contribution feel right just now. Phenology — from the same root as phenomenon — is about the timing of recurring seasonal events in plants and animals, 'timing that is a function of environmental conditions,' Dr. Crimmins said in a recent conversation. These events don't happen on the same date each year; the variables exerting the strongest influence on their timing, especially in plants, are temperature, day length, and moisture. As gardeners, our biggest question about timing right now is probably pretty straightforward, though: Is it spring yet? The calendar insists that the new season arrives in the Northern Hemisphere precisely on March 20. Instead we can piece together a more textured sense of its start from real-time clues: the first shoots poking through the soil surface, perhaps, or leaf buds swelling and gradually opening. Is the shadbush (Amelanchier) — always one of the first bloomers — awake yet, or have the magnolias' furry bud scales parted to make way for the blooms? Was it spring when the Eastern chipmunks, absent since late fall, were suddenly scurrying around in numbers the last week of February? Or will it not truly arrive until the first peeper peeps, or I see a mourning cloak butterfly on the wing — a species that overwinters as an adult even here in my Northern zone, hence its early flight? It feels as if each organism has its own answer — or maybe more accurately, holds a tiny but essential clue to the vast, intricately connected puzzle. Tuning into phenology is an exercise in attention — specifically in learning to catch the moments of transition in plants and animals, to discern one phenophase from the next, from the first leaf bud starting to burst open to the last leaf to drop in autumn. But even with plant species I have long grown, do I really know how to read their signals? In December, the network's website published its 240-page, lavishly illustrated 'Phenophase Primer' focused on the life stages of flowering plants, to help observers differentiate each subtle phase in their seasonal cycles, including flower development, from bud break to open flowers and pollen release right through fruiting. Even deciphering what exactly an open flower is can be bewildering. 'In some species, like a tulip, it's very obvious,' Dr. Crimmins said. 'But in a lot of others, like maples, it's not so clear. You might not even know there are flowers on a maple tree, for example. And so this document is just super detailed.' Take the red maple (Acer rubrum), a species native to the Eastern and Central United States, which flowers before its leaf buds break. The trees are polygamodioecious, Dr. Crimmins said, meaning that some trees bear only male flowers and therefore produce no seeds, some trees bear only female flowers, and some are monoecious, bearing both. And apparently individuals can change year to year. 'Some of our observers in Maine have reported that individual trees are monoecious one year and entirely female in other years,' she added. Any day now, I plan to get better acquainted with the one growing here. Repeat Observations on the Same Plant With most of the familiar community-science apps, we are simply asked to record a sighting. The network's process of sharing is a bit more rigorous, because it seeks not just a species' presence but its phenological status — trying to get at the 'when' of each unfolding stage. Some 2,000 species are in the network's database as candidates to be formally observed, 80 percent of them plants. What's sought are repeat observations on the same individual specimens, so a user must name the individuals they intend to observe ('backyard purple lilac,' or 'front yard mayapple'), enter them into their account, then answer a series of structured, species-specific questions every time they check on one. How to make observations is one topic that will be covered in a series of virtual events the network is hosting to celebrate National Phenology Week March 17-21. The network's phenological records are the modern-day Western science application of a practice of keen observation that Indigenous cultures worldwide have relied on throughout history. Among farmers and gardeners, inferences about connections made from such observations have likewise been drawn, yielding bits of folk wisdom — Dr. Crimmins calls them adages — like to plant peas when the peepers peep, sow corn when the oak leaves are the size of a squirrel's ear, or prune roses when the Forsythia blooms. More than 40 million records have been submitted since 2009 to Nature's Notebook, data that can be put to many uses. The observations add up to a leading indicator of climate change, and get at the existential question around each plant and animal species: Can it adapt, or will it perish? And will longtime partners in nature adapt in tandem? 'Interactions between species are at risk of disruption when their seasonal events are cued by different environmental drivers,' Dr. Crimmins writes. Many plants respond to warmth, but many insects become active according to day length. These mismatches can be hard on both: no food for the one, and no pollination services for the other. Though the pollen season has extended by more than 20 days since 1990, that doesn't translate to more opportunities for pollinators to gather resources and provide pollination services. The data show some intimate synchronicities increasingly at risk of becoming costly mismatches, Dr. Crimmins explains. The records also provided insights for a 2020 Penn State study into an edge invasive species in the East hold over native plants, for example. The invasives leaf out earlier and may hold their leaves longer, adding as much as 30 days' active growing time (in the northern end of the study area) to 77 days at the southern extreme. And then there are happy stories, too, of species 'shifting their phenologies in tandem,' Dr. Crimmins writes, recounting observations by the pioneering conservationist Aldo Leopold, author of the 1949 book 'A Sand County Almanac.' Between 1935 and 1945, he noted that Eastern phoebes would arrive back in southern Wisconsin about a week after the early-to-arise native Eastern skunk cabbage (Symplocarpus foetidus) started blooming. The plant's foul-smelling flowers attracted insects that the returning phoebes happily devoured. This duet can still be witnessed today, though earlier than in Mr. Leopold's time. Watching Spring Roll Up the Country So when is it spring, anyhow? The network's records can help forecast its timing, and a popular website feature displays animated maps showing the gradual arrival rolling up the country, week by week. The maps indicate when different locations have experienced enough warmth to achieve conditions associated with spring's historical start — both leafing out, and the earliest blooms. In her Tucson yard, Dr. Crimmins is gathering clues on spring's progress as she makes her focused passes twice-weekly through the space, adding fresh observations into the app, and deepening her knowledge, too. 'I have a strong biology background and I think I know what's going on,' she said. 'But I have witnessed so much more incredible detail unfolding right in my midst, and learned a much deeper appreciation for these different organisms and what they do.' Observations that indicate the co-occurrence of animals and what they are doing in relation to plants always feel like a bonus round. A female broad-billed hummingbird chose Dr. Crimmins's back porch as its nest site three recent years running, darting to sip at the nearby yellow bells (Tecoma stans). Even absent 'mama hummingbird' some days, though, the scene is one of bounty. 'Seeing that progression, it's always surprise and delight, to discover what has happened since the last time I peeked,' she said. 'It's kind of reassuring to see everything goes on, even though we're not paying attention. And so when we do pay attention, there's a lot of gifts for us to receive.'
Yahoo
30-01-2025
- Climate
- Yahoo
Missed it by a day: Why has the 52-year-old record for no rain in Phoenix lasted so long?
Phoenix finally got a taste of rain Wednesday, but just barely. A scant 0.01 of an inch was recorded at Sky Harbor Airport, ending the city's 159-day dry streak, the second-longest on record. While Phoenix is known for its arid weather, receiving 7.22 inches a year on average at Sky Harbor, this dry spell stood out from the rest. "It doesn't rain here a lot, but we've got these two seasons that usually will cut these dry spells down," said Michael Crimmins, a climatologist at the University of Arizona. "Overall, this winter has been extremely dry, but Phoenix really stands out as having the longest dry stretch." The streak ended just one day shy of tying the current record of 160 days without measurable rain in Phoenix, a record set in 1972. And it's still dry. With the .01 of an inch recorded Wednesday, Phoenix is still 2.68 inches below average since Oct. 1, the start of the water year. Here's everything to know about Phoenix's dry spell, why the record is so hard to break and how other cities across the Southwest are faring during this unusually dry winter: Topography and seasonal weather patterns play a big role in Phoenix's dry climate, setting the stage for long dry periods. "Phoenix is standing on its own a little bit in Arizona. Phoenix is low desert and away from the mountains," Crimmins said. "It's easier to get precipitation in the high country." Phoenix is surrounded by mountain ranges that can block moisture from reaching Phoenix. It's also far from large bodies of water that provide a consistent source of moisture to fuel precipitation. Phoenix's low elevation prevents atmospheric lifting mechanisms that produce precipitation in higher elevations. The rains can travel from the mountains, but it doesn't always happen. During the monsoon, the sun heats the mountains first and spurs conduction for storms. But as the systems descend, dry air at lower elevations and higher temperatures can cause a storm to die out before it hits the valley. Low humidity and high temperatures also play a role, with extreme heat and dry air causing rapid evaporation in the Phoenix area. It's a dry one: It's now a La Niña winter, but it's a weak one. What to know about it in Arizona But why is the dry streak record so resilient? How has it stood for more than 52 years? Although rain is less common in Phoenix than in much of the country, it typically measures a few inches of rain every year during the "wet" seasons in the summer and winter. "We've got the monsoon in the summer and the winter weather pattern that can bring some precipitation," Crimmins said. "So that's just the seasonal cycle here — you get some weather system on the edges that usually breaks up the dry spells." But this year was different. The monsoon began early with some showers in June but largely died out by the end of the summer. The last day of measurable rainfall was Aug. 22, beginning the second-longest dry streak on record. "The dry spell was a byproduct of the monsoon not being great. We were already in trouble when the monsoon started to dry up," Crimmins said. Arizona can get some moisture from fall tropical storms to the south, but September and October remained extremely hot and dry in Phoenix. By December, Crimmins said the winter weather patterns that can bring precipitation south remained over British Columbia, one of the early signs of La Niña conditions. La Niña is a climatological event that typically brings drier and warmer conditions to the Southwest, stemming from colder-than-normal ocean temperatures in the eastern Pacific. This dry spell was also unusual because of its timing. Dry spells in Phoenix tend to occur in the winter and spring until the monsoon begins. "It's totally normal to have 90-day dry spells in the spring until the monsoon kicks off," Crimmins said. "Phoenix recorded zero precipitation from Sept. 1 to now, and that hasn't happened before in the records at Sky Harbor." Even during historically dry years, there were always two or three days that would break up the dry spells, according to Crimmins, making lengthy, 140-day-plus dry streaks uncommon. Rising heat: With little rain, long heat waves, 2024 will end as the warmest year on record in Phoenix Phoenix isn't the only city with an uncharacteristically dry few months. Las Vegas' dry streak is even worse — Wednesday marked the city's 200th day without measurable rain. This is also the second-longest dry spell for Las Vegas, but the longest streak is still a ways off. The current record was set in 2020 with 240 days. It's been a dry winter across Arizona. Flagstaff has had one of its driest cold seasons on record with just 5 inches of snow since Oct. 1, compared to a 47.8-inch average for that time frame. Yuma is also experiencing an ongoing dry spell at 174 days without measurable rain, but that does not come close to its record: 380 days, more than a full year with no rain in 2002 and 2003. While Phoenix's dry spell has ended, residents likely won't see much rain in the coming months. "Every day we get closer to spring, the chances of our precipitation events start to drop off," Crimmins said. "This is not a drought buster by any means. It breaks up the dry spell record, but it's not doing a lot of work otherwise. Hayleigh Evans writes about extreme weather and related topics for The Arizona Republic and Email her with story tips at This article originally appeared on Arizona Republic: Why does the rainless record remain unbroken in Phoenix?
