At that time, Mark O’Malley of the National Weather Service told the drought panel that the 2023 “monsoon” season would be late in arriving and that conditions were ripe for a much warmer and drier-than-normal summer overall.
“Moisture availability may be compromised for the first part of the monsoon,” O’Malley said at the time. He added that the National Weather Service’s Climate Prediction Center predicted “a better than 50 percent chance that the summer as a whole will be warmer than average.”
As is often the case with weather analysis presented at the ISG’s biannual meetings, O’Malley’s predictions proved remarkably accurate.
Arizona Water News asked the NWS’s lead forecaster to flesh out moisture and temperature expectations for the balance of the summer. Following are his conclusions (Spoiler Alert: It’s likely going to stay hot and dry):
“While the signal is not quite as strong as earlier in the season, the bulk of model evidence suggests odds for the remainder of the monsoon season tilted towards the drier side in Arizona,” said O’Malley.
“The signal is still consistent regarding temperatures with a distinct probability towards warmer-than-average conditions.
“One caveat is that El Nino during the September-October time frame favors enhanced tropical activity in the Eastern Pacific. Should this occur - and (should) the flow pattern align favorably later in the monsoon - it is conceivable that remnant moisture gets pulled north into the state. Everything needs to be set up right for this to happen, so probabilities are low and will not be reflected in a long-range forecast.
“The outlook for winter 2023-24 indicates at least a moderate El Nino event, but with minimal predictability across the Southwest United States.
“The official Climate Prediction Center outlook shows equal chances (that) temperatures through the winter as a whole will be above, below, or near normal. Precipitation odds are only slightly tilted towards wetter than average with still a 25-30 percent chance it will be below average.”