Not quite El Niño? Widespread areas of above-average sea-surface temperatures (SSTs) now exist in the equatorial Pacific (Figs. 1-2), but atmospheric conditions have lagged behind. Most forecasts and outlooks, while still bullish on the emergence of an El Niño in 2018, identified current conditions as ENSO-neutral, but see an imminent shift in atmospheric circulations more characteristic of an an El Niño event. (read more)

Precipitation and Temperature: October was relatively wet and cool across the Southwest. Precipitation ranged from average to much-above average in New Mexico and from above average to much-above average in Arizona (Fig. 1a). Temperatures were much cooler than normal, ranging from below average to average in Arizona and from below to above average in New Mexico (Fig. 1b). (read more)

Atlantic hurricanes Florence and Michael have understandably been the focus of attention this year, but as discussed on page 1, 2018 has been an extremely active year for tropical storms in the eastern North Pacific. While most of the storms expended most or all of their energy over the Pacific, a few had notable impacts on the Southwest. (read more)

Oceanic and atmospheric conditions are still within the range of ENSO-neutral (Figs. 1-2), but rising sea-surface temperatures (SSTs) and shifting atmospheric conditions are reflected in recent forecasts, which call for an El Niño event forming by the end of 2018 and lasting through the winter. (read more)

The precipitation rankings for the months that encompass the monsoon period (see Fig. 3 on p. 2) smooth out the variability over space and time that is characteristic of this season. The cumulative totals for the monsoon for most of the major metropolitan areas in the region (Fig. 1) came in at or above average, with the exception of El Paso. (read more)

Precipitation and Temperature: Precipitation in September ranged from average to above average in New Mexico and from below average to much-above average in Arizona (Fig. 1a). September temperatures were warm throughout the region, ranging from much-above average to record warmest in Arizona and mostly above average to much-above average in New Mexico (Fig. 1b). (read more)

Monsoon precipitation varies considerably in space and time across the Southwest, as illustrated by monthly totals for various stations. (Fig. 1). Statewide patterns highlight widespread areas of both above- and below-average totals (see Fig. 4 on p. 5). The Fig. 2 plots of daily precipitation, temperature, and dewpoint temperature for the same stations as Fig. 1 capture the intermittent nature of monsoon precipitation as well as the persistent elevated dewpoint most locations experienced this summer. (read more)

Precipitation and Temperature: Precipitation in August ranged from much-below average to average in New Mexico and from much-below average to above average in Arizona (Fig. 1a). August temperatures were mostly above average across Arizona and New Mexico, with swaths of much-above average and isolated locations of record-warmest conditions (Fig. 1b). (read more)

With little change from last month, the Southwest remains in an ENSO holding pattern. Oceanic and atmospheric conditions are still within the range of ENSO-neutral (Figs. 1-2), but the forecasts point toward the likely emergence of an El Niño event this fall and lasting into the winter. (read more)

Monsoon precipitation totals vary considerably across the Southwest. Monthly totals for select locations reveal near or below-average amounts compared to long-term averages (Fig. 1). There are widespread regions with above-average totals as well (see p. 5), revealing the challenge of characterizing monsoon performance using single stations. (read more)