Rain Chances – Jet Stream Weakens – Pattern Persists – Possible Tropical Development
The Jet Stream weakening and lifting farther north will be an emphasis of today's report. What does it mean? I will answer that question.
Welcome to this edition of the Weather 20/20 Intelligence Report. I’ve spent the past several hours diving deep into the data, analyzing the evolving pattern, and preparing this detailed update for all of you—our loyal customers and partners, as well as the many new faces joining us this month. Whether you’ve been with us for years or are just discovering the power of the LRC and long-range forecasting, we’re ready to share a lot of information for you to utilize in your decision making.
As always, this report is rooted in the science of the Lezak Recurring Cycle (LRC)—a proven method that continues to reveal atmospheric structure and order when traditional forecasting often sees only chaos. And right now, the atmosphere is giving us plenty to talk about.
We begin today with a sobering look back at the devastating July 4th flooding disaster along the Guadalupe River. From there, we’ll transition into a look at current rain chances, a noticeably weakening jet stream, and what this all means in the last 2 1/2 months of this year’s pattern.
We begin with a tragic and powerful reminder of just how serious weather can be.
At least 132 lives were lost in the catastrophic July 4th flooding disaster along the Guadalupe River, and nearly 100 more are still missing. The scale of this tragedy is difficult to put into words. Most people assume drowning is the primary cause of death in flash floods—but in reality, it’s often blunt force trauma. Victims are struck by trees, vehicles, debris—massive objects moving at high speeds in walls of water that leave no time to react.
This wasn’t just a random act of nature. As we’ve been tracking since last fall, Tropical Storm Barry (which is linked to Tropical Storm Nadine from last October)—whose remnants surged inland from the Gulf—played a role in the excessive rainfall that overwhelmed the region. Barry's moisture was on schedule, aligned with the same atmospheric segment that’s cycled through before, exactly as the LRC indicated it would.
It’s hard to fully grasp the weight of this for the families now beginning the long road to recovery—and for the emergency responders and local officials doing everything they can to assist. From all of us at Weather 20/20, our hearts go out to those affected. We remain committed to using the LRC to anticipate high-risk events like this before they happen—so that one day, tragedies like this can be mitigated, if not prevented. We already know this segment of the LRC will cycle through around mid-August. Will it manifest into another inland flood, or will it be a hurricane heading towards Texas? We will be monitoring closely.
The Jet Stream
The jet stream is a narrow, fast-moving ribbon of air that flows high above us—generally between 20,000 and 40,000 feet in altitude. It plays a major role in shaping our weather patterns, guiding storm systems, and influencing temperature swings across North America.
But what causes the jet stream in the first place?
It all comes down to temperature contrast. The greater the difference in temperature between the Arctic and the tropics, the stronger and more active the jet stream becomes.
Let me spare you the deep scientific breakdown and explain it this way:
In winter, you might have –50°F air over Canada and 90°F air near the Mexico–U.S. border. That’s a 140-degree temperature difference, which results in a strong, active jet stream that dives much farther south—typically reaching its southernmost average position in late January or early February.
In summer, the contrast is much weaker. You might see 70°F air over Canada and 110°F heat in the desert Southwest—just a 40-degree difference. This leads to a much weaker jet stream, which retreats far to the north, often flowing near the U.S.–Canadian border.
We are in that summer phase now—the jet stream is weakening and lifting northward, and that shift is already playing a role in the forecast for the weeks ahead, which I will show in just a second.
The LRC helps us anticipate where these jet stream features will track and how they’ll influence our weather weeks—even months—ahead of time. Right now, as you can see in the map above, the jet stream (marked by the blue line) is barely dipping into the northern United States, brushing areas like Montana while staying well to the north across much of the country.
We’ll break down the setups for rain in the coming days in just a moment—but first, here is today’s video update. In it, I walk you through the key pattern drivers, the tropical development zone we’ve been watching since last fall, and how the LRC continues to provide structure in this evolving summer weather story: