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Given the spatial variability of the monsoon, single weather stations are an imperfect measure. For example, if it rains at the station and not in surrounding areas or vice versa. They do provide an opportunity to track long term averages compared to the current year. Figure 1 compares 2019 precipitation to date with 2018 and climatology. This reveals 2019 is lagging behind average in terms of precipitation and is also a significant departure from 2018's widespread activity by mid-July. Dewpoint temperatures and daily precipitation for the same five stations (Fig. 2) illustrate that while increased dewpoint temperatures do not guarantee monsoon precipitation, it is rare to see monsoon precipitation in the absence of these elevated dewpoint temperatures. (Read More)

Forecast Roundup: Seasonal outlooks and forecasts focused on sea surface temperature (SST) anomalies and other oceanic and atmospheric indicators, all of which had generally remained consistent with a weak El Niño event (Figs. 1-2), at least until recently. On July 9, the Australian Bureau of Meteorology ended their ENSO Outlook and returned to ‘inactive’ status, identifying ENSO-neutral as the most likely outcome in 2019. On July 10, the Japanese Meteorological Agency (JMA) identified the end of this El Niño event, mostly due to the rapid dissipation of SST anomalies, as well as the return to normal for other atmospheric indicators. They called for a 60-percent chance of ENSO-neutral conditions to continue into Fall 2019. On July 11, the NOAA Climate Prediction Center (CPC) maintained their El Niño advisory based on the SST anomalies, but trends in oceanic and atmospheric conditions led them to expect this event would transition to ENSO-neutral in the next few months. On July 11, the International Research Institute (IRI) issued an ENSO Quick Look (Fig. 3), highlighting above-average SSTs consistent with a weak El Niño, but with most models predicting a transition to ENSO-neutral status by the end of summer. The North American Multi-Model Ensemble (NMME) shifted considerably in the last month, and now points towards a rapid decline to ENSO-neutral status by early fall (Fig. 4). (Read More)

June Precipitation and Temperature Recap: June precipitation was variable in Arizona, ranging from record driest to above average, with a majority of the region recording average to below average precipitation, while New Mexico was mostly average with pockets of both below and above average precipitation (Fig. 1a). June temperatures were mostly average in Arizona and New Mexico, with pockets of above and below average temperatures (Fig. 1b). Daily average temperature anomalies for Jun 1 – Jul 15 demonstrate the fluctuations above and below average (Fig. 2). (Read More)

Forecast Roundup: Seasonal outlooks are based on the persistence of sea surface temperature (SST) anomalies consistent with a weak El Niño event (Figs. 1-2), along with the presence of other atmospheric and oceanic indicators (convective anomalies, sub-surface temperatures). On June 10, the Japanese Meteorological Agency (JMA) noted persistent SST anomalies along with atmospheric and sub-surface indicators of El Niño, and called for a 70-percent chance of these conditions continuing into summer, and a 60-percent chance to last into fall. On June 11, the Australian Bureau of Meteorology maintained their ENSO Outlook at watch status, calling for a 50-percent chance of an El Niño event in 2019. (read more)

May Precipitation and Temperature: May precipitation was mostly above average to record wettest in Arizona, and New Mexico ranged from below average to much above average but most of the state was average or above-average (Fig. 1a). May temperatures were below average or much below average across most of the Southwest (Fig. 1b). (read more)

Seasonal outlooks highlight persistent sea surface temperature (SST) anomalies consistent with a weak El Niño event (Figs. 1-2), while other atmospheric and oceanic indicators such as convective anomalies and sub-surface temperatures are less definitive. The so-called ‘spring predictability barrier’ further limits certainty. Forecast discussions focus on how long the event will last and the potential for a second year of El Niño. (read more)

April Precipitation and Temperature: April precipitation was average to much above-average in most of New Mexico, while Arizona ranged from below-average to above-average (Fig. 1a). April temperatures were almost entirely above-average to much above-average across the Southwest (Fig. 1b), while temperatures so far in May have been mostly below-average. (read more)

El Niño Tracker: Seasonal outlooks and forecasts emphasize clear atmospheric and oceanic conditions that are consistent with a weak El Niño event, and the discussion has shifted to how long the event will last. On Apr. 10, the Japanese Meteorological Agency (JMA) highlighted that El Niño conditions had persisted in March, and with an 80-percent chance of these conditions lasting until summer. On Apr. 11, the NOAA Climate Prediction Center (CPC) maintained their El Niño advisory, identifying both oceanic and atmospheric conditions consistent with a weak El Niño event. (read more)

March Precipitation and Temperature: March precipitation was average to above-average across most of Arizona, New Mexico and west Texas, while the upper basin of the Colorado River was much above-average (Fig. 1a). March temperatures were average to above-average in Arizona and New Mexico, despite most of the United States being average to below-average (Fig. 1b).read more

February Precipitation and Temperature: February precipitation was above-average across most of Arizona and northwestern New Mexico (and much of the western United States), but quickly transitioned to below-average in southern and eastern New Mexico, a pattern that extended into western Texas (Fig. 1a). February temperatures were below-average in most of Arizona and northwestern New Mexico, and average to above-average in central and eastern New Mexico (Fig. 1b). (read more)