The Southwest remains in an ENSO holding pattern, with oceanic and atmospheric conditions still within the range of ENSO neutral over the last month (Figs. 1-2), and the forecasts and outlooks reflect that. (read more)
Precipitation and Temperature: Precipitation in July ranged from below average to much-above average in Arizona and New Mexico (Fig. 1a), illustrating the extent to which monsoon precipitation varies across the region. July temperatures were warmer than average in nearly all of Arizona and New Mexico (Fig. 1b), and since July 1, most of the daily temperature anomalies (deviations above or below the average temperature) have been warmer across the region (Fig. 2). (read more)
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). 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)
Oceanic and atmospheric conditions remained ENSO-neutral over the last month (Figs. 1-2) and most ENSO forecasts and outlooks reflect that. On July 10, the Japanese Meteorological Agency (JMA) identified neutral conditions in oceanic and atmospheric indicators, but with indications of warming oceanic temperatures in the coming months. The agency forecast equal chances (50 percent) of either ENSO-neutral or El Niño by fall 2018. (read more)
Precipitation and Temperature: Precipitation in June ranged from record driest to much-above average (Fig. 1a); the wetter-than-average areas were those impacted by the remnants of Hurricane Bud in mid-June. June is typically dry, barring an early onset of monsoon activity, so any pre-monsoon precipitation will boost percentile rankings. June temperatures were warmer than average across all of Arizona and New Mexico (Fig. 1b), including record-warm conditions in eastern Arizona and central New Mexico. (read more)
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)
Oceanic and atmospheric conditions remained ENSO-neutral over the last month (Figs. 1-2), and most ENSO forecasts and outlooks reflect these conditions. (read more)
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)
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)
Oceanic and atmospheric conditions returned to ENSO-neutral over the last month (Figs. 1-2) and most ENSO forecasts and outlooks reflect this transition. On May 8, the Australian Bureau of Meteorology maintained its ENSO Outlook at “inactive,” with indications of neutral conditions persisting through at least this summer. (read more)
