The University of Arizona
Monthly Archive | CLIMAS

Monthly Archive

Monsoon Recap - July 2019

Saturday, July 20, 2019
Ben McMahan

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)

 

Southwest Climate Outlook July 2019 - Climate Summary

Friday, July 19, 2019
Ben McMahan

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)

 

 

 

Southwest Climate Outlook - El Niño Tracker - July 2019

Friday, July 19, 2019
Ben McMahan

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)