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June 2018 SW Climate Outlook - Monsoon Tracker & Tropical Storm Bud

Friday, June 22, 2018

Was our mid-June precipitation the monsoon? In 2008, the National Weather Service (NWS) changed the definition of the start of the Southwest monsoon from a variable date based on locally measured conditions to a fixed date of June 15 (and a fixed end date of Sept 30). This allowed for a clear delineation of the period of monsoon activity (108 days) and focused NWS’s messaging strategy as it pertains to the expected hazards during that period, which include extreme heat, strong winds, dust storms, flash flooding, lightning, and wildfires (see NWS Tucson monsoon information hub). Prior to 2008, the flexible start date reflected the seasonal progression of the monsoon, with a considerable temporal gradient across the region (Fig. 1). (read more)

Southwest Climate Outlook June 2018 - Climate Summary

Thursday, June 21, 2018

Precipitation and Temperature: The Southwest was characterized by below-average precipitation in May, ranging locally from record driest to near average (Fig. 1a). Temperatures were above average to much-above average across most of the Southwest, with small pockets of record-warm conditions in the northwest corner of New Mexico and along the eastern edge of the state (Fig. 1b). The March through May period exhibited similar patterns of mostly drier-than-average to record-dry precipitation (Fig. 2a) and much-above-average to record-warm temperatures (Fig. 2b). (read more)

 

May 2018 SW Climate Outlook - May Climate Summary

Monday, May 21, 2018

After a warm and dry winter (detailed in past issues of the SW Climate Outlook), drought, fire, and poor air quality (dust and pollen) are growing concerns as spring turns to summer. In May, warm temperatures (Fig.1), including triple-digit highs (Fig. 2), are increasingly common, while average precipitation is among the lowest monthly totals for the region (Fig. 3), and additional precipitation is unlikely. At the same time, the winds are picking up due to seasonal transitional conditions (Fig. 4), further increasing fire risk (Figs. 6a-b) and impacting air quality and public safety (e.g. dust storms). (read more)

Southwest Climate Outlook May 2018 - Climate Summary

Thursday, May 17, 2018

Precipitation and Temperature: The Southwest was characterized by below-average precipitation in April, ranging locally from record driest to near average (Fig. 1a). Temperatures were mostly above average for yet another month, with record-warm conditions along the eastern third of Arizona and the edge of western New Mexico, but also with a band of average to below-average temperatures on the eastern edge of New Mexico (Fig. 1b). (read more)

April 2018 SW Climate Outlook - Cool Season Precip Summary (Oct - Mar)

Wednesday, April 25, 2018

Monthly and cool-season (Oct-Mar) precipitation totals demonstrate how this La Niña year compares to previous years, and helps characterize the influence of ENSO on cool-season precipitation. Figures 5a-8a describe monthly and cool season precipitation totals at four weather stations (Flagstaff, AZ; Tucson, AZ, Albuquerque, NM, and El Paso, TX), where each dot corresponds to observed monthly and cool-season precipitation for each year since 1950, color coded by the ENSO status of that year, and the horizontal black lines correspond to 2017-2018 precipitation. Figures 5b-8b are scatterplots of ENSO index vs. precipitation totals for the regional climate division that contains each weather station. (read more)

April 2018 SW Climate Outlook - La Niña Tracker

Monday, April 23, 2018

Oceanic and atmospheric conditions over the last month remained generally consistent with a La Niña event (Figs. 1-2), but given the rapid decline of these conditions and the imminent seasonal transition, it is only a matter of time before ENSO-neutral conditions return. The current ENSO forecasts reflect this steady weakening, with most indicating a likely transition to ENSO-neutral conditions over the spring, and others having already declared an end to this La Niña event. On April 10, the Japanese Meteorological Agency (JMA) identified ongoing La Niña conditions but called for a 90-percent chance that this event will end in spring. On April 10, the Australian Bureau of Meteorology maintained their ENSO Outlook at “inactive,” stating “there is little sign of El Niño or La Niña developing in the coming months.” On April 12, the NOAA Climate Prediction Center (CPC) continued its La Niña advisory but expected a transition to ENSO-neutral conditions by May and forecast a greater-than-50-percent chance of ENSO-neutral lasting through summer. On April 19, the International Research Institute (IRI) issued its ENSO Quick Look, which still identified weak La Niña conditions present but called for a rapid transition to ENSO-neutral conditions over spring (Fig. 3). The North American Multi-Model Ensemble (NMME) is consistently indicative of a return to ENSO-neutral conditions, but with greater uncertainty over what the latter half of 2018 might hold (Fig. 4). (read more)

Southwest Climate Outlook April 2018 - Climate Summary

Friday, April 20, 2018

Precipitation and Temperature: Precipitation varied across the Southwest in March, but temperatures remained warm throughout the region. Precipitation amounts ranged from record driest to above average (Fig. 1a). Temperatures ranged from average to above average in Arizona, and from above average to much-above average in New Mexico (Fig. 1b). 2018 year-to-date (Jan-Mar) precipitation ranged from near average to much-below average (Fig. 2a), while temperatures for the same period were above average to much-above average (Fig. 2b). (read more)

Southwest Climate Outlook March 2018 - Climate Summary

Tuesday, March 20, 2018

Precipitation & Temperature: Precipitation varied considerably across the Southwest in February, but temperatures remained warm throughout the region. Precipitation amounts ranged from below average to much-above average, with the wetter areas concentrated in southern Arizona and southwestern New Mexico and the driest areas occurring in the Four Corners region and northeastern New Mexico (Fig. 1a). Temperatures ranged from average to above average in Arizona, and from above average to much-above average in New Mexico (Fig. 1b). (read more)

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