You've been there. You check your phone, it says "0% chance of rain," and ten minutes later you're getting absolutely drenched on Main Street. It’s frustrating. It feels like the apps are just guessing, and honestly, sometimes they are. But the real issue isn’t just the forecast; it's how you’re reading the radar for Ann Arbor.
Most people treat radar like a movie of the future. It’s not. It’s a snapshot of the right now, and in Southeast Michigan, "right now" changes faster than the line at Zingerman’s on a Saturday. If you want to stop getting caught in the rain—or worse, a sudden January snow squall—you have to understand the tech sitting up in White Lake and why it sometimes lies to you.
The Giant Golf Ball in White Lake
When we talk about radar for Ann Arbor, we are primarily talking about the KDTX WSR-88D. It’s located in White Lake, Michigan, operated by the National Weather Service (NWS) Detroit/Pontiac office. If you’ve ever seen a giant white sphere on a tower while driving through Oakland County, that’s it.
That dish is constantly spinning, sending out pulses of energy. These pulses hit things—raindrops, snowflakes, hail, or even a swarm of dragonflies—and bounce back. The time it takes for that signal to return tells the computer how far away the storm is. The strength tells it how "heavy" the precipitation is.
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But here is the thing about Ann Arbor. We are about 35 to 40 miles away from that dish. Because the Earth is curved, the further the radar beam travels, the higher it gets in the sky. By the time the beam from White Lake reaches Ann Arbor, it might be looking at clouds 3,000 or 4,000 feet up.
This creates a "blind spot" near the ground. You could have a light drizzle or a fast-moving "clipt" of snow happening right over Michigan Stadium, but the radar is looking clean because the moisture is sitting below the beam. Meteorologists call this "undershooting." It’s why you’ll sometimes see a clear map while your wipers are on full blast.
Why 2026 Weather Tech Still Struggles with Snow
Snow is a total nightmare for radar. Raindrops are mostly uniform spheres. They’re easy to track. Snowflakes? They are jagged, they flutter, and they vary wildly in density.
In January 2026, we’ve been dealing with a lot of "lake-effect" moisture. This stuff is notoriously shallow. Unlike a massive summer supercell that reaches 50,000 feet into the atmosphere, a Michigan snow band might only be a mile high.
If the KDTX radar beam is passing over the top of that snow band, the radar for Ann Arbor will look empty. This is where "Dual-Pol" technology comes in. Back in the day, radar only sent out horizontal pulses. Now, they send vertical ones too. This helps the NWS figure out if they’re looking at a flat snowflake or a round raindrop. It’s much better than it was ten years ago, but it still isn't perfect.
The Apps You Should (And Shouldn’t) Use
Most people just use the default weather app that came with their iPhone or Android. These are basically just pretty interfaces for massive data models like the GFS or ECMWF. They aren't "live" in the way you think they are.
If you want the real-deal radar for Ann Arbor, you need to look at "single-site" data.
- RadarOmega: This is what the storm chasers use. It gives you the raw data directly from the White Lake tower without any smoothing. "Smoothing" is what makes those pretty, blurry green blobs on TV. In reality, weather is pixelated and messy. Seeing the mess helps you see where the wind is actually turning.
- MyRadar: Great for a quick glance, but be careful with the "forecast" layers. They use AI to predict where the rain will go, and in the Great Lakes region, that AI often gets confused by the temperature change near the water.
- The NWS Mobile Site: Honestly? It’s ugly. It looks like it was built in 2005. But it is the most accurate source because it includes the "Area Forecast Discussion" (AFD). This is where the local meteorologists in White Lake write out their "expert opinion" on why the radar looks weird. They’ll literally say, "Radar is overestimating the rain because of mid-level moisture." You won't get that nuance from a cartoon sun icon on your phone.
Real Talk: The "Ann Arbor Dome" Myth
You’ll hear locals talk about the "Ann Arbor Dome." The idea is that storms seem to split right before they hit the city, leaving us dry while Ypsilanti gets hammered.
Is it real? Sorta, but not for the reasons people think. It isn't a magical shield. Ann Arbor sits in a bit of a valley compared to the surrounding hills to the west. Sometimes, as air sinks into that valley, it warms up just enough to evaporate the bottom layer of a rain clouds.
Also, the "Urban Heat Island" effect is real. All that concrete on the U-M campus and downtown holds heat. In the summer, this can sometimes cause a small storm to "fizzle" as it hits the city, or conversely, it can provide the extra energy needed to make a storm explode right as it moves east toward Canton and Detroit.
When you’re looking at the radar for Ann Arbor during a summer heatwave, watch for those tiny "popcorn" cells. They don't move in a straight line; they go wherever the heat is.
How to Read Velocity (And Why You Should Care)
Most people only look at "Reflectivity"—the green, yellow, and red colors. But if there’s a severe weather warning, you need to switch to "Velocity."
Velocity shows you which way the wind is blowing.
- Green means air is moving toward the radar (toward White Lake).
- Red means air is moving away from the radar.
If you see a bright green spot right next to a bright red spot over Scio Township, that’s a "couplet." It means the wind is spinning. That is how you spot a tornado before it’s even confirmed on the news. In a place like Ann Arbor, where trees are everywhere and can fall on houses easily, knowing which way the wind is moving is actually more important than knowing if it’s raining.
Actionable Steps for Tracking Local Weather
Don't just stare at the blue dot on your map. If you want to actually use radar for Ann Arbor like a pro, do this:
- Check the Tilt: If your app allows it, look at "Tilt 1" (the lowest angle). This is the closest to what’s actually hitting your roof.
- Ignore the "Clear" Map in Winter: If it’s 30 degrees and the sky looks "heavy" and grey, but the radar is clear, check the NWS Detroit Twitter/X feed. They often post "composite" images that show low-level snow the main radar misses.
- Look West: Our weather almost always comes from the West/Southwest. If you see a line of storms over Jackson or Battle Creek, you have about 45 to 60 minutes before it hits the Big House.
- Watch the Loop: Don’t just look at a still image. Loop the last 30 minutes. Is the storm growing (getting redder) or shrinking? Is it speeding up?
The tech is incredible, but it's still just a tool. The next time you're planning a walk through the Arb or heading to a game, remember that the radar for Ann Arbor is a bit like a flashlight in a dark room—it shows you a lot, but it can’t show you what’s hiding under the bed. Trust your eyes as much as your screen. If the clouds look "mean" and greenish-black, get inside, regardless of what the app says.
To get the most accurate local data right now, navigate to the National Weather Service DTX page and look for the "Hourly Weather Graph." It breaks down the precipitation potential by the hour, combining radar data with local ground observations from the Ann Arbor Municipal Airport (KARB).