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Monthly Archive | CLIMAS

Monthly Archive

Winter of Weather (2014-2015)

Monday, February 23, 2015


This mini-segment was taken from the Jan 2015 SW Climate Podcast

Image & Story Credits

El Niño Tracker - Southwest Climate Outlook February 2015

Friday, February 20, 2015

Originally published in the Feb 2015 CLIMAS Southwest Climate Outlook

2014-15 El Niño Tracker

A definitive 2014–2015 El Niño forecast remains elusive. Weak El Niño conditions have continued in 2015, but recent backsliding in SST anomalies (Fig. 1), especially in the Niño 1-2 regions (Fig. 2), along with the ongoing lack of coordination between atmospheric and oceanic conditions, give little confidence that the 2014–2015 event will be characterized as anything more than a weak El Niño.

Image Source - Australian Bureau of Meteorology

Image Source - NOAA-National Climatic Data Center

The most recent forecasts dialed back the probabilities for El Niño this winter and spring, and hinted we could swing to ENSO-neutral by late spring. On Feb. 5, the NOAA-Climate Prediction Center (CPC) issued another El Niño Watch, maintaining a 50–60 percent probability of an El Niño event, most likely a weak event extending into late winter or early spring. On Feb. 10, the Japan Meteorological Agency continued its assessment that El Niño conditions had been present in the equatorial Pacific for multiple months. They noted uncertainty as to the length or intensity of an El Niño event, with emphasis on a weak event that would transition to ENSO-neutral by early spring. On Feb. 17, the Australian Bureau of Meteorology kept its El Niño tracker status at neutral, given the fade in SST anomalies and lack of clear atmospheric signal. On Feb. 19, the International Research Institute for Climate and Society (IRI) and CPC reasserted a 50–60 percent probability of an El Niño event (Fig. 3).  Given the declining SST anomalies and lack of clear atmospheric signal, they characterized this event as a “borderline El Niño” that would last through early spring 2015. The North American multi-model ensemble shows a weak event that extends into summer (Fig. 4). This graph highlights the possibility of a continuation of a stronger El Niño signal into 2015 (a possibility that was discussed in the IRI-CPC forecast event), depending on how ocean and atmospheric conditions progress from summer into fall.  The dynamical models currently favor a resurgence of El Niño conditions, while the statistical models suggest an ENSO-neutral state.

As with last month, we remain in “El Limbo” with seasonal forecasts still indicating an increased chance of above-average precipitation across the Southwest for winter and early spring. These forecasts are linked to the projected influence of El Niño conditions, but impacts associated with weak El Niño events are less certain than those associated with moderate or strong events (past weak events have brought both dry and wet conditions to the Southwest during the winter). A number of storm events have moved through the Southwest in late 2014 and early 2015, but conditions have not converged to produce widespread above-average precipitation over an extended period of time.  For this El Niño event to be of some utility in mitigating longer-term drought conditions, we would hope to see this convergence this winter into spring, with more widespread and sustained precipitation events.

Image Source - International Research Institute for Climate and Society

Image Source - NOAA-Climate Prediction Center

Notes from an Applied Climatologist: East/West Cold/Hot Dichotomy Q&A

Friday, February 20, 2015

Originally published in Feb 2015 CLIMAS Southwest Climate Outlook:

Why has it been so cold on the East Coast, and so warm in the Southwest?  Where does this fit into climatic patterns?  And is this extraordinary or just variability?

The weather pattern across the U.S. has been pretty extreme over the past weeks, with record cold and snow across the East and record to near-record warmth in the West. Why is the country so divided? In short, a wavy jet stream is to blame (Fig. 1). This high-altitude stream of fast-moving winds has been carving a circuitous path around the globe for much of the winter. The path of the winter mid-latitude jet stream around the globe (in both hemispheres) can give a good indication of where storms are tracking and where warm and cold spots at the surface are emerging. If the jet stream gets stuck in any position, then places getting storms can continue to see a parade of storms, while warm and dry places stay warm and dry. 

Image Source - NOAA-Earth Systems Resarch Laboratory (ESRL)

This winter, the mid-latitude jet stream in the Northern Hemisphere has been very wavy, or meridional [1], with ridges—large-scale bulges—to the north and troughs to the south. Ridges are associated with warm and dry conditions, while troughs are associated with cold and possibly snowy or rainy conditions. Over the past several weeks, this warm West/cold East pattern has dominated, with a persistent ridge of high pressure across the West and a very cold trough across the East (Fig. 2).  Last year, similar conditions drove California and much of the Southwest deeper into drought and unleashed record-setting cold [2] in the eastern U.S. This year, these conditions have broken down on occasion, allowing for storms to bring some precipitation to the West and for the East to warm up for brief periods.

Researchers are trying to determine why this dichotomous pattern has emerged and persisted over the past couple of years. Some climate scientists propose that a warming Artic and declining sea ice [3] are contributing to an increasing frequency of wavy and stuck jet stream events. Other scientists argue that warming water [4] in the tropics and shifts in tropical convection are at play in impacting the winter jet stream pattern. This winter appears to be a complex interaction of many different factors [5] and will be studied in more detail over the coming year to see how it fits into these active areas of research.

Image Source - NOAA-ESRL &

Additional Resources

  1. Meridional: In meteorology, a flow, average, or functional variation taken in a direction that is parallel to a line of longitude; along a meridian; northerly or southerly; as opposed to zonal. 
  2. U.S. temperature extremes and the polar jet stream
  3. Evidence for a wavier jet stream in response to rapid Arctic warming
  4. Record-breaking winters and global climate change
  5. Synoptic Discussion - January 2015

Climate Summary - Southwest Climate Outlook February 2015

Thursday, February 19, 2015

Originally published in the Feb 2015 Southwest Climate Outlook

Precipitation: The borderlands region of southern Arizona and portions of southern, central, and northeastern New Mexico all recorded above-average precipitation, but most of Arizona and New Mexico received average or below-average precipitation in the past 30 days despite a number of January storms (Fig. 1).

Images Source - NOAA/NWS - Advanced Hydrologic Prediction Service

Temperature: After a record year for Arizona (and a top five year for New Mexico), temperatures remained well above average in the Southwest over the past 30 days (Fig. 2). This means pleasant weather compared to the frigid and snowy conditions in the eastern and central U.S. but has implications for drought, water storage, phenology, and human health.

Images Source - High Plains Regional Climate Center

Snowpack: Snow water equivalent (SWE) is low across Arizona, ranging from 1 to 62 percent of average. New Mexico is also quite low, ranging from 32 to 85 percent of average (Fig. 3). Well above-average temperatures are a significant factor, as many precipitation events fell primarily as rain, with the snowline as high as 8,000 feet in some cases.

Images Source - Natural Resources Conservation Service - NRCS

Water Supply: In January, total reservoir storage was 45 percent in Arizona (compared to 46 percent last year) and 23 percent in New Mexico (same as last year) (see reservoir storage on page 5, for details). Unseasonably warm temperatures mean more precipitation falling as rain and an early start to snowmelt runoff. This may increase reservoir storage in the short term, but losses to evaporation/sublimation may counter these gains in the long term. 

Drought: The 2014 monsoon, along with an active eastern Pacific tropical storm season, provided temporary relief to regional drought but did little to change long-term conditions. The U.S. Drought Monitor (USDM) expanded the drought designations in Arizona and New Mexico following variable and generally below-average precipitation (Fig. 4). 

Images Source - National Drought Mitigation Center

Plant Ecology & Human Health: Above-average temperatures and winter rains jumpstarted plant activity across the region. Plant enthusiasts are anticipating a banner year for wildflowers, but this comes at a cost. Pollen counts are already at levels that affect most allergy sufferers, a pattern almost certain to extend through the spring. 

ENSO: The NOAA-Climate Prediction Center maintained a 50–60% probability of an El Niño event this winter and into early spring.  Declines in sea surface temperatures, especially in the Niño 1-2 region, were partially offset by increased atmospheric activity.  Consensus is on a borderline weak event extending into early spring, with the potential for a resurgence of El Niño conditions later in 2015 (see ENSO tracker on page 3, for more details).

Precipitation & Temperature Forecasts: The Feb. 19 NOAA-Climate Prediction Center seasonal outlook continues to predict above-average precipitation through the winter and into spring for most of the Southwest (Fig. 5). It remains to be seen how much this forecast depends on El Niño conditions, which are currently trending weak to neutral. Temperature forecasts remain split across the region, with elevated chances for above-average temperatures along the West Coast and into Arizona and increased chances for below-average temperatures along the Gulf Coast into New Mexico (Fig. 6).

Images Source - NOAA-Climate Prediction Center

2015 CLIMAS Climate & Society Graduate Fellows

Thursday, February 12, 2015

The Climate & Society Graduate Fellows Program supports University of Arizona graduate students whose work connects climate research and decision making. Fellows receive $5,000 and guidance from members of the CLIMAS research team (Climate Assessment for the Southwest) for one year. The program’s main objective is to train a group of students to cross the traditional boundaries of academic research into use-inspired science and applied research. While CLIMAS research generally occurs in the Southwest U.S., the Fellows program allows students to work anywhere in the world.

Fellows’ projects may follow two tracks. Students who want to conduct collaborative research may use their funding for use-inspired projects. Students who have conducted climate research and want to communicate their findings to audiences outside of academia may use their funding for outreach. Fellows may also use their funding for a combination of the two tracks.

The Climate & Society Graduate Fellows Program helps students address the world’s climate-related problems by funding projects that engage people outside of the university.

The 2015 Climate Assessment for the Southwest (CLIMAS) Climate & Society Graduate Fellows are:

Christina Greene

Abstract: A history of prolonged droughts has long challenged the food system in the Southwest, and these challenges will become steeper under a future of climate change. This project seeks to better understand the vulnerability of the food system to drought by focusing on the impacts of the California drought on farmworkers. By identifying the needs of farmworkers during drought and evaluating the distribution of drought relief boxes through community food banks, this research seeks to connect the environmental and social dimensions of drought, labor, and food insecurity.

Eric Magrane

Abstract: As a CLIMAS fellow, Eric Magrane will design and teach a community course for the University of Arizona Poetry Center called “Climate Change and Poetry.” Climate change is both a scientific and a social issue. It is a threat to life on Earth as we know it as well as an opportunity for social change and environmental justice. A growing body of poetry addresses climate change, and this course will use poems as boundary objects to both communicate climate change and to examine its different frames or narratives. It will explore what role the imaginative and emotional resonances of poetry might have in the way we think about adaptation and mitigation. 

Valerie Rountree

Abstract: In March 2015, the City of Tucson Office of the Mayor will hold a half-day summit on Energy and the Economy with policy makers and business owners in Tucson to discuss the economic opportunities associated with increasing energy and the use of renewable energy. The purpose of Valerie’s CLIMAS project is to enhance the summit and evaluate its success in engaging participants and initiating action on energy efficiency and renewable energy in the private sector.  The project will include three parts: first, a pre-summit survey of prospective attendees will be administered to get baseline data regarding participants’ opinions and knowledge of energy efficiency.  The results of the survey will also be used to tailor the content of the summit to participants’ interests.  Second, a post-summit survey of attendees will be administered to evaluate the impacts of the summit on attendee opinions, knowledge and perceptions.  And third, follow-up interviews will complement surveys to evaluate whether participants plan to implement energy efficiency measures.  The results of this project will be used by partners in the Mayor’s Office to enhance the 2015 Summit and improve summits in future years.

Bhuwan Thapa

Abstract: Nepal’s water resources and agriculture sectors are one of hard hit sectors by climate variability and change. There are about 25,000 irrigation Systems which are managed by farmers and which irrigate about 25 percent of total irrigated area in Nepal. Though Farmer-managed irrigation system (FMIS) is considered a robust system, it is facing increasing stresses from climatic and non-climatic elements including competing water demands, frequent infrastructure damage from flooding and landslides, degraded water quality, and poor governance. My study will conduct use-inspired research on adaptation strategies of FMIS in order to strengthen their management capacity. As a part of the project, I will conduct i) participatory assessment of biophysical and social vulnerabilities of the FMIS to climatic stresses; and ii) support the irrigation managers with development of appropriate adaptation strategies.