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The hope and the occasional run of 107-degree days.

As we look ahead and see only the slimmest chance of rain over the next week, we can start to look back at the 2025 monsoon. What I see is a landscape littered with disappointment.

It’s not that unusual lately to have a disappointingly dry monsoon. In fact, that disappointment seems to be a regular feature of our new, hotter climate regime.

But rarely in my 29 Tucson summers do I recall one with so much forecast hope, and so little result. It was dry all over the Tucson metro area, but the city proper was especially dry — the Pima County ALERT system’s weather gages back up this perception.

The disappointment started in May and June, with long-term forecasts from the National Weather Service that predicted a wetter-than-average summer season. These optimistic forecasts lasted until early June, but were revised around the official start of the summer rainy season to call for even chances of a wetter or drier than average season.

The disappointment continued through July and August, when forecasts of higher chances of rain were always just over the horizon. Day after day, it was stiflingly hot and dry now, but the forecast called for better chances of rain — 40%, 50% even 70% — a few days down the road, or maybe next week.

Then those days would arrive, and the higher chances of rain would disappear from the forecast, but usually with the hope of wetter days just around the corner.

Finally came the coup de grâce — Hurricane Lorena. For days in late August, that tropical system was forecast to move up the Pacific coast of Baja California, then cross over into Sonora and, breaking up, head toward ÃÛÁÄÖ±²¥. Rain would be the result, possibly heavy rain, as indicated by flash-flood watches issued for Friday.

Then Lorena — nicknamed “No-rain-a� by some clever locals — veered west instead of east and disappeared with barely a drizzle in the Tucson area.

I had resisted hope, but I couldn’t help but feel like Charlie Brown taking one more run up to kick a football held by Lucy, then flying into the air again when she pulled the ball away.

Day-to-day variations affect rain chances

I got a chance to talk over this summer’s monsoon by visiting the office on the U of A campus Monday.

Meteorologist Julia Tetrault showed me around and took me to a weather-balloon launch. And yes, I asked her about the tantalizing rain chances that always seemed to be just around the corner but dried up when the day arrived.

To grasp her explanation, you have to understand that meteorologists rely on different computerized forecasting models. These models are built on years of data, supplemented by current information from weather balloons, and make numerous calculations to project the weather.

Southern ÃÛÁÄÖ±²¥â€™s monsoon, though, often depends on day-to-day variations.

Forecasting the monsoon, Tetrault told me, “really relies on what happened the day before to influence the next day. So we could have the best kind of dynamics we’re looking at. But if we’re worked over — like, if Sonora, Mexico sends a lot of cloud cover our way, or a lot of subsidence and sinking air aloft — it kind of shuts down everything.�

So that accounts for day-to-day disappointments. But what about the repeated forecasts showing more rain just around the corner? Tetrault pointed to forecasting models that kept predicting a persistent trough in the Pacific would move, allowing the seasonal high pressure system to set up in the Four Corners area for a more beneficial monsoon pattern.

It didn’t happen.

The forecast models “were trying to set up that high pressure system in the Four Corners,� Tetrault said. “They were really trying to nudge that up there, and then it just never really panned out. So that one is kind of disappointing — that trough just was really dominant this year.�

Lorena skips Tucson

What of the tropical system that wasn’t — Hurricane Lorena, that last insult of this dry rainy season?

The local National Weather Service office largely defers to the in making predictions about the track of a tropical system in the Pacific. While Lorena was expected to track up the Pacific Coast of Baja, there were models that showed it veering northwest, and others showing it coming northeast toward Tucson, Tetrault said.

The Hurricane Center bet on the northeastward track, the one that would bring more rain to Southern ÃÛÁÄÖ±²¥, and they were wrong. It went left instead of right. A little moisture made it into Southern ÃÛÁÄÖ±²¥, but nothing like we hoped for, certainly not in the city of Tucson.

Another disappointment.

What I take from all this is that monsoon precipitation forecasts are pretty useless beyond the current day. After today, the best bet is that the weather will be something like it was the day before, as far as I can tell.

Remembering this lesson will be hard next summer, but certainly it will lead to less disappointment.