Southwest Climate Outlook March 2020 - Climate Summary

March 31, 2020
Ben McMahan

Monthly Precipitation and Temperature: February precipitation ranged from below average to much below average in Arizona and New Mexico (Fig. 1a), while February temperatures were average to above-average across nearly all of Arizona and New Mexico (Fig. 1b). The daily average temperature anomalies for Feb 1 – Mar 18 (Fig. 2) highlight the fluctuations at select stations around the region.

Figure 1

 

Seasonal Precipitation and Temperature: Winter precipitation (Dec 2019 - Feb 2020) ranged between below average and above average across Arizona and New Mexico, with large areas of below-average conditions in other parts of the Southwest (Fig. 3a). Winter temperatures were average to much above average across most of the region (Fig. 3b).

Figure 3

Water Year Precipitation: Water year precipitation to date (since Oct 1, 2019) has been normal to much above normal for much of Arizona and New Mexico (Fig. 4). The Four Corners region remains a notable exception, with mostly below-normal precipitation since Oct 1.

Snowpack & Water Supply: As of Mar 15, snow water equivalent (SWE) was mostly below median in Arizona, New Mexico, and southern Colorado, while southern Utah was more consistently above median (Fig 5). Many of the reservoirs in the region are at or above the values recorded at this time last year, but most are below their longterm average (see reservoir storage).

Figure 5

Drought: The Mar 10 U.S. Drought Monitor (USDM) maintains drought characterizations similar to last month in the Four Corners region while expanding drought characterizations in central Nevada and California, and scaling back drought characterizations in southeastern New Mexico (Fig. 6). “Moderate Drought” (D1) and “Severe Drought” (D2) characterizations are centered on the Four Corners region, reflecting localized acute and accumulated precipitation deficits.

ENSO Tracker: Oceanic and atmospheric conditions are generally consistent with an ENSO-neutral outlook for 2020.

Precipitation and Temperature Forecast: The three-month outlook for April through June calls for slightly increased chances of below-average precipitation in small pockets of California, southern Nevada, and northwest Arizona, which much of the rest of the southwestern U.S. and northern Mexico calling for equal chances of above or below average precipitation (Fig. 7, top). The three-month temperature outlook calls for increased chances of above-normal temperatures across most of the southwestern U.S. and northern Mexico (Fig. 7, bottom).

Online Resources

  • Figures 1, 3 - National Centers for Environmental Information - ncei.noaa.gov
  • Figure 2 - Climate Assessment for the Southwest - climas.arizona.edu
  • Figure 4 - West Wide Drought Tracker - wrcc.dri.edu/wwdt
  • Figure 5 - Natural Resources Conservation Service - nrcs.usda.gov
  • Figure 6 - U.S. Drought Monitor - droughtmonitor.unl.edu
  • Figure 7 - International Research Institute for Climate and Society - iri.columbia.edu