Single radar / Texas

Laughlin AFB radar KDFX

The weather service radar at Laughlin AFB, Texas, alone: each picture it makes from its own scans, at four tilts from its lowest up, every few minutes. Reflectivity, velocity, storm relative velocity, correlation coefficient and differential reflectivity, the storms it tracks and where they are headed, and how high its beam passes. How to read them.

Latest scan: 9:47 AM UTC
Scanning: Precipitation mode, pattern 215
Tilts: 0.5°, 1.3°, 2.4°, 3.1°
Stands at: 29.273°N 100.280°W, 1,131 ft above sea level
Reaches: 286 mi with reflectivity, 186 mi with velocity, 143 mi with storm relative velocity

KDFX on the map

Storms it tracks

The radar follows each storm cell from scan to scan, measures the way it is moving, and puts it ahead 15 to 60 minutes. Each is drawn on the map above, its track to the hour ahead marked each quarter hour.

Storm cells KDFX tracks, from its scan of 9:42 AM UTC
Storm	Where	Moving	In 30 minutes	In 60 minutes	Last forecast off by
F3	127 mi southwest of the radar127 mi from the radar, bearing 218°	Toward the northeast at 7 mph	124 mi southwest of the radar	-	1.4 mi
L3	20 mi north northwest of the radar20 mi from the radar, bearing 348°	Toward the northwest at 2 mph	21 mi north northwest of the radar	22 mi north northwest of the radar	1 mi
P2	12 mi north of Brackettville, TX18 mi from the radar, bearing 326°	First seen this scan	-	-	0 mi
N9	4 mi east of Junction, TX91 mi from the radar, bearing 22°	Toward the south at 9 mph	6 mi southeast of Junction, TX	10 mi south southeast of Junction, TX	0.5 mi
W4	53 mi west of the radar53 mi from the radar, bearing 264°	Toward the west southwest at 9 mph	58 mi west of the radar	62 mi west of the radar	0.3 mi
B0	33 mi north northeast of the radar33 mi from the radar, bearing 26°	Toward the south southwest at 13 mph	28 mi north northeast of the radar	22 mi north northeast of the radar	1 mi
Y3	55 mi west southwest of the radar55 mi from the radar, bearing 251°	Toward the southwest at 17 mph	-	-	3.1 mi
N4	112 mi west of the radar112 mi from the radar, bearing 268°	Toward the southwest at 14 mph	116 mi west of the radar	122 mi west of the radar	0.5 mi
W9	110 mi west southwest of the radar111 mi from the radar, bearing 254°	First seen this scan	-	-	0 mi
I3	10 mi south southwest of Cienegas Terrace, TX45 mi from the radar, bearing 267°	Toward the west at 9 mph	13 mi southwest of Cienegas Terrace, TX	54 mi west of the radar	0.3 mi
P3	5 mi west northwest of Cienegas Terrace, TX46 mi from the radar, bearing 280°	Toward the south southwest at 14 mph	9 mi southwest of Cienegas Terrace, TX	15 mi southwest of Cienegas Terrace, TX	0.6 mi
M3	68 mi southwest of the radar68 mi from the radar, bearing 232°	Toward the west southwest at 16 mph	75 mi southwest of the radar	83 mi southwest of the radar	0.9 mi
L2	91 mi north northeast of the radar91 mi from the radar, bearing 31°	Toward the west at 6 mph	15 mi east southeast of Junction, TX	-	2.1 mi
E3	39 mi west southwest of the radar39 mi from the radar, bearing 240°	Toward the west southwest at 7 mph	43 mi west southwest of the radar	46 mi west southwest of the radar	0.3 mi
X6	66 mi north northeast of the radar66 mi from the radar, bearing 31°	Toward the southwest at 7 mph	63 mi north northeast of the radar	60 mi north northeast of the radar	0.8 mi
J1	58 mi southwest of the radar58 mi from the radar, bearing 235°	Toward the southwest at 18 mph	66 mi southwest of the radar	-	2.3 mi
Y8	39 mi north of the radar39 mi from the radar, bearing 5°	Toward the southeast at 16 mph	-	-	2.6 mi
Y0	82 mi west northwest of the radar82 mi from the radar, bearing 289°	First seen this scan	-	-	0 mi
H8	68 mi northwest of the radar68 mi from the radar, bearing 313°	Toward the south southwest at 8 mph	67 mi northwest of the radar	64 mi northwest of the radar	0.5 mi
K1	66 mi north of the radar66 mi from the radar, bearing 6°	First seen this scan	-	-	0 mi
E2	35 mi north of the radar35 mi from the radar, bearing 3°	First seen this scan	-	-	0 mi

How high it sees

The beam leaves the radar tilted up and the earth curves away under it, so the farther from the radar, the higher it passes. Rain or snow falling under the lowest beam is not seen: far from the radar, shallow snow and drizzle can fall unseen. The heights are the standard ones, the air bending the beam as the weather service’s own rule takes it.

The middle of each tilt’s beam, in feet above the radar’s antenna, and how wide the beam has grown
Tilt	25 mi	50 mi	100 mi	150 mi	200 mi
0.5°	1,500 ft	3,600 ft	9,600 ft	18,200 ft	29,200 ft
1.3°	3,300 ft	7,200 ft	17,000 ft	29,300 ft	44,000 ft
2.4°	5,800 ft	12,300 ft	27,200 ft	44,500 ft	64,400 ft
3.1°	7,500 ft	15,600 ft	33,600 ft	54,200 ft	77,400 ft
Width	2,200 ft	4,400 ft	8,800 ft	13,100 ft	17,500 ft

How to read the pictures

Reflectivity: How strongly rain, snow and hail send the pulse back, in dBZ: the stronger, the heavier.
Velocity: The wind along the beam, in mph: green toward the radar, red away. Where the two meet tightly, the wind turns.
Storm relative velocity: The same wind with the storms’ own motion taken away, so a storm’s turning stands out: a tight pair of green and red is a rotating storm.
Correlation coefficient: How alike the returns of one pulse are, 0 to 1: rain and snow near 1, hail and melting snow lower, and debris a tornado lifts well below 0.8.
Differential reflectivity: How much wider than tall what falls is, in dB: large flat raindrops read high, hail and dry snow near 0.

Each picture is one tilt of one scan, as the radar sent it: its lowest tilt first, then three above it, the angles its scan pattern sets. A picture at a higher tilt sees higher into a storm, and farther over the ground at each distance. Press a point on the map to read the value there.

As data: /radar/now.json?show=sref&site=KDFX, the times of its frames, and /radar/s/KDFX/storms.json, the storms it tracks.