Forecast - August | September | October
Temperature
The three-month NOAA temperature outlook (August-October; Figure 5) favors chances for above-average temperatures for all of New Mexico and Texas through October. The one-month outlook also favors chances for above-average temperatures in both states for August (figure not shown).
Figure 5 (right): NOAA three-month temperature outlook (August-October). Forecast made on July 19, 2018 by CPC.
The CONAGUA´s Meteorological Service (SMN) outlook for August predicts above-average maximum temperatures in Tamaulipas, Nuevo León, Coahuila and southern Baja California. Below-average maximum temperatures are predicted for northern Baja California, Sonora, Sinaloa, and Central Chihuahua. For September, SMN predicts above-average anomalies in Tamaulipas, Nuevo León and Coahuila, and below-average maximum temperatures in Baja California Peninsula, Sonora and Chihuahua (Figure 6).
Figure 6 (above): Predicted maximum temperature anomalies for northern Mexico in (°C), August (left) and September (right). Forecast made on July 1, 2018 by SMN.
Precipitation
The NOAA three-month precipitation outlook (August-October; Figure 7) predicts equal chances for below-average, average, or above-average precipitation for the eastern half of New Mexico and the western half of Texas through October. Forecasts also favor increased chances of below-average precipitation for eastern and southern Texas during the same time period, and above-average precipitation for the western half of New Mexico, due to the predicted transition to El Niño during the summer and fall. The one-month NOAA outlook (August; figure not shown) shows a pattern of forecast probabilities similar to the three-month outlook, but favoring chances for below-average precipitation across most of Texas.
Figure 7 (above): NOAA three-month precipitation outlook (August-October). Forecast made on July 19, 2018 by CPC.
For August, the SMN precipitation outlook predicts above-average precipitation in Baja California Sur, Sonora, Central Chihuahua, and Southwest Coahuila. Below-average precipitation is predicted for Tamaulipas, Nuevo León, Coahuila, Northwest Sonora and Baja California. The precipitation forecast for September favors above-average conditions in some regions of Baja California Peninsula, Northwest Sonora, Chihuahua, Coahuila, southern Nuevo León and Central Tamaulipas, while the rest of the region is predicted to experience average precipitation (Figure 8).
Figure 8 (below): Predicted precipitation anomalies for northern Mexico (in %), August (left) and September (right). Forecast made on July 1, 2018 by SMN.
Fire
Monsoon precipitation moved into the Southwest U.S. and northern Mexico towards the end of June and has eliminated prospects for above-average fire potential across the region, according to the North American Seasonal Fire Assessment and Outlook. Before rains arrived, however, over 316,000 acres (128,000 hectares) burned in Chihuahua, since late May. Forecasts for August and September indicate average fire potential for all of the Southwest U.S. and Mexico, except for the peninsula of Baja California (Figure 9).
Figure 9 (above): Fire outlook for August (left) and September (right). Red shading indicates conditions that favor increased fire potential. Green shading indicates conditions that favor decreased fire potential. Forecast made on July 16, 2018 from NIFC and SMN.
El Niño-Southern Oscillation (ENSO)
As of mid-July, sea-surface temperatures in the tropical Pacific Ocean were slightly above average, and continue to indicate ENSO-neutral conditions. Neutral conditions are forecast through the summer, with El Niño conditions forecasted to develop by the fall (IRI; NOAA). Chances of El Niño have increased from last month’s forecasts, nearing 65% during the fall and ~70% during winter (Figure 10). There is considerable uncertainty in ENSO forecasts made during the spring, but that barrier has mostly passed and forecasters have come to a consensus that El Niño will develop later this year. If forecasts are correct, chances of a wet winter in the Southwest U.S. and northern Mexico are likely to increase.
Figure10 (above): Probabilistic ENSO Forecast from IRI.
For more ENSO information:
English: http://iri.columbia.edu/our-expertise/climate/enso/enso-essentials/ y http://www.ncdc.noaa.gov/teleconnections/enso/.
Spanish: http://smn.cna.gob.mx/es/climatologia/diagnostico-climatico/enos y http://www.smn.gov.ar/?mod=biblioteca&id=68