KGRR radar — Grand Rapids, MI
KGRR is the National Weather Service's WSR-88D Doppler radar for the Grand Rapids area, operated with the NWS office GRR. View it live in TALON — the loop, super-res reflectivity, storm-relative velocity, rotation and correlation coefficient.
| Station | KGRR (Grand Rapids, Michigan) |
|---|---|
| Location | 42.8940°, -85.5450° · Kent County |
| Elevation | 873 ft above sea level |
| Type | WSR-88D (NEXRAD) S-band dual-polarization Doppler radar |
| Products in TALON | Super-res reflectivity (0.25 km), velocity, storm-relative velocity, rotation (azimuthal shear), correlation coefficient PRO |
How high can KGRR see?
A radar beam travels in a nearly straight line while the Earth curves away underneath it, so the farther a storm is from KGRR, the higher above the ground the radar is looking. Tornadoes start in the lowest few thousand feet, so storms close to the radar show low-level rotation much better.
| Distance from KGRR | Lowest scan (0.5°) | Next scan (1.5°) |
|---|---|---|
| 10 mi | 500 ft | 1,400 ft |
| 25 mi | 1,500 ft | 3,800 ft |
| 50 mi | 3,600 ft | 8,200 ft |
| 75 mi | 6,300 ft | 13,200 ft |
| 100 mi | 9,600 ft | 18,800 ft |
| 150 mi | 18,200 ft | 32,000 ft |
Height of the beam's center above the radar, using standard refraction. Terrain can raise or block the beam.
Severe weather inside KGRR's range
Since 1950, NOAA has recorded 305 tornadoes within 60 miles of the KGRR radar, 76 of them rated EF2/F2 or stronger. They have been most common in May and June. The strongest was an F5 on April 3, 1956, which passed about 14 miles northwest of the radar and caused 17 deaths. The most recent was an EF0 on May 15, 2025, which passed about 18 miles west-southwest of the radar.
Hail: 550 reports of hail 1 inch or larger within 60 miles of the KGRR radar since 1955, 56 of them 2 inches or larger. The largest was 4.50-inch hail (grapefruit size) on March 27, 1991.
| Tornadoes since 1950 | 305 |
| EF2/F2 or stronger | 76 |
| Strongest tornado | F5 · Apr 1956 |
| Busiest tornado month | May |
| Largest hail | 4.50 in · Mar 1991 |
Source: NOAA Storm Prediction Center severe weather database — tornadoes 1950–2025, hail 1955–2025 (the latest year is preliminary). Distances are to each tornado's recorded track; ratings before February 2007 use the original Fujita (F) scale.
Cities covered by KGRR
- Chicago, IL 127 mi west-southwest
Nearby radars
- KDTX · Detroit, MI 106 mi
- KIWX · Fort Wayne, IN 106 mi
- KAPX · Gaylord, MI 145 mi
- KMKX · Milwaukee/Sullivan, WI 152 mi
- KLOT · Chicago, IL 158 mi
KGRR radar FAQ
How often does KGRR update?
Every NEXRAD radar completes a full scan about every 4–6 minutes in storm mode, and repeats the lowest tilt more often (SAILS) during severe weather. TALON loads each new scan as it arrives.
What is the range of KGRR?
Reflectivity reaches about 290 miles and velocity about 185 miles, but useful low-level detail is within roughly 100 miles — see the table above.
Is KGRR down?
Radars occasionally go offline for maintenance. When one does, TALON's US radar map fills the gap from neighboring radars (KDTX, KIWX, KAPX).